i46074
This publication is a product of the National Security Agency history 

program. It presents a historical perspective for informational and 

educational purposes, is the result of independent research, and 

does not necessarily reflect a position of NSA/CSS or any other U.S. 

government entity.
UNITED STATES CRYPTOLOGIC HISTORY

Sources in Cryptologic History

Series IV

Volume 1 

American Signal Intelligence

in Northwest Africa

and

Western Europe

George F. Howe

National Security Agency

2010
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Table of Contents

 Page

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Author’s Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

PART ONE: THE MEDITERRANEAN SEA

Chapter 1: Situation Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

 Early Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

 Early British Experiences with Field SIGINT . . . . . . . . . . . . . . . . 10

 German Army and Air Force SIGINT Organizations . . . . . . . . . 11

 U.S. Preparations for SIGINT Service in the West . . . . . . . . . . . . 13

 The Call of the Mediterranean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chapter 2: Beginnings in Northwest Africa . . . . . . . . . . . . . . . . . . . . 19

Planning SIGINT Service in Operation TORCH . . . . . . . . . . . . . . 19

Operation TORCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

Tunisia: Organization for the Second Phase . . . . . . . . . . . . . . . . 28

Action during January 1943 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Chapter 3: Axis Initiative in February 1943 . . . . . . . . . . . . . . . . . . . . 35

Axis Plans — Allied Expectations . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Allied Reversals, 14-17 February 1943 . . . . . . . . . . . . . . . . . . . . . . 36

Through Kasserine Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Recapitulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Two Opposing Army Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Chapter 4: The March Offensives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Expectations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

II Corps Attacks: Gafsa, Maknassy, and El Guettar . . . . . . . . . . 46

The Enemy Retreat to the Bridgehead . . . . . . . . . . . . . . . . . . . . . . 48

Chapter 5: The Final Phase of Tunisia . . . . . . . . . . . . . . . . . . . . . . . . . 51

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

The Attack Begins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

The End in Tunisia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Page iv

Chapter 6: From Africa to Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Decisions in 1943 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

French Aid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Beginnings of the 849th Signal Intelligence Service . . . . . . . . . . 58

Detachments and Detachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

SIGINT Before Operation HUSKY . . . . . . . . . . . . . . . . . . . . . . . . . . 64

“J” Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Invading Sicily . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Allies Push — Enemy Pulls Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Some Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Chapter 7: Salerno to Rome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

 Preliminaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

 Operations AVALANCHE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

 Enemy Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

 Tactical SIGINT Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

 In the “Winter Line” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

 Operation SHINGLE at Anzio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

 “Y” Service during the First Phase of Anzio . . . . . . . . . . . . . . . . . 91

 From Landing to Stalemate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

 The Liberation of Rome — 4 June 1944 . . . . . . . . . . . . . . . . . . . . . . 95

Chapter 8: The Final Months in the Mediterranean Theater . . . . . 101

 Pursuit to the Arno and Beyond . . . . . . . . . . . . . . . . . . . . . . . . . . 101

 Po Valley and Surrender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

 Southern France: Operation DRAGOON . . . . . . . . . . . . . . . . . . . 105

PART TWO: WESTERN EUROPE

Chapter 9: The Forming of Signal Intelligence Service, ETOUSA . 113

 Derivation and Beginnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

 Planning in the Theater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

 The Invasion Begins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

 The Structure of SIS, ETOUSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

 Final Stage of Training in the United Kingdom . . . . . . . . . . . . . 124

 Assignment of the SRI Companies . . . . . . . . . . . . . . . . . . . . . . . . . 125

 Into Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

 Early Days for the Corps Signal Service Companies (RI) . . . . 128

 3rd Radio Squadron Mobile and Its Detachments . . . . . . . . . . . 133

Chapter 10: A Summary Version of the Campaigns in ETOUSA . . 137
Page v

Chapter 11: Aspects of Collaboration in Special Intelligence . . . . . 143

 Beginnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

 U.S. Navy Attempts to Produce Special Intelligence . . . . . . . . . 147

 U.S. Army Preparations to Produce Special Intelligence . . . . . 150

 The U.S. Army-GCCS Agreement in May 1943 . . . . . . . . . . . . . . 152

 The Friedman, McCormack, and Taylor Mission

 April to June 1943 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

 Collaboration under the Army’s 17 May Agreement . . . . . . . . . 159

 Later Collaboration between OP-20-G and GCCS . . . . . . . . . . . 164

 Special Intelligence in the 

 Invasion of Normandy — June 1944 . . . . . . . . . . . . . . . . . . . . . 165

Chapter 12: From Normandy to the Seine . . . . . . . . . . . . . . . . . . . . . 169

 General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

 The Breakout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

 Circling the Enemy’s Southern Flank . . . . . . . . . . . . . . . . . . . . . . 174

 SIGINT and the Capture of Brest . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Chapter 13: To The Westwall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

 Pursuit to the North . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

 Pursuit to the Moselle River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

 Improvement in Enemy Cryptography . . . . . . . . . . . . . . . . . . . . 185

 Seventh Army . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

 Third Army Reaches Westwall . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Chapter 14: The Ardennes Offensive, 

 16 December 1944 to 20 January 1945 . . . . . . . . . . . . . . . . . . . 189

 Situation at the Outset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

 The Enemy Is Contained and Pushed Back . . . . . . . . . . . . . . . . . 191

 SIGINT Coverage during the Ardennes Campaign . . . . . . . . . . 192

 Examples of SIGINT during the Enemy’s Advance . . . . . . . . . . 195

 Special Intelligence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

 Example of “Y” SIGINT as the Attackers Withdrew . . . . . . . . . . 199

Chapter 15: Winter and Spring Battles — 1944-1945 . . . . . . . . . . . . 203

 Through the Westwall to the Rhine . . . . . . . . . . . . . . . . . . . . . . . . 203

 The Bridge to Remagen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

 Samples of Special Intelligence in March 1945 . . . . . . . . . . . . . . 205

 German Collapse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Page vi

Chapter 16: Some General Considerations . . . . . . . . . . . . . . . . . . . . 209

Appendixes

 A. Agreement between the War Department and G.C. & C.S.

 17 May 1943 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

 B. War Department Letter, “Intercept Directive,” 

 26 March 1943 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

 C. HQ, ETOUSA Letter, “Operational Control of Signal Intelligence

 Service, ETOUSA,” 27 July 1943 . . . . . . . . . . . . . . . . . . . . . . . . 223

 D. War Department Letter, “Special Cryptanalytic Project

 in Signal Intelligence Service” . . . . . . . . . . . . . . . . . . . . . . . . . . 225

 E. HQ, ETOUSA Directive, “Organization of Field Detachments

 for Signal Intelligence Division,” 8 February 1944 . . . . . . . . 229

 F. HQ, ETOUSA Letter, “Operational Control and Technical Direction

 of Signal Intelligence and Signal Radio Intelligence Units,”

 7 February 1945 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

 G. U.S. Navy Department Agreement with the Admiralty, 

 1 October 1942 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

 H. Excerpts from Reports by U.S. Army Ultra Representatives

 with Army field commands in the ETOUSA . . . . . . . . . . . . . . 235

 Part 1, Use of Ultra at 12th Army Group, 23 May 1945 . . . . . 235

 Part 2, Ultra Intelligence at U.S. First Army, 21 May 1945 239

 Part 3, Ultra and the Third Army, 28 May 1945 . . . . . . . . . . 247

 Part 4, Use of Ultra by Ninth U.S. Army, 27 May 1945 . . . . . 253

 Part 5, Ultra and Its Use by XIX, TAC, 30 May 1945 . . . . . . . 257

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

Illustrations

Maps

 The Mediterranean Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

 Allied Invasion of Northwest Africa . . . . . . . . . . . . . . . . . . . . . . . . 20

 Battles in Tunisia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

 The End in Tunisia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Page vii

 Sicily . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

 Italy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

 Operations in Italy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

 Southern France — Operation DRAGOON . . . . . . . . . . . . . . . . . . 106

 Cross Channel Plan of Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

 The Breakout from the Bocage Country . . . . . . . . . . . . . . . . . . . . 173

 Exploiting the Breakout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

 Pursuit to the Westwall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

 At the Westwall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

 Ardennes and Roer River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

 Across the Rhine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

Photographs

 Brigadier General Carter W. Clarke . . . . . . . . . . . . . . . . . . . . . . . . . 8

 Brigadier General Carter W. Clarke 

 and Colonel Alfred McCormack . . . . . . . . . . . . . . . . . . . . . . . . . . 14

 Captain Solomon Kullback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

 Colonel George A. Bicher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

 Captain Richard L. Downing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

 First Lieutenant Herrick F. Bearce . . . . . . . . . . . . . . . . . . . . . . . . . 65

 849th SIS Mediterranean Theater camouflaged intercept van 84

 849th SIS Mediterranean Theater van interior intercept

 equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

 849th SIS Mediterranean Theater intercept van with 

 BG 342, BC 344, and S-36 receivers . . . . . . . . . . . . . . . . . . . . . . 94

 Brigadier General Telford Taylor . . . . . . . . . . . . . . . . . . . . . . . . . 116

 Lieutenant Paul E. Neff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

 Major Charles L. Allen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

 U.S. Seventh Army van . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

 Captain Laurance F. Safford, USN . . . . . . . . . . . . . . . . . . . . . . . . 145

 Lieutenant Leo Rosen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

 Captain Abraham Sinkov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

 Alistair G. Denniston, Professior E.R. Vincent, and 

 Brigadier John H. Tiltman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

 Bombe deck, OP-20-G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

 Commander Joseph Wenger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

 Dr. Alan M. Turing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

 William F. Friedman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

 Brigadier General Harold G. Hayes . . . . . . . . . . . . . . . . . . . . . . . 154

 Brigadier General W. Preston Corderman . . . . . . . . . . . . . . . . . 155

 Sir Edward Travis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Page viii

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Page ix

The volume at hand, Dr. George F. Howe’s American Signals Intelligence in Northwest Africa 

and Western Europe is important professional reading for those interested in cryptologic history or 

in World War II.

The first historian for the National Security Agency was Captain Thomas Dyer, USN, who had 

made significant contributions in cryptanalysis during the war. When Dyer retired in 1954, NSA 

decided to hire a professional historian as his replacement. That was Dr. George F. Howe. 

Dr. Howe was born in Vermont in 1901, and received his Ph.D. from Harvard in 1926. He was a 

professor of history at the University of Cincinnati for the next two decades. In 1945 he joined the 

research and writing staff of the Army’s Historical Division. While in that position, he wrote 

Northwest Africa: Seizing the Initiative in the West, published in 1957 as part of the official series 

on World War II, commonly known to historians as the “Army’s green books.”

At NSA Dr. Howe supervised a small staff in preparing a number of specialized histories as well 

as a general study of the Armed Forces Security Agency, NSA’s predecessor. Dr. Howe retired in 1971, 

although he was called back to assist part-time with several history projects. He passed away in 1988.

It is fitting that, for his own major project at NSA, Dr. Howe chose to write about signals 

intelligence support in North Africa (and Western Europe), drawing on the expertise developed for 

the “green books” and adding to it a dimension he could not write about for unclassified publication 

in the 1950s.

Dr. Howe’s book deals primarily with organizational matters for providing SIGINT support in 

combat. Thus, the reader will not find stories of high-level cryptanalysis underlying big decisions by 

famous leaders. In my estimation, by concentrating on the less flashy aspects of wartime support in 

favor of the background work, Dr. Howe has again added a dimension of great worth to our knowledge 

of SIGINT and of the war. 

The study of World War II SIGINT has concentrated, by and large, on ULTRA, the exploitation 

of high-grade cryptographic systems used by Germany and Japan, and the use of ULTRA material by 

senior wartime decision makers. This effort unquestionably is important for understanding the 

decisions and events of that terrible era, but the overwhelming focus on this aspect has resulted in a 

slightly skewed understanding.

The production of ULTRA and its effective use depended on a strong and well-organized structure 

working in conjunction with now-legendary cryptanalysts. Since the distribution of ULTRA was 

Historian’s Introduction
Page x

limited to a small number of officers and civilian leaders, the bulk of SIGINT support to the warfighter came from tactical SIGINT units working at or near the front lines.

Dr. Howe has restored to us essential details about the organization, maintenance, deployment, 

and service of the military cryptologic units that undergirded the ULTRA effort and supported 

combat forces directly. 

This is an important subject for understanding what happened in World War II and for studying 

the principles of SIGINT organization today.

Dr. Howe’s book was released in part in the late 1980s as a “Special Research History,” an early 

NSA method of declassifying documents and studies. That was a time when much of the SIGINT 

story, even from World War II, was still classified; thus, significant portions were blanked out. It is a 

pleasure now to be able to present an unexpurgated version of this fine history. 

David A. Hatch

NSA Historian

2010

2009

Dr. Howe receiving an award in 1982

from Ms. Ann Caracristi, then the deputy director of NSA
Page xi

Foreword

It is most fitting that the first volume of the chronological history series to be published is one 

written by Dr. George F. Howe, who directed and shaped the cryptologic history program during its 

first fifteen years. In addition, as many readers know, before he came to NSA, Dr. Howe had written, 

among other histories, the volume on Northwest Africa in the official series, The U.S. Army in World 

War II.

Working part time in the years since his retirement, Dr. Howe has produced a comprehensive 

history of U.S. Army SIGINT operations in North Africa and Europe in World War II. A distinctive 

feature of this history is the manner in which SIGINT activities are presented in the context of 

military operations and military strategy. Dr. Howe performed most of the research for this work 

before NSA’s archives were established, which means he had a monumental task simply locating 

some of the cryptologic records for this work.

The Agency has been fortunate to have such an experienced and distinguished scholar writing this 

important chapter in the history of American cryptologic operations.

Vincent J. Wilson, Jr.

Chief, Cryptologic History Publications and Staff

[1980]
Page xii

Author’s Note

The completion of this cryptologic history in its present form has been accomplished by the 

efforts of many persons. Of those with whom the author has worked directly and to whom much 

credit for substance and form is due, he gratefully acknowledges the contributions by members 

of the NSA History and Publications Staff — Vincent J. Wilson, Jr., Chief; Henry Schorreck, 

Historian; Priscilla Pitts, Editor; Jean Hall, Secretary; and Linda Dinan, an ex-member; as well as 

Charles White Eagle, cartographer; and Wallace Winkler, Ray Schmidt, and E. Dale Marston, 

in their role as historical researchers.

George F. Howe

3 June 1980
Page 1

Production of signal intelligence during World 

War II for use by American armed forces was a 

process more elaborate than the creation of a set of 

oriental rugs. Looking back today, patterns are 

recognizable but variations abound. The interdependence of different participants in production is 

as evident as that of the shepherds, spinners, loommakers, dyers, and weavers, whose common 

product, like SIGINT, might end up in an office 

with a parquet floor under a handsome chandelier 

or in the tent of a nomad, or in something in between those extremes. But in any setting, it would 

be highly prized.

During World War II, Americans preferred the 

term “communications intelligence” (COMINT) as 

a near equivalent to the British term “signal 

intelligence,” but they accepted the abbreviation, 

SIGINT, and used it. After World War II, the 

United States armed forces distinguished electronic intelligence (ELINT) from COMINT, and for 

several years reserved control over ELINT matters 

from the province of the U.S. Communication 

Intelligence Board. When that segregation ended, 

the term SIGINT soon displaced COMINT in general practice. Without wishing to predate American 

use of the term “SIGINT” instead of COMINT, I 

have used it in this account of events in World War 

II.

American and British units, both together and 

separately, produced SIGINT used by the armed 

forces of both countries, either separately or in 

combined actions. Each country had a SIGINT organization with a center at its capital and 

tributary stations elsewhere in the country and 

overseas throughout the world. The British had a 

unified organization and three separate Service 

organizations. The Americans had no unified organization; each Service had its own and coordinated 

with each of the other’s. In the overseas theaters 

they had centers in rear areas and mobile units in 

combat zones. The latter could be teams, parties, 

platoons, sections, detachments, companies, or 

groups – anywhere from 3 to more than 200 men. 

The ground and air components of the U.S. Army 

developed related but distinctive operations and 

units.

A theater’s Signal Intelligence Service (SIS) 

provided tactical SIGINT to commanders. 

Dissemination was subject to security regulations 

appropriate for a product of high value and precarious availability. Enemy communications from 

which tactical SIGINT was derived were those 

passed between low and intermediate levels of 

command in low-grade or medium-grade cryptographic systems, or in plain language. When enemy 

communications at high military levels and in highgrade cryptographic systems could be read, the 

product – special intelligence – took form after 

elaborate processing at the British center in England; it was forwarded under stringent controls to 

eligible recipients, including commanders in the 

theaters of operations. Thus, there was a dual 

Allied SIGINT operation-production and dissemination of tactical intelligence (“Y”) and special 

intelligence (“Ultra” or “U”).

This narrative, while noting the existence and 

relevance of special intelligence, makes no attempt 

to explain the methods of its production, or to 

show with any precision how it applied to particular operations. Instead, the history centers on

 American production and use of tactical SIGINT 

(“Y”), as accomplished in the western Mediterranean and European Theaters of Operation, U.S. 

Army. It treats Ultra marginally, as it had tactical 

applications.

Introduction
Page 2

Radio communications among American combat units were monitored by the enemy for the 

same purposes that the Americans were served by 

radio surveillance of the Germans. American traffic 

was also monitored by Americans for two 

purposes: to detect and correct communications 

insecurities that the Germans could exploit, and to 

keep track of advance American elements in order 

to keep American commanders continuously and 

currently informed of their positions, situations, 

and intentions. This history does not deal with 

those operations beyond indicating their claims on 

radio intercept sources.

Some information about the German Army 

field SIGINT service is included here. The war was 

a competition not only between the operators of 

guns, tanks, aircraft, and other weapons, but between the operators of radio receivers, radio 

direction finders, and the facilities available to intelligence analysts. Since it is axiomatic that 

SIGINT emerges from defective COMSEC, instances of German SIGINT success are likely to be 

examples of American COMSEC failures. To that 

extent only, is American COMSEC a part of this account.

The Mediterranean theater was only one of 

many in a conflict often described as “global” in 

scope and “total” in depth. Military application of 

technology was accelerated during the conflict. It 

may be helpful to cite some of the relatively new 

and distinctive features of World War – features 

which have become less striking in the light of later 

and newer developments. Between World Wars I 

and II, aviation, called “air” or “air power,” had 

become transformed. It relied, however, on single 

and multimotored propeller aircraft; jet-powered 

planes were being used, but not widely, as the 

hostilities ended. Missile systems had been sufficiently developed by the Germans to be used in 

warfare, but they had not perfected accurate delivery systems. Rockets were widely used by ground, 

sea, and air forces. The bombsight was sufficiently 

refined to achieve fair accuracy from great heights. 

The role of “air” made the acquisition and defense 

of airfields essential.

During World War II, automotive transportation largely supplanted that by animals; animals 

were still being used, but primarily as pack animals 

in mountainous terrain. The newer vehicles rolled 

on either tires or “tracks.” They ranged from small 

cars and motorcycles to massive, heavily armored 

tanks equipped with thick armor, 150-mm 

long-barreled guns, as well as lighter weapons. Artillery was adapted to the new kinds of targets. 

Shells could be armor-piercing, incendiary, high 

explosive, white phosphorus, smoke, or high velocity. The “proximity fuse” caused detonation with 

maximum effect. Bombs, like artillery shells, varied 

in character as well as in size. Napalm and flamethrowers were used against sheltered positions. 

Radar and sonar were widely used. Beacon signals 

assisted ships and aircraft in navigation. Radio direction finding (DF) – goniometry – was a reversing 

of that procedure.

To offset the military control of ports by hostile 

forces, the Allies developed the means and the 

methods necessary to land men, weapons, supplies, 

trucks, and even armored vehicles through surf and 

across beaches.

Naval ships bore on their decks small aircraft 

for reconnaissance and for directing naval gunfire 

on shore targets. Carriers with flight and hangar 

decks were used as floating bases for fighter and 

bomber aircraft.

The control of numerous dispersed units – 

ground, air, surface, and submarine – required 

extensive facilities for radiotelegraph and radiotelephone communications.

In Northwest Africa, during 1942-1943, American “commanders began to realize as never before 

the potentialities of mobile radio, radiotelephone, 

carrier telephone, and teletype, to say nothing of 

the immense possibilities of radar, radio intelligence, radio countermeasures, propaganda, and so 
Page 3

on. Commanders began to take for granted facilities undreamed of in any previous conflict. They 

expected to be able to communicate at any time 

with subordinates, even in moving vehicles widely 

scattered over a mobile front. They expected to be 

able to talk with headquarters however distant. In 

fact, they began to demand facilities not yet 

developed.”1

Technology to meet the COMSEC requirements 

produced, among other devices, high-speed, automatic Morse telegraphy and non-Morse 

radioprinters. For security, communicators 

employed cipher machines and telephone “scramblers.” The communications traffic of both sides 

became voluminous; each sought successfully to 

derive SIGINT from the other’s signals.

Note

1. George E. Thompson, Dixie R. Harris, Pauline M. Oakes, Delaney Terrett, The Signal Corps: 

The Test. (Office of the Chief, Military History, 

1957), 381.
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Page 5

Part One

The Mediterranean Area
Page 6
Page 7

Early Conditions

American SIGINT operations during World 

War II were conducted by separate Service Cryptologic Agencies. Both in their Washington centers 

and in the field, the Army and Navy went largely 

separate ways. In the Army, moreover, cryptologic 

activities followed divergent lines for ground and 

air forces. Different and somewhat separate organizations were developed to serve the needs of ground 

and air commanders.

The U.S. Army had produced and applied 

SIGINT in France during World War I. Signal 

Corps units had then engaged in radio interceptions and goniometry, a term more frequently 

expressed later as direction finding (DF) or position finding. The intercepted material and “fixes” in 

1917-1918 were delivered to G-2, American Expeditionary Force, for exploitation.

Between World Wars, the Army and Navy each 

supported a small and slowly growing group of 

radio intelligence units and analysts, in each case 

placing them within the communications segment 

of that service. The material intercepted and the intelligence derived were for the most part from 

diplomatic communications. Foreign armies and 

navies in the 1920s and 1930s were distant from 

the United States, and diplomatic communications 

were therefore much more readily intercepted. 

Diplomatic intelligence was welcome at high policy-making levels. The Army and the Department 

of State cooperated in producing such information 

in connection with the Conference on the 

Limitation of Naval Armaments in Washington in 

1921, and persevered in such an effort until stopped 

by orders of the secretary of state in 1929. A new 

effort to prepare to utilize SIGINT in wartime took 

place most secretly in the next decade.1

In the U.S. Navy communications exchanged 

during grand maneuvers of the Japanese fleet were 

made the basis of traffic analysis that, as a test, 

demonstrated how much intelligence could be ascertained without reading the contents of messages. 

It was sufficiently successful to convince Navy leaders that their small communications intelligence 

effort should be expanded and supported.

In the twenties and thirties, the Army had 

worked on Japanese communications to develop 

technical competence and to help U.S. policy makers become sufficiently informed about Japanese 

political and military intentions. Japanese cryptography made use of machine encipherment of 

diplomatic messages. The cryptanalysts of the U.S. 

Army and Navy successfully devised counterparts 

to the main Japanese enciphering device and 

quickly read much Japanese traffic that the senders 

believed to be completely protected.

German naval operations in the Atlantic were 

closely directed from the homeland. Submarines 

reported daily, or more often, and received specific 

instructions by radio. Even before the U.S. became 

a belligerent, the nation provided war material 

essential to the British. After Hitler and Mussolini 

declared war against the United States, it became 

more than ever vital that German sea warfare be 

checkmated. Toward that goal, the United States 

Navy and the Royal Navy cooperated in exploiting 

German naval communications.

By presidential order in 1942, the two service 

SIGINT organizations, usually calling their products COMINT, collaborated with the Federal 

Bureau of Investigation (FBI) only and kept other 

U.S. agencies (such as the Federal Communications Commission) from engaging in production 

operations.

Chapter 1

Situation Report
Page 8

The British developed a unified SIGINT agency 

known as the Government Code and Cypher School 

(GCCS), which was ready when war came in 1939 

to begin joint-service operations at a preselected 

site near London. Each of the British armed services had its own intelligence system to which 

SIGINT contributed Information.

During the war, the United States Army and 

Navy separately entered into several specific agreements with the London Signal Intelligence Board 

and its instrumentality, the GCCS. In all matters of 

SIGINT policy, GCCS could present a single British 

position, while SIGINT officials of the U.S. Army or 

Navy usually could not.

As the war continued, changes in methods of 

warfare and developments in enemy cryptography 

brought about endless modifications of the organization and operations of the SIGINT producers. 

Not only technical adjustments but also administrative arrangements were prompted by new 

experience. In the U.S. Army, the Signal Corps’ Signal Intelligence Service (SIS) in mid-1943 became 

the Signal Security Agency; both were under the 

supervision of the Military Intelligence Division 

(G-2), War Department. On 15 May 1942, Colonel 

Carter W. Clarke of G-2 was designated as G-2’s 

representative to supervise the SIGINT operations 

of the War Department and to manage the handling and dissemination of all the special material 

produced. He was at the same time made G-2 Liaison Officer with the Department of State, 

Department of the Navy, FBI, Federal Communications Commission, Office of the Coordinator of 

Information, and Office of Facts and Figures. When 

the Signal Intelligence Service became the Signal 

Security Agency, G-2 exercised direct operational 

control and disseminated SIGINT products through 

a Special Branch, G-2. Ultimately, in September 

1945 as the Army Security Agency, the SIGINT 

organization, was transferred from the Signal Corps 

and incorporated into the Military Intelligence Service.

Before Pearl Harbor, to reduce overlapping effort by Army and Navy producers of diplomatic 

SIGINT, the two armed services alternated 

responsibility daily. On 25 January 1942 Colonel 

Frank W. Bullock, Chief, Signal Intelligence 

Service, and Commander John R. Redman, Commanding Officer, OP-20-G (the SIGINT element of 

the Office of Naval Communications), agreed orally 

that the Army would process all diplomatic traffic 

and would furnish to the Navy intelligence service 

translations of all messages of interest to the Navy. 

The Army expanded its SIGINT establishment to 

cope with the traffic of enemy ground and air forces 

as well as diplomatic material.

OP-20-G remained in the Office of Naval Communications throughout the war, expanding 

tremendously and disseminating its products 

through combat intelligence officers at various 

headquarters. Its contribution to Allied triumph in 

the Battle of the Atlantic against German submarines, and in the campaigns in Pacific Ocean areas, 

would be hard to exaggerate.

The Army Signal Corps in 1938 had a single 

radio intelligence company and five small radio intercept detachments of signal companies in Texas, 

California, the Canal Zone, Hawaiian Islands, and 

Brigadier General Carter W. Clarke

(Photograph courtesy of the

Department of Army)
Page 9

the Philippines. A Second Signal Service Company 

was activated early in 1938. Fort Monmouth, New 

Jersey, was the site of the original training center. 

Under a Headquarters, SIS, that acquired in 1942 

the property of a girls’ school at Arlington Hall, Virginia, the Second Signal Service Battalion (as it 

became in April 1942) and its detachments provided the organizational framework for cryptologic 

work. The cryptologic school, first at Fort Monmouth, and after October 1942 at Vint Hill Farms, 

near Warrenton, Virginia, tried to train communicators, intercept operators, and analysts in various 

types of cryptologic operations. The number of beginners who finished the forty-eight-week course 

was reduced by an endless drain of men either 

bound for Officers’ Candidate School, sent to fill 

spaces in divisional units, or transferred for 

inability to keep up with the training.

Radio intelligence companies were organic to 

the staff of a general headquarters of a field army. 

Radio intelligence platoons were similarly part of 

the tables of organization of divisional signal companies until October 1943. Then these platoons 

were shifted from divisional signal companies to 

the signal battalions of the various corps. While 

these units conducted the monitoring of American 

communications in the interests of security, they 

were drawn more and more into surveillance of 

enemy communications for intelligence.

The high-grade cryptographic systems under 

exploitation by the Army’s SIGINT organization 

when the U.S. entered the war were Japanese only. 

The expectation then was that intercept stations in 

forward areas would collect such material and send 

it to a Washington center or a theater center for 

analysis. Under Army organization, a theater of operations was expected to determine its requirements 

and control the means of satisfying them, after they 

had been obtained. In the Zone of the Interior, men 

were to be trained, organized, equipped, and 

“shipped out.” In the theaters to which they went, it 

was believed that more training and seasoning 

would make them fully productive. There was no 

system in 1941 for the rapid, secure dissemination 

of SIGINT produced at any center to distant 

commanders in the field. For that and for many 

other aspects of producing and disseminating SIGINT, the U.S. Army (Signal Corps and Military 

Intelligence Service) sought illumination in the experience of its British ally.

In 1942 the Signal Intelligence Service sent 

some partly trained personnel to the United Kingdom for advanced training. At that juncture, the 

American SIS drew no distinction between the resources and protection required in producing what 

the British called “Special Intelligence” (SI) or 

Ultra and those needed for what they called “Y” (or 

“Yorker”). The British derived Ultra from cryptographic systems of high grade (when they could 

read such systems) and distributed it directly from 

London via radio links, exclusively for that purpose, connecting GCCS with Special Liaison Units 

(SLUs) at certain headquarters. The officer in 

charge of an SLU conveyed special intelligence 

face-to-face to a few eligible individuals and protected all materials in accordance with extremely 

exacting security rules. The contents and the application of SI to current operations were guarded so 

thoroughly because of the extraordinary value attributed to it and the readiness with which a 

disclosure could bring about crippling cryptographic changes by the enemy. It is probable that 

even SI was unknown to more than a few score officers in any theater.

The British had achieved, in special intelligence, a source into which they had had to pour 

prodigious intellectual effort and substantial monetary outlay. The American participation in either 

producing or receiving Ultra was, therefore, always 

on terms to which the British agreed, an agreement 

that might have been affected by pride of possession but certainly was controlled by concern for 

continuation in the future. It was only when Allied 

victory in Tunisia was at hand that the American 

participation in special intelligence became the 

subject of a formal, written agreement.2

“Y,” on the other hand, was produced in the 

field as well as at GCCS from traffic in cryptographic systems of medium or low grade, or in 

plain language. It consisted largely of messages 
Page 10

between lower echelons of command and between 

ground stations and aircraft in flight. “Y” also utilized information from DF “cuts” and “fixes” and 

from the externals of messages. The British called 

that “Wireless Telegraph Intelligence” (WTI). The 

American term for it was traffic intelligence.

“Y” (or traffic intelligence) helped to identify 

the enemy links of greatest merit for surveillance 

and to furnish cryptanalysts with clues to subject 

matter by identifying the sender, receiver, and time 

of transmission. From “Y” alone the information 

about enemy movements and order of battle was 

often enough to guide command decisions. Knowing exactly where a specific enemy formation was 

stationed could sometimes be of more benefit to a 

commander than the substance of the very message 

that had revealed the location.

At the time Operation TORCH – the Allied invasion of French North Africa – was being planned, 

two other terms in use by British producers were 

“Y-Inference” and “Fusion.” The former was a kind 

of traffic intelligence that amounted to interpretations of messages in the light of probabilities. The 

latter, as used at Bletchley Park (the main British 

SIGINT center), meant comparing “Y” with SI to 

insure that the interpretation of the former was 

consonant with the substance of the latter. But the 

word “Fusion” was also employed to mean collating 

several varieties of intelligence information, such 

as “Y,” interrogations of prisoners of war, interpretation of photographic reconnaissance pictures, 

and reports from agents.

Early British Experience with Field SIGINT

From September 1939 to November 1942, the 

Mediterranean area was the scene of many actions 

of the first phase of World War II. The British and 

Italian navies contended for control of the Mediterranean-Suez route. British forces ousted the Italians 

from Ethiopia and defeated them in Libya. Then 

German forces augmented the Italians to recover 

Libya, gained control of the Balkan countries, and 

drove the British out of mainland Greece and Crete. 

The German Air Force disputed with the Royal 

Navy the use of the Mediterranean route to Egypt 

or to Malta. But Malta remained in British hands, 

while the British successfully defended Egypt in return for extensive use of that country as a British 

base.

By October 1942 a German-Italian Panzer 

Army, Afrika, was threatening Egypt from positions in Egypt’s Western Desert while the British 

Eighth Army, partly armed with American tanks 

and supported by Royal Air Force (RAF) and Royal 

Navy units, was preparing to drive the Axis out of 

the country altogether.

At the western end of the Mediterranean, Gibraltar remained the British possession, as it had 

been for more than 200 years. From airfields in 

Sicily and southern Italy near Foggia, as well as 

mainland Greece and Crete, German Air Force 

units had made the surface of the entire Mediterranean extremely dangerous for British ships. 

German and Italian submarines heightened the 

risks and caused the total tonnage of sunken ships 

to mount alarmingly.

SIGINT confirmed in May 1942 that bombing 

of Malta by day had been rendered too costly to be 

continued and that the German Air Force would resort to night bombing only. Despite the failure to 

subdue and occupy Malta, the Axis high command 

allowed Field Marshal Rommel to drive into Egypt, 

threatening Cairo and the Nile Delta. During the 

campaign he lost his advanced SIGINT unit at a 

time when British SIGINT was strongly supporting 

the ground and air forces in his path. At General 

Headquarters, Middle East, in Cairo, the direct link 

between GCCS at Bletchley Park and the principal 

Army and RAF intelligence officers in the theater 

was active, beginning in March 1941. At 

Headquarters, Western Desert Air Force (WDAF) 

at Gambut, the commander and his principal intelligence officer were recipients of special intelligence 

which, whenever security would not thus be compromised, became the basis for tactical air action. 

After July 1942 a source of SI in the Western Desert itself was exploited at Heliopolis; there the RAF 

installed a miniature version of one of GCCS’s divisions to process incoming material near a Special 
Page 11

Liaison Unit. A special communications link to 

Headquarters, Eighth Army, was then used often to 

supplement the SI from London on which Army 

and Air Staffs relied. General Claude Auchinleck 

was said to have attributed to this forward auxiliary 

SIGINT service his success in stopping Rommel 

from getting as far as Cairo.

From late February to late May 1942, preceding 

the Axis thrust into Egypt, British Eighth Army had 

its “Y” units at army and corps headquarters. (Division headquarters had been obliged to move too 

frequently for efficient SIGINT production there.) 

They divided intercept coverage. At Corps, the 

units exploited all immediately readable traffic. At 

Army, and at a military base near Heliopolis, cryptanalysts and traffic analysts derived more results 

from the material transmitted in cryptographic systems of greater difficulty. The base unit furnished 

not only such decrypts but technical data of help to 

analysts further forward. After the Germans began 

their attack into Egypt in 1942, they provided so 

much more traffic that British cryptanalytic successes were facilitated.

In May 1942 a dramatic demonstration of what 

“Y” could do for the Eighth Army occurred. When 

Rommel was preparing to attack from the Gazala 

area, SIGINT provided an interpretation of the enemy’s dispositions and probable intentions. It was 

based on the correlation of readable messages in 

low and medium-grade systems with compromises 

of enemy code names, with DF fixes, reconstruction of enemy nets, and data gleaned from 

interrogating prisoners of war. The Eighth Army’s 

operations officer, like most British commanders 

then, was inclined to discount Army SIGINT unless 

it took the form of a readable message text disclosing significant information. Compared with SIGINT 

from deductions, he preferred to trust inferences 

derived from other forms of intelligence. After the 

attack came, and the interpretations by the 

SIGINT staff had been wholly confirmed while that 

from other intelligence was shown to have been incorrect, the validity of SIGINT was more readily 

accepted than before. Information from other 

sources about pending British operations and about 

Axis situations thereafter became much more fully 

available to the SIGINT staff, thus further improving the quality of its output.

By October 1942 the British Eighth Army was 

receiving strong field SIGINT (“Y”) support as well 

as SI. The fruits of experience were being harvested. Deficiencies in training, in equipment, in 

selecting sites, and in operating secure, SIGINT 

communications facilities had all been reduced. Intercept control by the SIGINT unit near Army 

headquarters was recognized to be the most satisfactory. That all intercept of low-powered German 

tactical traffic had to be accomplished at points 

within 100 miles of the transmitters was clearly realized. The value of secure circuits used exclusively 

for SIGINT communications between field units 

and a fixed station at base, and between field stations and commanders, had become apparent.

Doubtless it was Ultra more than “Y” which enabled General Montgomery, before his first big 

battle at Alam Halfa, to tell his officers what he expected Rommel to attempt; it was a prophecy of 

such accuracy as to gain even more credit for 

Eighth Army’s intelligence service in the future.3

German Army and Air Force SIGINT Organizations

While the Allies prepared for SIGINT 

production in the field in French North Africa, the 

Germans who were to confront them there relied 

for similar services upon the abilities of a SIGINT 

organization that primarily had been directed 

against Soviet targets on the Eastern Front and 

only secondarily against the British forces in the 

eastern Mediterranean region.

The German Army had begun the formation of 

a SIGINT service during the 1920s by establishing 

then, and in the next decade, several fixed intercept 

stations at sites within Germany. Under control 

from a center in Berlin, they were able to monitor 

military traffic from the low countries, France, the 

British Isles, and the Soviet Union. The RussoFinnish War offered ample opportunity to develop 

German ability to read Soviet cryptographic 
Page 12

systems. During the interval preceding the German 

invasion of western Europe in 1940, field SIGINT 

regiments (KONAs) had been formed for army 

group and army commands from personnel taken 

from the fixed stations, plus linguists and mathematicians who had been drafted as reinforcements. 

In the months between the collapse of France and 

the invasion of the Soviet Union in June 1941, the 

German SIGINT structure expanded rapidly.4

From 1941 to 1944, the German Army SIGINT 

Service operated centers in Berlin and Zossen. All 

were under policy control of the Field Army’s 

Chief of Intelligence. KONA 4 and KONA 7 (an 

abbreviation of “Kommandateur Nachrichten 

Aufklaerung”) were intercept and processing units 

attached to regional headquarters in Greece and 

Italy, respectively. A unit known as Fernaufklaerung Kompanie 621 (FAK 621) was a forward 

intercept and analytic unit operating under KONA 

4 with the Deutsche Afrika Korps (DAK) in the 

Western Desert of Egypt. Not before Rommel’s 

German-Italian Panzer Army, Afrika, began its 

retreat westward across Libya to Tunisia and only 

when the Fifth Panzer Army assumed command of 

the Axis forces in Tunisia was KONA 7 organized in 

1943 and assigned to Oberbefehlshaber Sued 

(Kesselring). FAK 621 while in Tunisia came under 

control of KONA 7 and obtained technical support 

from KONA 7’s “Evaluation Unit” at Rocca di Papa. 

The latter contained about 150 men in sections 

concerned with cryptography, cryptanalysis, and 

the elements of traffic analysis, direction finding, 

and intelligence. The German Air Force put a 

SIGINT unit in Sicily at Marsala or Taormina 

which cooperated with the Army SIGINT service.

FAK 621, when commanded in the Western 

Desert by Captain Alfred Seebohm, included specialists in the cryptosystems used by the British, 

men who had been used during the campaign of 

1940 that ended with the French surrender. Their 

work in North Africa was aided by the capture, during the invasion of France, of at least one British 

War Office code, and also for a time much 

strengthened by the detailed communications to 

Washington from the U.S. Army Attaché in Cairo. 

These communications were transmitted in a U.S. 

system that the Germans could readily solve.

During the summer of 1942, at just about the 

time the Allies decided to invade French North Africa, FAK 621 was attacked and overrun by British 

Forces. Captain Alfred Seebohm, the commanding 

officer, was fatally wounded. About one-third of its 

authorized strength of seven officers and 300 enlisted men was lost. Their excellent receivers and 

direction finders had been used effectively to produce intelligence reports on British order of battle, 

plans, morale, and tactical dispositions — reports 

on which Rommel could and did rely. FAK621’s 

captured files identified British systems which the 

Germans had analyzed and exploited, causing British communications changes that henceforth 

deprived the Panzer Army, Afrika, of most of the 

SIGINT on which it had been able to rely. The captured records also included German ciphers and 

radio schedules, which, of course, they had to 

change. There was no evidence that British special 

intelligence had yet been compromised; the British 

“Y” service also continued to provide information 

of important value to the Eighth Army as it prepared for the battles that ended the German-Italian 

threat to Egypt. Remnants of FAK 621 and reinforcements were placed under command of a 

Captain Habel and reequipped for service in Tunisia.5

German intercept units covered the British 

Eighth Army from Italy and the British First Army 

from Sicily, while the fixed German Army station at 

Montpellier continued to monitor French communications, including the XIX Corps d’ Armee in 

Tunisia. Three direction-finder nets, controlled 

from Gabes, Taormina or Marsala, and Rocca di 

Papa and connected by combined wire and radio 

channels, functioned during the main battles in 

Tunisia. Intercept material could be sent to 

Oberbefehlshaber Sued (O.B. Sued) that way, or by 

courier planes that ran every other day from 

Bizerte and every day from Sicily. In the last days of 

the Tunisian campaign, after the Allies had gained 

air superiority, SIGINT became the main reliance 

of the Axis command.
Page 13

When the German Air Force transferred Luftflotte 2 from the Eastern Front to the Mediterranean, 

with headquarters in Sicily, its two main divisions, 

Fliegerkorps II at Messina and Fliegerkorps X at 

Heraklion, were given SIGINT services. Until Operation TORCH, during a period of almost two 

years, they operated against the Royal Navy, the 

Royal Air Force, and the British Eighth Army. The 

German-Italian Panzer Army, Afrika, which pushed 

its way across the Western Desert into Egypt after 

the fall of Tobruk in June 1942, became highly 

dependent upon the support of the German Air 

Force. Rommel’s defeat at El Alamein and long retreat to Tunisia gave his forces some respite from 

the RAF until the Allies gained air superiority there 

in April 1943.

The German Air Force SIGINT service came 

from units of varying size that were placed with 

operating units at Mediterranean bases. The 

Luftwaffe had created its SIGINT agency, Chi/

Stelle, OB dL, in 1937 and worked on air traffic 

there thereafter. It had a fixed station within 

Germany at Oberhaching known as W-Leit 13 

which monitored French and British traffic from 

Africa. Luftwaffe SIGINT South with units at Athens and a fixed station near Athens, was augmented 

when Field Marshal Kesselring took up his air and 

theater commands as O.B. Sued.

The German Air Force units each made their 

own evaluations of what they had intercepted and 

deciphered. Deciphered messages were sent immediately to higher SIGINT headquarters, to other 

SIGINT organizations, and to the flying units, 

where the air intelligence officer made an ultimate 

evaluation. Luftflotte 2 had in Taormina an Evaluation Company (W-Leit 2) attached. During 1943 

several outstations to intercept HF communications were established under W-Leit 2. Like British 

Army traffic in northern Africa, RAF operational 

communications also ceased to be readable in 

1943, obliging W-Leit 2 to rely on traffic analysis, 

tracking of flying routes, interception of radiotelephone traffic, and radar intelligence (RADINT).

At the end of the campaign in Tunisia, when the 

invasion of Sicily was in preparation, and when the 

surrender of Italy was the subject of highly secret, 

clandestine negotiations, W - Leit 2 departed 

Taormina a few days ahead of the Allied parachute 

and beach landings farther south. It set up at Frascati to remain there almost a year before being 

bombed out.

U.S. Preparations for SIGINT Service in the 

West

Special intelligence produced by the U.S. before 

the Japanese attack had gone under the designation of MAGIC. Precautions taken to shield it were 

somewhat akin in spirit to those that the British 

used for their special intelligence. Expanded use of 

SIGINT in the wartime production of U.S. military 

intelligence for field commanders required suitable 

innovations in handling SIGINT products. 

On 18 January 1942 Mr. Alfred McCormack was 

appointed special assistant to the secretary of war 

to devise methods that would serve all requirements. On the basis of his recommendations, the 

Military Intelligence Service (MIS) of the War Department acquired a Special Branch, headed by 

Colonel Carter W. Clarke, GSC. As a new lieutenant 

colonel, McCormack became its deputy chief. The 

Special Branch handled all SIGINT, and produced 

a daily “MAGIC Summary,” which at first largely 

pertained to diplomatic communications.

The Signal Corps organization for producing 

SIGINT, known by several successive titles – including Signal Intelligence Service (SIS) and Signal 

Security Agency (SSA) – served the Special Branch, 

MIS, as a “customer.” MIS was attached to, but not 

a part of, the War Department General Staff. It was 

controlled by the assistant chief of staff, G-2, and 

provided intelligence to the General Staff, the Army 

ground forces, Army air forces, Army service forces, 

overseas theaters of operations, and certain federal 

agencies. The chief signal officer came under the 

command of the commanding general, Army Service Forces. Thus the Signal Intelligence Service/

Signal Security Agency and its theater counterparts 

were not directly under the assistant chief of staff, 

G-2 (intelligence) until very late in World War II. 
Page 14

In the last status, it was renamed the Army Security 

Agency, effective 15 September 1945.

The U.S. Army contingent in Europe began 

with a Special Observers Group first stationed in 

the United Kingdom in May 1941 (before Pearl 

Harbor). On 3 January 1942 that staff was 

superseded by a larger Headquarters, U.S. Army 

Forces in the British Isles (USAFBI). On 8 June 

1942 that was replaced by Headquarters, European 

Theater of Operations, U.S. Army (ETOUSA). 

ETOUSA was to control preparations for ground 

and air operations of the Allied central 

strategic undertaking – invasion across the English 

Channel and penetration as far as the heart of Nazi 

Germany.

The U.S. Army intended to provide in the theater a signal intelligence service that would come 

abreast of British capabilities already derived from 

two years of actual war experience. It was in the 

best interests of both Allies that the Americans 

learn as soon as possible to produce and apply tactical SIGINT. Soon after Pearl Harbor, the 

Americans sought detailed knowledge of British organization and methods through observation of 

operations in the United Kingdom. The U.S. Army 

staff element through which those attempts were 

first funneled was the SIS officer (First Lieutenant 

R. J. Doney), Signal Section, HQ, USAFBI.

One platoon of an intercept unit, 122d Signal 

Radio Intelligence (SRI) Company moved from the 

United States to Northern Ireland and by 15 May 

1942 was attempting to collect German traffic 

from that location. Several young officers visited 

British Army SIGINT stations. Captain Harold 

Brigadier General Carter W. Clarke presenting the Distinguished Service Cross to Colonel 

Alfred McCormack in November 1946, for exceptional service to the War Department while 

serving in the Military Intelligence Service 

(Photograph courtesy of the Department of Army)
Page 15

McD. Brown investigated the British Army “Y” Service, wrote a lucid report, and submitted it on 10 

July 1942.6 Others studied the situation at fixed 

and mobile “Y” stations. At the British SIGINT center at Bletchley Park, about forty miles outside 

London, Captain Solomon Kullback and Captain 

Roy D. Johnson observed British procedures for 

decrypting systems used by several countries.

Certain discoveries by the observers were startling. They amounted to recognition of a whole 

repertoire of methods employed by the German 

communicators to camouflage radio links – both 

transmitter and receiver – as well as to encrypt the 

substance of messages. Successful intercept operations were dependent upon effective direction by 

specialists to radio targets identified through the 

application of what the British called “Wireless 

Telegraph Intelligence” (WTI). It determined the 

identity of stations in radio links and nets by analyzing the externals of messages, and it assisted 

cryptanalysts in other ways to ascertain the identities of senders and receivers. Already the British 

“Y” Service had developed TINA (to identify radio 

operators by their “fist,” i.e., sending characteristics) and radio fingerprinting (to identify 

transmitters by distinguishable traits of their signals), as well as DF as adjuncts of analysis. It was 

obvious that the training of American radio intercept operators had to be brought up to date by 

enough exposure to live German traffic. Another 

discovery by early Amer- ican observers was that 

the RAF had to monitor and read much more than 

communications between aircraft in flight and terminals on the ground. It had to extend the scope of 

coverage to include ground links, navigation aids, 

air transportation, air rescue service, and others.

In August 1942 Lieutenant Colonel George A. 

Bicher, SigC, became the first director, Signal Intelligence Division, (SID) Signal Section, Headquarters, 

ETOUSA. After establishment of the Headquarters, 

Services of Supply, ETOUSA, his division passed 

like the whole office of the chief signal officer to the 

jurisdiction of that headquarters. SIS, ETOUSA, 

was an operating organization under the theater 

SIGINT staff element (SID).

Colonel Bicher’s mission became manifold. He 

supervised and conducted all SIGINT production 

activities within the theater, in close contact with 

G-2, ETOUSA, and acted as an advisor to that element on technical matters. He supervised a special 

War Department SIGINT production unit cooperating with GCCS in the latter part of the war, but 

did not supervise the representatives of Special 

Branch, MIS, War Department, who had been stationed in the U.K. He had normal liaison with U.S. 

Army “Y” Service in other theaters, cooperated with 

GCCS on technical matters of mutual interest, and 

supervised liaison activities of the representatives 

from the Signal Security Agency, GCCS, and the 

London SIGINT Board. He furnished that Agency 

with technical infor-mation concerning SIGINT 

operations in the European theater. For a while he 

represented the Army Signal Corps during early efforts of the U.S. Army Air Forces to build an Air 

Intelligence Service, but in 1944, the Signal Corps 

yielded to the determination of the U.S.A.A.F. to 

control separately the SIGINT operations on which 

it relied, and Colonel Bicher’s responsibilities were 

correspondingly reduced.

In the summer of 1942, the SIGINT duties of 

SID, ETOUSA, were chiefly those of planning the 

expansion of SIS, ETOUSA, and of conducting liaison with War Office and Air Ministry concerning 

assignments and itineraries of American observers 

on temporary duty. SIS, ETOUSA, established 

Captain Solomon Kullback

(Photograph from NSA History Collection)
Page 16

security and intelligence branches, and grew from 

four officers and three enlisted men on 4 August 

1942 to fourteen officers and fifteen enlisted men 

on 10 September. Four days later, two lieutenants 

were detailed to a two-week course at the RAF Station at Newbold Revel for “computors” (the British 

word for traffic analysts), thus beginning the training that led to establishment in January 1943 of the 

Air Intelligence Section, SIS, ETOUSA. Throughout 

the war signal security was also an area of responsibility for SIS, ETOUSA. It involved the 

development of signal operating instructions for 

the theater, distribution of and accounting for cryptographic machines and material, security 

monitoring of American communications, and related training.

The War Department eventually approved 

plans for theater training of 100 SIGINT officers 

and 400 enlisted men. Authorized personnel began 

arriving before a table of organization had been approved. But the planning and preparations in 1942 

to meet the requirements of an American component of an Allied force invading Europe to establish 

a bridgehead across the channel were suddenly 

submerged by the demands of Operation TORCH 

in French North Africa. Mediterranean requirements took precedence for more than a year.

The Call of the Mediterranean

The Allies were committed to defeating the Axis 

not by attacks at the edges of the territories they 

controlled but by thrusting at the heart of the 

strongest, Nazi Germany, as soon as that became 

practicable. In 1942, however, they agreed that attacking Germany itself was not practicable, so they 

began “closing the ring” around the Third Reich. As 

a prelude to regaining control of the western Mediterranean, they concluded that they had enough 

forces to seize the area along Africa’s northern 

coast, and that Allied seapower could maintain the 

long lines of communication from home bases to 

overseas combat areas there. The Axis lines, though 

shorter, would involve rail, sea, and air transport. 

The combat troops of each side would therefore 

meet at the periphery of possible effectiveness.

The Allied strategic decision to occupy French 

North Africa greatly altered the course of the war, 

but the extent to which it would affect the ultimate 

cross-Channel attack was reinforced by subsequent 

choices.. During the remainder of 1942 and the first 

part of 1943, the Mediterranean became the major 

theater of Allied initiative. That it was intended to 

be so only temporarily was reflected in the arrangement to include North Africa and the western half 

of the Mediterranean within the European Theater 

of Operations, U.S. Army (ETOUSA). The boundaries of the European theater were extended to 

include that area on 18 August 1942.7

Following the decision of the Allies at 

Casablanca in January 1943 that Sicily would be 

occupied next, after Tunisia had been won, a new 

North African Theater of Operations, U.S. Army 

(NATOUSA), was established on 4 February. General Eisenhower then relinquished his position as 

commanding general, ETOUSA, to Lieutenant 

General Jacob Devers and became commanding 

general, NATOUSA, as well as commander in chief, 

Allied Force. The new theater included the Iberian 

and Italian peninsulas and adjacent waters, but no 

part of European France.

Colonel George A. Bicher (Photograph 

courtesy of the Department of Army)
Page 17

For Operation TORCH, an “Allied Force Headquarters” under General Eisenhower originated in 

the United Kingdom in August 1942, used Gibraltar 

briefly for an advance command post, and moved 

on 25 November 1942 from London to Algiers. In 

1944 Headquarters, AFHQ, moved to Caserta, 

Italy. Under successive commanders, Anglo-American forces and associated forces of other nations 

engaged in campaigns in French North Africa, Sicily, the Italian peninsula — from Calabria to the Po 

Valley and the Alps — and on major islands like 

Sardinia and Corsica. AFHQ mounted Operation 

DRAGOON, the invasion of southern France, in 

August 1944.

Before the hostilities in the Mediterranean area 

ended on 2 May 1945, U.S. Army and Army Air 

Forces had been participants in eight Mediterranean campaigns. The official designations of these 

campaigns are as follows:8

Algeria-French Morocco Anzio

Tunisia Rome-Arno

Sicily North Apennines

Naples-Foggia Po Valley

The Allied and American theater organization 

in the Mediterranean underwent major changes. In 

December 1943 AFHQ’s responsibilities were extended to include operations in Greece, the Balkans, 

or Turkey, and in the same month General Eisenhower was designated to command the invasion 

across the English Channel. He relinquished both 

Allied and U.S. Army commands in the Mediterranean. On 8 January 1944 General Sir Henry 

Maitland Wilson succeeded him as Allied commander in chief, Mediterranean Theater. The 

eastern Mediterranean, where British forces had 

been engaged for so long, ceased to be separate. 

General Wilson’s principal sea, ground, and air 

commanders were British officers. The British became executive agent for the Combined Chiefs of 

Staff in the whole theater, replacing the Americans 

in the western Mediterranean. Maitland Wilson’s 

deputy as Allied commander became General Devers, who also succeeded General Eisenhower as 

commanding general, NATOUSA. Headquarters, 

NATOUSA, was expanded. At the time of the 

changes, General Sir Harold Alexander commanded Allied ground forces in Sicily and Italy; 

eventually he succeeded Wilson as Supreme Allied 

Commander, Mediterranean Theater (SACMED), a 

title established on 9 March 1944. In that capacity 

he received the German surrender in Italy in May 

1945.

About one month after General Wilson took 

command, and in view of the possibility of an Allied 

invasion of southern France, NATOUSA’s boundaries were enlarged to include the southern part of 

France. The invading forces would be organized 

and Operation DRAGOON would begin, as a responsibility of AFHQ. But when the invaders had 

penetrated far enough to require unified control, 

their activities would come under control of General Eisenhower’s Supreme Head-quarters, Allied 

Expeditionary Forces (SHAEF); their administration and logistical support would pass to ETOUSA. 

In fact, SHAEF assumed operational control on 15 

September 1944 of the forces that had participated 

in Operation DRAGOON. HQ, ETOUSA, took over 

the line of communications behind those forces on 

20 November 1944. All NATOUSA/MTOUSA units 

in southern France were officially reassigned to 

ETOUSA. The Mediterranean Theater, having 

mounted the invasion, had its northern boundary 

once more changed and thereafter employed diminished resources in northern Italy and in 

wide-ranging air operations from bases in Italy.

These organizational aspects of the war in the 

Mediterranean area underlay the circumstances of 

the SIGINT effort. The conditions of combat affecting the performance of SIGINT units are treated as 

the narrative proceeds.

Notes

1. See the description by G. Raynor Thompson and 

Dixie R. Harris The Signal Corps; The Outcome (Washington, D.C., 1966), 328ff.

2. See Chapter XI.

3. “Ultra at Eighth Army and 21 Army Group,” a report by Brigadier E. T. Williams, 5 Oct 1945.

4. General Albert Praun, German Radio Intelligence, and European Axis Signal Intelligence in World 

War II as Revealed by “TICOM” Investigations and by 
Page 18

Other Prisoner of War Interrogations and Captured 

Material, Principally German, 9 vols. Prepared under 

the Direction of the Chief, Army Security Agency, 1 May 

1946. NSA Archives. A61-136 X56-48-3 S-3424-3430.

5. General Albert Praun, German Radio Intelligence, 51-72, tells the story of FAK 621, placing the 

capture at El Alamein instead, as stated in the GCCS 

History, Vol. XI, 237, of Bardia. David Irving, The Trail 

of the Fox, 234, emphasizes the extent of the deprivation 

which the capture caused Rommel to suffer. Anthony 

Cave Brown, Bodyguard of Lies, 102 ff. gives details of 

the capture, when Rommel’s main forces were far away 

to the south.

6. British ‘Y’ Service (Land and Air), Copy in AHS 

A52-20, Box 34/2, Folder M42/002.

7. See map, R. G. Ruppenthal, Logistical Support of 

the Armies, I, 112.

8. AR675-5-1; Army Pamphlet 672-1, 6 Jul 1961.
Page 19

Planning SIGINT Service in Operation TORCH 

U.S. Army preparations for Operation TORCH 

were permeated by haste and improvisation, in 

part because the planning elicited conflicting strategic concepts that took time to reconcile, and in 

part because the participants in that planning were 

in two clusters on opposite sides of the Atlantic 

Ocean. American resources were being stretched to 

the limit. Critical decisions on which a whole series 

of actions depended were delayed or changed during the planning process. Ultimately, insistence by 

the U.S. Joint Chiefs of Staff (JCS) on gaining a 

base on the Atlantic coast of Morocco and entering 

Tunisia from Algeria produced an amphibious assault in three areas of French North Africa in the 

vicinities of Casablanca, Oran, and Algiers. Subsequent seizure of Bizerte and Tunis in northern 

Tunisia was to be sought by pushing ground, sea, 

and air forces along the coast from Algiers eastward. Success would depend to a large degree on 

the response of French forces stationed in Morocco, Algeria, and Tunisia to an Allied invitation to 

join in expelling all vestiges of Axis power from Africa.1

Operation TORCH was to be executed by three 

task forces. The Western Task Force, mounted in 

the United States, would cross the Atlantic and 

launch its assault directly upon arrival, weather 

permitting. The Center Task Force and the Eastern 

Assault Force, transported from the United Kingdom, would pass through the Straits of Gibraltar 

and simultaneously attack and occupy Oran and 

Algiers. From the latter the Eastern Task Force, reinforced by British troops and commanded by a 

British general, would advance as rapidly as possible upon Bizerte and Tunis. Since French military 

forces in the African colonies were believed to be 

more amenable to American than British appeals 

for cooperation, Operation TORCH was to be made 

as American as was feasible in 1942. The commander in chief, Allied Force, was American. In the 

amphibious phase, commanders of all three invading forces were American. But the British Army 

supplied some of the troops needed in the Eastern 

Assault Force, and provided the commander as 

well as most of the troops of the Eastern Task Force 

which subsequently invaded Tunisia. The Royal 

Navy conducted the naval operations near Oran 

and Algiers; the U.S. Navy furnished the sea forces 

near Casablanca. Royal Air Force (RAF) and U.S. 

Army Air Force units provided air support during 

landings and during the overland advance into Tunisia. 

Preparations to provide “Y” service in Operation TORCH reflected the same considerations that 

affected planning and preparing for other aspects 

of the undertaking. Underlying them was the continual adaptation of the means and methods of 

production to changes validated by experience. In 

the United States and United Kingdom, field personnel were being trained for inclusion in Signal 

Radio Intelligence companies, detachments of 

which were to go to the Casablanca and Oran areas 

with the Western and Center Task Forces. The British provided units for the production of “Y” for 

elements of the Eastern Task Force. 

Army “Y” intercept and exploitation teams for 

the three major segments of Operation TORCH 

were divided into echelons that would move to objectives in two successive convoys. Their equip- ment 

was loaded in follow-up transports that were 

crowded to the limit. At Arzew, near Oran, the 

American Radio Intelligence (RI) detachment 

landed, completely separated from its equipment 

and from G-2, on 10 November 1942. The main 

body arrived on 21 November, having lost 

Chapter 2

Beginnings in Northwest Africa 
Page 20
Page 21

all equipment on a freighter torpedoed en route. At 

Algiers, the two parts of 100 Special Wireless Section (Type B) landed on 12 and 15 November. With 

46 Wireless Intelligence Section, they moved toward Tunisia, attached to the principal ground 

force organization – Headquarters, British 78 Division, at first, and after 8 December 1942, 

Headquarters, V Corps. At Casablanca, as at Oran, 

French resistance ceased before the somewhat prepared radio intercept and exploitation detachment 

could make any significant contribution. The intercept operators were inadequately directed and 

insufficiently trained. They lacked DF equipment 

and lacked guidance concerning French or Armistice-Commission communications links that 

would be most profitable to cover. While they were 

getting established, they could do little that yielded 

real results. 

The “Y” units of the RAF participating in Operation TORCH were to be, first of all, a small team of 

radio and radio telephone monitors stationed on 

Gibraltar known as 351 Wireless Unit (WU). A second group, 380 WU, would land at Algiers and 

remain nearby. The third, 381 WU, would land at 

Algiers but would move into Tunisia with the Eastern Task Force, monitoring voice traffic. 

When France had surrendered to the Nazis in 

June 1940, many small French naval units came 

over to the United Kingdom and brought with them 

their code and cipher documents. The British 

GCCS arranged to sort the documents out and to 

match them with appropriate links, and thereafter 

maintained a small exploitation unit. Vichy authorities continued to use the same codes while 

depending for security upon novel encipherments. 

In the United States, late in 1938 the Signal Intelligence Service had begun work on the diplomatic 

systems of the Germans and of various Romance 

language countries. In July 1942 an attack on 

French meteorological traffic, as broadcast from 

North Africa and metropolitan France, began in 

preparation for Operation TORCH. Within a month 

solutions became available by teletype or courier to 

the director, Weather Central Division, USAAF, 

and they continued until American troops had captured the stations broadcasting from French North 

Africa.2

In planning for “Y” service to support ground 

force commanders advancing into Tunisia, Allied 

commanders took as a model arrangements developed by the British Army in the Western Desert. At 

Allied Force Headquarters, the staff structure 

would parallel that of General Headquarters 

(GHQ), Middle East, in Cairo. Each would have a 

General Staff Intelligence (Signals) Section and a 

General Staff Signals (Intelligence) Section within 

its respective major staff divisions. The latter would 

supervise the operations of field radio intercept 

units; their material would be analyzed by associated intelligence personnel for the extraction of 

“spot” items of tactical intelligence, and to obtain 

wireless telegraph intelligence (WTI). Mobile SIGINT units similar to those then at work in the 

Eighth Army would be allocated to Headquarters, 

British First Army (Eastern Task Force), and to the 

Corps headquarters under that Army’s command. 

The British SIGINT units would produce cryptanalytic results. 

In Morocco, American Signal Radio Intelligence (RI) units near Casablanca and Oran might 

be used to keep Spanish armed forces under radio 

surveillance. It was reasoned that if the seizure of 

French North Africa from Axis control were successful, and if subsequently Libya fell to 

Anglo-American forces, no other campaigns in the 

Mediterranean might occur before the assault 

across the English Channel. At the time Operation 

TORCH was planned, some such operation in 

Western Europe was thought likely in 1943. Commitment of SIGINT resources to the Mediterranean 

area seemed only temporary and subject to the 

need to prepare them for later service elsewhere. 

Once the decision to execute Operation TORCH 

had been made, the British set about arranging for 

the provision of special intelligence (SI) to the 

planners and commanders. Wing Commander F. 
Page 22

W. Winterbotham, who held the main responsibility for the methods of dissemination, has described 

from memory the indoctrination in London of the 

principal American officers: Lieutenant General 

Dwight Eisenhower, commander in Chief, Allied 

Force; Major General W. Bedell Smith, his chief of 

staff; Major General Mark W. Clark, his deputy; 

Major General Carl Spaatz, USAAF, his principal 

American air officer; and Colonel Palmer Dixon, 

A-2, USAAF, who had been attached to the British 

Air Ministry.3 Measures taken during the planning 

phase included organizing a Special Liaison Unit 

(SLU) to accompany Eisenhower to Gibraltar on 

the eve of the landings in French North Africa, and 

another to be with Major General Kenneth Anderson, General Officer Commanding (GOC), British 

First Army/Eastern Task Force, during the advance 

of his headquarters through Algiers to Tunisia. 

When AFHQ moved to Algiers, SI would be available to the commander in chief and to his principal 

naval (Admiral Sir Andrew B. Cunningham) and 

air (General Spaatz and Air Vice Marshal William 

Welch) commanders. Given a continuation of productive capabilities at GCCS during to operations 

in Morocco and Algeria, the commanders would be 

able to know what opposition to expect. In the race 

eastward to secure Tunisia, they might see benefit 

from foreknow-ledge of German countermeasures. 

The Army intelligence officers at GCCS were 

more concerned with utilizing SI than with providing “Y.” In the field since 1940, production and 

application of “Y” by British SIGINT units had progressed rather independently beyond what was 

fully appreciated at Bletchley Park during the summer of 1942. The plans to provide SI to commanders 

in Northwest Africa were adequate, even if arrangements to collect and transmit German raw 

traffic in high-C grade cryptographic systems to 

GCCS were not. Planning for producing and handling tactical SIGINT in Tunisia simply paralleled 

the structure of GHQ, Middle East, and British 

Eighth Army, but allowed a key SIGINT slot at First 

Army Headquarters to remain unfilled until after 

the race for Tunis in December had been lost to the 

enemy.

Training which might have made American “Y” 

units in Northwest Africa better prepared to operate effectively after the unavoidable period of 

initiation, suffered from one serious deprivation: 

only for a very short period before American units 

embarked from the U.K. was a British “Y” officer 

with field experience brought into the training program in London. Technical documents and data 

necessary to guide intercept and to expedite solution and exploitation during the first stage of the 

invasion were lacking. The units themselves were 

newly organized. No unit with British First Army 

was ready to cope with Italian Army communications. In short, “Y” service in the invasion of 

northern Africa was organized for a quick victory or 

a prolonged campaign.

The principal intelligence officer of General 

Eisenhower’s Allied Force Headquarters was Brigadier E.E. Mockler-Ferryman, British Army. The 

chief air intelligence officer was Group Captain R. 

H. Humphreys, RAF, who began work on that assignment in September 1942 at Norfolk House. 

While keeping track of German Air Force intentions and of indications of awareness of Allied 

intentions, in the Mediterranean, he also had to 

prepare for efficiently and safely exploiting special 

intelligence pertaining to air matters there.

The Navy, Army, and Air branches of the Intelligence Division, AFHQ, had to cooperate closely to 

be effective. Headquarters, XII U.S. Air Force, 

under Major General James H. Doolittle, was to be 

provided with special intelligence at Oran. Headquarters, Eastern Air Command at Algiers, under 

Air Marshal William Welch, was to receive parallel 

service and was to insure that the RAF 242 Group, 

providing close support to the Eastern Task Force, 

was sufficiently in the picture. Production and dissemination of “Y” by the Air Ministry and units in 

the theater would be controlled separately. A Special Liaison Unit at Headquarters, AFHQ, would 

handle SI. 

The special intelligence segment of G-2, AFHQ, 

while engaged in the necessary preparations, 
Page 23

included, besides the chief air intelligence officer, 

one man each from the Air Ministry, the Fighter 

Command, the Fusion Party at GCCS, the Headquarters, Eastern Air Command, and Headquarters, 

RAF 242 Group, and two from Headquarters, XII 

Air Force. Four British Army and two Royal Navy 

intelligence officers were also indoctrinated for 

Special Intelligence. 

On the enemy side, German Army strategic intelligence continued to falter and to cause reliance 

to a greater degree, perhaps, on German agents. 

Within the United Kingdom, British control of 

those agents was surprisingly thorough, and perhaps as complete as claimed in a postwar report.4

Whatever the reasons, the preparations for Operation TORCH were completed and the landings 

began without interference. 

Early in the war the basic book of a German Air 

Force code in use by reconnaissance and combat 

aircraft was captured by the British.5 That document went through three editions, each consisting 

of 1,000 three-digit groups arranged, like the German Army’s counterpart, by subject matter and 

equated with words, phrases, numbers, and an alphabet with variants. In messages, the code was 

enciphered by daily sheets of 500 digital groups. In 

the Mediterranean area the German Air Force used 

other codes for special purposes and for relatively 

brief periods. Probably because of suspicion that 

the system had become readable by the Allies, the 

volume of traffic transmitted in it during operational flights dwindled. 

Operation TORCH

The enemy realized that the Allies were preparing an operation for which Gibraltar appeared to be 

a staging point. Allied special intelligence indicated 

that the enemy was alerted at least to that extent. 

The TORCH convoys were not only observed6 

passing the Strait of Gibraltar but some deck cargoes indicated that they were bound for beach 

landings rather than simply the resupply of Malta. 

Once they had entered the Mediterranean, it 

became obvious that they were not heading for a 

second attempt to take Dakar. German fighters and 

short-range bombers (JU-87s) were concentrated 

at fields in Sicily and Sardinia for attacks on the Allied ships when they came within suitable range. 

The Allied convoys made their southward turns 

toward Oran and Algiers unobserved after dark. 

The Western Naval Task Force arrived off the Atlantic coast of Morocco before the lights ashore 

were extinguished, indicating the degree of surprise. All three task forces thus began their landings 

without German or Italian resistance. 

German intercepts furnished the Axis with information on the Allied landings and their progress. 

The Allied landing parties used radios of various 

types. One was the American SCR-299, a truckand-trailer-borne equipment which turned out to 

have a transmitting range, with a whip antenna 

only, of more than 2,000 miles. Whether from 

SCR-299s or other radios, Allied signals from the 

Mediterranean were clearly heard in the vicinity of 

Bergen, Norway, and in the Netherlands, at German intercept stations. Soon the messages were 

recognized to contain terms like those in traffic that 

had been collected during the Dieppe raid, and as 

time passed, Americans could be heard reporting 

the absence of determined opposition by the 

French. 

The French Navy headquarters at Toulon received reports from Dakar, presumably tele- phoned 

to Dakar from Rabat or Casablanca, on the course 

of the invasion ashore in Morocco. French messages from Dakar to Toulon describing the course 

of the invasion were intercepted by U.S. Navy RI 

units. These reports gave a running account of the 

action. A report made about 2200 hours on 8 November 1942 gave the situation from 0800 to 2000 

hours: 

First, the dissidence in Morocco had 

been suppressed. Heavy bombardment of Casablanca harbor had 

produced serious losses. Strong 
Page 24

forces landing at Safi and Fedala had 

been strongly resisted, and at all 

points Morocco was being resolutely 

defended.

Second, off Arzew and west of Oran, 

numerous enemy had landed. Two 

enemy craft had been sunk, and one 

French destroyer and one French torpedo boat had been lost.

Third, at Algiers, troops landed during severe sea and air attacks had 

been able to encircle the city because 

of disaffection among troops at Blida 

airfield. Most of Algiers is occupied 

by British and Americans.

Fourth, no attacks had been made in 

Tunisia.

Fifth, except for the case at Blida airfield, troops and populace have 

shown perfect loyalty and it is understood that order continues in France.

During the next evening, the situation at 1300 

hours was again reported from Dakar to Toulon: 

First, Port Lyautey had been occupied by invaders with tanks. Three 

columns were attacking Casablanca 

from Fedala, combining tanks with 

other forces. American PT boats had 

been sunk by AA guns and dispatch 

boats, and 76 prisoners had been 

taken. The French battleship Jean 

Bart had been struck on 8 November 

by six naval shells and one air bomb, 

but was still firing. The French Navy 

had suffered serious losses in aircraft 

and ships. French personnel who had 

been repatriated to Casablanca by 

steamer from Dakar just before the 

invasion had arrived in time. 

Second, at Oran the general attack in 

great strength was still being

resisted. AA batteries were still operating. A destroyer and a torpedo boat 

had tried to return to Toulon unsuccessfully. 

Third, everywhere else the situation 

remained the same, with no clash in 

Tunisia. 7

General Nogues reported to Vichy from Fez on 

9 November 1942 what the situation was as of 1830 

hours: 

1. In Morocco. Our mobile forces are 

in close contact with troops that have 

landed at three points. Landings 

there are continuing. The maneuver 

against Casablanca pointed out in 

my preceding telegram is continuing. 

Our forces which are strongly pressed 

are making a stand east of the city. 

The situation remains very serious. 

2. I have not yet been able to meet 

General Boisseau, who is now encircled by the enemy, whose troops are 

at the gates of the city, but I am still 

in close telephonic communication 

with him. Tomorrow four columns 

will converge on Oran from the directions of Ain Temouchent and other 

interior points. 

3. Near Algiers fighting continues.

4. Nothing has occurred in the southern region.

5. General Juin is at Algiers. In Morocco, enemy forces are growing 

hourly. They have overwhelming superiority, especially in armament I 

call attention to the magnificent attitude of the troops, honorable and 
Page 25

loyal to the orders of the Marshal. 

For instance, one town was occupied 

by the enemy, was retaken yesterday 

by the 1st RTM, then lost that evening 

and retaken during the night, lost 

again this morning and recaptured 

this afternoon, thereby obliging the 

enemy to halt debarkation farther 

south. The native population is deeply 

impressed by the news from Algeria, 

which is beginning to be circulated in 

spite of our precautions...

 On 11 November 1942, from Rabat to Vichy 

(No. 1370-1372), Nogues sent a report “For Marshal Petain, Chief of State” as follows: 

Yesterday, November 10, about 1400 

by way of ___, then again about 1630 

via Oran, a telephone message came 

to me from Admiral Darlan, who in 

your name ordered suspension of 

hostilities for the whole of North Africa. In spite of the apparent 

authenticity of this last message, 

transmitted by General Boisseau 

himself, I waited for the written confirmation which had, at the same 

time, been promised me. It came to 

me about 9 o’clock by Commander 

Dorange ... and later by coded telegram. 

Since no communication from the 

Government had reached me, and the 

substance of the radiogram had been 

communicated to me only at about 

three o’clock, I never doubted that 

this order conformed to your directive. 

The situation having deteriorated 

gravely during the day, with Port Lyautey captured, the road to 

Marrakech opened, and Casablanca 

threatened by a general offensive, my 

decision was adapted to the necessity 

of the moment. I executed the order 

received and commanded that firing 

cease in the course of the evening, 

and that the Americans be notified. 

Admiral Michelier agreed with me 

that it was no longer possible to make 

any effective resistance. 

At 1500 I went to meet the Commander-in-Chief of the forces landed 

at Fedala to discuss with him the conditions under which hostilities would 

cease. I have just received a liaison 

agent from Admiral Darlan, who informed me of the terms accepted by 

the Americans at Algiers: strict 

neutrality in the politics and administration of the three countries, 

maintained by military armament. 

I shall report to you the result of the 

parleys at Fedala. 

That report was made on 12 November 1942 in 

Rabat-to-Vichy, No. 1374: 

The conference proceeded in a very 

much eased atmosphere. After the 

American general had paid a tribute 

to our bravery, he presented a plan of 

agreement that had been drafted in 

Washington and whose terms were 

more... than the Franco-German armistice agreement. I observed that 

this text did not correspond at all to 

the circumstances which were anticipated in the agreements...at Algiers, 

and that before recognizing these 

terms, it was necessary to reach an 

understanding on points of most importance to a settlement, with regard 

to French sovereignty and to retention by French authorities of enough 
Page 26

military forces to fulfill the French 

mission. 

It was agreed that the country’s military and political administration 

would remain strictly un-changed 

and that French forces would immediately resume their stations; that 

the Americans could use our ports, 

our airdromes, and our means of 

communication; that since the Americans are using Morocco as a base for 

a drive to the eastward, these various 

facilities would continue to be operated and protected by the usual 

French personnel; that the use of 

these facilities would be regulated by 

direct contacts between the manager 

of French military transportation 

and his American counterpart. 

It was further decided that the conferees having agreed that relations 

would be resumed on a basis of mutual confidence, these terms would be 

subject to conformity with conclusion of the Algiers agreement. 

[My translation differs slightly from that of 

French Diplomatic No. 55235, 12 November. Note: 

Patton and Colonel Hobart Gay, his CIS, remembered the conference as one in which Patton took 

the initiative in declaring the alternate terms 

drafted in Washington as inappropriate. One set 

assumed French acceptance without resistance and 

with immediate participation in the war against the 

Axis as a belligerent. The other set assumed resistance to the point of a surrender abject because of 

being destroyed and overwhelmed by force. The actual circumstances fell in between. The French quit 

before they were beaten but took a neutral position 

rather than adopting the course of a belligerent. 

The “much eased atmosphere” may well have summarized the Patton toast in champagne and the 

luncheon that brought Hewitt and Michelier as well 

as Nogues and Patton to the same table.] 

If Allied plans had led to enhanced radio intercept coverage from Gibraltar, Malta, and Egypt 

during the TORCH landings, the Axis traffic then 

collected might temporarily have been more open 

to analysis, and SIGINT on Axis countermeasures 

might have been ampler. One can only surmise. 

But even so, the G-2 Section, AFHQ, advance command post at Gibraltar was able to combine 

information that came via London or directly from 

the three task forces and from agents at key points, 

so that it yielded a fairly clear understanding of the 

military and political situation in French North Africa during the first phase of Operation TORCH. 

By diverting to Tunisia reinforcements that had 

been assembled in southern Italy for transit to 

Field Marshal Rommel’s command in Libya, the 

Axis quickly built up a German Corps in Tunisia, 

and then a Fifth Panzer Army Headquarters that 

controlled both German and Italian Corps. In Tunisia enemy battle groups (Kampfgruppen) and task 

forces, rather than divisions, would do the ground 

fighting. Only the 10th Panzer Division staff functioned as a normal divisional headquarters. German 

divisions were likely to vary widely in numbers of 

personnel and to be commanded by colonels rather 

than by general officers. Allied regiments and combat commands were likewise temporarily split and 

deployed in task forces specifically directed by 

army and corps commanders. 

Axis field SIGINT was able to exploit the insecure communications of British and American 

battalions and regiments (or armored combat commands) during the critical days in December near 

Tunis. That information, for example, contributed 

to the failure of the Allies at first to get past Tebourba and Djedeida into Tunis and later to gain 

control of a key topographic feature known as 

“Longstop Hill.”

Before the landings, German communications 

showed no evidence that the Allied intentions 

were recognized. Italian and Vichy French 

SIGINT likewise revealed no threat to the 

landing forces. Special intelligence provided 
Page 27

the reassurances assignable to silence. After the 

landings, special intelligence quickly disclosed to 

AFHQ that the Germans were pressing Vichy to oppose the Allies and to admit German forces. Next it 

reported the German seizure of Tunisian airfields 

near Bizerte and Tunis for air transport of German 

and Italian forces, and the German intention to 

consolidate the two areas into one bridgehead. 

That elements of Panzer Regiment 104 had been 

ordered from Italy to Tunisia, that German antiaircraft units would defend the air fields, and that a 

Colonel Lederer was given command there were all 

made known through special intelligence to AFHQ 

and to the British commander of British First 

Army. General Nehring’s transfer from the German 

Afrika Corps to relieve Lederer and be subordinated to O. B. Sued (Kesselring) was next added to 

the important information provided through Ultra. 

If the occupation of Tunisia by Allied forces, 

with whom the resident French could join, were to 

be successful, the Allied command knew that it 

would have to be accomplished by getting there in 

strength faster than the Axis command could reinforce the bridgehead. Although the Allies gained 

control of ports and airfields between Algiers and 

Tunisia, they could not provide sufficient air support or quite enough coordinated assault forces on 

the ground. German and Italian forces, including 

armored and aviation units, used sea transport and 

port facilities so effectively that they won the race. 

That situation was understood by the Allied 

command on the basis of special intelligence and 

some “Y” intelligence, but the means of thwarting 

Axis intentions were unavailable. Before the end of 

November, General Eisenhower knew that the Germans had accumulated enough strength in the 

Tunisian bridgehead to start extending along the 

coast southward beyond Sfax and Gabes and southwestward to Gafsa and Tozeur. 

The reconnaissance spearhead of the Eastern 

Task Force (known as “Blade Force”) got within 

about ten miles of Tunis before first being checked. 

When enough Allied strength had been 

concentrated for a sustainable effort, the enemy 

ground and air units demonstrated the superiority 

of their coordinated tactics. Near Tebourba the Allies were thrown back toward Medjez el Bab in a 

decisive engagement. German interception of communications among Allied units on the tank 

frequency band elicited without difficulty “some 

very useful information.” Then and later, chatter 

between American fighter pilots disclosed takeoffs 

and approaches by Allied aircraft.8

Axis reaction, besides establishing what they 

called their “bridgehead,” consisted principally of 

air bombing of ports, ships, airfields and troop convoys along the coast from Algiers to Tabarka. Until 

radars were installed and working, “Y” furnished 

the needed warning. An RAF “Y” unit at Gibraltar, 

where Luftwaffe signals were not well heard, moved 

to Algiers, and thence to Bóne, where the signals 

came in strongly. At G-2, AFHQ, one officer was so 

knowledgeable about the German Air Force that he 

could quickly recognize in tactical messages evidence showing the nature of any formation on its 

way to deliver an attack. The principal air intelligence officer had previously been in command of 

the RAF party in a division at Bletchley Park. 

The Allied force remained concerned lest the 

Germans should somehow use Spain to control the 

Strait of Gibraltar, and thus cut Allied lines of supply and reinforcement. Near Oran, British 55 

Wireless Section (headed by Captain Hugh Skillen) 

worked with a detachment of the U.S. 128th Signal 

RI Company on French and Spanish traffic. 

They used nine or ten positions to watch for indications that Spanish forces were mobilizing, or that 

Spanish radio circuits were carrying German messages. The three 122d Signal RI Company 

detachments originally with the Western Task 

Force, reinforced on 18 November 1942 by the rest 

of the unit, also engaged in monitoring for evidence 

of hostile reaction in Spanish Morocco, or at 

airports in southern Spain, southern France, Majorca, Sardinia, Corsica, western Algeria, all French 

Morocco, and French colonies to the south. The 

two units, one under G-2, Western Task Force, 
Page 28

and the other under G-2, Center Task Force, exchanged products and technical information.

Looking back in 1943 on what lessons might be 

learned from Operation TORCH, the SIGINT personnel advised that only a small reconnaissance 

detachment of any independent SIGINT unit 

should come ashore with the assault forces, that 

two officers and three enlisted men would be 

enough. Their mission should be to make detailed 

plans for the most effective use of the operating 

units that should come on follow-up convoys with 

full equipment. The small detachment could expedite the preparations absolutely necessary for work 

to start.9 On the other hand, the intercept platoons 

of a divisional signal company (as then constituted) 

were needed in an assault. They would not be at a 

loss, as would the other type of unit, for support facilities and personnel. 

Even before the Allied thrust toward Tunis and 

Bizerte came to a halt in December, the Axis sought 

to protect a coastal corridor southward to the 

boundary between Tunisia and Libya and southwestward toward Gafsa. In the hill-studded zone 

between the great ridges (the Eastern and Western 

Dorsals), the Allies either disputed Axis efforts or 

established blocking stations. They appeared to the 

Axis leaders, however, to be in a position to strike 

offensively southeastward from Gafsa to Gabes in 

strength whenever such a maneuver became opportune. 

Tunisia: Organization for the Second Phase

By 6 January 1943 Allied “Y” units were preparing to move eastward in conjunction with 

Headquarters, British First Army, Headquarters, 

U.S. II Corps, and later, Headquarters, British V 

Corps, which had not yet arrived in Tunisia. Headquarters, First Army, at Constantine, would have 

with it a British team. On 15 January British 55 

Wireless Intelligence (under Captain Hugh Skillen) 

and the U.S. 128th Signal RI Company (under 1st 

Lieutenant Shannon D. Brown) moved from the 

Oran area to a site in Dernaia Pass near Tebessa at 

the Algerian border, to join Head-quarters, 

II Corps. In support of the U.S. Twelfth Air Force, 

the British 380 Wireless Unit and the U. S. 122d 

Signal RI Co., which arrived at Boufarik in January, 

would cooperate closely. Before the end of January, 

the U.S. 849th Signal Intelligence Service (SIS) 

Battalion would bring 33 officers and 192 enlisted 

men to the Algiers area, where they would train 

with an experienced British field SIGINT team.10 

At AFHQ the coordination of “Y” operations 

was supervised by a “Y” Northwest Africa (YNA) 

Committee; Lieutenant Colonel Harold G. Hayes, 

chief american SIGINT officer, Signal Division, 

AFHQ, was the chairman. The other members represented ground, sea, and air “Y” organizations, 

and with one exception were British officers. The 

Signal Intelligence Section of the Intelligence Division (SIGS I, G-2), AFHQ, was headed by British 

Lieutenant Colonel Forrer. 

The section’s mission was to handle all SIGINT 

matters for G-2, including the organization and 

control of fixed and mobile “Y” units, liaison on “Y” 

matters with the War Office in London and other 

commands in the Mediterran-ean, and liaison with 

all the “Y” services of the Allies in the theater. Distribution and security of “Y” information and 

preliminary examination of captured signal equipment and signal documents were also its 

responsibilities. 

Control of forward intercept operations from 

First Army’s Headquarters near Constantine was 

difficult to correlate, while collection there could 

not match that in Libya because of the intervening 

150 miles or so of mountainous terrain. Coordination at First Army Headquarters of all the DF 

operations was ineffective until the campaign was 

almost over. From First Army, weekly predictions 

of callsign changes were distributed to intercept 

units that lacked the necessary documents and 

technical data. They might thus avoid intercepting 

traffic of concern primarily to Eighth Army, or reconstructing codes already broken. But the 

organizational paralleling in Tunisia of SIGINT 
Page 29

resources used in the Western Desert did not yield 

comparable SIGINT service. Production in Tunisia 

was to disappoint the British for several months, 

and the American novices in SIGINT production 

were unavoidably affected. At the same time, the 

Germans retreating ahead of Eighth Army and in 

Tunisia in January 1943 adopted new methods of 

improving their own communications security. 

Daily changes of the encipherment of the three-letter codes, insertion of sections in Playfair cipher to 

complicate, a message in three-letter codes, and 

frequent shuffling of the code names of units – all 

increased the difficulties for Allied analysts in the 

field. 

The SIGINT Section of British First Army issued daily and weekly summaries based on “Y,” 

and after its activation late in February 1943, 18 

Army Group began combining material from both 

First and Eighth Armies in a Daily Summary. The 

field sections of First Army sent daily decrypts to 

SIGS I, G-2, AFHQ and to the staff SIGINT officers 

at 18 Army Group and First Army. 

 British Eighth Army’s daily intelligence summary included material attributed specifically to 

“Yorker,” but others – Army Group, “AFHQ- inthe-Field,” and G-2, AFHQ – were less explicit. 

Information gained from “reliable sources,” for example, constituted one paragraph. Although no 

references were made to special intelligence, the 

estimates of enemy intentions in AFHQ’s Weekly 

Intelligence Summary were stated with a confidence which reflected sources of the highest 

reliability. 

Early field intercept operations by teams associated with British First Army were, for the most 

part, not well guided. Lacking basic technical data 

about enemy radio nets, First Army’s intercept operators covered some of the same links copied by 

SIGINT units with Montgomery’s British Eighth 

Army, and an unusually high proportion was found 

to be German Air Force traffic. Exploitation also 

produced redundancy, as First Army personnel 

tried to solve codes previously broken at Eighth 

Army. At the same time, First Army was not prepared to exploit Italian traffic until late in the 

Tunisian campaign, after personnel from the Middle East Command had been transferred to 18 

Army Group. Radio direction-finding operations in 

Tunisia were not effective until First Army began to 

coordinate them very late in the campaign. 

General Kenneth Anderson’s principal SIGINT 

officer did not arrive at Headquarters, First Army, 

in Constantine until January 1943, and then found 

himself at least 150 miles from the fighting front at 

a place where it was impossible to intercept enough 

pertinent traffic. Despite the semi-aridity of wide 

areas in Tunisia, the terrain there differed greatly 

from the Libyan desert. Mountain chains and clusters of hills not only forced the ground forces to 

employ different tactics, but also seemed to interfere with good radio reception. Moreover, the Axis 

forces used unfamiliar gridded maps and “target 

points” to indicate their positions; until such maps 

were captured, the bases for the indicators remained unknown. 

As a further restraint on the application of “Y” 

to operations, many intelligence officers of corps 

and divisions in First Army neither appreciated the 

useful potentialities of “Y” nor realized how much 

more effective it could be if all “Y” efforts and the 

results obtained in the whole First Army area were 

shared. General Alexander, however, brought to 

the staff of 18 Army Group in late February as his 

principal SIGINT Officer the man who had held a 

similar position on the staff of British Eighth Army 

and who knew the benefits of pooled “Y” information. Alexander also caused 101 Wireless Intelligence 

Company to be flown to Tunisia from Headquarters, British X Corps, then in reserve. Thereafter, 

the SIGINT efforts of both Eighth and First Army 

were better coordinated. 

Action during January 1943 

When the U.S. II Corps moved to the Tebessa 

area in January 1943, the ground forces in its command consisted primarily of the mobile 1st Armored 
Page 30

Division, reinforced by elements of the 1st Infantry 

Division and the 34th Division. Eventually those 

entire divisions and the 9th Infantry Division were 

to be assigned to II Corps, but the beginnings were 

smaller. French troops of the XIX Corps, commanded by General Louis M. Koeltz, were stationed 

in January at various points along the Eastern Dorsal, the mountain barrier that separated the eastern 

coastal plain from the higher ground and mountains of the Tunisian interior. Axis troops sought 

possession of the openings where roads through 

the Eastern Dorsal connected the interior with 

Kairouan, Sousse, or Sfax. French, British, and 

American troops were interspersed within the II 

Corps area. 

The Axis high command, Italy’s Comando Supremo, advised by the German theater commander, 

Oberbefehlshaber Sued (Field Marshal Albert Kesselring), intended to maintain an overland route 

from Tunisian ports to Field Marshal Rommel’s 

German-Italian Panzer Army, Afrika, then retreating westward across Tripolitania. The Allies, after 

first planning to use the U.S. II Corps to break 

through to the coast at Sfax (Operation SATIN), 

and to cut the Tunisian line of supply to Rommel, 

abandoned that plan during consultations at the 

Casablanca Conference. The British Eighth Army’s 

pursuit of Rommel’s command, the Allies reasoned, would leave the latter free to send veteran 

German armored units against the unseasoned 

U.S. II Corps in an area of Axis air superiority. General Eisenhower therefore directed II Corps to 

concentrate the 1st U.S. Armored Division on the 

southern flank, able to move in strength against 

any Axis thrust. 

German tactical SIGINT was efficient. American troops were to discover that fact repeatedly as 

their own “Y” service kept improving. It was nonetheless possible for Allied radio deception to lead 

the enemy to believe that he was facing a much 

larger force than was actually the case, perhaps almost twice as large. Allied SIGINT kept a daily 

watch on enemy reports of Allied order of battle 

and observed the discrepancies between those 

reports and the actualities. The enemy SIGINT 

units could by DF spot Army and Corps headquarters, and by traffic analysis generally infer the 

divisions in each corps. They could recognize the 

appearance of new formations in corps' nets without being able to appraise their strengths, and 

sometimes they could determine the components 

of divisions. 

German SIGINT, supplementing captured documents, interrogations of prisoners, agents’ reports, 

and photographic reconnaissance, left the Axis 

commanders still unable to estimate Allied intentions in the area between Gabes and Sfax. They 

correctly concluded that the Americans on the 

south wing intended in January 1943 to cut the 

coastal corridor and to seize Sfax, but they did not 

recognize before the end of the month that the 

project had been abandoned. They seem to have 

been uncertain about the strength of American 

forces there, and to have been pleasantly surprised 

by the successes they achieved in February between 

Faid Pass in the Eastern Dorsal and Kasserine Pass 

in the Western Dorsal. They would doubtless have 

been appalled by the accuracy with which the Allies 

usually understood the Axis situation and plans. 

After El Alamein, Rommel recommended that 

all German forces leave Africa, but since such drastic action was not countenanced by Hitler, he 

continued falling back into Tunisia, where he might 

use the old French fortified Mareth Position, or a 

naturally strong one near Gabes, to block the advance of British Eighth Army. General Montgomery’s 

forces would be far from his Middle East base. 

Tripoli would be a demolished port. At Mareth the 

odds against the Axis army would therefore be reduced.

General Jirgen von Arnim, commanding the 

Fifth Panzer Army, thinned his defenses in the 

north and created task forces able to dislodge the 

French from the passes, including that at Faid. The 

French were able to draw reinforcements from the 

American elements at various points. The U.S. II 

Corps, as SATIN Force, had been scheduled 
Page 31

to control the 1st Armored, 1st Infantry, and 34th 

Divisions. By committing elements of those divisions as reinforcements elsewhere, First Army kept 

postponing the kind of concentration in Central 

Tunisia that General Eisenhower had prescribed. 

South of Faid, the Eastern Dorsal swings southwesterly. With other adjacent mountains it provides 

the northerly edge of another east-west corridor, 

bounded on the south by extensive areas of marsh 

and salt lakes (chotts). From Gabes a highway in 

that corridor links the coastal zone with the oasis of 

Gafsa and communities west of it, while from Gafsa 

roads and railroad thread many valleys eastward 

and northeastward in the ridge-strewn region of 

Central Tunisia. Allied and Axis concern about vulnerability applied to the Gabes-Gafsa route, as well 

as to passes farther north near Faid and Fondouk. 

On 3 January 1943, while the Allies were working out their plans and arrangements for the sequel 

to the discontinued Operation TORCH, the Axis 

forces seized and occupied the pass at Fondouk, 

through which major roads went northwestward 

and southwestward into the regions held by scattered British, French and American forces. As a 

sort of offset, on 11 January French units obtained 

control of two gaps farther north, between the 

coastal plain of the Kairouan area and the Ousseltia Valley. They were dislodged about ten days later 

by a German task force that included a number of 

the very heavy “Tiger” tanks, a force which pushed 

down the valley from the north and cut off French 

defenders on the eastern heights. Units from three 

different U.S. divisions were brought into the area 

in circumstances that revealed the deficiencies of 

Allied command and control in the field and 

brought about successive measures to improve it. 

II Corps, after Operation SATIN was cancelled, 

planned to retake Fondouk in an American-French 

attack on 23 January, but the Ousseltia Valley battle made cancellation of the Fondouk operation 

necessary. 

II Corps then planned to occupy Maknassy and 

the gap east of it through which ran a railroad and 

a highway connecting Gafsa and Sfax. As two task 

forces moved on Maknassy, the enemy launched an 

operation against Faid Pass and Faid Village. The 

French defenders held out valiantly for two days. 

Attempts by U.S. II Corps failed either to relieve 

them or to regain the pass from the enemy. II Corps 

called off the attack at Maknassy; instead, it placed 

sufficient elements of the 1st Armored Division 

(and attached infantry) near enough to the passes 

from Fondouk to Maknassy to contain any incursions through them by Axis columns. Although the 

elements of II Corps were not concentrated on the 

southern flank, their mobility was expected to result in a swift concentration whenever that was 

required. 

The enemy, because of the need to control the 

rear of the Mareth Position and the narrows north 

of Gabes (often called either the “Chott Position” or 

the “Wadi Akarit Line”), redrew the boundary between the areas of Rommel’s and von Arnim’s 

commands on 2 February 1943 so that both Sfax 

and Gafsa were within the former’s area of responsibility. 

Special intelligence confirmed the interpretation of Axis intentions that went into the Weekly 

Intelligence Summaries from G-2, AFHQ. An order 

issued by O.B. Sued on 24 January 1943 made clear 

what was in store. The enemy expected Allied attacks against both the Bizerte-Tunis bridgehead 

and the Sfax-Gabes corridor. Von Arnim’s command, while parrying such thrusts in the north, 

was to refrain from any large offensive operations 

that would tie down his reserves. At the southern 

extreme, while the Mareth Position was being occupied and developed, a mobile force would be 

built around Headquarters, 21st Panzer Division. 

To gain initiative for the Axis forces, a mobile battle group under cover of the Mareth Position would 

drive toward the Allied base at Tebessa, doing so 

before the Allied forces could launch the flanking 
Page 32

attack on Gabes about which the Germans expressed great apprehension. 

At the end of January 1943, the Allies recognized that the enemy was already regrouping his 

forces in Tunisia in order to form a mobile striking 

reserve. Its mission would be to counterattack any 

Allied effort to break through to the coast of eastern 

Tunisia. Meanwhile, by local operations, the enemy 

would try to prevent the Allies from concentrating 

for a major offensive against any of the more vulnerable Axis positions. To achieve the best results, 

the enemy might place some elements of Rommel’s 

command at the disposal of von Arnim. Ultimately, 

the Axis forces would strike at the Allied line of 

communications in eastern Algeria, both to isolate 

the garrisons in south central Tunisia and to prevent direct contact between the Allied Force in 

Tunisia and the British Eighth Army. The bases for 

that estimate were said to be recent Axis advances 

west of Sfax through Faid Pass toward Faid and 

Sidi bou Zid, and farther south toward El Guettar.11 

Notes

1. See George F. Howe, Northwest Africa: Seizing 

the Initiative in the West, passim. (Washington, D.C., 

1957) 

2. The Western Task Force received weather reports 

by message up to the eve of the assault landings. On 10 

November 1942 Headquarters, USAAF, commended the 

Signal Intelligence Service (SIS) for that contribution. 

Secret Annual Report for FY 1943, Cryptanalysis Branch, 

SSS; see also AFHQ G-2 Intelligence Reports Nos. 8 (26 

Oct 42) to 14 (6 Nov 1942). 

3. Winterbotham, The ULTRA Secret, 90-91. 

4. See J. C. Masterman, The Double-Cross System in 

the War of 1939 to 1945. (Yale University Press, 1972).

5. It was known as the Aukatafel, an abbreviation of 

Aufklaerungs und Kampfllieger Tafel, Land and Sea. 

6. Special Intelligence disclosed that Kesselring’s 

command was insistent that his air units needed reinforcement by long-range reconnaissance aircraft and 

that such planes were shifted from Norway, to the benefit of Murmansk convoys, and from Bordeaux, so that 

the TORCH convoys were not observed while in the Atlantic en route to the Strait of Gibraltar. The planners 

were able to route the convoys in the light of that intelligence. Colonel Alfred McCormack reported that he had 

learned of this accomplishment while visiting the U.K. in 

1943. NSA Hist Coll., Book No.9, 3-5. 

7. Paraphrase of messages in L-921 TL No. I, Allied 

Communication Intelligence and the Battle of the Atlantic, 6 Vols., Vol. II, Part D., App. II to Chap. XII, 

228-251; Part A, App. B. 

8. Captain Sidney L. Jackson, Tactical Communications, 91, citing information gained during 

interrogation later of a German pilot. 

9. Operation TORCH, Lessons Learned in Chief Signal Officer, AFHQ, para 16. Copy on AFHQ Microfilm 

Reel lG. 

10. Msg, Forrer for Lycett, MI 8, 061214Z Jan 1943. 

No. 4393.

11. AFHQ G-2 Intelligence Report No. 23, 1 February 

1943 (Reel 23A). Special Intelligence reflected those intentions but suggested that they were not solid.
Page 33

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Page 34
Page 35

Axis Plans – Allied Expectations

Less than a week later, after Faid Pass had indeed been taken and held by Axis troops despite 

counterattacks by II Corps, the Allied estimate was 

confirmed and expanded. The Axis forces were now 

expected to try to contain as much as possible of 

the Allied force in the north and to improve their 

hold on mountain passes in the Eastern Dorsal, in 

order to avoid either an Allied penetration of the 

bridgehead or an Allied turning of the “Tunis position.” The Axis mobile striking force could be 

expected to move into areas from which to threaten 

Sbeitla and perhaps Maktar farther north. The objective of Axis operations still further south would 

be to strengthen the defense of Gabes. Lastly, work 

on the Mareth Position would be pushed in order to 

contain a frontal attack there by British Eighth 

Army. New defensive works southwest of the existing ones would be designed to prevent infiltration 

or a wide turning movement. The activities of II 

Corps had stimulated greatly increased Axis air activity, particularly in the areas near Faid and Sened 

villages.1

Early in February, possibly from their own SIGINT operations, the Axis high command learned 

that the U.S. II Corps had abandoned its plan to execute Operation SATIN (the offensive across the 

Eastern Dorsal and the coastal plain to seize the 

port of Sfax and to cut the land communications 

between northeastern and southern Tunisia). SIGINT later disclosed that the Axis leadership 

realized that the “American Army” did not intend, 

for the time being, to continue its advance. Allied 

SIGINT showed that the Axis command had decided, in consequence, on 11 February 1943 to 

modify its own concept of operations.2

Further SIGINT disclosure to the Allies of Axis 

intentions led to an appraisal of where, if not when, 

the enemy could be expected to strike. The enemy 

would try to capture the Ousseltia plain and passes 

west of it, moving into the valley from the north 

and east; he might also make one direct westward 

thrust from Kairouan, and another, as flanking 

support, from Faid. Besides maintaining the Axis 

hold on Faid Pass he would endeavor to increase 

his control of the heights southwestward between 

Faid and Gafsa. Ultimately he would advance to 

Sidi bou Zid. If that did not precede the drive across 

the Ousseltia plain, it might occur at the same time 

or be coupled instead with an advance upon Gafsa. 

The great enemy interest in controlling Gafsa 

seemed likely to induce a direct attack there soon 

and even before that, an attempt to establish a defensive ring around it while Axis mobile forces were 

being strengthened.3

These deductions by Allied intelligence concerning Axis intentions, however correct, were 

reached without knowledge of the conflicting views 

and ambitions among the enemy. General von 

Arnim and Field Marshal Rommel disagreed over 

priorities and objectives. Each had uses to which he 

wished to commit, under his own command, the 

mobile 10th, 15th and 21st Panzer Divisions.

Rommel’s mood fluctuated between pessimism 

and hopefulness. Once he himself had seen the dilapidated condition of the “Mareth Line,” his doubts 

about its strength were confirmed. He concluded 

that successive spoiling attacks against both Allied 

armies must be made, if only to gain time. While 

von Arnim’s command sent one battle group to 

take Sidi bou Zid, he would send another to take 

the oases at Gafsa and Tozeur. But if he were to 

press on afterward into Algeria to strike the Allied 

base at Tebessa, he would need the 10th Panzer Division too. The attacks which opened on 14 February 

were intended only to drive the Allies back from the 

Eastern Dorsal and from Gafsa. Exploitation 

Chapter 3

Axis Initiative in February 1943
Page 36

thereafter would depend upon prospects indicated 

during the first stage. Rommel and von Arnim had 

conflicting plans for subsequent operations. The 

former wanted to destroy Tebessa and perhaps to 

threaten farther north the long line of communications of the British First Army. The latter wanted to 

expand the northern bridgehead. Each would need 

the 10th Panzer Division for his attack. The arbiter 

had to be Kesselring. Ultimate authorization had to 

be gained from the Comando Supremo in Rome.

Presumably concerned about the signs of enemy 

interest in taking Gafsa, II Corps on 12 February 

queried First Army about the Axis intention to defend the Mareth Position. First Army replied that 

apparently “Rommel intends to defend the Mareth 

Line” and to develop delaying positions in front of 

it to provide more time for strengthening the defenses.4 Late that day, Colonel B. A. Dickson, G-2, 

II Corps, relayed from the II Corps “Y” unit to the 

commanding officer at Gafsa word that an Axis 

unit, ARKO 104, had been sound-ranging Allied 

Gafsa guns that morning. ARKO 104 was known 

normally to operate with a division or a divisional 

task force, one that included the Ramcke Brigade of 

Rommel’s Afrika Korps (DAK).

(During February and March 1943, ARKO 104 

was using a code designated among the Allies as 

APE 20, consisting of 400 groups alphabetically arranged against numerical groups from 001 to 400. 

An encoded text was enciphered by using ten letterfor-number equivalents that changed daily. 

Plaintext messages were enciphered in a separate, 

daily changed, randomly mixed alphabet.)

On 13 February 1943 the Allies were expecting 

Axis action; they were uncertain chiefly about the 

routes of attack and the strength of enemy forces. 

The main thrust might be made either west of Kairouan or west of Sfax. If Fifth Panzer Army supplied 

the major striking force that would certainly involve the 10th Panzer Division. If it struck near 

Pichon, certain II Corps units might move north to 

reinforce Combat Command B, 1st U.S. Armored 

Division. If the 10th Panzer Division moved south 

to penetrate the Faid area, Combat Command B 

could release troops via Sbeitla to reinforce Combat 

Command A, already deployed according to II 

Corps orders in the vicinity of Sidi bou Zid.

Advance Headquarters, First Army, advised II 

Corps and other subordinate commands on 13 February that reliable sources reported (wrongly) that 

only a few days earlier Rommel had undergone an 

operation at the Civil Hospital in Tunis.5

Allied Reversals, 14-17 February 1943

At first light on 14 February 1943, one column 

of armored and mobile German troops came 

through Faid Pass to encircle defending forces on a 

hill rising from the rolling desert while another 

crossed the Eastern Dorsal farther south to isolate 

forces on the other hills near Sidi bou Zid. Those 

columns were elements of Battle Group Ziegler, 

Fifth Panzer Army. Before dark they had driven 

Combat Command A, 1st U.S. Armored Division, 

out of Sidi bou Zid and had marooned American 

troops on the nearby hills. 

Kampfgruppe DAK, a mixed German and Italian Battle Group controlled by the Head-quarters, 

German Afrika Korps, approached the town of 

Gafsa cautiously, and prepared to attack only after 

being reinforced by part of Group Ziegler. During 

the night of 15/16 February the Allied garrison 

withdrew in haste, and many civilians evacuated 

Gafsa. The next day the enemy marched in unopposed.

Throughout the first day of the attack, Colonel 

B. A. Dickson, G-2, II Corps, was unable to determine that any captured troops were from von 

Armin’s 10th Panzer Divison: “As the 10th Panzer 

Division does not seem to have moved south, the 

tanks engaged in the Sidi bou Zid area and to the 

south appear to be from either or both the Panzer 

Battalion 190 and the 21st Panzer Division (of von 

Arnim’s mobile reserve). Late report gives 

prisoner of war identification from the 21st Panzer 

Division.” The report that Mark VI (Tiger) tanks 

were near Faid, if it could have been confirmed, 

would have established participation by Panzer 

Battalion 501, which, like 10th Panzer Division, 

was under Fifth Panzer Army command.6
Page 37

On 14 February 1943, however, German prisoners taken near one of the hills were positively 

identified as being from infantry and artillery units 

of the 10th Panzer Division; at least part of that formation had indeed moved south to make the 

attack. Two German reconnaissance units and elements of the Italian Centauro Division had also 

been identified, probably by SIGINT, in the force 

moving along the roads approaching Gafsa from 

the northeast and southeast.

The weakly armed French troops that once had 

defended the eastern passes without being relieved 

in time by mobile, well-armed Americans, now had 

their counterparts among the American forward elements stationed on the isolated hills near Sidi bou 

Zid. Unable themselves to oppose the enemy effectively, they became bait, luring a would-be relieving 

force into an attack in which it was outmatched.

Intelligence might have identified that first Axis 

attack of February 14 for what it was, a main effort 

rather than a diversion. But the surprise applied 

not only to the weight of the Axis attack but also to 

the tactics that they employed and to the accuracy 

of their tank and artillery fire. Moreover, although 

the skill and power of Axis air support of ground 

troops were not new, the strength in this instance 

greatly exceeded that which the Allies had experienced during recent battles.

The British 55 Wireless Intelligence Section, 

under Captain Hugh Skillen, provided G-2, II 

Corps, with certain unit identifications and some 

information concerning enemy movements. The 

enemy had an observation post on Djebel Orbata, 

southeast of Gafsa, connected with a German artillery unit. On 15 February Captain Skillen warned 

that the artillery unit was preparing to move toward Gafsa. On 16 February he followed movements 

by the German 580th7 and 33d Reconnaissance 

Units (RU). The former moved to the vicinity of 

Sened Station and sent elements into Gafsa. The 

latter went farther north.

On 17 February Group Ziegler advanced slowly 

toward Sbeitla from Sidi bou Zid. The 1st U.S. Armored Division was then deployed for only a 

delaying action at Sbeitla. The enemy had learned 

that from his own SIGINT service. Elements (33d 

RU) of the 21st Panzer Division reconnoitered in 

force along the roads from Gafsa to Feriana, Thelepte, and Kasserine. 

After relinquishing Sbeitla, the Allies pulled 

back west and northwest to the farther side of the 

Western Dorsal. The main body of II Corps retreated through Kasserine Pass from Sbeitla and 

Feriana. Other routes to the west were defended in 

an atmosphere of emergency and improvisation.

The seizure of Sidi bou Zid had been accomplished by elements of the Fifth Panzer Army. The 

associated attack to take Gafsa brought forces 

under Rommel (Kampfgruppe DAK) into the area 

between Maknassy and Sened Station. On 15 February the abandonment of Gafsa without a fight 

surprised Rommel. He sent in a garrison the next 

day and reconnoitered toward Feriana, while the 

decision was reached for Fifth Panzer Army to push 

from Sidi bou Zid to Sbeitla, using primarily the 

21st Panzer Division. For his planned attacks in the 

Fondouk area and toward Bedja and Medjez el Bab 

farther north, von Arnim wished to move the entire 

10th Panzer Division northeastward as soon as 

Sbeitla had fallen. Rommel, on the other hand, 

having concluded that the American troops were 

much less formidable than he had supposed, 

awaited the results of the attack on Sbeitla and of 

the successful reconnaissance in force that he sent 

to Feriana and Thelepte airfield. He then proposed, 

on 18 February, that he drive through the Western 

Dorsal to Tebessa.

Through Kasserine Pass

Over von Arnin’s objections, Rommel was authorized by Kesselring to use both the 21st and 10th 

Panzer Divisions and the German-Italian mobile 

and armored units under the Deutsches Afrika 

Korps for a thrust through the mountains to the 

valleys beyond. Comando Supremo did not accept 

the choice of Tebessa (across the Algerian border) 

but instead designated Le Kef (well to the north in 

Tunisia) as Rommel’s objective. Success there 

would disrupt Allied operations then in progress 
Page 38

and, by threatening the First Army’s vital line of 

communication, might either cause that command 

to pull back from the bridgehead boundary, or so 

weaken the Allied defenses there that von Arnim 

could press forward successfully. Fifth Panzer 

Army could itself help Rommel’s thrust by dropping paratroops near Le Kef, sending a force by sea 

to Tabarka from which to threaten British First Army’s northern flank and rear and by holding Allied 

troops along the bridgehead line.8

Very early on 19 February 1943, five days after 

the initial Axis assault on Sidi bou Zid, Rommel 

started his main attack into Kasserine Pass. During 

the afternoon of 20 February 1943, the II Corps’ “Y” 

unit reported a request by the 33d Reconnaissance 

Unit for maps of the Tebessa-Bone area.9 German 

infantry had already been reported to be holding 

various heights along the pass and their objective 

was presumed to be Tebessa. When the Axis force 

in the pass emerged, one portion did head toward 

Tebessa to block any Allied attacks on the western 

flank of the main body. The other portion took the 

other branch of a road junction within the pass and 

headed northward toward Thala on the way to Le 

Kef, as ordered by Comando Supremo.

For the next two days they probed, struck, and 

almost broke through Allied defenses hastily established near Thala, as reinforcements streamed 

toward what the Allies had learned from special intelligence would be the critical spot. 10

During the night of 21/22 February, a liaison 

officer at 18 Army Group relayed to II Corps a report that the enemy armored columns were going 

to withdraw through Kasserine Pass, beginning 

that same night.11 The actual withdrawal occurred 

twenty-four hours later, after Rommel, conferring 

with Kesselring near the town of Kasserine, persuaded the latter that the attacking force must pull 

out.

Discouraged by indications that the Allied defense was becoming stronger rather than weaker, 

and mindful of the necessity of gaining time to 

strengthen the Mareth Position by attacks on the 

van of British Eighth Army far to the southeast, 

Rommel had concluded that he must break off the 

whole operation toward Le Kef. He was authorized 

late on 22 February to retire through Kasserine 

Pass and was directed to leave one garrison at 

Gafsa and others at key points between the Western and Eastern Dorsals.12

Back through Feriana and Gafsa to Gabes, back 

past Kasserine and Sbeitla to Sidi bou Zid, Faid, 

and Maknassy, and through the mountains to the 

Sfax-Gabes corridor, most of the enemy withdrew. 

What had begun as a testing of U.S. II Corps had 

grown into a deep penetration. It ended simply as a 

disorganizing attack.

AFHQ-in-the-Field (General Eisenhower’s forward Command Post) reported that German 

armored forces were still in the area between Thala 

and Kasserine Pass on 22 February [Stott en Group 

and Panzer Grenadier Regiment Afrika (from Panzer Army Afrika) and II Battalion, 69th Panzer 

Grenadier Regiment (from 10th Panzer Division) 

were identified]. Next day, “Y” identified the 

334th Mobile Battalion as having moved to the vicinity of Thelepte. A German-Italian order of battle, 

compiled at that time from SIGINT and other 

sources, listed the locations of all but three German 

units.

For several months, a former headquarters security detachment under Rommel’s command had 

functioned as a motorized reconnaissance unit, the 

Kampfstab Oberbefehlshaber, abbreviated as the 

KASTA O.B. In the February operations it was 

working with Panzer Grenadier Regiment Afrika. 

“Y” sources were able to identify and track it as it 

reported by radio in a readable system.13

Advance First Army kept providing “Y” of concern to II Corps. By noon on 24 February 1943, 

they were advising that Panzer Grenadier Regiment Afrika and Group Stotten would return to the 

DAK. The 10th Panzer Division was going to an 

area from which it might renew an attack in the 

Ousseltia valley. The 33d R.U. and Centauro Division, possibly reinforced by more German troops, 

would defend Gafsa. The 21st Panzer Division 
Page 39

would stop near Blida (Sbeitla) or Faid village. The 

next day, Advance First Army relayed a report from 

Eighth Army “Y” that Group Stotten expected to 

have reached its parent regiment on the 27th of 

February.

A letter found near Thala, presumably on a German casualty, and dated 22 February 1943, included 

the sentence: “Yesterday we were again visited by 

General Rommel, who is commanding here.”14 The 

Allies circulated that bit of intelligence.

Another trophy of the Faid-Kasserine Pass operations was a German code book found under the 

seat of an immobilized tank about five miles south 

of Sbiba. It contained the order of battle of the 21st 

Panzer Division, confirming information previously obtained, and was passed by the Acting G-2, 

34th Division, to the II Corps SIGINT unit on 28 

February 1943.15

On the other side of the picture – communications security – American units were less than 

perfect. When the 34th Reconnaissance Troop 

neared Sbiba, north of Sbeitla, its commanding officer reported in the clear that he had arrived north 

of the town; enemy artillery soon fell there. The 

Troop quickly moved to the south, and he again reported in the clear where he was. Enemy fire 

shifted at once to that area.

Recapitulation

Neither the Axis nor the Allied commands had 

begun the February battles with a correct view of its 

enemy’s strength or intentions. The surprise on 14 

February was not the attack itself but, as in the later 

cross-channel attack into Normandy, the site of the 

main effort. The logical operation for the Axis to attempt had seemed so apparent that a general 

officer commanding British First Army’s line of 

communications wrote out an argument for it in 

the form of an imaginary intelligence appreciation 

that Rommel might have presented to high command. The AFHQ intelligence estimates also 

showed an accurate appraisal, or foreknowledge, of 

the time but not the point of main attack.16

Nor did AFHQ realize the clumsiness of Axis 

command relationships. Rommel was using mobile 

and armored elements from the German- Italian 

Panzer Army. Von Arnim was committing, among 

other troops, the 21st Panzer Division, which Rommel had previously sent ahead into Tunisia but 

which had had to be re-equipped with tanks upon 

arrival. After von Arnim succeeded in the initial action at Sidi bou Zid, he was to release them to 

Rommel’s control so that Rommel might be strong 

enough to take Gafsa. Axis forces met no resistance 

in taking Gafsa, which the Americans and French 

had abandoned. The American counterattack to retake Sidi bou Zid failed; II Corps then abandoned 

Sheitla and Feriana, as well as the airfield at Thelepte, offering nothing more than rear-guard 

actions. At that stage things were going so well for 

the Axis forces that Rommel persuaded Kesselring 

to approve the use of all mobile Axis divisions in a 

drive to Tebessa. Von Arnim, who opposed a project that would absorb elements of his command to 

which conflicting missions had already been assigned, was slow in releasing the 10th Panzer 

Division. The high command changed Rommel’s 

objective from Tebessa to Le Kef in hopes of so 

threatening British First Army’s line of communications that their forces would have to pull back 

westward and thus allow the Tunisian bridgehead 

to expand at least to include certain north-south 

roads.

Rommel’s drive through Kasserine Pass, though 

slower than he thought satisfactory, did cause a 

quick American exodus from Tebessa. The blocking 

forces that Rommel had sent toward Tebessa and 

elsewhere left him too weak and too far behind 

schedule to push through Thala to Le Kef. At all 

times he was looking over his shoulder toward the 

Mareth Position near the Tripolitanian border, 

where he felt that he must be able to launch a spoiling attack against Montgomery’s pursuing forces. 

He may have become aware that his actual 

objective, Thala, was recognized and that Allied 

preparations there would greatly strengthen the resistance he would receive if he kept on. He obtained 

authority to end the operation and withdraw, but 
Page 40

some of his opponents found it hard to believe that 

the Axis attack was really over.

Two Opposing Army Groups

As the Axis forces were preparing to exploit 

their successes against the Americans of II Corps, 

the Allies were completing a reorganization that established 18 Army Group under General Sir Harold 

Alexander. Operations of the British First and 

Eighth Armies, French XIX Corps, and U.S. II 

Corps would be coordinated by that headquarters 

at Constantine in eastern Algeria. Alexander actually assumed command late on 19 February 1943. 

His staff, though Anglo-American, consisted predominantly of British Army officers who had 

participated in victories over the German-Italian 

Panzer Army, Afrika, while serving in GHQ, Middle 

East, or in the Eighth Army. His principal intelligence officer was Brigadier T. S. Airey; the chief 

signal officer was Major General W.R.C. Penney. 

(Both men brought abilities to their jobs that later 

carried them upward, during and after World War 

II. Brigadier Airey was to participate with General 

Lyman L. Lemnitzer in negotiating the surrender of 

German forces in Italy in 1945. Both men were later 

to hold important positions in the NATO military 

establishment.)

Upon activation, Headquarters, 18 Army Group, 

assumed control of the SIGINT operations of First 

and Eighth Armies. The functions covered by “control” were specified in a memorandum from G-2, 

AFHQ, to Brigadier Airey, on “Intelligence Procedure,” dated 10 February 1943. The objective was 

to coordinate the production and interchange of 

pertinent information, both military intelligence 

and technical “Y” data (WTI). SIGINT from the 

armies would go to 18 Army Group, which would 

send a daily summary of “Y” activities, as well as 

supplementary reports, to the SIGINT Subsection 

of G-2, AFHQ. The latter would forward through 18 

Army Group any technical information, documents 

and the like to the two armies.

As long as 101 Special Wireless Section (flown 

with equipment from X Corps in Eighth Army reserve) and 40 Wireless Intelligence Section (“this 

‘Y’ unit”) were not placed under control of either 

the First or the Eighth Army SIGINT staff but remained at Constantine among the vans and trailers 

at Alexander’s headquarters, they would receive direction from 18 Army Group’s SIGINT subsection.

To insure AFHQ’s proper control of theater SIGINT operations, all moves of “Y” units were to be 

reported to G-2, AFHQ; and all communications on 

“Y” matters with MI 8, War Office in London, or MI 

8, Mideast in Cairo, were to be conducted through 

G-2, AFHQ. When necessary, 18 Army Group 

would look to AFHQ for an advisor on communications security matters. On all matters of personnel, 

it was later agreed, First Army could continue to 

deal directly with AFHQ. An SLU at Headquarters, 

18 Army Group, handled the special intelligence 

available to General Alexander.

When the Axis thrust toward Le Kef in February ended, Axis forces were also redeployed and 

reorganized. On 23 February 1943 the Axis established Headquarters, Army Group Afrika, at Sbeitla 

and put Field Marshal Rommel in command until 

he left Africa on 9 March 1943. He was then succeeded by General Jirgen von Arnim, who, in turn 

was succeeded in the command of Fifth Panzer 

Army by General Gustav von Vaerst. What had 

been termed the German-Italian Panzer Army, Afrika became the Italian First Army under General 

Giovanni Messe, who exercised nominal command 

over the remnants of the German Afrika Corps 

(DAK) through a German deputy.

General Alexander used a lull in central and 

northern Tunisia to sort out the units of different 

nationalities, to get them into defined sectors, and 

by reinforcement, resupply, and other necessary 

measures to have them ready for offensives by midMarch. U.S. Corps acquired Major General George 

S. Patton, Jr. as its new commander on 6 March 

1943. Major General Omar Bradley was his deputy 

and, by prearrangement, his successor about one 

month later, when Patton began devoting himself 

to the impending campaign in Sicily.

The adversaries in Tunisia had certain major 

actions to execute. For the Axis, time was essential 
Page 41

to acquire resources sufficient to thwart the Allied 

offensive in the making. To gain time, during which 

the fortified lines at Mareth and Wadi Akarit might 

be rendered stronger, the Italian First Army, while 

still controlled by Rommel, sought to blunt the 

British Eighth Army’s spearhead near Medenine. It 

was reasoned that by falling on the advance elements with strong mobile forces and perhaps with 

surprise, Rommel might deliver an effective spoiling attack. The corridor between northern and 

southern Tunisia had to be kept open, whether to 

maintain Italian First Army or to permit withdrawal from the Mareth to the Wadi Akarit position, 

and thence into the main bridgehead. To keep the 

Allies from attacking the rear of the southern Axis 

defensive positions or disrupting the line of communications in the corridor or accumulating 

superior strength at critical points along the perimeter of the bridgehead, the much reduced 10th, 15th 

and 21st Panzer Divisions (or their mobile elements) were to be used as much as possible as a 

mobile reserve from which to make limited attacks 

that would keep the Allies off balance.

The Allies correlated all other operations with 

Montgomery’s effort to get past the Mareth Position. Corps was to seize and defend Gafsa, holding 

it as a base of supplies for Eighth Army to use when 

it came north. U.S. II Corps was to recover Thelepte 

airfield and establish others from which to furnish 

air support to Eighth Army. II Corps was to draw 

Axis reserves from the path of Eighth Army, weakening the opposition at the Mareth position and 

Chott position. The French XIX Corps, after rearming, was to defend routes through the mountain 

passes on the southern flank of British First Army. 

The latter was to prepare for a renewed drive into 

the Axis bridgehead to begin after Eighth Army had 

succeeded in coming north as far as the enemy’s 

Enfidaville Line.

The Intelligence Section, 18 Army Group, which 

was responsible for coordinating all intelligence activities of the First and Eighth Armies, did not 

collate intelligence but provided up-to-date 

information of the enemy derived from AFHQ, regarding the broad picture, and from the armies, 

regarding the battle picture. Into that information 

went the SI of its own SIGINT unit. Both armies 

furnished daily situation reports by wire to AFHQ 

and 18 Army Group, and issued written intelligence 

summaries giving detailed information not included in the daily message.

Captured documents and reports of interrogation of prisoners of war were handled similarly. The 

prisoners taken by First Army were passed back to 

the Allied POW camp at Constantine, while those 

taken by Eighth Army in southern Tunisia were 

evacuated through its line of communications to 

Egypt, until the Army had moved up the coastal 

corridor to Enfidaville. U.S. II Corps obtained “Y” 

from the British 55 Wireless Intelligence Section 

under Captain Hugh Skillen, and Detachment A, 

Intelligence Branch, 849th Signal Intelligence Service, working together on the low-level German 

Army traffic intercepted by the 128th Signal Radio 

Intelligence Company. These units were attached 

to Headquarters, II Corps. Most of the intercepted 

traffic was in three-letter or jargon codes, enciphered by transposition or simple substitution 

systems. G-2, II Corps, received spot SIGINT from 

a liaison officer at Headquarters, 18 Army Group, 

and daily summaries from 18 Army Group and 

AFHQ-in-the-Field. The tactical SIGINT came 

from a few enemy units whose messages were 

being read quickly, and from traffic analysis. The 

10th Panzer Division used a reciprocal system in 

which code groups were identified by cipher groups 

during stated periods of perhaps six days before a 

new table of cipher groups became effective.

Identification of Axis units at known locations 

was imperfect but helpful. The II Corps SIGINT 

unit, known as “Snoopy,” kept track of the German 

580th Reconnaissance Unit, the artillery unit 

ARKO 104, and the mobile “KASTA O.B.,” mentioned above.

Notes

1. AFHQ G-2 Intelligence Report, No. 24, 6 Feb 

1943.

2. CX/MSS2118/T13 deciphered on 14 Feb 1943, 

while the attack began, cited in GCCS Air and Military 

History, IV, 308.
Page 42

3. Ibid., No. 25, 15 Feb 1943. G-2, AFHQ deduced 

from Ultra that the main attack would be that west of 

Kairouan, while that at Faid would be a feint. See Eisenhower Diary, V, A-236. That error led to the relief of 

Brigadier Mockler-Ferryman by Brigadier Kenneth 

Strong.

4. Ibid., No. 16.

5. II Corps G-2 Jnl for 13 Feb 1943, item No. 34.

6. II Corps G-2 Periodic Report for 0001 - 2400A, 14 

Feb 1943.

7. The 580th Reconnaissance Unit from February 

through March 1943 used a code designated as Rabbit 

42, or WSW, because that was its code group for zero. 

The alphabetical sequence of code groups and equivalents each ran in the same direction, like most but not all 

German field codes; in some, the equivalents were alphabetically in a reverse sequence. 

To obtain greater security, users of those German 

codes and others like them periodically slid the equivalents so that the last part of the alphabet came before the 

first part. A few code groups might be omitted or some 

new groups inserted, having the effect of site ring the 

new interval between code groups and former equivalents. Occasionally, blocks of equivalents were shifted by 

randomly scrambling the alphabetical sequence. 

Changes like those were readily made at set times, in addition to the regular changes made at periodic intervals 

of one or more months. The 10th Motorcycle Battalion, 

for example, slid one group per day, or more than one 

after three such daily changes, and altered the sequence 

of equivalents as well.

8. CX/MSS/2140/T11.

9. The basic code used by the 33d Reconnaissance 

Unit had been captured. It was found to contain 482 

code groups taken from the German Army Signals Table 

(HST) with 482 meanings, both in alphabetical sequence. The code groups, however, were organized to 

provide equivalents for numbers, compass directions, 

thrust line references, map scales, times, light signals, 

radio procedures, indicators, place names, tactical 

terms, and then the main body of general subjects for 

communication.

10. CX/MSS/2140/T11, cited in GCCS Air and Military History, IV,312.

11. Telephone call, General Porter to Colonel Honeycutt, 2240/21 Feb 1943, in II Corps G-2 Jnl, 21 Feb 

1943, no. 73.

12. CX/MSS/2161/T11; 2172/T20.

13. AFHQ-in-the-Field, G-2 Report No. 109, 25 Feb 

1943.

14. AFHQ-in-the-Field, G-2 Report No. 111, 27 Feb 

1943.

15. Memo for G-2 II Corps, from Acting G-2, 34 Div 

(Lieutenant Colonel Hubert H. DesMarais), 28 Feb 

1943.

16. A contemporary record is an excerpt from the 

unpublished version of General Eisenhower’s War Diary 

kept by Captain Butcher, as follows:

An explanation of the defeat, as seen 

by Ike, lies in a misinterpretation

of radio messages we regularly

intercept from the enemy. This source 

is known as Ultra. It happens that 

our G-2, Brigadier Mockler-Ferryman, relies heavily upon this source. 

It has frequently disclosed excellent 

information as to the intentions of 

the Axis. However, the interpretation 

placed by G-2 on the messages dealing with the place of attack – an 

attack that has been expected several 

days – led Mockler-Ferryman to believe a feint would be made where the 

attack actually occurred through Sidi 

bou Zid, and that the real and heavy 

attack would come farther north. Our 

reconnaissance and air observations 

plainly showed the massing of tanks 

and troops, presumably for attack, in 

the Sidi bou Zid area, but did not 

show considerable additional forces, 

particularly tanks, which had been 

cleverly hidden. Basing his judgment 

on the reliability of Ultra, MockerFerryman was confident the main 

attack would come to the north. As a 

result, General Anderson kept in reserve approximately half of the First 

Armored Division to meet an attack 

that never came. The result was that 
Page 43

the other half of the First Armored Di-

vision was chewed up by 

overwhelming forces, particularly by 

Mark VI tanks (Tigers).

Now we are told by General Paget 

that Mockler-Ferryman had been re-

leased by him for lack of imagination. 

He said he was surprised Mock had 

been assigned to TORCH. He suggests 

sending as his relief another British 

G-2 [Brigadier Kenneth Strong] 

whom he describes as knowing how 

Germans think and act, as he was for 

a considerable time Military Attache 

in Berlin.

General Paget left this morning in [sic] route to the U.K. and is to handle 

with Sir Alan Brooke (the C.I.G.S.) 

the replacement of Mock in such a 

manner that he will not be discred-

ited. His error was simply a 

misinterpretation of the meaning of 

the intercepted German messages. 

However, Ike insists we need a G-2 

who is never satisfied with his infor-

mation, one who procures it with 

spies, reconnaissance, and any 

means available. Ike thinks Mock re-

lied too heavily upon one source of 

information - the intercepts. [See ex-

cerpt version in Ronald Lewin, 

ULTRA Goes to War, 273-4.]
Page 44

THIS PAGE INTENTIONALLY LEFT BLANK
Page 45

Expectations 

The enemy thinned out his positions in central Tunisia in order to attack in the north at the 

beginning of March 1943. On 2 March, 18 Army 

Group passed on a report from the Allied defenders that twenty-five Axis tanks were lying 

abandoned in front of their positions after a halfhearted attack by two battalions from the 47th 

Grenadier Regiment and one from Regiment 

Barenthin. Another Axis drive along the road 

through Sedjenane was only partly successful 

and quite costly. On 3 March these attacks were 

renewed without understandable objectives and 

were interpreted as possibly “the execution of 

rigid orders no longer applicable to the present 

situation.”1 Of thirty tanks immobilized at one 

point, and others elsewhere, at least twenty were 

demolished.

The Allies took advantage of the situation to 

retake Pichon, where the enemy was either too 

weak or too surprised to put up serious opposition, and took no steps to recover it.

When the Axis attack at Medenine began on 6 

March, as expected by Eighth Army, the enemy 

simply dug in along the roads in the northern sector where he recently had been stopped. “Y” 

disclosed that he was sending an infantry/artillery battle group from the north to central Tunisia. 

One more Axis offensive in the far north, near 

Tamera, began on 8 March, while in the extreme 

south, at Medenine, Rommel broke off his spoiling attack after having sacrificed about one- fourth 

of his tank strength to no purpose.2

One illustration of the way in which field SIGINT could be turned to account so impressed a 

German SIGINT officer that he remembered it 

with relish after the war. During a conference at 

Headquarters, O.B. Sued, a current message reporting to the Eighth Army command that a 

heavy traffic jam had developed in a certain wadi 

was intercepted and read. Although the exact location of the wadi was uncertain, its general 

position could be guessed. Air reconnaissance 

was therefore ordered at once. Even before the 

enemy conference was over, the commanders 

there had received a further report that the vehicle-filled valley had been bombed.3

In March the enemy sent his mobile armored 

divisions to an area from which they could protect the rear of the Mareth Position and also 

threaten the Allied southern flank in the vicinity 

of Faid and Maknassy. An Allied force in the Ousseltia valley discovered that it had become an 

extensive “no-man’s land,” where only patrols 

were likely to be met.4

Believing that Rommel was still in command, 

Alexander concluded that another attack around 

Feriana was likely; it would be a characteristic attempt to anticipate the expected Allied attack on 

Gafsa, and to spoil it. But when “Y” showed on 15 

March that the 580th Reconnaissance Unit had 

moved to Gafsa, the probabilities changed; the 

21st Panzer Division was thought more likely to 

operate offensively in the vicinity of either the 

Maknassy-Gafsa or Gabes-Gafsa roads than on 

the Feriana plain. Patrols toward Gafsa showed 

that the enemy there was aware of the imminent 

threat to Gafsa being prepared by II Corps.5

The Italian Centauro Division evacuated 

Gafsa before the U.S. 1st Infantry Division attacked it; the German 580th Reconnaissance Unit 

acted only as a rear guard.6 The enemy was 

therefore believed to be shifting to stronger 

Chapter 4

The March Offensives
Page 46

positions near El Guettar and between Sened and 

Sened Station, positions that were blocking the 

roads leading from Gafsa via El Guettar to Gabes 

and from Gafsa via Maknassy and Mezzouna to 

Gabes. While accepting the possibility of a counterattack, General Alexander’s Intelligence Section 

thought it unlikely that another thrust would come 

through Faid, since concentrating for that attack 

would leave the defense of the southern GafsaGabes route almost wholly to the Centauro Division, 

a risk believed to be “incon-ceivable.”7

The German-Italian Panzer Army, Afrika, 

awaited Montgomery’s attack on the Mareth Position, uncertain for about one week when it would 

begin. Then, on both 13 and 14 March, a British 

battalion sent the same message to subordinate 

units: “Remember to observe radio silence until 

2200 hours, 16 March.” That brought about a 

timely alert to the Axis commanders in Africa via 

O.B. Sued, based on German SIGINT.

II Corps Attacks: Gafsa, Maknassy, and El 

Guettar

The area of the offensive operation in March 

planned by U.S. II Corps was drenched by downpours of heavy spring rains beginning on 14 March 

and continuing for three days. Combat Command 

B, 1st Armored Division, moved through it to block 

the road from Sidi bou Zid to Gafsa, while the main 

body of the 1st Armored Division got into position 

northeast of the town for an attack through Sened 

and Sened Station to Maknassy. To avoid being 

mired, that operation had to wait until the night of 

20/21 March.

The 580th Reconnaissance Unit was traced by 

“Y” from a screening position east of El Guettar to 

the Maknassy road, where it opposed the advance 

of the 1st Armored Division beyond Sened and then 

beyond Maknassy. The latter was evacuated during 

the night of 21/22 March.

The Germans intercepted an Allied report in 

the clear that observers could see German soldiers 

digging in at a certain site. Without delay, that led 

to better concealment. Another Allied report, that 

observers could see the sun flashing off the windshields of German vehicles, caused the enemy to 

correct his defective camouflage.

On the other hand, reports by enemy reconnaissance of the movements of II Corps elements 

were intercepted and read by Allied SIGINT personnel as Allied advances toward and east of El 

Guettar began on 21 March.

The enemy sought to offset his weakness in 

numbers by using every advantage of position. He 

pulled back, while offering little or no resistance, to 

rugged hills where he had the advantage not only of 

good observation but of protected bases of fire. He 

placed his antipersonnel mines most effectively. II 

Corps expected intervention, at least by the 21st 

Panzer Division, as soon as the weather allowed 

mobile operations. Until 22 March 1943, II Corps’ 

mission of drawing off forces otherwise available to 

oppose British Eighth Army at Mareth had not 

been realized. As the enemy calculated the risk that 

II Corps might break through into the coastal corridor, however, he was bound to forestall that 

danger, if he could, by counterattack.

After occupying Maknassy on the morning of 

22 March, the 1st Armored Division might have 

pressed on a few more miles into the hills to seize 

the highway and railroad pass in the mountains 

east of that town. Had their mission called for it, 

they would have done so. Had intelligence been 

able to warn them that the pass was weakly held by 

a mixed force (chiefly Italian) but that German reinforcements were being rushed there from further 

north, the division would have saved itself from 

many adverse consequences by pushing ahead on 

22 March. Instead, for lack of reasons to keep moving for the third straight day, into an area 

inadequately reconnoitered, they waited to make 

the attack until night, and almost, but not quite, obtained control during the following day.

On 22 March 1943 General Alexander altered 

the II Corps’ mission by requiring seizure of the 

Maknassy Pass in preparation for sending armored 
Page 47

raiding forces through it. Up to that time, the only 

evidence of possible enemy reaction had been 

heavy wireless activity by the 10th Panzer Division 

which was understood to be moving south after refitting.9

East of Maknassy, other Axis reinforcements 

arrived to defend the pass under the command of 

Colonel Rudolf Lang, one of General von Arnim’s 

troubleshooters. The Allies learned about his presence and identified his German tank and infantry 

units from “Y.” When not in the pass itself, Colonel 

Lang directed operations from a headquarters discovered by Allied intelligence to be two miles south 

of Mezzouna. Tiger tanks later joined his force, 

which enabled him to counterattack strongly on 28 

March.

On 22 March, a 10th Panzer Division Battle 

Group, including about fifty tanks, made two attacks against the 1st Infantry Division’s positions 

along the Gafsa-Gabes road on the other side of the 

mountains from Maknassy.

After shelling Allied observation points with artillery and smoke shells, German infantry and 

tanks, both medium and heavy, assaulted twice, 

and Stukas also dive-bombed during the intermission. The attack failed to dislodge the Allies, who 

remained under further air bombing through the 

ensuing night, when Gafsa also was bombed. Although the Axis forces then went back to the 

defensive, they continued successfully to block any 

further advance eastward by II Corps. The U.S. 9th 

Infantry Division vainly tried to get control of certain southern mountains from which the enemy 

could spot all American movement. Despite this 

disadvantage, a U.S. armored force tried to push 

toward Gabes through mine fields and antitank 

fire, and it too lost its best chance.

The enemy’s last counterattack against the Allied threat along the El Guettar-Gabes road came 

on the night of 25/26 March. He then tried what he 

had failed to accomplish in daylight three days before, and after breaking off the first attempt about 

0200, he resumed his offensive in the afternoon. 

Allied intelligence concluded that the 10th Panzer 

Division Battle Group had failed to make any progress, although he had committed all his reserves to 

prevent an incursion by II Corps into the coastal 

corridor. As soon as it became apparent that the 

enemy, after leaving the Mareth Line, would make 

another stand at the Chott position (Wadi Akarit), 

General Alexander directed that II Corps press toward the rear of the Gabes position. Stabilizing the 

II Corps pressure east of Maknassy and stepping up 

threats at passes further north, he called for action 

by the 1st Infantry and 9th Infantry Divisions in the 

El Guettar area, to open the way eastward for an 

American mobile armored force.

The Germans and Italians on the heights along 

the Maknassy road to Gabes thwarted those infantry operations. Behind minefields and barbed wire 

positions, their antitank guns, artillery, mortars 

and machine guns, all aided by excellent observation points, were too strong for the Americans to 

penetrate. The II Corps SIGINT unit identified elements of the enemy’s battle group and ascertained 

that on 31 March Germans were complaining of desertion by Italians. Other messages showed that the 

blocking force expected to move into the coastal 

corridor before very long.

By then, General Alexander had revised the 

mission of II Corps once more. An armored Combat Command under Colonel C.C. Benson, 1st 

Armored Division, was ordered to plunge ahead 

without waiting for the infantry to open the way. 

The Eighth Army’s attempt to break through the 

enemy's main line of resistance at the Chott position would be aided by the II Corps’ drive against 

the enemy’s flank and rear, if additional Axis forces 

were thus drawn from the path of the Eighth Army.

The enemy apparently recognized a danger and 

did send the mobile elements of 21st Panzer Division to reinforce the 10th Panzer Division Battle 

Group. Axis air attacks in the II Corps area of attack 

multiplied. The II Corps column, known as “Benson Force,” could not get through on 30 March. 
Page 48

They almost made it on 31 March but thereafter 

were stopped until the enemy rear guard had 

slipped away on 8 April. Contributing to the failure 

of Benson Force was a deplorable lack of secure 

communications on its command net. Unit designations, locations, plans and intentions were given 

freely in clear text.10

On 2 April, by 18 Army Group orders, II Corps 

went back to the plan that the infantry should open 

the way through the successive defiles on the Gabes 

road until Benson Force could press through without such losses from antitank fire as it had 

experienced during three successive days.

The II Corps SIGINT unit ascertained where 

Axis ammunition dumps were located. It listed 

artillery units and their operational weapons, established unit identifications, and interpreted 

miscellaneous indications of enemy movements. 

When an Allied reconnaissance team captured a 

motorcycle from the German 580th Reconnaissance Unit, and the latter planned to get it back on 4 

April, “Snoopy” was able to pass the warning.11

On 2 April a code list of the 21st Panzer Division was captured, showing that it had incorporated 

a Marsch Battalion, redesignated as IV Battalion, 

104B Infantry Regiment.

The Enemy Retreat to the Bridgehead

Air observers noted a thinning out of the enemy 

forces near Maknassy beginning on 4 April. On 5 

and 6 April, the roads running northeast and north 

from the El Guettar area began bearing long columns of Axis trucks, tanks, and guns. Allied air 

then gave them some of the same kind of treatment 

that Axis air had been meting out to Allied vehicles 

and men for so long.

On 6 April II Corps met tank and artillery fire 

near El Guettar from a rear guard. At that time the 

enemy was pulling northward from the Chott Position, too, and to hasten his departure, General 

Alexander ordered II Corps to provide maximum 

aid to Eighth Army. General Patton furnished it in 

the form of a lunging drive along the Gabes road by 

Benson Force. Once within Eighth Army’s zone, 

Benson Force was ordered back before encountering Axis opposition, although many enemy troops 

had surrendered to it. At Maknassy Pass, the 

enemy pulled out after dark on 8 April, as did 

enemy units in the area north of it as far as Faid 

Pass. During 9 April Allied forces went through the 

undefended passes after lifting mines. The next 

day, an American armored column went through a 

minor gap (between Maknassy and Faid Passes) to 

the eastern edge of the Eastern Dorsal, then northward as far as Fondouk Pass; it then retraced its 

route as far as Faid Pass and returned westward 

through that defile to rejoin the 1st Armored Division.

The enemy, meanwhile, had been moving north 

in the coastal corridor toward his next defensive 

position, the “Enfidaville Line,” thus evacuating the 

small, shallow ports of Sfax and Sousse and the 

many airfields and other facilities near Kairouan. 

On occasion, when communications difficulties denied to Field Marshal Kesselring the periodic 

situation reports from Tunisia that would have 

helped to keep his headquarters abreast of developments, German SIGINT then supplied him with 

information derived from deciphering Allied reports of Axis locations. Concentrated henceforth 

within the bridgehead, the enemy sought reinforcement and resupply. If he could not outstrip the 

Allies in those activities in April as he had in November and December, he would lose his African 

bridgehead entirely. If he could not hold it, despite 

the nearness of his Sicilian and Italian bases, how 

could the Axis expect to escape ultimate defeat?

While U.S. II Corps began its efforts in midMarch to draw as much as possible of the Axis 

reserves from the path of Eighth Army, the condition of Allied field SIGINT units was being reviewed 

by the “Y” Northwest Africa (YNA) Committee. 

American participation remained in substance that 

of an auxiliary, or client, of the British “Y” organization. With the U.S. II Corps, Captain Skillen’s 

British 55 Wireless Intelligence Section was 
Page 49

reinforced by ten Americans in Detachment “A,” 

849th SIS. The 128th Signal RI Company that 

provided field intercept was not yet fully manned 

or fully equipped, though much had been done to 

replace its vehicles and equipment, lost at sea off 

Oran.

Other U.S. SIGINT personnel arrived in the Algiers area only a short time before the March 

operations. The YNA Committee agreed that none 

of the American units was ready to operate independently.

When II Corps shifted in mid-April from central Tunisia to the northern sector for the Allied 

offensive against the bridgehead, Detachment “A,” 

849th SIS, and the 128th Signal RI Company were 

sufficiently experienced to act more independently, 

but the “Y” intelligence provided by 55 WI Section, 

with which Detachment “A” was working, was limited. Air reconnaissance reports and interrogations 

of Axis prisoners probably continued to contribute 

more than field SIGINT to Allied intelligence until 

the enemy suddenly surrendered, less than one 

month after the offensive in the north began.

As for intelligence from medium-grade systems, by the time British Eighth Army had reached 

Tunisia, it had put a thousand miles between it and 

the British base at Heliopolis. Getting intercepted 

traffic back to the fixed SIGINT processing station 

there took so long that the effort appeared to have 

foundered. The need for high-speed communications channels exclusively for SIGINT was shown 

to be imperative. As the last phase of the campaign 

in Tunisia proceeded, a field processing facility was 

established there.

Notes

1. 18 AG ISUMS, 3/4 Mar 1943.

2. Ibid., 1800/8 Mar 1943.

3. Praun, German Radio Intelligence.

4. 18 AG ISUM No. 1/144, 122140A Mar 1943.

5. Ibid., 15 Mar 1943 (No. 1/155).

6. One form of secure communications promptly 

brought a report of the occupation of Gafsa by II Corps, 

to rear headquarters at Tebessa. The pigeon “Yank” of 

the 829th Signal Service Battalion’s Pigeon Platoon, flew 

the message over mountains for a distance of about 

ninety miles. During subsequent operations near El 

Guettar, pigeons carried forty-five messages in about 

five days.

7. Ibid., 17 Mar 1943.

8. Ibid., 22 Mar 1943 (1/183). 

9. Intell Appreciation No. 1/89, 222130Z Mar 1943

10. II Corps G-2 Jnl, Report for 30 Mar to 8 Apr 

1943 by S-2, Benson Force.

11. II Corps G-2 Jnl, 30 Mar-3 Apr 1943.
Page 50
Page 51

Summary

The U.S. II Corps moved in April 1943 from 

central to northern Tunisia to occupy a sector on 

the northern wing of First Army. The main assault 

was to be delivered on their right by British V and 

IX Corps, supported by most of the Allied aviation. 

British Eighth Army released divisions to First 

Army for commitment as part of a powerful armored and infantry thrust on a relatively narrow 

front. Lieutenant General Omar Bradley, now commanding II Corps, operated directly under 18 Army 

Group, which expected him to play much the same 

role in respect to the First Army’s attack that Patton’s II Corps had been assigned when Eighth 

Army faced the Mareth and Chott positions. In 

short, II Corps was to push hard enough to pin 

down as many enemy forces as it could while the 

main effort broke through. After Tunis had fallen to 

British First Army, it would send elements to join II 

Corps in seizing Bizerte.

The campaign did not work out that way. II 

Corps had a French component at the extreme 

north, the U.S. 9th Infantry Division in the center, 

and the 1st Infantry Division at the south. As the 

front developed, the 34th Division went into line 

near the center, and the infantry of the 1st Armored 

Division attacked among the hills on the extreme 

south flank, next to British V Corps. The armored 

elements of the 1st Armored Division, except for 

small-unit operations in support of infantry, remained in reserve until they could be committed on 

terrain better suited to armored offensives than 

was the zone of steep-sided hills and narrow deffies 

where the infantry struggled. The attack advanced 

slowly until the tired enemy lost whole groups of 

mutually reinforcing hills at the same time, and 

then fell back to defend other such groups. Once 

the way had been cleared, II Corps made rapid 

progress, first to cut all connections by land 

between Tunis and Bizerte, and next to envelop 

and occupy Bizerte and its valuable port. That occurred on the same day that British troops entered 

Tunis.

The Attack Begins

At 1400, 15 April 1943, the II Corps Command 

Post (CP) opened about two miles from Bedja after 

the Corps moved, by divisions, from central Tunisia. At 1800, 19 April, II Corps assumed control of 

its area.

The 128th Signal RI Company established itself 

in vans nearby with nine sets monitoring medium 

frequency (MF) and two sets monitoring very high 

frequency (VHF) voice transmissions. For DF they 

had a SCR-255 at hand and, about ten miles out on 

the diverging roads from Bedja to Mateur and from 

Bedja to Medjez el Bab, two SCR-200s with semiportable loop antennas. They used a telephone line 

to Headquarters, II Corps (G-2) and were in touch 

with Headquarters, First Army, by radio on a twohour schedule. During the advance by II Corps 

from 24 April to 11 May 1943, through the mountains, across the Tine River Valley, and over the last 

hilly barriers to the coast, the company intercepted 

a total of 2,766 messages on about 50 different frequencies.1

The analysts were soon able to produce useful 

SIGINT: 55 Wireless Intelligence Section identified 

and located V Battalion, 90th Armored Regiment, 

and sought recognizable signals from the 580th 

Reconnaissance Unit. The VHF radiotelephone 

used by elements of Regiment Barenthin was heard 

reporting that the Allied line facing them had been 

reinforced and seemed to be moving toward an attack. The voice traffic of that unit could be heard 

thereafter at distances of fifteen to twenty miles. In 

Chapter 5

The Final Phase in Tunisia
Page 52

time, they could read traffic of the dismounted 10th 

Motorcycle Battalion (operating as an infantry 

unit), which transmitted in a system involving resetting a code by sliding. The meanings of an 

alphabetically arranged code, in which all digits 

were in the “W,” were slid one group daily in the 

Heeressignaltafel (HST), the basic German Army 

book of codes. At intervals, the daily shifting was 

augmented by random rearrangement of blocks of 

code meanings from that of the HST. Captain Skillen’s unit could also read traffic on a link between 

Headquarters, ARKO 104 and one of its batteries, 

plus traffic of the 580th R.U., of I Battalion, 43d 

FLAK Regiment and Regiment Barenthin.

Before the Allied attack opened on 23 April, the 

Corps “Y” unit gave G-2 a series of items. On 19 

April, about an hour after intercepting a report that 

showed which areas had been covered by night patrols during the preceding night, the unit furnished 

a translation to G-2, II Corps.2 Another report 

showed that the ration strength of the 3rd Company, II Barenthin Regiment, was less than 194, 

plus one horse and four mules, and that effectives 

were less than 10 officers, 33 NCOs and 105 enlisted men.

II Corps was not yet sufficiently familiar with 

the terrain ahead of it when its attack began. SIGINT identifications of the order of battle and 

positions of the foe were therefore the more important. Air reconnaissance by bombers on their return 

from bombing targets well within the bridgehead 

contributed information that was “fragmentary 

and scanty.” At first, requests of the XII Air Support Command, to which II Corps looked for aerial 

reconnaissance, had to be submitted via British 

First Army headquarters in time for a committee 

that met daily at 1900 hours. The committee then 

decided what requests would be accepted for execution the next day. Spot requests were made 

through air-liaison parties with the division headquarters. For the first two days all requests from II 

Corps were rejected; on the third day, weather precluded air reconnaissance.

At the beginning of the Allied attack, a captured 

set of code lists showed the composition of various 

enemy formations.3

The daily G-2 reports from AFHQ-in-the-Field, 

beginning on 25 April 1943, contained an annex in 

which units and locations were identified. The information was largely attributed to interrogation of 

prisoners and interpretation of captured maps and 

documents. 

First Army furnished a daily “Y” Summary to 

the three SIGINT sections with V Corps, IX Corps, 

and adjacent U.S. II Corps, summaries in which 

identifications, locations, and activities of the Axis 

forces facing each of them were made available.4

From readable Barenthin traffic, “Snoopy” reported on 26 April that I/Barenthin was moving 

that night. On 27 April the “Y” unit reported at 

0200 hours the enemy’s quiet withdrawal from Hill 

407 but not from Hill 473. Troops from the former 

became company reserves in a sheltered ravine 

exit. Other shifts were noted in advance of evacuation, and the enemy’s situation on various hills was 

ascertained by SIGINT.

On 27 April 1943 First Army informed II Corps 

that German military leave to Europe, even under 

compassionate conditions, was no longer permitted. Presumably that came from Ultra. The enemy 

was obviously becoming desperate.

The End in Tunisia

On 2 May 1943 almost all reports to II Corps 

from the 9th, 34th, 1st Infantry, and 1st Armored 

Divisions showed that the stubborn Axis forces facing them either had already withdrawn, were 

withdrawing, or had become scattered and inactive. Early next morning, the 1st Armored Division 

ran the thirty miles to take Mateur. On 3 May there 

was further “Y” evidence that elements of the 

Barenthin Regiment were pulling back generally 

south and east of Mateur. Meanwhile, British V 

Corps was grinding down the 7th Panzer Regiment, 
Page 53

the 10th Panzer Division, and other enemy formations opposing the main British assault toward 

Tunis.

II Corps moved its Command Post eastward on 

3 May 1943, as the 1st Armored Division attacked 

out of the narrow valleys onto the plain, and 

pressed northeastward into Mateur. At the same 

time, the 1st Infantry Division attacked eastward 

toward the enemy’s improvised line on the far side 

of the Tine River Valley. One armored force thrust 

through extremely rough terrain to a point of vantage above the coastal plain southeast of Bizerte 

while other II Corps troops encircled Bizerte’s 

closer landward approaches. A British mobile reconnaissance unit coming along the road from 

Tunis toward Bizerte found Americans already solidly established and German forces scattered in 

separate, disorganized, and surrendering segments. Both Tunis and Bizerte were occupied by 

the Allies on the same day, cutting the Axis forces 

off from support by sea. Soon, more or less immobilized for lack of motor fuel, the enemy facing the 

Eighth Army south of Tunis was attacked from the 

rear and forced to surrender.

The end of the Battle for Bizerte brought praise 

from II Corps, G-2 for the “Y” service that it had received. Some SIGINT had been derived from the 

traffic of enemy formations that had formerly operated within the II Corps area in central Tunisia but 

which, in northern Tunisia, faced British V or IX 

Corps. The SIGINT unit quickly discovered the 

vulnerability of the VHF communications of Regiment Barenthin and exploited it fully; timely 

SIGINT information enabled the 1st and 34th Divisions to benefit materially, and II Corps to sense 

the trends.5

Perhaps because American officers were unaware of how much intelligence the Allies gained 

from enemy radio signals, they could not recognize 

the need for adequate communications security.

It is shocking, reported one divisional 

signal officer, to find the number of 

officers who have no idea what this 

term (signal security) means. Officers are prone to discuss all plans, 

present and future, over the telephone. Names of commanders and 

units are frequently mentioned... Radiotelephone was used to a great 

extent. Signal security was violated 

extensively. Codes and ciphers were 

available but no use was made of 

them. For some unknown reason telephone directory names are used as 

addresses over the air [Monitoring] 

gleaned the information that one unit 

was in danger of being cut off and 

that artillery and mortar fire of the 

enemy was extremely accurate. Our 

reconnaissance troop always telephoned when it started out...and 

when it was returning...

At the end of the campaign in Italy, one captured German general said, during an interrogation 

(as translated):

I recollect especially the interception 

of wireless messages sent in clear by 

U.S. units in Tunisia. The enemy situation became known to us by this 

means right down to the setting of 

detonators in mine fields and the minutest changes inside enemy units.7

“Why are you not observing the truce which has 

been in effect since 1200 hours?” Thus on 9 May 

1942 Headquarters, Fifth Panzer Army, queried its 

subordinate division commanders according to radioed orders in normal form, using correct callsigns 

and the right frequencies. It was in fact an instance 

of Allied radio deception, recalled by the army’s 

chief SIGINT officer during an interrogation four 

years later. If it was ineffective, because of detection and exposure, it may have been that surrender 

superseded any truce.8
Page 54

German SIGINT became more valuable to German commanders as reports of air observations 

dwindled, either because of weather conditions or 

because of Allied air supremacy. When the interrogation of Allied prisoners of war yielded scanty 

results, German SIGINT provided information 

from men as yet uncaptured. As Axis commands in 

Tunisia failed to provide information on which 

Kesselring’s headquarters in Italy could base its periodic reports to Hitler’s headquarters, SIGINT 

provided an alternative source of information. 

From the intercepted reports by Allied field commanders in Tunisia to higher headquarters there, 

German SIGINT enabled O.B. Sued in Italy to determine the Axis situation in various parts of 

Tunisia.

The end was a quick collapse. In the bridgehead 

the Axis forces fared no better than farther south in 

respect to supplies of ammunition, fuel, food, and 

ordnance. Their routes of resupply from Italy were 

less varied and the Tunisian terminals fewer than 

had been the case before the concentration. Tunisian airfields used by the Luftwaffe either for 

combat operations or air transport were less widely 

dispersed and correspondingly more vulnerable to 

Allied air attack. Protection of ports, airfields and 

sea approaches diminished. Ultra furnished advance notice of Axis shipments. By sea and air the 

Allies cut down the tonnages brought to Tunisia, 

more than offsetting the shortened routes of overland delivery. Despite the rapidly deteriorating 

situation, the Fuehrer allowed no substantial evacuation, even of highly valued specialists, until too 

late. FAK 621 was captured. Left to become Allied 

prisoners of war were Italian troops that might 

have defended Sicily, and German commanders 

and veteran troops that could later have strengthened the defense of continental Europe.

Notes

1. Captain Sidney L. Jackson, Tactical Communications in North Africa, 145, OCMH, DA, records. See 

also G.R. Thompson and others, The Signal Corps: The 

Test (Washington, D.C. 1957), 386.

2. II Corps G-2 Jnl, 15, 19 Apr 1943.

3. AFHQ-in-the-Field, G-2 Report No. 166, 23 Apr 

1943. 

4. GSO I (S), First Army “YO” Summary, 2245/24 

Apr 1943, (No. 314) in n Corps, G-2 Jnl, 25 Apr 1943, No. 

21.

5. Annex C to II Corps G-2, Battle for Bizerte, 13 May 

1943.

6. 34th Division, Lessons Learned, Signal Officer, 

para on “Signal Security.”

7. CSDIC/BP/No. 297 on Microfilm Reel, Source, 

Boehme.

8. Interrogation Report No. 5929 (Col. Ludwig 

Karn), 27 Feb 1946. IF-204.
Page 55
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Page 57

Decisions in 1943

The conclusion of hostilities in Tunisia cleared 

the way for future Allied operations. Seizure of Sicily was to be next, as decided in the preceding 

January during the Allied conference near Casablanca. Components of the Allied force for the 

Sicilian operation had been selected, and final 

plans and preparations occupied the next month 

and a half. At Quebec another Allied conference 

produced a decision to invade southern Italy as 

soon as Sicily had been secured, with the goal of 

liberating Rome. Surrender by the Italian government to the Allies was expected to precede the 

second invasion. Forcing a withdrawal of German 

forces up the Italian peninsula to the Po Valley or 

the Alps was also thought to be not only possible 

but probable.

For the invasion of Sicily (Operation HUSKY), 

American ground forces were to be known as the 

U.S. Seventh Army under Lieutenant General 

George S. Patton, Jr., a command consisting of U.S. 

II Corps under Major General Omar Bradley and, 

as circumstances developed, a U.S. Provisional 

Corps under Major General Geoffrey Keyes. The 

British Eighth Army, under General Sir Bernard 

Montgomery, was expected to land at the southeast 

corner of Sicily and attack generally north along the 

coast, past Mt. Etna, to Messina. The Seventh Army 

was to cover his western flank and sweep up the 

western part of Sicily and gain the harbor of Palermo near its northwest corner, before pushing 

north of Mt. Etna to Messina.

Controlling both armies was Headquarters, 15 

Army Group, under the command of General Sir 

Harold Alexander, the ground force commander of 

the Allied Force. At that stage of the war in the 

Mediterranean area, British confidence in the 

performance of American troops, whatever their 

potentialities, had not yet been fully established.

The decisions to attack Sicily and mainland 

Italy confronted SIGINT planners with overlapping 

problems. They had to provide adequate “Y” service 

for the Seventh Army in Sicily and the Fifth Army 

in Italy, as well as for the Twelfth Air Force and for 

the commander, U.S. Naval Forces in North African waters, supporting the two armies. They had 

also to develop the level of competence of American 

“Y” units. A brief review of the SIGINT situation at 

this point may be useful.

The technical aspects of U.S. tactical SIGINT 

production remained for more than a year under 

the impediment of a NATOUSA security policy 

which obligated intelligence personnel to withhold 

from intercept personnel even the technical cryptologic information and intelligence requirements 

underlying their tasks. Instead, the intercept operators received daily assignments to cover specified 

frequencies and callsigns while SIS personnel supervised in order to ensure proper coverage. The 

production of “Y” by American SIGINT personnel 

had begun in Northwest Africa with field training; 

it required from three to five months for a unit to be 

able to perform well. That period was one of tutelage, while the more experienced British “Y” 

organization did what could be done to expedite 

the process. At the same time, all production of “Y” 

required endless adjustments and innovations by 

the British themselves to cope with the enemy’s ingenuity in providing security for his radio 

communications and to surmount technical difficulties in collection. For the British, especially in 

the first months of campaigning with the Americans, it was tempting to continue improving their 

own SIGINT organization and to use Americans in 

a contributory role rather than to devote the 

Chapter 6

From Africa to Europe
Page 58

necessary British resources to train Americans 

until they might act in a coordinate role. However 

strong the temptation, it could not wholly prevail 

against the determination of the U.S. Army to acquire the competence appropriate for its longer-run 

interests.

While American SIGINT personnel learned 

how to produce “Y” effectively in field conditions, 

American field commanders and staff officers had 

to discover for themselves the solid merit of 

SIGINT. Like their British counterparts, the American field commanders were skeptical of its validity 

and careless about using what they got. In Tunisia 

they had to be shown. In Sicily American ground 

troops got along without much “Y” until the last few 

days. In Italy the U.S. Fifth Army and Twelfth Air 

Force began to make full use of “Y.” On the Anzio 

Beachhead, “Y,” like Ultra, played a major role.

For the British “Y” organization, once they had 

accepted the determination of their American allies 

to develop a tactical SIGINT service, the immediate 

goal was to insure that the overall Allied “Y” service 

operated efficiently; a second goal, to expedite 

training of the Americans. Partially trained Americans either had a few more experienced British 

personnel with them on temporary duty, or they 

“double-banked” with a whole British unit. Intercept operations were conducted at forward sites to 

provide more effective coverage as soon as that became practicable.

At AFHQ, as we have seen, the “Y” North Africa 

Committee became the instrument for coordinating activities and agreeing on policy. Meeting in 

March 1943 and semimonthly thereafter, it dealt 

with preparations for Sicily and Italy. The original 

chairman was Colonel Harold G. Hayes. The four 

British members varied, but each represented his 

armed service in the Signals Intelligence Section of 

G-2, AFHQ.1

French Aid

In French North Africa a French SIGINT organization had operated clandestinely before 

Operat-ion TORCH, in spite of the presence of German and Italian armistice commissioners. The 

location of the French unit had been known to the 

British. After the French in North Africa joined the 

Allies as belligerents, their SIGINT unit cooperated. By April 1943 about twenty-five intercept 

operators and analysts were engaged in collecting 

and analyzing traffic from German Air Force and 

Italian networks. Both raw traffic and analytic results came to AFHQ.

After French forces reoccupied Corsica, a detachment of the French “Y” service operated for a 

time at Calvi. Collaboration between British and 

French SIGINT producers focused on the German 

Air Force. The British gave to the French SIGINT 

chief (Commandant Black) a full set of the German 

Air Force codes known at GCCS as the “Orchestra” 

series. He was also told that the Allies in the Mediterranean area were benefiting from a SIGINT 

service based upon a greatly extended intercept 

cover directly from the UK, but that participation in 

it could not be broadened to include the French. 

The disclosures may well have allayed French suspicions that they were being denied knowledge of 

matters about which they should be informed.2

Beginnings of the 849th Signal Intelligence 

Service

The first two United States “Y” units in the 

Mediterranean area, like the other combat troops 

in Operation TORCH, came from two geographically separate sources. The 122d Signal Radio 

Intel- ligence (SRI) Company with the Western 

Task Force crossed the Atlantic directly to the western coast of Morocco. The 128th SRI Company was 

sent from the UK to Oran, Morocco, as part of the 

Center Task Force. At Casablanca and Oran, detachments of each company were in the first or 

second convoy to arrive; the remainder of each 

company followed before the end of November 
Page 59

1942. With each detachment and each company as 

a whole were intelligence personnel detached from 

another American SIGINT unit, or, in the case of 

the 128th SRI Company, the British 55 Wireless Intelligence Section (WIS), consisting of three officers 

and twenty-two of other ranks. All were assigned to 

the Allied force. They were under the staff supervision of its chief SIGINT officer, the head of a 

SIGINT section in the Signals Division, AFHQ.

After the landings had succeeded and the 

French in Northwest Africa had joined the Allies in 

fighting the Axis forces there, the immediate objective of the Allied “Y” Service was to assist in the 

swift seizure of Tunisia. The 849th Signal Intelligence Service (SIS) was activated to provide 

American Army elements of the Allied Force with a 

field SIGINT center and with teams of intelligence 

personnel working with intercept operators of SRI 

companies. The teams would be attached to ground 

commanders (Army and Corps) and air commanders (Numbered Air Force or Air Support Command).

Compared to the United States, Iceland, or 

Northern Ireland, England was a better place for 

intercepting live German Army and Air Force radio 

traffic and for learning the intricacies of effective 

coverage. The work could be done in tents, huts, or 

vehicles adapted for the purpose, but actual, rather 

than simulated, ground combat conditions in the 

West were to be experienced in 1943 in the Mediterranean area only. Before it could be known how 

extensive and prolonged the campaigns there 

would be, ETOUSA sent more personnel to Algeria 

to become the basis of an American “Y” Service, 

while others went there directly from the United 

States. When NATOUSA was activated on 3 February 1943, the 849th SIS became the theater 

equivalent there of SIS, ETOUSA, in the UK. The 

latter could not avoid thinking of the diversion of 

its SIGINT personnel to the Mediterranean area as 

a drain instead of a seasoning process, but the experience gained was to be turned to account in 

preparing for the campaigns in western Europe.

The 849th SIS was activated at Fort Devens, 

Massachusetts, on 2 December 1942 with a strength 

of sixteen officers and 102 enlisted men. On 14 January 1943 the new unit, under Captain Richard L, 

Downing, embarked for Algiers, where it arrived on 

1 February 1943. Meanwhile, another group of intelligence analysts, trained at Vint Hill Farms 

Station and Arlington Hall Station of the Signal Security Agency, was formed on 8 November 1942 as 

Signal Intelligence Detachment 9251-A and shipped 

to the United Kingdom for advanced training in 

SIS, ETOUSA. After that training was completed, it 

moved to Algiers, arriving there on 20 February 

1943. Its strength was then fourteen officers and 

seventy-seven enlisted men. It provided much of 

the original personnel of the Intelligence Branch, 

849th SIS.

Men like Major Herrick F. Bearce, who had 

come to Morocco with the Western Task Force, 

Major Millard F. Rada, who had been in London 

with Signal Intelligence Division (SID), ETOUSA, 

and Captain Richard J. Doney, who had been there 

Captain Richard L. Downing, 1942

(Photograph courtesy of the 

Department of Army)
Page 60

in the original SIGINT Section, AFHQ, were already in Africa when NATOUSA was established 

and before the 849th SIS arrived. They and a few 

other officers were assigned to the 849th SIS.

In the United States, when the 849th SIS was 

being planned, it had been expected that it would 

become an AFHQ staff element. The table of organization and the special list of equipment for which 

War Department approval was obtained were 

based on the belief that direct support would be received from Allied headquarters units. Instead, it 

was sent to operate in the field at Hammam Melouane, about thirty miles from Algiers, without the 

necessary “housekeeping” personnel and equipment. Major Rada became its commanding officer.

Like SIS, ETOUSA, the 849th was responsible 

for communications security, as well as communications intelligence, among United States Army 

organizations. Part of its mission was thus distribution and accounting for cryptologic systems, 

equipment, and material, and the security monitoring of their use.

The site taken by the 849th SIS at Hamman 

Melouane included buildings previously used by 

the French. At first, the electric power supply that 

had met French requirements with a thirty-kilowatt transformer gave much trouble. Fuses blew 

and had to be repaired rather than replaced. Circuit 

breakers separated. Insulation burned. Until the 

supply could be increased, it was necessary to establish a rotating schedule for the use of power for 

light in offices, mess halls, kitchens, day-rooms and 

quarters, and for operating the photographic laboratory and the communications equipment. An 

auxiliary five-kilowatt generator was found and a 

certain amount of rewiring lessened the inconveniences. Not until June 1944 did the 849th obtain 

two new diesel-powered, thirty-kilowatt generators. After a move to Italy, two more generators 

were added.

Communications technicians in the 849th SIS 

installed telephone and radio connections, 

and organized a message center which linked the 

Intelligence Branch at Headquarters with its detachments by radio and teleprinter. A captured 

German fifty-watt transmitter was first used with a 

U.S. Army receiver. In August 1943 an SCR-188, 

then one of the Army’s better receivers, was installed, enabling the communicators to use a wider 

range of frequencies and more power, and, when 

replacement parts were needed, to obtain them 

more rapidly. Later a 500-watt transmitter came 

into service.

Headquarters, 849th SIS, had executive, administrative, and “overhead” personnel. The two 

main operating elements were the Intelligence and 

[Communications] Security Branches. A third element was the Enemy Equipment Intelligence 

Service, which included a Laboratory and Analysis 

Section, Editing and Publications Section, and two 

field detachments. The Intelligence Branch was supervised by the SIGINT Section, Signal Office, 

AFHQ (Lieutenant Colonel Harold G. Hayes), 

through Headquarters, 849th SIS, which furnished 

its products to G-2, AFHQ, through the same channel. The Telephone Monitoring Section of the 

Security Branch was also in direct touch with the 

Signal Office, AFHQ.

In February 1943 the new Intelligence Branch, 

849th SIS, consisted of sections concerned with 

traffic analysis and cryptanalysis (“solution”), all 

working on low-grade German Army and Air Force 

traffic collected by the SRI companies as they arrived and set up their apparatus. A unit known for 

a while as the “Fusion Section” coordinated intercept and exploitation tasks, controlling intercept 

with information gained from a variety of intelligence sources. By May 1943 the changed nature of 

its work was reflected in a new designation, Records and Research Section. For almost a year 

more, it maintained records on German Air Force 

order of battle, compiled in the main from special 

intelligence and supplied via SID, ETOUSA, in 

London.
Page 61

Detachments and Detachments

The Intelligence Branch, 849th SIS, created 

eight detachments. They were allocated, in association with parts of the four SRI companies that came 

to the Mediterranean, to Army and Army Air 

Forces commands. The 128th SRI Company, after 

participating in Operation TORCH, moved to Tunisia from the Oran area in January 1943. The 122d 

SRI Company, also in Operation TORCH, left the 

Atlantic Moroccan coast in January 1943 for training near Algiers. The 123d SRI Company arrived in 

Algeria directly from the United States in March 

1943. Like the 122d, it served the Twelfth Air Force. 

The fourth SRI Company to arrive in Africa was the 

117th, which came by sea directly from the United 

States to Oran, and thence to Boufarik, Algeria, on 

30 March 1943. 

Three detachments of the 849th SIS and two 

SRI companies were trained in North Africa to produce air tactical SIGINT. Detachment “D,” formed 

in February 1943, and Detachment “F,” formed in 

July 1943, worked with parties from the 122d and 

123d SRI Companies on German Air Force 

low-security radio and VHF radiotelephone 

communications. Detachment “G,” the third, was 

organized in July 1943 to process encrypted weather 

reports intercepted by a segment of the 122d SRI 

Company, and to pass them to intelligence units of 

the American tactical (Twelfth) and strategic (Fifteenth) Air Forces from a station near Foggia, Italy. 

Detachments “D” and “E” (VI Corps) both participated in the campaigns at Anzio and in southern 

France. Detachment “F” was involved, with the 

123d SRI Company, in the formation of the 9th 

Radio Squadron, Mobile, USAAF.3

Comparable to German low-level ground force 

communications intelligence was that from German Air Force units. Aircraft-to-aircraft in flight, 

ground nets supplying navigational aids to aircraft 

in flight, messages passed point-to-point dealing 

with aircraft movements, reports by pilots of ship 

sightings, traffic on the enemy’s safety service (rescue) nets, and miscellaneous items, when 

correlated, became the means of recognizing takeoffs, air bases, and aircraft in flight on long-range 

bombing missions. Analysts developed competence 

gradually, aided by the instructions furnished by 

experienced analysts of 329 Wing, Royal Air Force, 

stationed near Algiers. Beginning in March 1943 

they got their intercepted material from the 123d 

Signal RI Company. At Headquarters, 849th SIS, 

all but one section of the Intelligence Branch 

worked on low-grade German air traffic.

The practice of German air-reconnaissance pilots of radioing detailed reports when they observed 

Allied shipping or land convoys enabled Allied 

monitors to take bearings on the transmissions. 

Several reconnaissance planes were intercepted 

and shot down before the practice of reporting directly from aircraft was stopped. Later, at Anzio, 

the interception of such reports made it possible to 

warn ships, ground installations, and even artillery 

spotter planes to expect German air attacks. Occasionally, German ground controllers were heard 

vectoring fighters for attacks on Allied aircraft in 

flight, thus allowing a flash warning to be passed to 

the intended victims.

German communications were mostly plain 

language intermixed with jargon codes. An experienced monitor could tell whether the transmission 

was coming from a ground station (characterized 

by a lack of motor noise), a fighter aircraft (which 

employed standardized procedures and frequencies and was characterized by a larger number of 

voices during combat and by stereotyped orders 

concerning altitude and course), a reconnaissance 

aircraft (which made references to weather), or a 

training flight (which contained instructor’s maneuver commands).

During flight, either aircraft were heard reporting their own positions, or they made it possible to 

locate them by taking DF bearings on their transmissions. Allied intercept operators were often able 

to report the number, type, position, altitude, 

course, and mission of an enemy formation and the 

fact that it had reported seeing Allied aircraft. Voice 
Page 62

traffic among the German pilots could be heard 

well before Allied radar scopes disclosed their position. The extent to which SIGINT successes were 

masked from the beneficiaries by attribution to 

radar or other sources of intelligence was to leave 

largely unappreciated the actual role of SIGINT 

teams.

In June 1944 two detachments with Army commands were reorganized and redesignated. 

Detachment “A,” with Headquarters, Fifth Army, 

became the 3200th SIS Detachment (Type A), 

working with intercept operators from the 128th 

SRI Company. Its authorized strength under the 

new T/O rose from three officers and eighteen enlisted men to five officers and thirty-eight enlisted 

men. Detachment “E,” with VI Corps, became the 

3201st SIS Detachment (Type B), with a strength of 

three officers and eighteen enlisted men. In its new 

status it accompanied VI Corps into the Seventh 

Army under General Alexander Patch as that command made ready for Operation DRAGOON. A 

third unit, Detachment “B” (five officers and 

twenty-six enlisted men) and the 117th SRI Company in 1944 became the Seventh Army’s 

Headquarters “Y” section but underwent no unit 

redesignation.

In May 1943 a new phase in the field training of 

American “Y” units began. The intelligence personnel at headquarters were distributed elsewhere. 

The original Solution Section and part of the Traffic Analysis Section were assigned to a new 

Detachment “F,” 849th SIS. The men moved from 

Hammam Melouane to Boufarik, Algeria, in order 

to train with RAF “Y” service experts. The other 

part of the Traffic Analysis Section moved to Constantine in eastern Algeria to work with a party 

from the 122d SRI Company, which was engaged 

for a short period in attempting to intercept highgrade traffic for transmission to Arlington Hall in 

Washington for processing. They also collected 

German and Italian encrypted weather reports.

At the end of the month, as plans for developing 

SIGINT capabilities that were commensurate with 

American Army and Army Air Force undertakings 

in the Mediterranean seemed to promise success, 

they received a severe jolt. As far back as 10 February 1943, the War Department had been asked to 

authorize and man a pool of SIGINT personnel in 

the Mediterranean, a group able to process German 

and Italian military communications by radiotelegraph and radiotelephone. It was planned that 

analysts would reach the Mediterranean after a period of suitable training in the UK The 849th SIS 

would manage their use. When they arrived, however, the specified requirements had been 

disregarded. The Signal Security Agency had had 

no opportunity to screen the officers and men selected. Proficiency in German or Italian languages 

had not been assured.

The Signal Security Agency had not been able 

earlier in 1943 to meet a requisition from the chief 

SIGINT officer, AFHQ. He had been given officers 

trained in Japanese, French, and Spanish, and meteorological SIGINT, whom he was ready to have 

returned to the United States for assignments 

where they could be better used, and to keep only 

two officers who knew German.

Detachment “H” was the last to be created. 

Most of its members had come to Northwest Africa 

in September 1943 after passing a short course in 

the analysis of low-grade German Army systems. 

They then began a few months of training in Sicily 

before moving to Italy (near Caserta) in December, 

with a detachment of the 128th SRI Company and, 

temporarily, Detachment “A,” 849th SIS. From 

January 1944 to the end of the war, Detachment 

“H” was the SIGINT unit with Headquarters, II 

Corps, being redesignated in February 1945 as the 

3915th Signal Service Company (RI).

These items pertaining to the union of detachments of the 849th SIS and detachments of the SRI 

companies demonstrate that in the Mediterranean 

area production of tactical SIGINT was accomplished by improvising suitable units. To look 

ahead, the operations in which those teams of intercept and intelligence specialists were to 
Page 63

participate demanded flexibility in organization. 

The campaigns included five major amphibious assaults. They extended from southern Tunisia to 

northern Italy and southern France. Air operations 

from the bases in Italy ranged far into southeastern 

Europe. The SIGINT team went through intermediate and advanced training under combat 

conditions and then into full production. The administrative processes of the U.S. Army called for 

standardized organization determined by adequate 

operational tests. In 1944 and 1945, certain new 

designations for modified tables of organization 

were applied in the theater.

An important consequence of the establishment in 1944 of Corps Signal Service Companies 

(RI) was the termination of the dual chain of command over SIGINT teams when two types of 

detachment interceptors and analysts were united. 

Under NATOUSA policy, SRI intercept operators 

had been denied access to technical SIGINT information, including the information governing 

selection of their intercept assignments. They received daily assignments to cover specified callsigns 

and frequencies; the SIS personnel had supervised 

intercept activities to insure correct coverage. After 

the merger, the barrier between the two types was 

abandoned. That was a major change for the 3915th 

Signal Service Company with II Corps, and in the 

3916th with the IV Corps (under General Willis D. 

Crittenberger) in northern Italy. IV Corps had been 

served by the British 100 Special Wireless Section 

and a detachment from the 128th SRI Company 

until the new 3916th was formed; the British stayed 

on until April 1945, while the American analysts 

became expert. Since the central effort to change 

organization was that of ETOUSA, the subject will 

be taken up in more detail in that portion of this 

history.

During the westward movement of British 

Eighth Army across Libya into Tunisia after the 

Battle of El Alamein, the lengthening distance from 

the advancing SIGINT units with the Army Headquarters, the three Army Corps, and the Western 

Desert Air Force, to the base SIGINT center back 

in Egypt affected production adversely. On 20 February 1943 the shift of Eighth Army’s subordination 

from GHQ, Middle East, to the new Headquarters, 

18 Army Group, Allied Force, required adjustments 

in the SIGINT structure. When Eighth Army was 

selected to make the main effort in Sicily with a 

five-division assault, that also prompted adjustments. Once it was decided in July 1943 that, after 

Sicily, the Allied force would invade southern Italy, 

the prospect for Allied operations in the Balkans or 

eastern Mediterranean areas diminished greatly. 

Some British SIGINT resources in the Middle East 

had already been used in Tunisia and Sicily; in 

order to be well employed, others had to be brought 

west.

To cope with SIGINT production from Italian 

traffic, British Army and RAF sections that had 

worked in the Western Desert on Italian Army 

communications were flown into Tunisia. There 

they supplemented what a cooperating French “Y” 

organization was able to provide.

With General Alexander at Headquarters, 18 

Army Group, at Ain Beida were British 40 WIS and 

107 Special Wireless Section, operating in vans.

The 122d SRI Company moved to Constantine 

on 28 March 1943, relinquishing its quarters at Boufarik to the 117th SRI Company, which shifted 

eastward from Oran. In May the 122d moved via 

Bone, to La Marsa, near Tunis; the 117th shifted 

from Boufarik to Bedja; and the 123d SRI Company, with Detachment “F,” 849th SIS, then moved 

to Boufarik.

Within a week after the Axis surrender in Tunisia, a small British intercept unit began operating 

at Fort du Kebir, three miles from Bizerte. Soon elements of two U.S. intercept companies occupied 

adjacent sites. At Bone the Royal Navy and at La 

Marsa the RAF developed stations for producing 

field SIGINT. SIGINT communications from Bizerte to Algiers, for relay to London and Washington, 

enabled the Americans to pass intercepted enemy 
Page 64

traffic in high-grade and medium-grade systems 

for processing at national centers.

It was not long before U.S. participation in producing special intelligence from German 

communications was covered by an Anglo-American agreement, causing American intercept 

resources in Tunisia or Algeria to be turned to 

other targets.

SIGINT before Operation HUSKY

For a while after the Axis surrender in Tunisia, 

a dearth of enemy high-level radio communications seemed to confirm an apprehension that on 

the continent such traffic would be carried by wire. 

Production of special intelligence like that accomplished while the German Army and Air Force 

commanders in Africa kept in radio touch with 

their superiors in Europe seemed likely to have 

come to an end. Happily for the Allies those forebodings were shown to be false during preparations 

for, and the actual defense of, Sicily. Both the German Air Force and the German Army on the 

mainland resumed the kind of radio traffic from 

which special intelligence of great value to the Allies could be extracted.

Special intelligence on the buildup of Axis 

forces in Sicily was carefully sought and studied. 

The transfer to Sicily of German troops from the 

mainland was observed in some detail. The divisions, tanks, guns, and vehicles became known, 

and their disposition was inferred. The calculation 

set the total at about 45,000 German ground 

troops and over 100 German tanks, most numerous in eastern Sicily. Attempts by the Allies to 

mislead the enemy so that he prepared for an attack elsewhere were only partly successful. In the 

event, the main cause of tactical surprise at the 

time of the landings was to be like that experienced 

later in Normandy: the onset of stormy weather 

while the convoys were en route.

The concentration of Allied vessels in the ports 

from Oran to Tripoli did not go unnoticed or 

unopposed by the enemy. One of the objectives of 

Allied “Y” service was to anticipate German air attacks on the coastal convoys and the ships moored 

in ports behind barriers of mines, under concealing 

smoke, and within a screen of antiaircraft artillery. 

When a German aircraft shadowed an Allied coastal 

convoy (if so ordered by its controller), it emitted 

homing signals which guided attacking planes to 

the target for action after dark. Interception of 

enemy reports and homing signals might, however, 

lead to a disrupting Allied air operation before the 

vessels could be struck. Enemy submarines also 

preyed on convoys between Algiers and Bizerte and 

had to be watched. The Lac de Bizerte was a highpriority target for German bombers, especially 

during the first week of July 1943 – a target protected by antiaircraft guns and Allied fighters, with 

the assistance of radar and SIGINT to furnish specific warnings.

In June a German reconnaissance plane reported seeing a certain number of vessels at Bizerte. 

Both British and American intercept operators copied the report, but the British and American 

decrypts differed. The former translated the message as reporting forty-six ships, twelve under 

steam, while the latter construed it to be fifty-eight 

under steam.

The Mediterranean Air Command and the 

Northwest African Air Forces in May 1943 set up a 

command post at La Marsa to control all air operations against Sicily and mainland Italy relevant to 

Operation HUSKY. The Chief Intelligence Officer, 

(Group Captain R. H. Humphreys), Mediterranean 

Air Command (MAC), organized his division into 

sections making use of special intelligence or “Y,” 

and sited them adjacent to a Special Liaison Unit. 

The SLU worked twenty-four hours per day and 

gave direct service from the Air Ministry, Bletchley 

Park, and Headquarters, Mediterranean Air Command, in Algiers. One American officer worked 

with four British officers in the section handling SI 

on the German Air Force.4 In a separate area for 

combat intelligence, three American officers dealt 

with “Y” and collateral non-SIGINT material. In a 
Page 65

nearby trailer, one American and one RAF officer 

handled target intelligence.

The Combat Intelligence Section was in close 

touch with Headquarters, Northwest African Air 

Forces (NWAAF), at Constantine, which relayed 

data from its elements to La Marsa. At La Marsa 

Airfield, the photographic interpretation unit provided information gained from reconnaissance 

missions which were recommended, in the light of 

intelligence and operational requirements, as necessary. “Y” information came to the section directly 

from the “Y” unit at La Marsa.

The Target Intelligence Section of the Command Post was in touch with its counterpart at 

Headquarters, Northwest African Air Forces 

(NWAAF), and with the Photographic Recon-naissance Unit at LaMarsa. Its dossiers were assembled 

to meet the requirements of either strategic or tactical bombing missions, as indicated by general 

policy, by SI, or by other sources. When SI indicated that intended targets had already been 

sufficiently bombed, changes were made the next 

day. The guidance provided through these arrangements, and the execution of the missions which 

they supported, damaged severely the German Air 

Force in Sicily and Italy.

“Force 141,” the planners for Operation HUSKY, 

provided for “Y” service to ground and air commands from command ships during the landings 

and from units ashore during subsequent inland 

penetration.

To provide field SIGINT to American ground 

troops of the U.S. Seventh Army in Sicily, the 

American SIGINT units that had been training in 

Tunisia set up three detachments of intercept operators, each with a section of analysts. As Signal 

Intelligence Officer, Major Herrick F. Bearce, who 

had been in Tunisia attached to the “Y” unit supporting II Corps, was attached for Operation 

HUSKY to the Signal Section, Seventh Army. The 

three groups of analysts were to be Detachment 

“A,” 849th SIS (with Headquarters, Seventh Army), 

52 Wireless Intelligence Section and Detachment 

“B,” 849th SIS (with II Corps), and Detachment 

“E,” 849th SIS (with 3rd Infantry Division, Reinforced). About 10 officers and 310 enlisted intercept 

operators and analysts were involved in those preparations.

Small advance parties, equipped with transmitter-receivers, a special cipher system, and one 

3/4-ton truck for each party, were prepared for 

landings with the three segments of the American 

assault force. The remainder would continue working in the Bizerte area until the beachhead extended 

about ten miles inland and would then move to Sicily. There they were to take up their tasks at sites to 

which the advance parties would guide them.

Those plans were never executed, although by 

20 June all were ready. A little later the advance 

parties embarked. The main body never heard 

from them again until near the end of the invasion. 

Not until 9 August did the main body arrive in Palermo; the next day two detachments joined 

Headquarters, Seventh Army, near San Stefano; 

the third went to Headquarters, II Corps.

First Lieutenant Herrick F. Bearce, 1941

(Photograph courtesy of 

the Department of Army)
Page 66

“Y” service for Allied air controllers during the 

landings was to be supplied by one unit with each 

invading army. They would have to await the establishment of Sector Operations Rooms before their 

information could be applied, so they were assigned to the D+ 5 follow-up convoy from Tunis. 

Two RAF SIGINT units were designated to join 

RAF 211 Group and the XII Air Support Command, 

respectively. The RAF 380 Wireless Unit was ordered to form and equip one self-contained, mobile 

radiotelephone team large enough to cover two HF 

and four VHF channels and to operate two DF vehicles (HF and VHF). They were to work at 

Headquarters, XII Air Support Command. Enemy 

use of radiotelephone communications in Sicily, 

however, yielded little material for Allied “Y” production compared to later developments in Italy.

For British ground forces, General Harold Alexander’s Headquarters, 15 Army Group, acquired a 

British “Y” unit at Bizerte before the invasion, and 

General Montgomery’s Eighth Army Headquarters 

had a similar one. The two Corps used in the 

assault, 13th and 30th, each also had field “Y” units 

of standard organization. The intermediate field 

SIGINT processing center, known as the 7th Intelligence School, which provided analytic support 

during the invasion of Sicily, discovered that interception from Tunisia was unsatisfactory. It met 

that situation by working on traffic collected by forward elements and sent back by airbag until an 

analytic unit could be shifted from Tunisia to Sicily.5

“J” Service 

When the British Eighth Army came into Tunisia and some of its innovations became known at 

AFHQ, they were thought to be worth adopting. 

One example was a “J” Service, a monitoring of the 

communications of Eighth Army nets for two purposes. The “J” units could report accurate 

information swiftly to the intelligence and operations staff divisions at Army and Corps levels. They 

could also detect breaches of communication security and report them through Corps to the offending 

divisions for correction and discipline.

The Combined Signal Board, North Africa, on 

26 March 1943, favored such an activity for the 

Fifth Army, then training in eastern Morocco. Brigadier General Lowell Rooks, G-3, AFHQ, directed 

the chief signal officer to form an “American Staff 

Information Intercept Organ-ization” from Fifth 

Army personnel, which would commence training 

by 19 April 1943.6 AFHQ also ordered two British 

officers on 29 May 1943 to provide “J” Service to 

U.S. Seventh Army during Operation HUSKY. They 

were attached to Head-quarters, I Armored Corps, 

Reinforced, and placed under control of the Corps 

G-2. The RI platoons of divisional signal companies 

did the monitoring, under control of Division G-2. 

They caught many examples of insecurity.7

The mobile forward “Phantom Teams” of observers provided information of great value, despite 

occasional inaccuracies, on the locations, situations, and intentions of the individual units in 

combat. Corps headquarters rarely reported the 

exact locations of individual units, so the “Phantom” reports to higher headquarters filled a gap in 

information. Moreover, their reports arrived in a 

more timely way. Because the reports described a 

unit’s situation without the benefit of a bigger picture, they tended to be less “balanced” than they 

might otherwise have been. Their reports of Allied 

intentions were obtained usually at a level too low 

to be reliable. But whatever the shortcomings, Allied commanders found invaluable the information 

about units of the different corps on their flanks, 

information which thus became available to them 

via Army headquarters. Allied commanders seemed 

to be reticent about passing information directly to 

flank and higher echelons.

Invading Sicily

Defense of Sicily came under command of General Alfredo Guzzoni on 30 May 1943, a few weeks 

before the attack. As commanding general, Italian 

Sixth Army, he controlled four Italian and two 
Page 67

German mobile divisions, the second of which, the 

Herman Goering Panzer Division, crossed to Sicily 

in June. General Guzzoni had also under his command six coastal defense divisions and lesser 

formations of Italian reservists. A German general 

with a small staff and a communications unit was 

liaison officer from O.B. Sued. The Sicilian populace was weary of the war and expected the Allies to 

win it. The island was short of food and transportation.

General Guzzoni’s headquarters were at Enna, 

a central hill town southwest of Mt. Etna. The Italian XII Corps was responsible for the western, and 

the XVI Corps for the eastern, part of the island. At 

German insistence he split the armored elements 

into two major parts which were close enough to 

oppose Allied attacks wherever they began.

Although coastal defenses were spread rather 

thinly, three maritime areas were much more 

strongly prepared than others to deny access to 

ports. Under the command of the Italian Navy, 

clusters of coast artillery, antiaircraft guns, mobile 

batteries, motor torpedo boats, mine fields and 

special troops protected areas adjacent to Trapani 

on the west coast, Syracuse-Augusta on the southeast coast and Messina-Reggio on the Straits of 

Messina at the northeast corner. Having thus 

obliged the Allies to land over beaches, the defenders intended to delay by coastal defense forces and 

air bombardment the establishment of deep Allied 

beachheads. During the delay, mobile and armored 

columns would move to deliver overpowering 

counterattacks and to force withdrawal. If the Allies instead retained their beachheads, seized and 

captured a good port, they could be expected to 

grow stronger and become too powerful to be dislodged. The Axis forces would then face the choice 

of defeat by capture or defeat by withdrawal.8

The Allied Force established an advance command post on Malta, where General Eisenhower 

and his principal ground and sea commanders and 

their staffs kept their fingers on the push buttons. 

The headquarters of Air Vice Marshal Arthur Tedder, his air commander, remained in Tunis.

Two enormous naval task forces of warships, 

transports, landing craft, minesweepers, and other 

vessels conveyed the assault forces from African 

ports through seas that became stormy and rough 

but then abated during the transit. The Eastern 

Naval Task Force, under Vice Admiral Sir Bertram 

Ramsay, RN, carried the British Eighth Army of 

five divisions; about 250,000 men were aboard 

nearly 800 ships with 715 landing craft. The Western Naval Task Force, commanded by Vice Admiral 

Henry Kent Hewitt, USN, carried General Patton’s 

Seventh Army; about 228,000 men were aboard 

550 ships and 1,100 landing craft. Both armies included airborne troops to be dropped inland at key 

points to impede counterattacks and protect 

bridges from demolition.

Under General Alexander’s Headquarters, 15 

Army Group, the Allies entrusted the main effort to 

General Montgomery’s experienced Army. Its initial goal was to capture an air base near Cape 

Pachino and the ports of Syracuse and Augusta, 

which were well prepared to oppose attacks by sea 

and air but less strongly organized against ground 

attack.

The key to Syracuse was a bridge 

(Ponte Grande) on the main coastal highway which 

extended over a canal and the wide, deep Anapo 

River, just south of the city near the head of the 

harbor. About 200 British airborne troops were 

dropped on a peninsula southeast of Syracuse. 

Eight officers and sixty-five enlisted men got to the 

bridge, removed the demolition charges, set up defenses against Italian counterattack, and held out 

for hours against infantry, artillery and tanks until 

relieved by advance elements of the British 5 Infantry Division. Only nineteen men survived. Their 

sacrifice enabled the Eighth Army to enter Syracuse before midnight of 10 July and to turn back 

German counterattacks later. By 14 July British 

troops and ordnance were being unloaded from 

transports in Syracuse harbor. The Eighth Army 
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pushed north to the Catania plain, but there it was 

held to a slow advance at great cost.

The U.S. Seventh Army (Patton) had divided its 

assault forces into three elements which were 

headed for more than forty miles of coast – near Licata, on the west, Gela, in the center, and Scoglitti, 

on the east. Twenty miles farther east, the British 

beach landings took place. General Patton’s first 

mission was to protect the western flank of the 

Eighth Army in a beachhead that extended far 

enough inland to encompass enemy airstrips and 

all positions from which the ships and beaches 

could be shelled. Reinforcements and resupply 

would have to come ashore over the beaches; no 

ports of consequence would be available. Like the 

Eighth Army’s assault landings, those of the Seventh Army would benefit from naval gunfire. In 

fact, they were to find it invaluable.

Allied planes had previously bombed all but 

two or three of Sicily’s airfields and seaplane , bases 

out of service, and had forced aircraft to take refuge 

from them at airfields on Sardinia and near Foggia. 

Those airfields also had been hard hit. The enemy 

was understood to have in Italy 600 bombers and 

850 fighters. Northwest African Air Forces had 

about 3,680 aircraft. At first, the Allied fighters 

were used mostly to escort bombers that were 

striking enemy targets rather than to maintain 

combat air patrols over the armadas or to intervene 

quickly as enemy bombers approached. Requests 

by the commander of the Western Naval Task 

Force for air support had to be relayed through Admiral Cun-ningham on Malta to Headquarters, 

Mediterranean Air Command, in Tunis, whence orders went to aircraft that might be available.

HMS Largs was the command ship for the 

Eighth Army and its supporting air. The air “Y” unit 

aboard the ship had arranged with No. 10 Field 

Unit (RAF) on Malta to perform an essential service. At Malta all radio information and radar plots 

pertaining to the invasion were to be filtered from 

the normal welter of traffic and broadcast to Largs 

at half-hour intervals. The transmissions were 

given the codename CLATTER; they were helpful. 

The eleven positions on Largs could not, like the 

many receivers at Malta, monitor the numerous 

frequencies on which important information was 

passed; the Malta arrangement was turned to the 

advantage of all three services as material came in.

The Largs unit had borrowed from 10 Field 

Unit a noncommissioned officer who was adept in 

German Air Force traffic in order to avoid having to 

rely on a specialist in the very different German EBoat traffic who had been officially assigned. From 

13 to 15 July, the “Y” unit on Largs passed data to 

the RAF Senior Controller on HMS Bulolo and relayed some information to the XII Air Support 

Command (ASC) near Licata.

Near beaches where certain American units had 

landed, an American minesweeper engaged in intercept on an involuntary one-time basis. A carrier 

pigeon landed on the ship, and an alert sailor obtained the message, which was in Italian. In it, a 

division commander was reporting to his superior 

that the Allied forces were “overwhelming,” and 

that they were unloading material, undisturbed, 

from hundreds of anchored ships. Upon receiving 

this bit of “intercept,” Admiral Kirk determined 

that it was not too highly classified to share. He had 

it broadcast over the ship’s loudspeaker system to 

all hands.9

The arrival of paratroopers of the 82d Airborne 

Division during the night of 9/10 July 1943 alerted 

General Guzzoni that the attack had begun. He 

telephoned warnings to subordinate commanders. 

The commanding general of the Herman Goering 

Panzer Division (General Conrath) lost his wire 

communications with XV I Corps (General Rossi) 

and the Sixth Italian Army before his reconnaissance patrols could report encountering Allied 

paratroopers. A radio message from Kesselring’s 

Headquarters at Frascati informed him that a 

major attack was in progress.

The American forces were unable to maintain 

their schedule for inland advance. The troops 
Page 69

ashore dispersed coastal defenders and seized numerous key points, but the beaches became a 

confused mess of broached landing craft and disorganized material. Antitank guns and tanks to 

combat counterattacking armored columns were 

too few. Only the most determined resistance by infantry units, with the aid of naval gunfire, turned 

back the enemy – in one case when the enemy was 

close to the beach. At one stage on 11 July the German defenders believed that their SIGINT had 

intercepted an Allied order for the U.S. 1st Infantry 

Division to return to the ships. The enemy came 

perilously close to sweeping along the Gela beaches 

and giving that division no choice in the matter.

Enemy air struck mainly at the landing operations off Gela on 11 July but also struck farther east. 

That night was very calm and clear, ideal for a second Allied airborne operation. It was equally suited 

to a heavy bombing attack by the Luftwaffe against 

the tired and jittery troops on land and the flotillas 

offshore. Unfortunately for the Allied airborne operation, its route of approach took its planes and 

gliders over Allied ships and antiaircraft batteries 

where they were not expected, where they were not 

identified, and where they drew fire of the kind appropriate for the enemy bombers which had just 

preceded them.

On D+ 2, however, when Kesselring flew from 

Frascati to consult General Guzzoni at Enna, the 

Allies were ashore to stay. Syracuse and Augusta 

had either fallen or been encircled. Airfields had 

become available to Allied aircraft. The U.S. Seventh Army faced a mountainous area through 

which General Guzzoni was shifting forces eastward, trying to stop Patton’s advance and to 

reinforce the opposition to the Eighth Army. Kesselring concluded that delaying tactics alone 

remained feasible and so reported by radio to Hitler. The next day Hitler ordered such a defense, and 

on 14 July approved Kesselring’s decision to send 

more German reinforcements. A German XIV 

Corps headquarters under the capable General 

Hans Hube, plus two more German divisions (1 

Parachute Division and 29 Panzer Grenadier Division), and certain corps units were soon en route.

That night, Allied bombers destroyed Guzzoni’s 

headquarters at Enna. He moved it to Randazzo, on 

the northern side of Mt. Etna, where General Hube 

also set up Headquarters, XIV Corps. All available 

mobile troops in western Sicily were called eastward to thwart the Allied plans.

Orders from General Alexander for the next 

phase of the Sicilian operations came to the commander of the Seventh Army on 13 or 14 July. 

While one corps of Eighth Army drove north along 

the east coast to take Catania and another corps 

moved via Enna and along the western slopes of 

Mt. Etna to the northern coast, Seventh Army was 

merely to engage those enemy forces that might 

otherwise oppose Eighth Army, but it was not to get 

tied down in a battle in southwestern Sicily.

Allies Push – Enemy Pulls Out

General Patton sent a “reconnaissance in force” 

that, aided by air bombing and naval gunfire, took 

Porto Empedocle on 16 July and Agrigento on the 

next day. He then persuaded General Alexander to 

approve offensive plans for the capture of Palermo. 

At the same time, the German high command 

(OKW) directed that the defense of Sicily be conducted in such a way that the three German 

divisions [Herman Goering Panzer (which absorbed 1 Parachute Division), 29 Panzer Grenadier, 

and 15 Panzer Grenadier)] could be removed from 

Sicily. General Guzzoni concurred in General 

Hube’s program to accomplish that and planned to 

withdraw his Italian formations at the same time. 

Fitting nicely into that scheme was the change in 

Eighth Army’s plan of attack.

After finding progress across the Catania plain 

slow and costly, General Montgomery persuaded 

General Alexander to approve a shift of Eighth Army’s main effort to the west of Mt. Etna, what he 

called a “left hook around the enemy’s defense 

line.” It took his main effort away from tank terrain 
Page 70

into mountains, and far from the seaboard where 

he could, had he wished, have been assisted by 

naval gunfire; the new route would be beyond its 

range. The time required to get set for the new plan 

provided an opportunity for the opposing 29th 

Panzer Grenadier Division, as well as the paratroops, to be well deployed, and for the plans and 

means of German evacuation to be prepared.

Before Eighth Army’s revised attack started, 

Seventh Army had entered Enna on 20 July and 

Palermo on 22 July; soon afterward it swept up all 

organized opposition in western Sicily, Trapani included. Though the port of Palermo was a handy 

target for enemy bombers and was cluttered with 

the results of German demolitions, it soon relieved 

the Seventh Army of dependence on southern 

beaches and miles of trucking for reinforcements 

or supplies.

Seventh Army was next brought into the revised Allied attack as a “prime spearhead” along the 

western and northern slopes of Mt. Etna. Beside 

the Canadians in the Eighth Army (moving via 

Leon-forte and Adrano) was to be the U.S. 1st Infantry Division (heading for Petralia and Troina). 

Along the northern coastal road were to be the U.S. 

45th and 3d Infantry Divisions. To expedite the advance toward Messina by Seventh Army, U.S. 

Naval Task Force 88, under Rear Admiral L. A. Davidson, on 31 July 1943 began operations out of 

Palermo. While defending Palermo, it also furnished naval gunfire on request to troops fighting 

along the coast, provided transport and fire support for naval end runs around enemy defense 

positions, and ferried troops in order to relieve the 

burden on the coastal road. (Two cruisers and five 

destroyers were the escort and fire-support ships at 

the outset.) On 1 August the U.S. 9th Infantry Division arrived off Palermo in transports from Oran, 

and, after waiting out a heavy German dawn bombing attack on the city and harbor, landed and 

headed for the Troina area.

On 3 August the evacuation of Italian troops 

across the Strait of Messina began; on 10 August, 

the parallel German program (Operation Lehrgang) started. Special intelligence released on 6 

August disclosed major aspects of the German program and the orders to practice ferrying. On 8 

August more SI gave Kesselring’s report of two 

days earlier that the Germans would withdraw 

across the strait by stages which had already begun 

and would continue through 12 August. General 

Hube had set successive main lines of resistance 

and had fixed the times to pull back from one to the 

next.

Seventh Army tried three end runs to cut off use 

of the northern coastal road for retreat by the 29th 

Panzer Grenadier Division. The first, on the night 

of 7/8 August around San Fratello, where the U.S. 

3d Infantry Division had been stopped for five 

days, was fairly successful. The enemy was not cut 

off. He pulled back eastward, probably as much because of the loss of Troina, at the inland end of that 

line of resistance, as because of an unhinging at San 

Fratello. The second, on 10/11 August, to Brolo, 

was less satisfactory. The enemy learned from his 

own SIGINT that it was in progress, and sent 

bombers against the Allied ships. The troops that 

had gone ashore unopposed were later attacked 

from both east and west, and were also bombed by 

friendly aircraft. The troops inland with which they 

were to link up were not close enough. The Brolo 

operation was unable to check the eastward withdrawal by the enemy during the night of 11/12 

August; indeed it may have speeded up the retreat. 

The third end run, on a larger scale and including paratroops was intended to overtake the enemy. 

He was then probably already in Italy across the 

Strait of Messina.

The occupation of Sicily was already complete 

when the principal U.S. Army officer in charge of 

communications security received examples of violations during the operation, examples taken from 

intercepted German reports that were graded as SI. 

Those American messages disclosed military information of significance. They revealed the 

participating commands, certain intended 
Page 71

operations, places, times, and other details to the 

enemy. The route by which they had come to the 

knowledge of the officer commanding the Signal 

Security Agency precluded uninhibited use. It was 

a case of security impeding security.10

In the hotel in Taormina which had housed part 

of the German Air Force command in Sicily, records of its Horchdienst (Listening Service) 

covering a few days preceding the Allied assault 

landings, were found by Allied intelligence. A daily 

air situation report for the twenty-four hours before 0700 showed the efficiency and limitation of 

the German SIGINT service.11

Some Results

After the severe defeat in Tunisia, the Axis coalition began to collapse. The Italian Army had lost 

so large a portion of its best troops there that Hitler 

proffered five German divisions for the defense of 

Italian soil. Two of them were already in Italy en 

route to Tunisia. Instead of three more, Mussolini 

agreed in mid-May 1943 that one more would be 

acceptable, but he required that all three in Italy be 

under Italian tactical control. He did not then think 

it prudent to have too many German troops in Fascist Italy.

By the time he had changed his mind and was 

ready to accept more, Hitler had recognized that 

the Italians might eject Mussolini from power and 

seek a separate peace, so the matter remained uncertain even when Mussolini was indeed 

overthrown.

The Allies occupied Sicily as a step toward accomplishing Mussolini’s downfall and “knock Italy 

out of the war.” What ensued after Il Duce’s incarceration was foreseeable. The Badoglio government 

first sought to reach an armistice or peace between 

the Axis partners and the Allies. Hitler would have 

none of that. Under various plausible pretexts, German divisions moved into northern Italy without 

either the consent or the resistance of the Italians, 

and while preserving the amenities with their 

Italian brothers-in-arms, all but invested Rome in 

the guise of protecting it from Allied invasion. The 

Badoglio government, recognizing that Italy’s interests demanded peace, then entered into 

clandestine negotiations with the Allies. The Allies, 

on 20 July 1943, had finally decided to move into 

the Italian peninsula from Sicily and Africa, employing the British Eighth Army, the new U.S. Fifth 

Army, and naval and air components that had just 

participated in the Sicilian landings. Whether the 

Allies would receive active assistance from the Italian Army or passive resistance, or might even have 

to rescue them from German reprisals, remained in 

doubt. After Mussolini’s fall, more than six weeks 

passed before Allied troops first entered the Italian 

peninsula. 

While the occupation of Sicily was progressing 

successfully and other operations against the Italian mainland were in prospect, it was apparent that 

some British “Y” units in the Mediterranean should 

be shifted to sites where they could be used more 

efficiently. By the time the invasion of southern 

Italy began, the strategic situation of the Middle 

East was more thoroughly altered. The Western 

Desert and Northwest Africa, as separate fronts, 

had merged. Northwest Africa was the base from 

which the campaign in Italy would be sustained. 

Intercept stations in Tunisia had to shift to Sicily or 

the Italian peninsula to be effective against weak 

and fading signals. “Y” resources in the Middle East 

needed pruning. If unified control of air and sea 

operations in the Mediterranean could be established, control of “Y” activities would seem to 

require parallel treatment. For the RAF “Y” organization, that would involve termination of one Wing, 

transfer of its personnel to other “Y” units or to 

other duties, and only a temporary prolongation of 

British involvement in “Y” service to the U.S. 

Twelfth Air Force.

Thus, while the Americans were nearly ready to 

meet the “Y” requirements of their ground and air 

forces in the Mediterranean area, the British were 

obliged to consolidate their Mediterranean “Y” resources, and to squeeze out unneeded, experienced 
Page 72

personnel for employment in western Europe or in 

the Pacific.

Major Millard E. Rada, the commanding officer 

of the 849th SIS, went in July 1943 to GHQ Middle 

East for more information about British “Y” operations. He learned there what was done with German 

Army and German Air Force double Playfair encipherment and with Italian traffic in various systems 

and noted that AFHQ was better equipped for voice 

monitoring than was the British theater.12

Notes

1. An incomplete set of minutes is to be found on Microfilm Reel 37-C of the Mediterranean Air Command 

records with others of AFHQ, at NARC, Suitland, Md. 

Also in AHA records.

2. Memo from Chief SIGINT Officer, Mediterranean 

Air Command, to O.C. No. 276 Wing, O.C. No. 329 

Wing, 15 Dec 1943, Subj: Liaison with French “Y” Service; Memo from MAC to DDI 4, Air Ministry, 5 Oct 

1943, same subj.; msg from Chairman, London SIGINT 

Board, to Chairman, YNA Committee, 1 Dec 1943.

3. Hq, 849th Signal Intelligence Service [NATOUSA/

MTOUSA], Operational History, (in NSA Hist. Coll) submitted to CSigo, War Dept (Attn: SPSIS) , 27 July 1945. 

Preface signed by Lt. Col. M.E. Rada, SC, Co., 849th SIS. 

4. Humphreys, “The Use of ULTRA in the Mediterranean and Northwest African Theatres of War.” (Oct 

1945). Copy in NSA Hist Coll.

5. See “Report on Visit to North Africa/Sicily, July 

28th-August 23rd” 4 Sept 1943, by Major J.M. Browning, for the disposition of British field “Y” units. AFHQ 

Film A/52/2. (Most Secret).

6. Minutes from A.C. of S., G-3, to SIG, 27 Mar 1943, 

Subj: Staff Information Radio Intercept Organization. 

AFHQ Microfilm Reel 58-I.

7. Report of Signal Section, Seventh Army, “Historical Data and Lessons Learned in the Sicilian Campaign.” 

319.1 Box 34/11, AHS Recs.

8. Garland and Smyth, Sicily and the Surrender of 

Italy, passim.

9. John Mason Brown, To All Hands, 144, cited by 

Morison, IX 144 n. 26.

10. See Folder: G-2 Corr, May 42-Sept 43. 20.1 in 

AHS Recs, A51-30, Box 1/72.

11. Report CSDIC AFHQ A 191 (F.N. 644) 11 Sept 

1943, from AFHQ Microfilm.

12. Memo for Colonel Harold Hayes, Signal Section, 

AFHQ, from Major Millard E. Rada, SC, Commanding 

849th SIS Battalion, AFHQ, Subj: Notes on Liaison Trip 

to Cairo, July 1-11 1943,19 July 1943.
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Page 75

Preliminaries

The third major amphibious assault in the 

Mediterranean area, that at the Gulf of Salerno, 

was much smaller than that at Sicily. It did not go 

wholly “according to plan,” as the saying goes, and 

one might well ask, “What plan?” Not that it was 

unplanned, but, because the planning was subject 

to so many contingencies, it bristled with amendments of alterations of changes. Before the invasion 

of Sicily, the nearest that Allied leaders could come 

to an agreement on the next operation in the West 

was to charge General Eisenhower with drafting a 

plan for reaching certain conflicting goals. They 

would then review the plan and decide later what 

should be tried.

The operation that followed Sicily, they prescribed, must eliminate Italy as an adversary and 

tie down as many German divisions as possible, yet 

enable the Allies to make a cross-Channel attack in 

great strength beginning in May 1944. Part of that 

strength would have to be drawn from the Allied 

forces in the Mediterranean. Moreover, sealift and 

covering naval ships from the Mediterranean would 

be required for both a November 1943 amphibious 

assault in Burma, and a May 1944 invasion of 

France. The planners of AFHQ concluded, when 

Operation HUSKY (Sicily) was about to start, that 

its sequel would be governed by the rapidity with 

which the Allies succeeded in Sicily. General Eisenhower advised the Combined Chiefs of Staff (CCS) 

that he could certainly expect to cross the Strait of 

Messina and crawl through Calabria and that he 

might be able to enter Italy farther north at the Gulf 

of Salerno.

The Combined Chiefs of Staff believed he should 

plan to seize Naples, and when Mussolini fell from 

power on 25 July 1943, they approved an attack at 

Salerno with the resources already at the disposal 

of the Allied force. At Quebec in mid-August 1943 

they confirmed that project, with the knowledge 

that the government of Marshal Badoglio was making overtures to the Allies for an armistice. Such a 

document was ultimately signed at Cassibele, Sicily, on 3 September 1943.1 The decision at Quebec 

was followed by orders to British Eighth Army to 

cross the Strait of Messina and advance into Calabria as soon as possible in August.

In Africa and Sicily the Allied force accumulated men, ordnance, vehicles, and supplies for 

Operation AVALANCHE, which was scheduled to 

begin with beach landings on the Gulf of Salerno at 

0330 hours, 9 September 1943.

The enemy was aware of the preparations but 

not of Allied uncertainties concerning destination, 

participants, and detailed plans that persisted as 

long as the role of the Italians remained in doubt. 

The Germans had already prepared plans for the 

military seizure of Italy as they had done for the 

military occupation of “Unoccupied France,” almost one year earlier. While negotiations between 

the Badoglio government and the Allies were in 

progress, the German forces in Italy moved to positions enabling them to assume complete military 

control. The next question for the Allies was 

whether they could, in conjunction with Italians 

who would gain control of Rome, oblige the Germans either to pull back north of that city or be cut 

off in southern Italy. Until the last moment, such 

an operation was seriously contemplated. American airborne troops, they reasoned, could land on a 

Rome airfield that would be protected by Italian 

troops during their arrival, and be followed by seaborne reinforcements and support. All was kept in 

readiness to the last minute, but that airborne project was abandoned as was an airdrop previously 

Chapter 7

Salerno to Rome
Page 76

planned – one designed to prevent troops in the 

Naples area from moving south to reinforce the defenders at Salerno.

The enemy did his best to shatter Allied preparations for embarkation at Bizerte. On the nights of 

17 and 18 August, large bombing raids inflicted 

substantial damage there, and on the night of 6/7 

September an even larger attack occurred. As the 

convoys heading for Salerno moved along the 

northern coast of Sicily, they too fought off persistent air assaults.

The Eighth Army’s postponement of departure 

for several days gave the enemy forces in Italy more 

time to prepare for the landings. And the end of a 

period of radio silence tipped the enemy off, but 

Eighth Army troops encountered only token resistance when they came ashore on the peninsula on 

3 September. A few days later, in trying to run 

along the coast to block retreat, they had the misfortune to approach the shore just as a German 

column was rolling by. The column stopped, swung 

into action, and inflicted considerable damage 

among the boats before resuming its withdrawal.

At the Gulf of Salerno, early on 9 September 

1943, the Fifth Army intended to land 55,000 

troops, using about 450 ships, and 250 landing 

craft, to establish a beachhead and to bring in 

115,000 more men for an advance to Rome. On 

some of the approaching ships men heard the BBC 

announcement of the Italian surrender on 8 September 1943, inducing a wave of misplaced 

optimism. Despite the many reasons for believing 

the invasion was expected by the Germans, Fifth 

Army planned to begin its landings at first light 

without preparation fire from the ships, lest the 

bombardment eliminate surprise.

A few hours earlier the king of Italy, his premier, Marshal Badoglio, and his chief of the 

Comando Supremo, General Ambrosio, barely escaped from Rome. The German plans for seizing 

military control and disarming Italian forces went 

into effect. The 2d Parachute Division and 3d 

Panzer Grenadier Division in the vicinity of Rome 

acted under orders of General Karl Student to disarm the Italian troops. As the Italian field 

commanders pulled back toward Tivoli, Germans 

occupied the headquarters and captured many Italian generals and other officers. Hitler expected all 

Italians to be treated as prisoners of war. Kesselring, who doubted that the Italians would defect 

from the Axis, was mainly concerned with the need 

to get unimpeded access to Rome at once for General Heinrich von Vietinghoff’s German Tenth 

Army in the south, and was willing to allow his former allies to stack their arms and disperse. Rome 

he agreed to treat as an “open city.”

For a day or so, an Allied airborne attack there 

was a subject of some anxiety, but the lines to German troops in southern Italy remained open. The 

Italian people, deprived of leadership – either political or military – made little difficulty for the 

Germans.

In accordance with the armistice terms, elements of the Italian Navy tried to sail to an Allied 

port. Many succeeded but almost fifty combat vessels were destroyed in Italian ports, or by air 

attacks while en route. German forces also overcame Italian bases in the Aegean Islands. Certain 

captured Italian officers were handed over to the 

new puppet government, headed by Mussolini, 

after his rescue on 12 September. They were then 

put to death.

Operation AVALANCHE

For Operation AVALANCHE at Salerno, the Allied Force used the American Fifth Army in its first 

campaign. The first American troops to go ashore 

were the Fifth’s 36th Division. That division was 

part of a large array, neither wholly American nor 

wholly new to amphibious operations. Unlike the 

dispersed beaches of Sicily, the Gulf of Salerno 

faced a crescent strip of sand at the edge of a rolling 

alluvial plain enclosed within swiftly rising hills in 

a vast amphitheater. The streams that meandered 

through the plain, especially the Sele River and its 
Page 77

tributary, the Calore, were too deep and wide to 

cross except by bridges. Fields and orchards 

crowded the plain, but most dwellings were on 

higher ground around the edges.

The attacking force was opposed by the 16th 

Panzer Division, deployed a few days earlier in time 

to get set for an invasion from the sea. Although 

thinly spread, they had prepared strong points to 

cover the approaches, beaches, and exits with machine gun and artillery fire and had mined the sea 

approaches and mined and wired the beaches 

themselves. Tank traps and batteries of mobile antitank guns would limit Allied armored support for 

an infantry that might succeed in getting off the 

beach. Antiaircraft gun positions were made ready. 

German tanks would move to danger points above 

the beaches.

Against those preparations, the Allies sent an 

Anglo-American naval force commanded by Vice 

Admiral Henry Kent Hewitt, veteran of Operations 

TORCH and HUSKY, who was aboard the USS 

Ancon. His armada divided into two Anglo-American attack forces, of which the northern had a 

Royal Navy commander and the southern, an 

American.

The U.S. Fifth Army, under Lieutenant General 

Mark Wayne Clark, consisted of the British 10 

Corps, under Lieutenant General Sir Richard McCreery, and the U.S. VI Corps, under Major General 

E. J. Dawley. Three battalions (1st, 2d, and 4th of 

U.S. Rangers) and a British Commando Unit 

formed a part of 10 Corps, which contained the 

British 46th, 56th, and (in reserve) 7th Armoured 

Divisions. General Dawley had the American 36th 

and 45th Divisions in the assault and the 3d Infantry Division in reserve. In Sicily, the 82d Airborne 

Division waited in Army reserve.

The landings were to be supported by both carrier-based and land-based aircraft. Two fleet 

carriers of the Royal Navy and five small carriers 

would endeavor to protect the ships; the XII Air 

Support Command (Brigadier General E. J. House, 

USAF) of the Northwest African Air Forces would 

provide tactical air support in the battle ashore. Allied fighters from Sicilian airfields could operate 

over Salerno for only about twenty minutes before 

turning back with just enough fuel to get home. An 

Italian airfield at Montecorvino near the inland 

edge of the 10 Corps’ sector was therefore a major 

D-Day objective.

The goal of Operation AVALANCHE was to occupy the small harbor at Salerno, the Salerno plain, 

the airfield at Montecorvino, and the road and 

railroad center at Battipaglia, nearby. In the steepsided mountains between the Gulf of Salerno and 

the Bay of Naples to the north, the Allied Force intended to occupy the passes and adjacent heights. 

Firmly ashore, the Fifth Army would wheel left 

through those passes and over roads farther inland 

to capture Naples. After clearing the port at Naples 

of the expected demolitions, Fifth Army would 

bring in the reinforcements and supplies necessary 

to reach planned totals of 225,000 troops, 34,000 

vehicles, and 118,000 tons of material.

A beachhead line to be reached, if possible on 

D-Day, ran along the hills ringing the plain. It embraced Vietri and Salerno on the north, Battipaglia, 

Eboli, Persano, and Ponte Sele in the center, Agropoli, Paestum, Capaccio, Albanella, and Altavilla, 

with an adjacent Hill 424, in the southern sector.

Like other amphibious assaults, AVALANCHE 

might have begun a race to establish stronger 

forces at key inland points. Instead, the 16th Panzer 

Division was there to greet the landing craft of the 

Italian surrender on on their way in, and to subject 

the troops of VI Corps and 10 Corps to a harsh reception. Next, it became a struggle to occupy and 

hold, or if driven away, to return and hold, key 

areas while opposing reinforcements approached. 

Lastly, it was a contest to strike weary troops, 

dispersed at various vulnerable points on the flanks 

or along the corps’ boundary, with stronger troops 

concentrated to attain superiority in numbers and 

fire power.
Page 78

On 9 September 1943 the Fifth Army got ashore 

despite the preparations to stop them en route or 

on the beaches. The enemy used his prepared positions plus his mobile tanks and artillery batteries in 

such a way as to make impossible any deep inland 

penetration. At the extreme left, a force of U.S. 

Rangers and British Commandos developed a separate beachhead on the steep-sided Sorrento 

peninsula, and got control of certain passes through 

the heights. At the right, elements of the 36th Division got to Paestum and Capacclo. But in both 10 

Corps and VI Corps zones, the advance was not 

deep, and retention was possible only because the 

enemy’s tanks had been neutralized or destroyed 

by naval gunfire, by two battalions of field artillery 

carried to the dunes by amphibious trucks (Dukws), 

and by resolute infantry armed with bazookas and 

grenades.

The British 10 Corps landings were preceded by 

shelling and rocket fire on the beaches south of the 

port city of Salerno. Their landings may thus have 

been less disrupted than those of VI Corps, but the 

enemy fought hard to hold them from access to the 

Salerno-Naples routes.

General von Vietinghoff, commanding the German Tenth Army, had two related missions. He had 

to hold the way north open for the 26th Panzer and 

29th Panzer Grenadier Divisions in Calabria. He 

had also to stop Allied Fifth Army where it could 

later be destroyed, as soon as he could assemble superior strength. He called back the two mobile 

divisions from Calabria, where they had been obstructing the advance of British Eighth Army, and 

he summoned from the Naples area the Hermann 

Goering Panzer and 15th Panzer Grenadier Divisions. They and other formations moved toward 

the passes leading to the Salerno plain. Part of the 

29th Panzer Grenadier Division was near enough 

on 9 September to begin assuming positions on the 

battle line before daylight. So Vietinghoff that night 

brought to the northern sector various units facing 

VI Corps. Fuel shortages slowed the movements of 

the 29th Panzer Grenadier Division, which straggled in during the next two days. The effect was to 

minimize opposition to General Dawley’s VI Corps 

on the second day (D+ 1).

On 10 September 1943 Dawley brought in his 

floating reserve, while the leading troops on the 

right reached the hills, and in the center started a 

push to Ponte Sele. The next day, the 36th Division 

extended its hold to all heights from Agropoli on 

the extreme right to Hill 424, near Altavilla. At the 

same time, the 45th Division took over the left sector of the Corps zone, which was enlarged northward 

beyond the Sele River. The narrowing of the British 

10 Corps zone permitted stronger British thrusts to 

take Montecorvino and Battipaglia and was an adjustment to the presence of more of the enemy in 

that zone. Salerno and Montecorvino were taken, 

but enemy artillery fire denied their use to shipping 

and aircraft. Around Battipaglia the battle surged 

in and out of the town.

By the night of 11/12 September, the situation 

looked favorable to the Allies. They were ashore to 

stay. The enemy’s reinforcements might make an 

advance to Naples more difficult but did not seem 

to have brought about more than local counterattacks. Vietinghoff, however, did have a chance to 

strike back before the British Eighth Army arrived 

near enough to draw German formations away 

from Salerno. On 12 September he showed growing 

power in action after action.

To help provide effective air support during the 

amphibious phase of Operation AVALANCHE, SIGINT parties were placed aboard the headquarters 

ship, USS Ancon, and two British vessels, H.M.S. 

Euryalus and H.M.S. Palomares. Ancon was 

equipped with an elaborate system of telephones, 

teleprinters, and pneumatic tubes between the offices of various commanders, the staff operations 

rooms, and message centers. An RAF flight lieutenant and three Royal Navy seamen radio operators 

were reinforced by a voice intercept team consisting of an American 1st lieutenant, an RAF sergeant 

interpreter, and three American enlisted men. The 

four Americans were from Detachment “B,’ 849th 

SIS. All were fluent in German but only the officer 
Page 79

and the interpreter were familiar with German Air 

Force voice communications during combat operations, and the latter had been obtained luckily at 

the last moment before embarkation, as an exchange with the party on Palomares.

At Salerno the RAF adopted a method of distributing SIGINT that had proved successful during 

the invasion of Sicily – a broadcast from Malta of 

pertinent SIGINT based on the much wider intercept coverage possible at the fixed station in Malta. 

This time, the material that came via Royal Navy 

channels was slow in arriving. The broadcasts were 

not heard distinctly. After the first three days, the 

unit therefore turned to a parallel broadcast from 

RAF 329 Wing at La Marsa, Tunisia which could be 

heard fairly well. The wide intercept coverage at La 

Marsa that supported production of SIGINT enabled that station to advise, through the unit on 

Ancon, the commanders at Salerno concerning the 

state of German Air Force units within striking distance. As Allied countermeasures weakened enemy 

air, SIGINT picked up a report to a higher headquarters by the German command at the Foggia 

airfield that a considerable number of JU-88s and 

DO-217s were there. Soon Allied bombers hit that 

target, and commanders at Salerno realized that 

the diminished German air activity would not soon 

revive.

“Y” from Ancon was a means of offsetting the 

Germans’ misuse of the same frequency employed 

by the Allied Fighter Director Officer. Their “phony” 

air raid warnings could be counteracted by prompt 

recognition.

The team from Detachment “D,” 849th SIS, had 

two receivers that had to be manned continuously. 

Contrary to expectation, they found that even night 

bomber pilots broke radio silence when over the 

target area and, even during the last stage of an approach to it, kept asking if the target had been 

sighted. Radar frequently noted an approaching 

flight, but voice intercept confirmed the nature of 

the enemy formation. Moreover, radio interference 

from transmissions on the command ship affected 

radar more than it did the SIGINT radio receivers.

Voice intercept materially helped the air 

defense of the ships and beachhead. The communications of fighters, fighter bombers, bombers, and 

reconnaissance aircraft became readily distinguishable. The fighter pilots talked the most, even though 

obviously aware that they might be heard. Before 

combat with Allied aircraft, the leader of the formation gave orders to the other pilots, usually prefacing 

the orders with word of sighting an Allied plane 

that might be entirely unaware of being seen. That 

enabled the Allied listeners to pass a warning to the 

endangered Allied pilot. Frequently the German 

pilot, upon seeing an Allied plane, would report his 

own altitude and that of the one observed. In reporting to controllers or other aircraft in flight 

where a pilot was, he also sometimes used a German grid system known to the SIGINT team, at 

other times a visible landmark which the team 

learned to recognize. The pilots used callsigns that 

permitted a close estimate of the size of a formation.

A German pilot having engine trouble usually 

reported that he was turning back to base; such an 

aircraft was therefore often vulnerable. When fighters reported that they had dropped their extra 

gasoline tanks, Allied aircraft could be warned that 

the enemy aircraft might become more maneuverable in any impending encounter. If a pilot reported 

that his gasoline supply was down to a certain level, 

that often indicated that he was going to turn back 

to base with an amount calculated to get him there. 

If verbal air reconnaissance reports were heard, the 

information was presumably to be used by a formation perhaps already airborne, and if no such 

reports were heard, it might indicate a night bombing to come. The talk between bomber pilots about 

their targets occasionally disclosed how thoroughly 

informed the enemy was about shipping, as in the 

case of USS Ancon and later, H.M.S. Palomares,

which controlled the carrier aircraft committed to 

supporting Operation AVALANCHE. Once the “Y” 

party had learned which callsigns and frequencies 
Page 80

to watch, it could give about twenty minutes advance warning of a bombing attack on the ships. 

For about five days, the alerts brought response 

from Royal Navy Sea fires and other aircraft. Then, 

as the Allied planes were “worn down,” the enemy 

began getting through to target shipping and the 

warnings went to ships’ skippers.2

Elements of three incoming German divisions 

had been committed at Salerno by 12 September. 

For a time it looked, before that day began, as if the 

Germans might have decided to withdraw, having 

lost the race. British 10 Corps had gotten the enemy 

out of the town of Salerno and its port and off the 

airfield at Montecorvino, even though both remained under enemy artillery fire and were 

unusable. VI Corps had almost reached Ponte Sele, 

and held Altavilla and Hill 424. But on 12 September the course of the battle reversed. The enemy’s 

reinforcements drove both 10 Corps and VI Corps 

units from their more advanced positions. As an 

offset to those setbacks, the U.S. Rangers on the 10 

Corps flank near Castella Mare opened to the 

enemy a disturbing possibility of an Allied advance 

on Naples along the coast. U.S. engineers completed the preparation of air landing strips near 

Paestum and Salerno. During that night, in anticipation of enemy pressure in the zone between 10 

Corps and VI Corps, General Dawley shifted battalions of the 36th Division to that flank.

General Clark, while on the Ancon, was in touch 

with GCCS via Admiralty channels and thereafter 

via a Special Liaison Unit with the Fifth Army CP 

ashore. Special intelligence was thus available before and during the landings. Information 

concerning the German strength in Italy was 

known, though German intentions there were obscure, perhaps because they were not definite until 

the Allies had been ashore more than a month. Intelligence showing the tactical disposition of the 

German ground formations that might oppose the 

landings was late in arriving. Cryptanalytic difficulties delayed a report from GCCS until the morning 

of 10 September, identifying general locations of 

some elements of the German Tenth Army. After 

Kesselring's first situation report to OKW had been 

sent at 2200 hours on 9 September, GCCS could 

send its import to General Alexander only a little 

more than one day later. Subsequent SI gave advance notice of enemy reinforcements and their 

disposition and of the tactical plans for counterattacks.

For the first two days, the German Air Force 

provided a relatively moderate resistance to the invasion. Bombing of the ships suddenly increased 

on the night of 11/12 September, when eighty-five 

hits by rockets and radio-controlled glider bombs 

occurred. During the afternoon of 12 September, 

General Dawley began strengthening his left flank 

by shifting all of the 45th Division north of the Sele 

River, leaving the 36th Division with thirty-five 

miles of front to cover. That afternoon, both General Clark and General House moved their 

command posts ashore. Ancon, known to be a special target of German bombers, was released only 

to be recalled when almost at Algiers and was then 

kept at Salerno until 19 September. Navy planes 

began using an airstrip near Paestum. While those 

actions on 12 September may have been based on 

Allied confidence that Fifth Army was ashore to 

stay, on 13 September the enemy’s success in blocking Allied seizure of inland objectives, and in 

launching counterattacks that regained lost ground, 

led Vietinghoff to believe that the Allied invasion 

had stalled before gaining a firm lodgment. Partly 

on the basis of German SIGINT, he actually believed for a time that the Allies were preparing to 

pull out. How else could one explain the gap he had 

recognized between British 10 Corps and U.S. VI 

Corps? He therefore prepared his strongest counterattack to exploit that avenue to the beaches.

The enemy had enough new power on 13 September to frustrate Allied attempts to regain Hill 

424 and Altavilla. His main effort was a heavy armored counterattack down the center near the Sele 

River. After almost wiping out American infantry 

in its path, his tanks ran onto a salient bounded by 

the Sele and Calore Rivers at their junction, perhaps expecting to use a bridge there that had been 
Page 81

demolished. Facing that narrowing area were two 

battalions of field artillery and other elements of 

the 45th Division. Converging fire struck the tanks 

as they reversed their course.

The night of 13/14 September was a time of intense effort by Fifth Army. Aware of the German 

intentions and tactical plan, the Fifth Army’s Staff 

Information and Monitoring Company (SIAM) 

Service intercepted a message early that morning 

in the 45th Division's traffic that said: “Fifth Army 

expects a coordinated attack this morning, possibly 

northwest from Albanella or south from Persano.”3

The Allied command brought over Fifth Army’s reserve, the 82d Airborne, in three sections. The first 

were dropped that night. The second came by air, 

and the third by sea on the 15th. The 3d Infantry 

Division was alerted for transfer from Sicily by 18 

September. General Alexander killed an idea that 

General Clark had discussed with Admiral Hewitt 

as a possible maneuver, should the enemy’s success 

require it. That was to shift by sea the troops of one 

corps into the zone being defended by the other. 

Instead, he encouraged the Fifth Army in its plan to 

give up some ground for the purpose of establishing a shorter and stronger defense line and to put 

into the line as reinforcements not only the newly 

arrived paratroopers but also all available service 

troops. They were to reinforce 10 Corps right and 

the VI Corps left, where the enemy’s attack was ultimately contained. In part that was accomplished 

by stalwart resistance at the Allied defense line. 

The enemy’s maneuvers could not have suffered 

from learning, from a 36th Division message sent 

in the clear at 1120 hours: “CUB need 57mm ammo 

at once.”4 In part successful defense came from 

heavy naval gunfire and from stepped-up air bombing further inland on concentrations of enemy 

armor and troops. Particularly in the area near Battipaglia and Eboli, the enemy found it costly to 

mount his thrusts. At the beaches and above the 

ships the air superiority of the Allied force was unmistakable.

By 15 September the enemy had accomplished 

the first of Vietinghoff’s missions, and had

 concluded that any opportunity to drive the invaders off the beachhead had gone. While the German 

high command weighed the merits of defending 

south of Rome or farther north, the German Tenth 

Army began a slow withdrawal, hinging on the 

passes at the base of the Sorrento peninsula. It retreated to the northern bank of the Volturno, 

relinquishing Naples and the surrounding area to 

the Allies.

Enemy air attacks on the ships offshore, some 

of them over the horizon from the beachhead, came 

to a climax on 15 September with the crippling of 

H.M.S. Warspite. That battleship had been sent, in 

response to Admiral Hewitt’s request, to provide 

naval gunfire far inland and had contributed some 

fifteen-inch shells to the devastating cascade near 

Altavilla. Radio-controlled glider bombs, however, 

scored two hits and two near misses that required 

that the battleship be towed back to Malta.

The “Y” parties on Ancon and Palomares were 

convinced that the glider bombs were being 

dropped from a higher altitude during lower-level 

diversionary attacks by other aircraft. When alerted, 

the Allies put aircraft still higher to terminate the 

practice. The next day they brought down two of 

the German bombers, and that success coincided 

with a general diminution in enemy air activity. He 

no longer could seriously affect the Allied 

operations ashore by interfering with the ships.

On 21 September the U.S. 34th Division began 

landing over the Salerno beaches rather than in the 

port of Naples as originally scheduled. A week later, 

as a storm suspended operations at the beaches for 

several days, the invaders found the enemy nevertheless releasing his hold on the passes and moving 

north. Naples was entered on 1 October by Fifth 

Army advance elements, while the Allies also 

gained control of Foggia. On 14 October unloading 

shifted from Salerno beaches to Naples. Meanwhile, the Fifth Army reached the south bank of the 

Volturno River.
Page 82

Enemy Strategy

Kesselring believed that the Allies could be held 

south of Rome indefinitely by using the topographic features and by building a series of major 

defense lines, of which the first would run across 

the peninsula through Mignano, ninety miles south 

of Rome, and the second, through Cassino, about 

twelve miles closer to the city.

Enemy tactics in the mountainous terrain made 

astute use of the limited road net, the vulnerability 

of stream crossings, and the advantages of ground 

observation points and sheltered artillery positions. Allied mobility was negated by mines, 

demolitions, and prepared fields of fire that obliged 

the attacking troops to make wide swings around 

road blocks, to construct their own bridges, and to 

engage in endless outflanking maneuvers on foot 

before a stretch of narrow road could be opened for 

vehicles.

As the Allies were about to cross the Volturno, 

the Badoglio government formally declared war 

against Nazi Germany. Italy became a cobelligerent, not an ally.

German troops on Sardinia were meanwhile 

moved to Corsica, and thence to Leghorn, while the 

battles in the south were in progress. They were 

then marched to the area southeast of Rome to reinforce the opposition to the British Eighth Army.

In the light of special intelligence, the Allies had 

begun operations in Italy expecting that the enemy 

would quickly relinquish the peninsula as far as the 

northern Apennines but would hold there in a prepared defense line shielding the Po Valley. 

Resistance in the south to gain time enough for 

construction in the north could be expected. The 

Allied objective at first was to liberate Rome, and 

they doubted that the Germans would make a 

stand south of that city. When they did just that, 

doubts emerged that the liberation of Rome would 

be worth the costs, but those doubts passed, and 

eventually it began to seem desirable to establish 

Allied control of the Po Valley.

Three weeks after landing on the Salerno 

beaches, the Fifth Army was in Naples. One week 

later it had reached the Volturno River. According 

to the schedule of withdrawal to a strengthened 

line of prepared defenses, the Germans pulled back 

from the Volturno toward the “Gustav Line” along 

the Garigliano-Rapido Rivers. It took the Allies several more weeks to break past an intermediate 

“Winter Line” and to advance through prominent 

hills and higher mountains. Hitler, after his initial 

uncertainty about a proper point at which to stop 

an Allied advance, on 4 October 1943 reached the 

conclusion that Kesselring, the optimist, had been 

right while Rommel, less hopeful, had been mistaken. The Germans would defend south of Rome, 

and continue to hold that political prize. Instead of 

entrusting the top command in Italy to his Army 

field marshal, he would give it to his Air Force field 

marshal. Army Group B in northern Italy was dissolved in November 1943. Its divisions passed to 

Kesselring’s command. The Germans reasoned 

that only in the air would Allied superiority persist, 

and possibly that situation might also be reversed.

Tactical SIGINT Service

The first SIGINT teams with Fifth Army, during 

the amphibious assault, were provisional units 

placed on command ships to support air defense. 

On the second day of the invasion, the regular VI 

Corps unit came by LST from Sicily. It consisted of 

Detachment “E,” 849th SIS, and about one-third, 

known as Detachment “R,” of the 128th SRI Company. At the beach on 11 November that LST was 

hit by a shell that injured two men of the intercept 

company. The VI Corps unit covered medium-frequency nets between lower echelons, on which the 

traffic was about equally three-letter (T/L) codes 

and plain text, and between middle levels of command, in Playfair ciphers. The daily SIGINT report 

to VI Corps G-2 was sparse and insignificant until 

the action reached the area between Naples and the 

Voltumo River. Certain units could then be heard 
Page 83

and their messages read, particularly the Engineer 

Battalion of the Herman Goering Panzer Division, 

the Reconnaissance and Artillery units of the 26th 

Panzer Division, and the Reconnaissance Battalion 

of the 3d Panzer Grenadier Division.

The Fifth Army had “Y” sections operating with 

army headquarters and each corps headquarters 

after Naples had been taken. On 16 October 1943 

an Army Group “Y” Section attached to Fifth Army 

began DF operations. Colonel Edwin B. Howard, 

G-2, Fifth Army, reported then that the SIGINT 

service was well set up, and was producing a large 

amount of information quickly and accurately.5

When the campaigns in Italy began, German 

Army low-level traffic was increasingly transmitted 

on VHF links. In Africa, almost all of it had been on 

MF/HF (1-4 MHz). British experience there showed 

that an intercept unit was needed at Army headquarters level to maintain MF/HF coverage of 

enemy links that Corps units either could not hear 

or lacked enough resources to cover while monitoring targets of higher priority. The Army headquarters 

also needed an intelligence unit to guide collection, 

process the traffic collected, and interpret to G-2 

the SIGINT obtained. But in Italy, as VHF traffic 

expanded and MF/HF traffic shrank, that arrangement had to be altered.

Since VHF transmissions were low-powered 

and line-of-sight, they could be heard usually only 

at forward sites by units working for Corps headquarters. Instead of reading current messages, the 

Army-level SIGINT units developed research, filing, and record-keeping techniques by which they 

reexamined traffic and logs in order to assist the 

work of the corps units.

Those changes attributable to alterations in 

communications technology were further encouraged in 1944 by new German signal security 

procedures. The resort to frequent and randomized 

callsign changes and the substitution in mediumgrade traffic of Rasterschluessel (“Raster”) for 

Playfair further complicated the situation.

Fifth Army tactical SIGINT was thought to be 

best obtained and used at the corps level by combining SRI detachments of 2 officers and 90 to 100 

enlisted men with SIS detachments of three officers 

and fifteen enlisted men. The latter directed the intercept coverage, including search. The operators 

manned from eight to ten positions, normally 

enough to cover a corps front and to communicate 

by radio with an army detachment. The SIS element analyzed and interpreted the traffic. Its men 

were trained to recognize enemy networks, to 

break simple codes and ciphers and to translate 

and/or interpret decrypts. The senior SIS officer 

reported results to the corps G-2 either in daily 

morning reports or, if more urgent, by wired telephone.

For the first stage of the campaign from Salerno 

to Cassino, the Fifth Army Headquarters “Y” unit 

consisted of a detachment (3 officers and 115 enlisted men) from the 117th SRI Company teamed 

with the British 44 WTI Section (four officers and 

sixteen other ranks). In January 1944, after an 

overlapping period, they were relieved by the Headquarters Detachment, 128th SRI Company (Captain 

Shannon D. Brown, CO, one other officer, and 119 

enlisted men) teamed with Detachment “A,” 849th 

SIS (three officers and eighteen enlisted men). That 

combination remained the Fifth Army “Y” unit to 

the end of the war.

The VI Corps “Y” Unit, as we have seen, was a 

similar combination – a small detachment (“E”) of 

849th SIS (2d Lieutenant Sidney Reisberg) teamed 

with another detachment of the 128th SRI Company.

The II Corps “Y” Unit brought together a third 

detachment of the 128th SRI company (Lieutenant 

Francis H. Smith) and Detachment “H” of the 

849th SIS. (Headquarters, II Corps, took command 

on 18 November 1943 of a sector of the Fifth Army’s front.)

British 10 Corps was served by a British Special 

WTI Section and attached WTI Section.
Page 84

Overlapping coverage by the army and corps 

units occurred by design. Either for speedier service on certain matters to the Army G-2, or for 

guaranteeing hearability, or for the coordination 

and control of all corps-level units, some duplication seemed desirable. The army unit studied the 

summaries and technical reports by corps units, 

conducted research on enemy codes and ciphers, 

engaged in traffic analysis, distributed results to 

the corps units, and kept them from repeatedly duplicating part of each other’s efforts.

After AFHQ had assigned the 128th SRI Company to Fifth Army, AFHQ retained no control over 

it. The 849th SIS detachments, on the contrary, although attached to the Fifth Army and completely 

under its operational control, remained under the 

administrative control of the 849th SIS at AFHQ. 

The detachments of the 128th SRI Company with 

the VI Corps and II Corps were only semi-independent, for they operated under corps G-2 control 

and received routine administation from corps 

headquarters, but they remained under Headquarters, 128th SRI Company (at Fifth Army) for 

matters involving personnel and equipment. An 

SIS officer assigned to G-2, Fifth Army, coordinated the operations of the Corps and Army “Y” 

units.

Headquarters, 15 Army Group, coordinated 

Fifth Army, Eighth Army, and 15 Army Group “Y” 

operations. The flow of technical information from 

research sections at Army Group aided the operations of Fifth Army sections immeasurably, in the 

judgment of the Signal Officer, Fifth Army.6 Direction finding in Italy was accomplished at army 

level. While each corps “Y” unit in Fifth Army had 

one apparatus of British make, and found useful 

the single line bearings thus obtainable, it found 

that it could not manage DF nets. The 15 Army 

Group furnished the personnel for it to the two 

armies. On the Fifth Army front, three mobile DF 

teams in one net concentrated on enemy division 

and regimental traffic. After the DF data were processed at Army Headquarters, G-2, Fifth Army, 

sent the finished product to corps SIGINT units 

and corps G-2 sections.

Fifth Army controlled one SIGINT communications net; the Army unit itself, within a SIGINT net 

controlled by 15 Army Group, passed intelligence 

reports, technical information, and essential administrative messages. In the SIGINT section at 

849th SIS Mediterranean 

Theater (128th SRI),

 2 1/2-ton camouflaged 

intercept van

(Photograph from the 

NSA History Collection)
Page 85

G-2, a daily “Y” report, segregated from intelligence 

gained in other ways, was prepared. When the 

codeword PEARL (for low-grade decrypts) and 

CIRO-PEARL (for medium-grade decrypts) went 

into effect, G-2 had a “PEARL Section.” Its daily intelligence reports tagged items for CIRO-PEARL, 

and in the case of the results of traffic analysis and 

direction finding, as THUMB 1 or THUMB 2, respectively.

Headquarters, Fifth Army, responding to instructions from AFHQ, created the 6689th Staff 

Information and Monitoring Company (SIAM), 

Provisional, which performed the functions of what 

the British Eighth Army had termed its “J” Service. 

Radio intercept operators in three corps and four 

divisional platoons monitored communications 

among Fifth Army units to detect violations of signal security that might benefit the enemy and to 

keep close watch on the positions, circumstances 

and intended actions of units at the front line. Their 

reports were intended to keep division, corps and 

army headquarters immediately aware of events at 

lower echelons and, at the same time, to keep the 

latter abreast of developments among the units on 

their flanks.

At the end of the war in Italy, the SIAM Service 

was appraised as efficient, desirable and “considerable,” and if kept fully mobile, worth maintaining 

at one platoon plus one additional liaison officer 

with each division.7

The ability of the VI Corps “Y” unit to monitor 

communications of the Hermann Goering Division 

Engineers yielded early reports of demolitions and 

thus showed the pattern of German delaying tactics 

to be expected as the Fifth Army moved north. On 

12 October the 3d Panzer Grenadier Division was 

identified as coming into the enemy line at the 

Volturno River. Its ability implied that it might be 

about to cover a withdrawal rather than to reinforce a longer stand at the river. By 15 October 

coordinates of the enemy’s main line of resistance 

had been determined. The entire German Tenth 

Army had pulled back to that line, conforming to a 

schedule of withdrawal that gave time for the 

strengthening of the so-called “Gustav Line” along 

the Garigliano-Rapido Rivers and at Cassino. 

The 3d Panzer Grenadier Division had relieved the 

16th Panzer Division so that the latter could be 

sent, at Kesselring’s insistence, to face the British 

Eighth Army on the Adriatic side of the Allied advance. The relief had the effect of interrupting 

certain defense preparations at the Volturno and of 

weakening the opposition to be met by the U.S. 3d, 

34th, and 45th Divisions as they crossed the 

Volturno and pushed up to the “Winter Line.”

Another example of the merit of SIGINT in 

yielding intelligence from the area behind the enemy’s main line came on 29 October 1943. The 

enemy was using a highway bridge at Mignano to 

move north. Allied bombers struck that morning 

with uncertain effect and were held available for a 

second attack. The VI Corps unit learned by noon 

from the Hermann Goering Division Engineers

that the bridge was no longer usable, and that German road traffic had been rerouted. Early that 

afternoon the alternate bridge was also bombed out 

of service.

The American “Y” units in Italy moved in trucks 

and vans. Between 1943 and 1945 Detachment “A,” 

849th SIS, with the Fifth Army used a large trailer 

which had been modified by cutting out windows 

and a side door. The walls held shelves and maps. 

Along the sides were tables, a packing case converted into a desk with drawers, and a file cabinet. 

Gooseneck lamps, two electric fans, typewriters, 

telephone, teleprinter, and an M-209 converter 

formed part of the equipment used by the analysts 

and reporting personnel. Other detachments of the 

849th SIS and those of the 128th SRI Company 

used two 2-1/2-ton trucks with solid walls and 

camouflaged canvas roofs at heights enabling men 

to stand under them. The vehicles would be parked 

rear-to-rear, connected by a platform to which a set 

of steps could be attached. Receivers were put on 

shelves and tables across the front and along the 

sides. Antenna lines and power and communication cables came in through openings. Each truck 
Page 86

had an exhaust fan for ventilation. Some had 

screens over windows. Tents were pitched beside 

them.

One or more of the intercept units mounted an 

H-shaped antenna on a rotatable shaft running 

vertically through the roof, turned by a wheel at the 

base. Calibration of the circle was marked on the 

ceiling.

When an intercept unit could occupy a dwelling, it set up shop in relative comfort among a swirl 

of wires coupling the receivers with the antennas 

outside.

Early in 1944 the 849th resumed extensive processing and research at its headquarters in Algeria. 

The field center developed only after many of the 

personnel had gained experience working with SIGINT units in Tunisia, Sicily, and Italy.

The Intelligence Branch 849th SIS was ready to 

undertake work on German Army and Air Force 

medium-grade (Playfair and double-Playfair) communications when months of preparation came to 

fruition in February 1944. A new Solution Section 

for that purpose then began operations. The preparations for it began with training in the United 

Kingdom of analysts who spent several months 

there becoming expert in Playfair analysis after 

preliminary analytic training in the United States. 

The first such group (three officers and twelve enlisted men) arrived in Algeria in July 1943. It was 

promptly added to a party from Detachment “B,” 

849th SIS (four officers and twenty-four enlisted 

men) and from the 117th SRI Company (two officers and ninety-seven enlisted men), all of whom 

went to Santa Flavia, Sicily, to develop their skills 

in covering the communications links on which 

medium-grade German Army traffic was being 

passed.

The second group (five officers and twenty-six 

enlisted men) reached North Africa in November 

1943. In the following February part of that group 

(three officers and twelve enlisted men) 

was assigned to the new Solution Section. Almost 

immediately afterwards, the cryptanalysts who had 

been with Detachment “B” at Santa Flavia, Sicily, 

returned to work in the new unit. The table of organization (T/O) of the Solution Section contained 

“slots” for six officers and eighteen enlisted men for 

the rest of the war, and although the turnover of 

personnel was considerable, at the end of the Playfair period in November 1944, nine of the original 

thirteen enlisted men were still on duty there.

The Solution Section tried to analyze traffic in 

medium-grade cryptographic systems with the 

benefit of all obtainable collateral and all the collaboration available from other analysts. To 

anagram Playfair, an analyst needed familiarity 

with the usual addressees, signatures, routine formats, personalities, and other recurrent 

probabilities. Of secondary value were the frequency and combinations of bigrams. The British 

center for such work in the Mediterranean in 1944 

was a Special Intelligence Company at Bari, Italy. 

Duplication of effort was reduced to a minimum, in 

part because of the slower delivery of traffic to the 

Solution Section. By the time the Solution Section 

could work on it, 7 SI Company had either broken 

the ciphers for that period or had turned to subsequent messages, leaving earlier ones unread. The 

Ameri-can output was normally available from five 

to seven days after the time of interception.

The Intelligence Branch had a Laboratory Section with both photographic and chemical units. 

The latter tested for the presence of secret inks, 

working in Sicily and Salerno with the Censorship, 

and later with the CIC and the OSS. When the 

needed photographic equipment finally arrived, 

the photographic unit was able to assist others at 

AFHQ as well as the 849th SIS.

In January 1944 the Intelligence Branch established a new Traffic Analysis Section of sixteen 

enlisted men, who had come to North Africa after a 

training period in the U.K. The section controlled 

the intercept operations of a station (at L’ile Rousse, 

Corsica) that collected German Army traffic from 
Page 87

northern Italy and southern France. The personnel 

of that station consisted of American intercept operators and traffic analysts who had previously 

been at Santa Flavia, Sicily, in the same group from 

which the cryptanalysts were to be taken for the 

new Solution Section of the 849th SIS in February 

1944. Another detachment of the 117th SRI Company, one that had been working in Italy, rejoined 

the company in Corsica. The station there was then 

manned by 5 officers, 1 warrant officer, and 201 enlisted men of the 117th, plus 4 officers and 32 

enlisted men attached from other units. 

Intercepted traffic went daily by air to Hamman 

Melouane.

There the new Traffic Analysis Section examined traffic logs for repeats, transmissions, 

references in plain text, names of communicators, 

and other clues of value in reconstructing nets. The 

unit maintained files and researched callsign allocations. When predictable systems of allocation 

were replaced by random assignments, the Traffic 

Analysis Section focused on identifications by other 

means in order to assist forward detachments.

849th SIS Mediterranean Theater, interior of van showing DF controls and Hallicrafter receiver and Panoramoscope used by Detachment “D” (Photograph from NSA History Collection)
Page 88

Both the Traffic Analysis Section and a new Coordination Section assisted the Solution Section. 

The former issued weekly reports on German 

ground radio networks and filed data on the Italian 

and Balkan nets in which the Solution Section was 

interested. The latter compiled data on order of 

battle, personalities, codenames, map references, 

and other matters relevant to Playfair traffic from 

Italy, the Balkans, and southern France.

About the same time that the other general 

command organization in the Mediterranean was 

changed, making it primarily a British responsibility, the RAF “Y” structure in that theater was 

altered. On 14 January 1944 Headquarters, RAF 

276 Wing moved from Heliopolis, Egypt, to Conversano, Italy, and assumed control of all British 

RAF “Y” Units in the theater. It took over the “Y” 

broadcasts. Headquarters, RAF 329 Wing, which 

had been created to control such activities in the 

Western Mediterranean, became simply a personnel pool for assignments to duty in the Mediterranean 

or elsewhere. The ten subordinate RAF SIGINT 

Field Units were renumbered; some were to move 

up the peninsula as the front shifted, while others 

were to remain at Conversano and Caserta. At Conversano with Field Units 2 and 3 was Detachment 

“F,” 849th SIS, and a party of intercept operators 

from the 123d SRI Company.

During the months of long-range bombing 

from bases near Foggia, such missions were accompanied by airborne voice interception teams. 

The logs of their collection efforts were studied in 

July 1944 for evidence of patterns in the defensive 

operations of the German Air Force; the study reproduced a fairly complete picture.

Locations and callsigns of the German controls 

were identified. From radar and visual observation 

posts, and from shadowing aircraft, it was noted 

that reports of the positions of Allied bombers were 

passed to a central controller, who relayed that information to fighter controllers. The latter got 

fighters airborne, assembled in formation, into and 

out of an attack, and then back on the ground. Also, 

if large numbers of Allied bombers and escorting 

fighters were reported to be approaching a target 

along several different routes, the controller would 

often confine himself to relaying observation reports leaving the choice of actual defensive tactics 

to the leaders of fighter groups.

It was also noted from these studies that as the 

Allies repeatedly attacked certain targets, they elicited German responses according to a regular 

pattern. SIGINT showed also that on several occasions the enemy had become aware of the Allied 

objective as early as two hours before the bombers 

arrived in the target area. On the other hand, when 

the enemy remained uncertain which of more than 

one possible target was to be bombed, he put fighters up to oppose more than one. Consequently, the 

Allies took a course that threatened several places, 

leaving the actual target in doubt as long as possible, and making a sharp turn to that place at the 

last minute. These feints successfully confused and 

delayed the enemy’s response.8

Eventually studying the logs ceased to identify 

fighter units or to determine where specific fighter 

units were based, since the resort to frequent and 

random callsign changes prevented timely access 

to reliable data. It was, however, possible to calculate the numbers of enemy aircraft involved. Also, 

in the course of an Allied bombing mission, an airborne intercept operator could sometimes warn the 

leader of the formation that enemy fighters were 

approaching or that an intense antiaircraft barrage 

could be avoided by a change of course.

In the “Winter Line”

By 4 November 1943, having crossed both the 

lower and upper stretches of the Volturno River, 

the Allied force had reached the “Winter Line,” 

which ran near several major Allied objectives. The 

advance took them through and over mountainous 

terrain, along dirt roads that the enemy had mined, 

and across streams where the enemy had demolished the bridges not previously wrecked by Allied 

air or artillery. Air support at that stage took the 
Page 89

form of prearranged missions rather than attacks 

on targets of opportunity in front of Allied infantry. 

Fifth Army became exhausted during the first 

phase of its efforts to break through the “Winter 

Line.” It broke off the attack in mid-November 

when the enemy was almost as tired.

It was possible for “Y” produced by VI Corps SIGINT unit to inform G-2 that elements of the 26th 

Panzer Division were reinforcing the 29th Panzer 

Grenadier Division in front of the U.S. 45th Division on 6 November. Three weeks later, the 26th 

Panzer Division was reported to be moving east to 

relieve the 16th Panzer Division on the Eighth 

Army front.

Both Allied armies girded themselves to renew 

the offensive. The U.S. 1st Armored Division arrived during November. A French Expeditionary 

Corps came, too. In the east, British Eighth Army 

sought to reach Avezzano, where it would threaten 

the Rome area from one direction. In the western 

zone, after getting through the “Winter Line,” Fifth 

Army was to cross the Garigliano and Rapido Rivers and push generally northwestward along the 

Liri-Sacco River valley and Highway No.6. When 

Frosinone, about fifty miles south of Rome, had 

been taken, Fifth Army, it was thought, might make 

an amphibious landing at Anzio-Nettuno, thus 

threatening the enemy’s flank and rear and hastening the Fifth Army’s progress to Rome.

The attack by the Eighth Army fell short of its 

objective. The Fifth Army was also unsuccessful. 

The end of 1943 found it still south of the Garigliano and Rapido Rivers facing about two more 

weeks of slogging battles before it could even 

launch a crossing. The projected Anzio “end-run” 

had been necessarily shelved by the delay.

The “Y” units in Italy found that certain German divisions and lesser units were particularly 

valuable sources. The more mobile they were, the 

more likely they were to communicate by radio in 

simple systems involving minimal complication in 

encipherment. The basic codes stayed the same 

and all changes were quickly followed. The VI 

Corps SIGINT Unit faced some of the same formation successively between Salerno and the Volturno, 

again at the “Winter Line” and once more at Anzio. 

The Hermann Goering Division (especially its Engineer Battalion), the reconnaissance units of the 

26th Panzer Division and 3d Panzer Grenadier Division, and the former’s 93d Artillery Regiment-all 

proved to be valuable sources in action beyond the 

Volturno, as did the 764th Heavy Artillery Battalion. During the relatively gradual approach to the 

“Winter Line,” they found few plain language transmissions on MF/HF but much more at lower 

echelons on VHF, both voice and radio. From battalions of the 26th Panzer Grenadier Division they 

obtained more and more. Then, at the “Winter 

Line” itself, during the stalemate in December and 

January, even though the enemy used wirelines to 

a greater extent, much material could be taken 

from MF/HF and VHF radio nets. Later, at Anzio 

they found the 764th Heavy Artillery Battalion and 

the 3d Panzer Division’s Artillery Regiment each 

using its own type of letter-code on MF/HF nets, 

and the 65th Infantry and 4th Parachute Division, 

each with VHF nets differing from the other’s. To 

the communications of German parachute divisions the Allied SIGINT producers felt greatly 

indebted.

The 15th Panzer Grenadier Division, which the 

U.S. II Corps Unit faced during the winter and the 

VI Corps fought during the breakout in May 1944, 

transmitted on MF/HF and used chiefly three-letter code; it was a generous source of SIGINT. 

During the Allied offensive of 11 May 1944 until the 

breakout, the II Corps “Y” Unit derived much of its 

material from the 71st and 94th Grenadier Divisions, particularly the latter’s 267th Grenadier 

Regiment, which passed voluminous amounts of 

traffic in long, nonalphabetic, jargon code. Other 

elements of the two divisions indulged in much 

plain language and three-letter code on VHF links.

During the cold, rainy winter campaign of 

1943-44, both sides were reinforced. By January, 

the German Tenth Army of fifteen divisions
Page 90

 (so-called) along the Gustav Line faced the 

eighteen Allied divisions of the U.S. Fifth and the 

British Eighth Armies. Fifth Army included the 

U.S. VI Corps and II Corps, British 10 Corps, and 

the French Expeditionary Corps, while Eighth 

Army had British, U.S., and Polish divisions. The 

Fifth Army advanced to the Garigliano-Rapido River’s southern bank along both sides of Highway No. 

6. There the Allied advance again stopped. Successive attempts to open the way into the Liri River 

valley for exploitation by American armor were finally abandoned after the enemy had held on 

stubbornly to his dominating position at Cassino 

through March. British Eighth Army, after being 

checked short of Pescara, took over the eastern part 

of the Fifth Army front at Cassino.

Operation SHINGLE at Anzio

Among Allied resources were sealift and navy 

escort for amphibious landings behind the enemy’s 

main line of resistance. Such an attack at Anzio, in 

the western coast about twenty miles from the 

Alban Hills and thirty-five miles southwest of 

Rome, remained under consideration for many 

weeks.

The first plan of an Anzio operation called for a 

thrust toward the Alban Hills from the west in coordination with another from the south. It was 

reasoned that it might force the enemy to withdraw 

beyond Rome. The next plan entertained for a week 

in December 1943 was to draw German forces away 

from the Gustav Line to the Anzio beachhead and 

thus to facilitate the long-sought breakthrough. 

Failure to take Frosinone caused the first plan to be 

dropped. Inability to move far enough and fast 

enough, after breaching the Gustav Line, to establish mutually supporting drives by II Corps and VI 

Corps (at Anzio) caused the second plan to die. 

Since the sealift for an operation at Anzio was subject to the higher priority of a cross-Channel attack, 

for which many LSTs would have to leave the Mediterranean early in 1944, the chance to expedite the 

liberation of Rome via Anzio seemed to be slipping 

away as the new year approached.

By decisions in December 1943 and the following month, command in the Mediterranean area 

shifted from General Eisenhower to General Sir 

Henry Maitland Wilson. The British high command assumed the degree of responsibility 

previously held by the U.S. Joint Chiefs of Staff. 

The prime minister strove successfuly to bring 

about a two-division assault landing at Anzio in 

January 1944, at a time when, he hoped, the enemy 

might have to divert formations from the Cassino 

front in order to prevent the Anzio force from cutting the German line of communications to Rome.

Operation SHINGLE was executed by U.S. VI 

Corps under General John P. Lucas, who had relieved General Ernest J. Dawley as its commander 

on 20 September, just after the critical days at 

Salerno had ended in victory. The landings at Anzio 

were scheduled for 22 January, with British 1 Infantry Division on the northerly side and the 

experienced U.S. 3d Division, plus Rangers and 

others, on the right, or southerly side. After rehearsals near Naples, the landing force would 

embark there to make a surprise, night attack.

Kesselring was alerted by German SIGINT to 

the fact that the Allies were about to make such an 

attack somewhere, but he lacked air reconnaissance reports to suggest the probable place. Admiral 

Canaris, then head of the Abwehr (counterintelligence organization), on a visit to Kesselring’s 

headquarters, assured Kesselring that no indication of such an operation in the near future had 

been ob- served. On 18 January Kesselring ordered 

two veteran divisions (29th and 90th Panzer Grenadier) and Headquarters, I Parachute Corps, to 

move from the Rome area to the mouth of the Liri 

River valley, there to relieve and reinforce the German troops facing the Fifth Army. On that same 

day, rehearsals for the Anzio landings turned out to 

be a sad fiasco; many Dukws and other craft, and 

the valuable, self-propelled 105mm guns that they 

otherwise would have borne ashore at Anzio, were 

lost.
Page 91

At 0200 hours on 22 January 1944, 40,000 

men and 5,200 vehicles started to land at Anzio 

Beach from 242 transport vessels and landing craft, 

escorted by minesweepers, destroyers, and other 

combat ships totaling 112. Tactical air support 

came from both British and American components 

of the Mediterranean Allied Air Force. The landings were not strongly opposed on the ground; by 

midnight the transports were 90 percent unloaded. 

Every three to four hours, however, German bombers struck.

General Lucas was expected to move his command inland as far and as rapidly as he could 

without becoming vulnerable to counterattacks. He 

would have to depend on daily convoys along the 

coast to maintain his force. Everything would be 

unloaded at a small port and on an exposed beach 

under bombing from the air and shelling from artillery. As the beachhead pushed inland, the line 

kept lengthening. To put the beach out of range of 

field guns and provide adequate area for dispersal, 

the line had to be long and thinly held. He doubted 

the possibility of penetrating far enough to interrupt completely the enemy’s line of supply leading 

to the Gustav Line farther south. 

“Y” Service during the First Phase at Anzio

The main opposition on D-Day came from 

mines in the lanes of approach and from mines 

planted in the sandy beaches, supplemented by artillery able to reach some of the shipping, and by 

aircraft that broke through Allied fighter defenses 

to hit beaches and some of the ships. During the 

next two days, the air attacks increased in strength 

and frequency and sought particularly to disrupt 

the influx of material. On D+ 3, despite bad weather 

that afflicted all unloading except within the small 

port of Anzio, enemy air pressed its program of curtailing the growth of VI Corps ashore while German 

troops assembled to contain the beachhead. Deliberate, savage German air attacks on illuminated 

hospital ships embittered the invading troops.

Generals Alexander and Clark came from Naples during D-Day to observe the action. General 

Alexander came back three days later to check on 

the progress toward the distant Alban Hills. He 

seemed then to approve the decision by General 

Lucas not to send raiding columns into the growing 

assemblage of German forces but to insure retention of his beachhead base against the threat that 

rapid German reinforcement was forging.

To cope with German Air Force attacks, the 

Twelfth Air Force had provided a considerable 

Fighter Control Squadron for the assault force and 

had put fighter-director teams on ships, as at 

Salerno. They found plenty to do. The results were 

mixed. On the ships, the fighter-director team on 

H.M.S. Royal Ulsterman was not kept informed of 

the movements by friendly aircraft, and the team 

on LST 305 specialized in defense by night fighters. 

The “Y” party with the latter was equipped to intercept traffic on VHF, inaudible during the periods 

from dusk to dawn when the control party was on 

duty, and audible only when the controllers were 

off. On USS Biscayne, the flagship, a fighter-director party kept in touch with others ashore. On the 

destroyer escort Frederick C. Davis, which provided protection for follow-up convoys, a “Y” team 

that had served on it as an air-warning unit before 

Operation SHINGLE, was able during the Anzio 

operation to earn a warm commendation, particularly mentioning T/5 Eric Marx of the 849th SIS.9

The small team from Detachment “D,” 849th 

SIS, that went ashore on D-Day consisted of Lieutenant Pierre de St. Phalle and four enlisted men. 

They worked with the 82d Fighter Control 

Squadron.1o The main body of Detachment “D” 

came later from Naples. The team first operated 

from its vehicle beside the road from Nettuno to 

Littoria. On 31 January 1944 it shifted to a site near 

a water tower north of the prominent Villa Borghese and placed an antenna where DF reception 

was better. Dependent for rations on the 82d 

Fighter Control Squadron, the team aptly named 

that unit GRUBSTAKE for coded calls. Keeping in 

close touch with GRUBSTAKE, reinforced by three 
Page 92
Page 93

DF operators and better equipped, the unit gained 

experience and reported important information for 

all Air “Y” service.

The team tested different methods and found 

some worth describing. By attaching loudspeakers 

to both receivers, the duty officer was free to telephone information at once to fighter control while 

the intercept operator controlled the set. The two 

receivers could be tuned to catch traffic transmitted on alternate frequencies. The DF set was also 

connected to a loud speaker; directional bearings 

were determined by the yield at the speaker rather 

than by using earphones and a carrier indicator. 

That arrangement improved the DF results.

When the unit began getting data from POW 

interrogations and documents that revealed the 

identities of many German units, their locations, 

types of aircraft, and state of training, its production improved correspondingly.

The “Y” detachment was able to aid the air 

warning service in determining the need for an air 

raid alert. It passed warnings to probable early targets of enemy air attacks as shown in radioed 

reports of enemy air observations.

From Landing to Stalemate

Although General Lucas, the VI Corps commander, was eventually relieved, as his predecessor 

at Salerno had been, his decision to consolidate his 

hold on the Anzio beachhead before sending a column charging the enemy's line of communications 

seems today to have been the wiser course. The 

enemy reacted to the Anzio landings with amazing 

speed and power. General Clark and presumably 

General Lucas had known from special intelligence 

that the Germans had been preparing, by reorganization and reinforcement, to counterattack near 

Cassino and that no major German formation was 

in a position from which it could counterattack at 

Anzio before the VI Corps was well ashore. They 

learned, however, during the morning of D+ 1, that 

the enemy was moving quickly to challenge them.

Kesselring concluded that his line farther south 

could hold without the reinforcements that had just 

begun to take their places there. Headquarters, XIV 

Panzer Corps resumed the control of divisions it 

had assigned to the I Parachute Corps. That command, directly under Kesselring, was shifted to 

control other troops being sent to Anzio.

The enemy sent “pick-up” formations from the 

Rome area, called back others from the Liri-Sacco 

valley, brought one division from the Adriatic side 

and others, more slowly, from the Balkans and 

southern France. To control the buildup and launch 

the counterattack, Headquarters, German Fourteenth Army (General Eberhard von Mackensen) 

was summoned from Verona. By 25 January 1944 

he was in charge at a command post near Rome. 

Four days after the landings had begun, elements 

of eight German divisions were already in place and 

five more divisions were en route. Special intelligence kept General Lucas aware in detail of the 

German regrouping.

VI Corps was ready on 30 January to expand 

the beachhead by attacking near the flanks. First, 

General Lucas sought to take Campoleone on the 

left and next, Cisterna, on the right. Campoleone 

was taken at considerable cost. The enemy, ready 

for the other thrust, ambushed and decimated the 

Rangers and checked the 3d Infantry Division 

short of Cisterna. The enemy’s line had almost broken by the time VI Corps broke off the attack on 1 

February and reorganized to meet the coming series of local German counterattacks and a German 

effort to drive the Allies back to the sea.

The Allied offensive began just before Kesselring believed his own forces could start their push. 

On 3 February Fifth Army learned from SIGINT 

how he had planned his main counterattack, and 

that he had hoped (in vain) to start it two days 
Page 94

earlier.11 Only on 15 February, however, did the 

suspense end and the big attack begin. It had become apparent that the enemy was concentrating 

near Aprilia for a drive from the northwest on a 

narrow front. Attacks elsewhere would be local and 

diversionary.

By that time, VI Corps had about 350 tanks and 

498 guns, and had established a good system of resupply. Although medium tanks could not operate 

effectively on the semisaturated marshland and 

mud between the roads, immobilized tanks could 

supplement field artillery. Assembled enemy troops 

would find little shelter anywhere from concentrations of Allied artillery fire.

The German thrust down the main road between Albano and Anzio on 16 February drove a 

gap between British and American troops. Next 

day, a heavier ground and air attack exploited that 

gap. Overrunning the 2d Battalion, 157th Infantry, 

45th Division, they caused the desperate battalion 

commander, under orders to hold at all costs, to 

warn the regimental commander of his plight. The 

tactical information that he radioed was quickly 

read by German SIGINT personnel and exploited 

by the attacking forces.12 The enemy’s attack was 

weakened by Allied artillery and checked by determined infantry. It came to a faltering stop on 20 

February, still short of the “final beachhead line.” If 

it represented the strongest drive that the enemy 

could mount, the Allies were at Anzio to stay.

Detachment “E,” 849th SIS (nineteen personnel) and an element (seventy-nine personnel) from 

the 128th SRI Company, as the VI Corps “Y” Unit, 

were at Anzio. Its advance party, carrying three 

VHF receivers, landed on D-Day. The remainder 

came ashore with Headquarters, VI Corps, on D+ 

5. As the enemy formations moved to face VI 

Corps, the “Y” team strove to identify and locate 

them. Differing characteristics of the communications procedures of divisions and artillery units 

made that problem easier to solve.

849th SIS Mediterranean Theater (3916th Signal Service Company) intercept van with double 

bank of receivers (BG 342 and BC 344) and the S-36 (VHF) in the middle

(Photograph from the NSA History Collection)
Page 95

During General von Mackensen’s preliminary 

attacks, a German battle group on 8 February 1944 

was supposed to secure a mound known as Hill 72 

and to join the enemy’s thrust at Aprilia. SIGINT 

disclosed that the battle group was too weak and 

that it was staying on Hill 72, thus exposing the left 

flank of the enemy’s attack for the defenders to take 

advantage of.

When a noon message on 15 February 1944 revealed that the 29th Panzer Grenadier Regiment 

had come into the line at Carroceto next to the 

809th Infantry Regiment, it tipped off VI Corps to 

the imminence of a stronger enemy offensive there. 

On 20 February, the last day of that attack, the VI 

Corps Unit decrypted orders sent to the 105th 

FLAK Regiment to fire, between 1720 and 1750 

hours, a total of 2,600 rounds on Allied troop concentrations along certain routes of approach. G-2 

thus warned the troops at least one hour in advance 

of the shelling.

During the German counterattack, Major General L. K. Truscott, Jr., commanding general, 3d 

Infantry Division, became General Lucas’s deputy 

commander. After it ended on 22 February, he relieved General Lucas as commanding general, U.S. 

VI Corps.

General von Mackensen made one more attempt. On 22 February 1944 he began regroup- ing 

for it, and SI disclosed that it would come on the 

other flank, along the axis of the Cisterna-Nettuno 

road. By the time it could be started, on 29 February, General Truscott knew what enemy forces 

would be committed and had regrouped his own 

formations. Allied air support was also primed. for 

it. By the second day, the enemy knew that this 

counterattack would also fail. As skies cleared on 2 

March, Allied bombers struck behind his lines and 

Allied ground troops dispersed all attempts to penetrate the beachhead. Kesselring had already 

decided to go on the defensive both at Anzio and 

the Gustav Line.

In March 1944, since the Allies had found 

themselves unable to break through near Cassino 

and the enemy had proved himself unable to crush 

the Allied forces at Anzio, the situation on both 

fronts was a stalemate. That condition lasted more 

than two months, until 11 May. The opposing forces 

sparred and jabbed. The Allies reinforced the Fifth 

and Eighth Armies, regrouped, accumulated fire 

power, wore down the German Air Force, and by 

extensive training got ready for the May offensive.13

During the long stalemate, as before it, enemy 

artillery fire struck endlessly at targets throughout 

the beachhead. Protection was achieved by digging 

in, by camouflage and smoke. “Anzio Annie,” nickname for any of the colossal railroad guns fired by 

the enemy, dropped shells from great distances. 

Detachment “E,” 849th SIS developed some special 

methods for coping with German artillery fire. It 

compiled detailed records of each German artillery 

group, the location and alternate location of its batteries, each fire mission and the rounds fired. Voice 

frequencies were continually watched. All radioed 

reports were tabulated in order to verify the number of rounds fired and the ammunition still on 

hand. Enemy reports of Allied counterbattery fire 

were used as correction data for Allied guns, and as 

SIGINT stalked the positions of certain enemy batteries, they were ultimately broken up by hits and 

forced displacements.

The Liberation of Rome — 4 June 1944

The spring offensive for which the “Allied 

Armies in Italy” had been preparing was scheduled 

to start when it might have the effect of keeping 

forces in southern France away from the forthcoming cross-Channel attack. On the southern front, 

General Alexander’s attack began with an unprecedented artillery preparation an hour before 

mid-night on 11 May 1944. On the Anzio front, the 

Allied offensive was timed to begin several days 

later, after reserves available to Kesselring might 

have been committed to holding the Gustav Line. 

Subsequent success in breaking out from the Anzio 
Page 96

beachhead might then, by threatening to block the 

long, motorized lines of communications to German Tenth Army, contribute to the progress of the 

southern attack.

The Allies had extended the Eighth Army to 

cover a wider front from the Adriatic southwestward. It faced the hitherto impregnable 

Cassino- Monte Cassino section of the Gustav Line 

and the adjacent Liri River Valley. Fifth Army’s 

French Ex- peditionary Corps, greatly enlarged to 

almost 100,000 men, was now ready to break into 

other mountainous parts of the enemy's defense 

system. From the Tyrrhenian Sea inland to the 

Minturno area was U.S. II Corps, consisting of the 

88th and 85th Divisions; in II Corps reserve was 

the 36th Division. In the Anzio beachhead under VI 

Corps were British 1 and 5 Divisions, U.S. 1st Armored, 3d Infantry, 34th and 45th Divisions, and 

1st Special Service Forces. 

The enemy’s Fourteenth Army at Anzio included two corps headquarters controlling eight 

divisions to contain the Allied forces and guard the 

coast north of Anzio. The German Tenth Army had 

two corps and ten divisions. In reserve were the familiar 26th Panzer and 29th Panzer Grenadier 

Divisions, the 90th Panzer Grenadier Division and, 

in the Leghorn area, the Hermann Goering Panzer 

Parachute Division.

Allied air superiority amounted to a ten-to-one 

advantage in aircraft. The German Air Force could 

manage only weak and infrequent strikes at the 

port of Naples and at the shipping off Anzio, while 

Mediterranean Allied Air Force (MAAF) had rendered the railroads unreliable south of Florence, 

and so had forced extensive resort to trucks. Along 

the coast Allied bombers struck enemy ships and 

ports.

The French Expeditionary Corps overcame desperate resistance in the mountains west of the 

lower Garigliano and immediately south of the Liri 

valley during the first eight days of the May offensive and broke through the Gustav Line. It helped 

both the Eighth Army on its right and the U.S. II 

Corps on its left. The latter also drove through the 

Gustav Line and captured Formia, Gaeta and Itri. 

Tactically, Allied success reflected accurate intelligence concerning the locations of enemy strong 

points, their artillery observation points, and the 

best routes for Allied penetration and encirclement. Strategically, the offensive quickly drew 

miscellaneous units to confront II Corps, after one 

German division there had been demolished, and 

attracted the 26th Panzer Division to try to stop the 

French Expeditionary Corps.

The enemy made a determined stand at Fico 

because of its importance in a defense line extending northeastward to Ponte Corvo, the next set of 

defenses beyond the Gustav Line. The French took 

Pico on 22 May. They had then advanced so far beyond the Eighth Army in the Liri-Sacco Valley that, 

for a time, General Alexander weighed the merits of 

swinging the Fifth Army northward to reach that 

valley. Despite heavy casualties, Eighth Army began 

crumbling the defenses it faced; so Fifth Army continued generally northwestward along the 

Tyrrhenian coast.

On 24 May II Corps was able to drive the Germans out of Terracina, where Highway No.7 ran 

along a narrow shelf between mountains and sea. 

That made it possible to link the two segments of 

Fifth Army by overland communications. And it 

enabled II Corps to bring more of its forces by land 

to join the 36th Division, which had gone to Anzio 

by sea, and to assume responsibility about one 

week later for pursuit of the enemy along Highway 

No. 6 to Rome.

By the time the Allied breakout from Anzio 

beachhead had begun on 23 May, the enemy was 

trying to bring the German Tenth Army back to the 

last prepared belt of defense south of Rome, that 

extending between Ardea near the coast to Avellano. It was not as strong as the Gustav Line had 

been but, south of the Alban Hills between Velletri 

and Campoleone Station, it was most formidable.
Page 97

On 23 May 1944 General Truscott sent the 1st 

Armored Division, on the left, and the 3d Infantry 

Division, on the right, across the sector of the 

beachhead line held by the 34th Division, that between Carano and Conca. The objective was to take 

Cisterna, block Highway No.7 between Cisterna 

and Velletri, and control the approaches to the gap 

north of Cisterna between the Alban Hills and the 

Lepini Mountains. Cori, northeast of Cisterna, and 

Velletri, northwest of it, were to be separated by 

further advances toward Valmontone in the valley 

and to Artena, on the southern edge of the gap. Although Cisterna was strongly defended, it was 

isolated and captured, while Cori, and beyond it Giulianello, were taken.

The enemy’s counterattacks were scattered and 

weakened by heavy Allied air attacks on jammed 

roads and by other factors that denied him opportunity to coordinate his efforts. During the fluid 

battle, Allied SIGINT was the main means of locating enemy units, though air reconnaissance noted 

concentrations and interrogation of prisoners 

yielded identifications. The enemy at one time was 

desperately trying to bring in armored reinforcements on the same roads that broken units were 

using to move in the opposite direction.

As Combat Command B, 1st Armored Division, 

headed for Cori on 24 May, a message sent by the 

German 105th FLAK Regiment divulged the location of a strong antitank barrier of mines and guns 

in the planned path of approach. Warning came in 

time to reroute the American force, which successfully eliminated the position and forced large 

numbers of enemy troops to surrender.

SIGINT also disclosed the enemy’s reactions to 

Allied progress. An element of the German 715th 

Division reported at 0910 hours an Allied breakthrough near Cisterna on 24 May and its own 

withdrawal northward to Bassiano. At 1608 another report described the Allies as again attacking 

Cisterna from the direction of Privorno. Later that 

day the 105th FLAK Regiment reported that the 

Genzano-Velletri road, close to the Alban Hills, was 

impassable because of bomb craters.14

On 26 May General Clark stopped VI Corps 

short of its original objective and switched the axis 

of its attack, sending it along the southwestern 

fringe of the Alban Hills to hit the enemy’s prepared main line of resistance between Velletri and 

Campoleone Station. II Corps was made responsible for the Allied line from the Lepini Mountains to 

Velletri, on the right of VI Corps.

Arrival of the Hermann Goering Artillery Regiment was noted on 26 May, and by 280150 Fifth 

Army reported that DF bearings on a Hermann Goering Panzer Regiment showed it to be moving 

along Highway No. 6; other PEARL items indicated 

that the main body of that division was in the valley, west of Valmontone. It held the 3d Infantry 

Division away from Highway No. 6 for several days.

Velletri was located on heights and approachable by draws that cut into terraced hillsides. 

Taking it was a job for infantry, not armor, and was 

unsuccessfully attempted by the 1st Armored Division for several days before they handed it over to 

the 36th Division and shifted to the attack on the 

Campoleone section of the enemy’s line. Lanuvio 

and Velletri held after Ardea and Artena both succumbed on 30 May. During the night of 30/31 May, 

the 36th Division climbed up Mt. Artemisio, where 

the enemy had depended for defense on the terrain, 

after shifting troops to other points where they 

were even more needed. Elements of the 36th Division moved over the hills and blocked the roads 

from Nemi and Genzano to Velletri as well as cutting Velletri off from Valmon tone. The Americans 

withstood a counterattack on 1 June and then took 

Velletri, while the enemy’s last bastion, at Lanuvio, 

held out one more day.

During 31 May “Y” units were able to report the 

locations, and reduced strengths, of elements of the 

105th FLAK Regiment, the 93d Artillery Regiment, 

and the 33d Artillery Regiment. By DF they located 

the command posts of the 334 Division, 1st 
Page 98

Parachute Division, 15th and 26th Panzer Division, 

115th Regiment, a tank regiment of the 26th Panzer 

Division, and a battle group based on the 67th Regiment. It was obvious that the enemy’s forces had 

been configured into improvised aggregations at 

various points, and that the retreat by large units 

behind stalwart rear-guard actions resulted in neither a rout nor a wholly orderly retreat. That night, 

German units were heard calling for artillery fire on 

designated areas and reporting where they thought 

the Allies would next strike.15

The German SIGINT service also supplied information of immediate tactical value to its 

commanders. One instance that impressed them 

enough to be remembered vividly in detail involved 

the French Expeditionary Corps. Its role in breaking through the Gustav Line was outstanding. Its 

drive through mountains toward the German line 

of communications in the Liri-Sacco Valley showed 

remarkable skill in adapting tactics and organization to the situations that arose. But on 31 May, 

French units in the vicinity of Gorga transmitted, in 

the clear, messages which enabled the Germans to 

avoid a critical situation. Higher German headquarters had believed that Allied forces were then 

in the vicinity of Carbineto. A German divisional 

intercept team learned from French messages that 

the 2d Tabor of Goums had already cleared Monte 

Pilocco and was going to Gorga for the night.

Gorga was so situated that it would have blocked 

German retreat in that whole sector. If the French 

had carried out their plan and had taken advantage 

of the favorable terrain, they could have disrupted 

German motor transport on the Via Casilina. The 

headquarters of the 29th Panzer Grenadier Division at Villa Magna would have had to surrender or 

run the gauntlet at great cost. The Germans instead 

were able to concentrate in time a force in Gorga 

that held the place for two more days while all other 

German units succeeded in getting out.16

On 2 June SIGINT showed that the German 

Army ration dump at Frascati would close that 

night; two nights later, the next issue of rations 

would be at a dump four kilometers north of Bracciano, well beyond Rome.17

On the first three days of June 1944, the Fifth 

Army advanced its line to the edge of Rome from 

the southeast and east. Highways No.5, 6, and 7 

and intermediate shorter roads through the suburbs of Rome were the scene of stubborn defensive 

measures to gain enough time for German Fourteenth and Tenth Armies to pass through or around 

the city. Into Rome went the 1st Armored Division 

(from VI Corps), an element (Task Force Howze) of 

that division operating with the 1st Special Service 

Force (from II Corps), and elements of the 88th Division. The welcoming crowd did what German 

troops could not accomplish: they forced the tanks 

and other vehicles to stop.

The city escaped any significant combat as the 

Germans pulled out and allowed Allied seizure intact of bridges across the Tiber. The Allied troops 

that entered on 4 June were followed by more, but 

none was allowed to linger. The enemy had to be 

pursued and pressed before he could reorganize, 

reequip, and construct another intricate defensive 

line.

On 6 June 1944 came the Normandy landings, 

executed in part by troops, commanders, naval 

forces, and airmen seasoned in the Mediterranean 

or trained in the light of the campaigns there. In the 

ensuing campaigns in western Europe, not only 

they but the SIGINT organization that served them 

would reflect lessons learned in the Mediterranean.

Notes

1. See Garland and Smyth, Sicily and the Surrender 

of Italy.

2. 849th SIS Report on Voice Intercept during Initial Phase of Operation AVALANCHE, 2 Oct 1943, by 

First Lieutenant Pierre de St. Phalle, Sig C; Log of 

“SALE” messages received from 329 Wing, Algiers.

3. VI Corps, G-2 Jnl, 14 Sep 1943.

4. Ibid.
Page 99

5. Fifth Army G-2 Biweekly Report, 16 Oct 1943. G-2 

Jnls, 1943-45, NARC Box 184.

6. Report, Adv Hq. FUSA, SIG I and Radio Intelligence Activities, Inclosure No.1, 20 Jan 1944, “Extracts 

from answers by the Signal Officer, Fifth Army, dated 6 

Jan 1944, to a questionnaire submitted to him by the 

Signal Officer, First Army.” AHS A52-20 Box 34/3 

Folder: 322. 

7. Fifth Army, Signal Section, Lessons Learned during the Campaigns in Italy. Fed Rec Ctr, Suitland, Md., 

105-04.

8. MAAF SIGINT Service, “Results Obtained from 

Study of Airborne R/T Logs,” 1 Aug 1944, by First Lieutenant J. D.Simmonds, RAF.

9. Besides Rear Admiral Lowry’s commendation of 

15 Feb 1944, Lieutenant Commander R. C. Robbins, 

USNR, commanding DE-136, on 1 December 1943 

transmitted to CO, 849th SIS, a message received from 

a sister ship that “Your ‘Y’ team certainly saved our 

lives.”

10. Report on Voice Intercept during initial Phase of 

Operation SHINGLE, 10 April 1944, by Lt. St. Phalle, 

Sig C, 849th SIS.

11. CX/MSS (Ser 2) 83/T7.

12. Remembered as an example during an interrogation of captured German generals at the end of the war. 

AFHQ Records, Reel 89-1. See also 45th Division, G-2 

Jnl, 16-18 Feb 1944. (Seen at Suitland.) Study of the 

157th Infantry Regiment’s S-3 Jnl for February 1944 

shows that the 2d Bn, 157th, had assumed control of its 

part of the front line during the night of 15/16 February, 

an hour before the enemy opened up his heavy artillery 

preparation. For the next four days it was under successive tank-infantry attacks. The enemy alternated 

between the 2d Battalion, 157th and adjacent British 

units, but on 18-19 February, concentrated on the former until night bayonet attacks seemed to have cleared 

the way for infantry infiltration and then a tank-infantry 

exploitation. Twice on 19 February the battalion requested help. When at noon the enemy sent an attacking 

infantry column down the road to break through, that 

column was cut to pieces by artillery, mortar, and longrange machine-gun fire. A somewhat similar decimation 

by Allied artillery had occurred during the previous 

night on another road. On 20 February the enemy’s intermittent artillery fire seemed intended to discourage 

Allied interference with the removal of his vehicles and 

the digging in at his forward positions.

13. SI produced long reports of plans and timing as 

well as of the current situation to the Fuehrer from DB 

Suedouest (Kesselring), 28 Feb and 1 Mar 1943.

14. Fifth Army, G-2 Jnl, Sitrep, 24 May 1944; Fifth 

Army, ISUM No. 260, to 252200 B May 1944, PEARL 

Section, Sigs I, G-2; Hq, AAI Sitrep, 25 May 1944, 

PEARL Items.

15. Fifth Army ISUMS Nos. 226-267, PEARL Section.

16. AFHQ Microfilm Reel 26A, AFHQ Intell Notes 

No. 68, 8 Aug 1944.

17. HQ, Allied Armies in Italy (AAI), ISUM No. 822.
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Page 101

Pursuit to the Arno and Beyond

The German strategy of resolutely defending 

successive belts of prepared positions across Italy 

south of Rome enabled the enemy to absorb Allied 

offensive power while inflicting heavy losses. It 

used up Allied resources that might have been used 

elsewhere, perhaps more injuriously. The same 

could be said, however, about the German divisions 

that remained in Italy instead of providing in 

France the defense in depth that might have turned 

the scale in the invasion of Normandy. The concept 

of the defensive line sustained the mistaken notion 

that battles were for territory rather than for the 

destruction of hostile firepower. On Hitler’s specific orders, place after place was held “at all costs”; 

the resulting action became more brittle than elastic. Once the Gustav-Hitler Line was pierced 

anywhere by strong forces, the whole line was 

threatened, and the formations had to pull back to, 

or through, the next line south of Rome. No matter 

how well executed, the retreat and rear-guard actions were inevitably costly. 

Four of the German divisions emerged from the 

Allied offensive below Rome as mere shells. Seven 

others were drastically depleted. On 5 June 1944 

both the German Tenth and Fourteenth Armies 

were weak and in retreat. A persistent, ruthless Allied pursuit could then have harried them swiftly to 

the outposts of the incomplete “Gothic Line” across 

Italy, north of the Arno River and through the 

Apennines to the Adriatic near Pesaro. Allied pursuit was neither strong nor quick, while the 

opportunity was most promising, but German reinforcements, including four new divisions, were 

speedily moved to northern Italy from the Balkans, 

Denmark, Holland, and Germany. Fourteenth 

Army received a new commander, General Joachim 

Lemuelson, on 6 June, in place of General von 

Mackensen. Kesselring intended to delay the Allied 

advance at every advantageous intermediate position so that the Allies would, at best, reach a belt of 

defenses north of the Arno too late to break through 

the Po Valley before winter.

For a few weeks it remained uncertain whether 

Alexander’s 15 Army Group would be allowed to remain at full strength until its adversaries in Italy 

had surrendered. An alternative claim upon some 

of the resources at his disposal would be an Allied 

amphibious invasion in southern France. That operation had been included among understandings 

between the Allies and Stalin; it had been a goal of 

the militant French at least since 1942 and perhaps 

since 1940. As a method of facilitating the success 

of Operation OVERLORD, the earliest possible invasion of southern France would be more than two 

months too late. As a contribution to Allied success 

in overcoming Germany, it might be argued that 

pushing all German forces from southern France 

into northern Europe would not accomplish anything more valuable than would defeating 

completely all German forces that could be drawn 

into northern Italy. Advocates of a campaign in 

southern France, to include the capture of Marseilles, finally prevailed at about the same time that 

the Germans were able to arrest the Allied pursuit 

north of Rome. The U.S. Seventh Army, commanded by General Alexander Patch, would land in 

southern France – Operation DRAGOON.

Transfers from the U.S. Fifth Army to the U.S. 

Seventh Army, for participation in Operation 

DRAGOON, took away from 15 Army Group the 

U.S. VI Corps of three divisions, the French Corps 

of four divisions, plus many nondivisional American units. In Italy IV Corps took over from VI Corps 

on 11 June 1944. The French left a month later. 

Many of General Alexander’s supporting air 

Chapter 8

The Final Months in the Mediterranean Theater
Page 102

formations were switched t0 support of Seventh 

Army. Thus, at the same time that Kesselring’s 

Army Group C was being replenished, the Allied 

force opposing him was reduced. After Hitler 

learned of the Allied reorganization, and in the face 

of crumbling German defense on both Eastern and 

Western Fronts, he withheld some of the reinforcing divisions promised to Kesselring. Eventually 

both the U.S. Fifth Army and British Eighth Army 

were strengthened in time for the final push to the 

floor of the Po Valley.

At first the Allied pursuit in June 1944 was led 

by the French Corps. After the French were withdrawn t0 embark for their return to France, Fifth 

Army moved up to the Arno River, with U.S. IV 

Corps along the west coast, U.S. II Corps further 

east, and, British Corps on the eastern wing. Ancona and Leghorn were captured on 18/19 July as 

valuable ports to support the renewed Allied drive. 

British Eighth Army successfully masked the swift 

shifting of the bulk of its strength to the Adriatic 

sector. Instead of making the main effort directly 

north of Florence through the Futa Pass and along 

the Florence-Bologna highway No. 65), 15 Army 

Group struck along the Adriatic coast. Eighth Army 

broke through the Gothic Line, took Rimini on 4 

September but stopped short of Ravenna. After 

Kesselring had moved troops eastward from the 

center of his line, in order to hold the Eighth Army, 

the Fifth Army on 10 September-began its attack; it 

started as the pursuit of a withdrawing enemy. On 

13 September, however, the Americans reached the 

main German defenses and fought a hard battle. 

Near Firenzuola, II Corps found a way to outflank a 

key pass on Highway 65 and thus to start working 

down through the northern mountains toward Bologna at their base. On 27 October, when Kesselring 

rushed troops to check that attack short of Bologna, 

Eighth Army resumed its advance. On 4 December 

it finally captured Ravenna, but it had reached an 

area of streams, marshes and lakes fed by the rains 

and snows of winter, where the roads were often 

causeways. The terrain was reminiscent of the 

Anzio beachhead in those respects. 

Italian Fascist forces fighting for Mussolini’s 

government on the side of the Germans tried in the 

Senio Valley during Christmas week to duplicate 

the contemporaneous Ardennes offensive, on a 

smaller scale. It was a feeble effort. 

From January through March 1945, stalemate 

along a static front prevailed among the ground 

troops. On both sides, important changes in command occurred. Kesselring went to Germany to 

direct the final defense. Vietinghoff moved up to 

become Oberbefehlshaber Sudouest, commanding 

Army Group C. Lieutenant General Traugott succeeded him in command of German Tenth Army. 

From AFHQ at Caserta, Field Marshal Sir Henry 

Maitland Wilson went to Washington to take up 

the mission there of the late Field Marshal Sir John 

Dill in the Combined Chiefs of Staff. General Alexander succeeded him as Supreme Allied 

Commander, Mediterranean Theater, and General 

Clark left U.S. Fifth Army to succeed Alexander as 

commanding general, 15 Army Group. General Oliver Leese turned over British Eighth Army to 

Lieutenant General R. C. McCreery in order to 

move to Burma. To command the Fifth Army, Lieutenant General Lucian Truscott was brought back 

from U.S. VI Corps, then in France.

The I Canadian Corps and its two divisions left 

Eighth Army for western Europe to join the First 

Canadian Army in the 21st Army Group. Fifth 

Army gained the new U.S. 92d Division and the 

specially trained U.S. 10th Mountain Division.

Po Valley and Surrender

The renewed Allied drive through German defenses shielding the Po Valley opened on 2 April 

1945 with diversionary operations on the two 

coastal wings. A week later, preceded by an extremely heavy artillery and air bombardment, the 

Eighth Army headed for Ferrara and Bologna. On 

14 April Fifth Army attacked on a relatively narrow 

front along mountain streams and over adjacent 

heights, to approach Bologna from the south and 

southwest. In turn, each army shared the benefits 
Page 103

of Allied air supremacy in support of its offensive. 

By nightfall on 20 April both Fifth and Eighth 

Armies had come to the valley floor, where mobility and armor could begin to play decisive roles.

The enemy had not been permitted by the highest command to develop strong defenses along the 

northern bank of the Po River and in the foothills of 

the Italian Alps. Since Allied bombers had destroyed all bridges across the Po, the enemy had to 

lay pontoons, to use boats and ferries, and after 

crossing, to develop defenses hastily that might 

have been better built if done during the previous 

winter. To reach the river he had to cross terrain 

that furnished little shelter from air observation 

and harassment. He was already short of fuel. 

Heavy vehicles and weapons had to be abandoned 

on the south bank. Moreover, the extensive road 

net in the valley offered the Allies an opportunity to 

separate the German forces into segments, and to 

cut them up further until their remaining forces 

were fragmented and their resistance uncoordinated. Hundreds of road blocks hampered retreat. 

Allied fighter-bombers and Italian partisans supplemented the guns of Allied ground units.

During the last ten days of April, as Eighth 

Army unhinged the last German defense line and 

both armies closed in at Bologna, Allied armored 

units began their deep penetrations, shattering 

German control of many towns at the centers of 

road nets. Part of the enemy got across the Po, 

leaving tanks and about 50,000 prisoners behind. 

As the Germans moved toward the mountains in 

the north, Allied forces also crossed the river in 

time to intercept and capture many more.

For several months, beginning before Kesselring had gone to Germany, highly secret negotiations 

for surrender in Italy had been conducted on neutral ground by representatives of AFHQ and certain 

German commanders in Italy who could see no 

benefit to be gained by further sacrifices. On 29 

April, at Caserta, the surrender was signed, to be effective at noon on 2 May 1945. By that time, Hitler 

was dead; surrender to the Anglo-American Allies, 

the Russians, and the French would end all hostilities in Europe in less than a week.

Negotiating the German surrender in Italy was 

not easy. On the Allied side, one impediment was 

the suspicion of the Soviet Union that the AngloAmericans would make a separate peace 

detrimental to Soviet interests. Having yielded to 

opportunism in the Nazi-Soviet Pact of 1938 and 

having been willing to meet von Ribbentrop to discuss an accommodation in 1943, they could fear a 

similar opportunism on the part of the Allies.

On the German side, the main difficulty arose 

from the divisions among them and from the intention of some officials to extract advantage from the 

way the cease-fire eventually came. The German 

Army and Luftwaffe officers were burdened by a 

personal oath to Der Fuehrer. The initiative and 

momentum of negotiations was maintained by an 

SS general directly under Himmler, a regional 

commander who saw no point in continuing a 

hopeless struggle in Italy. He was sustained by a 

German diplomat, Dr. Rudolph Rahn. Lesser officers and officials brought them into touch with 

American and British representatives in Switzerland. The train of negotiations began on 25 February 

1945 and ended about two months later, on 29 

April 1945, after the Allied offensive into the Po 

Valley had succeeded.

First, the negotiators on each side had to demonstrate their good faith. Then they had to insure 

that terms once agreed upon by representatives 

would be executed by the principals. At that point 

in a series of meetings, when unwillingness to accept the personal risks of ending the war in Italy 

seemed to have been overcome, the Combined 

Chiefs of Staff (CCS) in Washington, responding to 

a Soviet protest, on 20 April 1945 ordered termination of all contacts.

A week later the CCS had been persuaded to reverse that order; soon arrangements had been 

completed for emissaries of General Heinrich von 

Vietinghoff, the principal German commander in 
Page 104

Italy, to be taken to Caserta to complete and sign a 

document of surrender in the presence of a Soviet 

general. That transaction occurred on 28-29 April 

1945. The time for all hostilities to end was set at 

1400 hours, 2 May. That would allow enough time 

for the German envoys to return from Caserta via a 

French airfield, then by ground transport across 

Switzerland into Austria, and thence to Bolzano in 

Italy. Italian partisans and German police were 

avoided only to find that at Headquarters, O.B. Sudouest, and among the German Army commanders, 

an unwillingness to issue the necessary ceasefire 

orders persisted. Even after Hitler was known to 

have killed himself and the end had come for Nazi 

Germany, turmoil in Italy persisted. The orders did 

go out in time, but the instrument of surrender was 

not officially validated until later that afternoon.

On 4 May 1945 German and Allied staff officers 

began spelling out the processes of pacification. 

Two days later, in southwestern Germany Army 

Group G, facing General Devers’ 6th Army Group, 

surrendered.

After the surrender in Italy, General von Vietinghoff and some of his principal subordinates 

were interrogated about the role of SIGINT in their 

experience of command. They pointed out that they 

had been obliged to rely more and more on it 

because of the drying up of their other sources of 

intelligence. SIGINT provided data on activities in 

rear areas from which they might judge what the 

nature of future Allied operations would be SIGINT 

became the chief means of learning about reinforcements or reliefs by fresh Allied divisions. The 

communicators of Allied divisions had characteristic transmission traits. In view of the many different 

nationalities of the formations in British Eighth 

Army, reflected in languages, dialects, and to radio 

transmitters, it was easy to distinguish them. Traffic analysis showed the components of the Allied 

corps.

The communications among military police 

controlling highway traffic revealed Allied troop 

movements. Messages defining bomb lines 

disclosed places where streams were about to be 

crossed, or where other operations were impending.

During battles and pursuits, communications 

repeatedly revealed to German SIGINT teams the 

names of Allied officers and military units, artillery 

targets, bombing targets, and local tactical intentions. Bombing missions were compromised again 

and again in time to avoid damage by timely warning. If Allied aircraft were heard reporting that they 

had sighted concentrations of German tanks, the 

tank regiment was quickly warned. The generals 

were happy to say that in three-months’ time, only 

one tank of the 26th Panzer Regiment had been totally destroyed in an air attack. Whenever Allied 

bombers took off, German SIGINT furnished a 

general warning even before the target of the mission had been identified. Radio silences were 

considered to be indications of pending Allied offensive action.

German SIGINT was never acknowledged as 

such by the staff officers who used it. They adopted 

such euphemisms as “Reliable Source,” or covernames like “Ludwig Meldung” or “Otto Meldung,” 

whenever they referred to it. A rough appraisal 

rated the reliability of German SIGINT as 75 percent.

The SIGINT to which these interrogations and 

replies applied was tactical, not strategic. A German Army in Italy assigned the equivalent of a 

small Allied “Y” unit to most divisions. The German 

Supreme Command had ordered the inclusion of 

such a unit in every Army division, specifying that 

it consist of a noncommissioned officer in charge 

(NCOIC), two linguists, and three intercept operators. Equipment was to consist of one fixed and two 

pack receivers, reference books, and maps. The 

unit was expected to keep logs and, by traffic analysis, to reconstruct Allied networks. Its reports 

went to a corps unit able to provide competent interpretation.
Page 105

An Alsatian who had served in the German Afrika Korps as an interpreter was captured after 

serving in the SIGINT unit of the 29th Panzer 

Grenadier Division in Italy. He described the divisional intercept unit as operating four receivers in 

a radio vehicle at a site three or four kilometers forward of the division staff, with which it was 

connected by telephone.1

Southern France: Operation DRAGOON

The protracted efforts of 15 Army Group in 

northern Italy, before achieving victory there, could 

be attributed to the weakening transfers from the 

Fifth to the Seventh Army for the invasion of southern France in August 1944. That operation, and 

certain beneficial consequences that offset the arrested development of the opportunities in Italy, 

are summarized below. It should also be noted that 

until a few days before the landings, the prime minister persisted in efforts to reverse the decision to 

invade southern France, and he never became reconciled to it.

The southern invasion began shortly after Allied forces, far to the north, broke out of the 

hedgerow country in Normandy and began their 

swift advance across France. The troops of the U.S. 

Seventh Army came ashore on 15 August 1944 on 

portions of the coast between Toulon and Cannes, 

near the Gulf of Frejus. There the valley of the Argens River led inland, a natural invasion route to 

the two primary target areas – the coastal cities of 

Toulon and Marseilles and the inland valley of the 

Rhone River.

As the invasion forces approached southern 

France, the German radars that might have indicated their positions were jammed by transmitters 

of the 1st Signal Service Platoon (Special). The unit 

had spent several months on Corsica, identifying 

the sites of all German radars along the coast of 

mainland Europe and preparing for the critical occasion.2

After silencing German gun positions on islands and headlands, the Western Naval Task 

Force brought the troops of three divisions and certain special units to a series of beaches in bays and 

coves. The assault troops soon gained control of a 

beachhead extending inland about fifteen miles.

The German Army defenders were organized as 

seven infantry divisions. After the Germans became convinced that southern France was about to 

be invaded, one armored division started there 

from the vicinity of Bordeaux while the Allied convoys were at sea. Four of the German infantry 

divisions were stationed between Spain and the 

delta of the Rhone. One garrisoned Marseilles and 

another, Toulon. One held the area where the assault landings occurred. The coastal defenses 

resembled those that had recently been overcome 

in Normandy, but the tidal strip was much shorter 

because of the steeper pitch of the Mediterranean 

coastal shelf. Another difference was the ingenuity 

of the enemy in disguising gun positions as villas 

and other innocent structures. Perhaps not so different as it was surprising was the quantity of 

mines, moored offshore and buried in the earth 

near the water’s edge.

German Navy forces were not great. They occupied the French naval base at Toulon. One 

submarine moored there tried unsuccessfully, 

while escaping, to attack a large Allied ship. Two 

corvettes tried to reach Marseilles on the night of 

16/17 August but were sunk. Several small and 

speedy boats from that area and from the vicinity of 

Genoa made nuisance raids but accomplished little. From an old French battleship, perhaps one 

scuttled when the Germans moved into unoccupied 

France in Novem-ber 1942, a turret of great 340-

mm guns had been transferred to a cape south of 

Toulon and installed in a casemated position. It 

was adjacent to elaborate underground facilities for 

its crew and ammunition, and for defenders manning other guns emplaced nearby.

The German Air Force, greatly reduced and 

endlessly harried by Allied air formations, 
Page 106
Page 107

could assemble strength enough for a few attacks, 

generally at dusk. But for two previous weeks, Allied planes had struck several coastal areas, masking 

their actual choice of one for the assault, while 

damaging and destroying enemy defenses in them 

all. The results of such repeated bombings were 

supplemented by a final strike at the beachhead 

just before the landing craft approached on 15 August 1944. Perhaps 30,000 enemy troops were near 

the assault areas, and they were dazed and dispirited. The much larger number that might have been 

sent in as reinforcements could not be moved over 

destroyed bridges and disrupted roads or railroads 

with sufficient speed to equal the rate of Allied 

buildup. Allied air support from escort carriers and 

Corsican airfields was supplemented by new airstrips in the beachhead area.

Operation DRAGOON was a triumph attributable to the application of experience during 

planning, organization, training, and execution. 

Participants in earlier amphibious assaults were to 

be found at all levels, from commanders to GIs and 

able seamen. Vice Admiral Henry Kent Hewitt, 

USN, had been a naval task force commander in 

TORCH, HUSKY, and AVALANCHE. Lieutenant 

General Alexander Patch had commanded in the 

Pacific. Major General L. K. Truscott, Jr., had accompanied the Dieppe Raid by British Commandos 

and since then had had commands in TORCH, 

HUSKY, AVALANCHE, and SHINGLE. The 3d, 

36th and 45th Divisions had each been in one or 

more such assaults, and were veterans of tough 

battles ashore. Training under conditions resembling those in southern France had taken place in 

the Naples area. Moreover, after certain preliminary diversions and deceptions before daylight, 

the assault landings began in daylight. H-hour was 

0800 hours. And unlike earlier Mediterranean operations of the same type, they were preceded by 

heavy naval bombardment, as well as by air

 bombing. The success was no accident. Even an 

airborne force was dropped, for the most part, 

where it was needed.

On a misty morning, the troops approached the 

beaches through mine-swept lanes to find their inland objectives covered with clouds of dust and 

smoke. The left wing of VI Corps was the 3d Infantry Division, commanded by Major General John 

W. O’Daniel. Two of its regimental combat teams 

went ashore on opposite sides of a cape south of St. 

Tropez. Resistance was weak. Before noon the division CP was ashore. By nightfall, advance elements 

were about six miles inland. At midnight the inflow, in round figures, amounted to 16,000 men, 

2,150 vehicles, and 225 tons of supplies.

In the center of the assault was the 45th Division, commanded by Major General William W. 

Eagles, which landed smoothly without opposition 

at points along three miles of sandy beach. Land 

mines gave some trouble there, but before D-Day 

had ended, thousands more men and vehicles had 

landed. The troops overcame opposition at villages 

inland, and cleared the way for the division commander in the morning and the VI Corps 

commander in the afternoon to establish headquarters ashore.

The 36th Division, under command of Major 

General John F. Dahlquist, came in nearest to the 

Gulf of Frejus as the right wing. St. Raphael, on the 

northern shore of the Gulf, was a major objective. 

Despite the preparation fire and bombing, the invaders met considerable opposition. The plan 

called for eliminating enemy gun positions that 

covered the Gulf so that the waters could then be 

swept free of mines, after which assault troops 

would land during the afternoon of D-Day. The 

schedule could not be met. The earlier landings 

were accomplished in part by switching one regimental combat team (RCT) to a portion of the 

beach being used by a second RCT and in part, 

aided by naval gunfire, by clearing the enemy from 

headlands and high ground along the coast. The 

available beaches served for landing some 30,000 

men and 5,000 vehicles during the first three 

days, but only then could the sheltered beach at the 

head of the Gulf of Frejas be used.
Page 108

Late on D+1, General Patch was satisfied that 

the beachhead was firmly held. The French II corps 

under General De Lattre de Tassigny was then 

coming ashore despite an enemy air attack. Another French Corps would soon arrive. Patch’s 

Head-quarters, Seventh Army, left the USS Catoctin to occupy a villa near St. Tropez.

During the next two weeks the invaders gained 

control of the French coast from the border of 

Spain to that of Italy. Cannes and Nice were occupied by 30 August. A 1st Airborne Task Force in the 

hills and along the Var River, and a screening naval 

force offshore, protected the beachhead from possible depradations originating in northern Italy. On 

the western flank, French forces ashore and Allied 

naval units cleared the enemy from small ports and 

protecting islands. But the main objectives of the 

invasion were to gain two great ports – Toulon and 

Marseilles – and to press the German Nineteenth 

Army northward up the Rhone Valley, and perhaps 

destroy it.

In planning tactics, General Patch was able to 

disregard the risk of an enemy attack along an extended flank because from Special Intelligence, he 

knew that the Nineteenth Army had been ordered 

to retreat to the German lines much farther north. 

About two days after the landings began, Hitler ordered the withdrawal. On 17 August 1944, within 

five hours of their transmission, the orders conveying the decision had been decrypted and provided 

to SHAEF. General Patch thereupon sent a blocking force far ahead of the pursuing main body.

The 3d Division alone attacked up the Rhone 

valley while the 45th Division protected its east 

flank, and while the 36th Division and an armored 

task force tried, by a longer route, to block the German retreat at defiles near Montelimar or Livron. 

The attempted encirclement used a route through 

Sisteron and Aspres to the Drome River, which 

could be followed westward to the Rhone. Part of 

the 36th Division did not turn west but continued 

over the divide into the Isere River valley as far as 

Grenoble. Although part of the German forces 

avoided capture, about 57,000 men did not.

The French, moving westward from the bridgehead, encircled Toulon and began to invest 

Marseilles, while a naval force sought to open the 

way into Toulon harbor, past the islands and headlands on which German defenders remained. For 

about one week their 340-mm battery and some of 

the other guns defied the shells of Allied ships and 

the renewed Allied air bombing. On 26 August resistance there ended. Two days later, affected in 

part by news of the liberation of Paris and in part 

by the obvious strength of the Allied invading force, 

the enemy at Toulon and Marseilles surrendered. 

Remaining pockets of enemy in the coastal area 

were soon eliminated.

As early as 3 September, use of the port at Marseilles began while the demolitions were being 

cleared and repairs effected. In case Marseilles had 

held out longer or had been left unusable for too 

long a period, the Allies had cleared the mines at 

another port, Port de Bouc, some twenty miles west 

of Marseilles, and had opened a canal from that 

point to the Rhone River at Arles. By 25 September 

the captured beachhead was no longer needed; unloadings there had totaled more than 320,000 

men, 68,000 vehicles, nearly 500,000 tons of supplies and large amounts of gasoline. (At the end of 

hostilities in Europe, through the port of Marseilles, supplemented by Toulon and Port de Bouc, 

905,000 more men and over four million tons of 

cargo had moved inland.)

The arrival of French I Corps resulted in establishing a French Army “B,” temporarily subordinated 

to the U.S. Seventh Army but soon superseded by a 

French First Army which, like U.S. Seventh Army, 

came under the control of 6th Army Group. The 

latter, having moved from Bastia, on 15 September 

1944 assumed control at Lyon under Supreme 

Headquarters, Allied Expeditionary Forces. Seventh Army was then already in contact with the 

U.S. Third Army, first at Sombernon on 11 Septem-
Page 109

ber, and later at other points. On 21 September, XV 

Corps shifted from Third to Seventh Army control.

The tactical SIGINT service available to Seventh Army in the course of its invasion of southern 

France was inconsiderable by comparison with 

what came later. The VI Corps SIGINT unit consisted of the newly designated 3201st SIS 

Detach-ment (three officers and eighteen enlisted 

men) formerly known as Detachment “E,” 849th 

SIS, in combination with Detachment “B,” 117th 

SRI Company (3 officers and 105 enlisted men), 

and under command of Lieutenant Frederick V. 

Betts. The intercept operators had been working 

since March at a station on Corsica covering enemy 

traffic from southern France. The intelligence personnel had been preparing since June for the shift 

from Italy to France. They all sailed from Naples divided among three transports of the D+ 5 convoy. 

Assembling at St. Tropez, they moved 180 miles inland on 24 August to Aspres. A week later they were 

in Charnacles, and by 9 September were in the vicinity of Besancon when VI Corps, with all of 

Seventh Army, came under control of SHAEF.

The SIGINT unit at General Patch”s Headquarters, Seventh Army, consisted of five officers 

and twenty-six enlisted men. Detachment “B,” 

849th SIS, was combined with Detachment “A,” 

117th SRI Company (3 officers and about 143 enlisted men), and commanded by Captain Edward J. 

Heinen. The unit moved from Corsica, where it had 

been training with Lieutenant Bett’s detachment, 

to St. Tropez on the night of 30/31 August 1944. 

Three days later it moved almost 240 miles to the 

vicinity of Grenoble; by 20 September it was at Vesoul.

Relatively little use was made of tactical SIGINT during the landings and inland advance of 

Seventh Army, because of the fluid nature of the 

rapid advance, as the enemy withdrew. More important to Seventh Army’s pursuit was the 

monitoring of communications among its own forward units.

The 3151st Staff Information and Monitoring 

Company (SIAM), commanded by Captain Reinardo R. Perez, was an instrument for control by 

Seventh Army G-3 rather than for producing signal 

intelligence information for G-2. Fifth Army had 

had such a provisional unit from which it transferred all but a cadre to form the 3151st SIAM. After 

activation at Cecina, Italy, on 18 July 1944, the new 

unit assembled the personnel needed for its platoons. Besides a headquarters platoon, it consisted 

of platoons for each of two corps (U.S. VI and 

French II) and four divisions, supplemented by 

several liaison officers. Actual strength was 14 officers and 225 enlisted men.3

The platoons monitored all radio nets within 

Seventh Army for adherence to radio and cryptographic security instructions, but their main 

function became that of conveying to commanders 

the substance of messages passed at lower echelons 

that showed American positions, situations, and 

intentions. Instead of relying on periodic reports 

and other messages specifically intended to keep 

higher headquarters informed, the commanders 

benefited from what amounted to SIGINT about 

their own units. And from the SIAM company’s 

own radio nets the platoons copied, for their commanders, all tactical messages of consequence; the 

system was thus a means of prompt lateral as well 

as vertical movement of information. When enemy 

SIGINT was heard, it was, of course, passed to G-2 

via its SIGINT Section. During a pursuit like that by 

Seventh Army from southern France to Alsace, the 

SIAM company served its purpose so well as to 

draw observers from Third Army and 12th Army 

Group to see how that was accomplished.

One of the liaison detachments of the 3151st 

SIAM Company first reported that Seventh Army 

and Third Army reconnaissance units, the first 

from southern France and the other from Normandy, had made contact near Sombernon on 11 

September 1944.
Page 110

When XV Corps was transferred from Third 

Army to Seventh Army, it obtained a new SIAM liaison team on 29 September.4

After AFHQ had mounted Operation DRAGOON, the U.S. Seventh Army moved under 

SHAEF operational control and a little later under 

the administrative and logistical services of the European Theater of Operations, U.S. Army. As we 

have noted earlier in this history, the Mediterranean Theater shrank within a boundary that ceased 

to include southern France. The route through 

Marseilles and Toulon became that over which a 

tremendous volume of reinforcements and supplies reached the fighting front in eastern France 

and in Germany.

The Mediterranean became the secondary theater, as the Americans at least had expected. The 

cross-Channel invasion and the campaign in western Europe was executed by much larger forces 

using means and methods tested in the Mediterran-ean. Those campaigns were a culmination of 

Allied experience.

By 7 September 1945 two increments of the 

849th SIS had already returned to Fort Monmouth, 

N.J., from the Mediterranean Theater of Operations. One had been allocated to reinforcing the 2d 

Signal Service Battalion; the other was scheduled 

to augment the 3126th Signal Service Company 

(RI) for duty in the Pacific – events there made 

such deployment unnecessary. Both groups remained in the 849th SIS until its deactivation later 

that year.

Notes

1. AFHQ Interrogation Report, Microfilm Reel 98-1; 

AFHQ Intell Notes, No. 68, No.1 02, on Reel 26A.

2. The unit had previously prepared for operations 

to retake Kiska Island in the Aleutians, and after that episode moved to the Mediterranean. From Corsica it 

returned to the U.S. for redeployment to the Central Pacific. History of the SSA in WW II, Vol. X, 62-3.

3. Fifth Army organized the 3326th SIAM Company 

around a cadre from its provisional unit in September 

1944.

4. Historical Record Report, 3151st SIAM Co., 20 

Aug 1944.
Page 111

Part Two

Western Europe
Page 112

THIS PAGE INTENTIONALLY LEFT BLANK
Page 113

Derivation and Beginnings

The formation of SIS, ETOUSA, reflected both 

the early organizational concept of the SIS, War 

Department, and the experience gained overseas, 

particularly in the Mediterranean. When the United 

States became a belligerent in December 1941, both 

Army and Navy SIGINT centers in Washington operated in buildings of World War I vintage situated 

on lower Constitution Avenue and backing on Potomac Park. (Both structures survived until after 

the Korean conflict.) To cope with wartime requirements, each center moved to larger quarters which 

could be better segregated from non-SIGINT personnel of the same armed service. Each acquired a 

girls’ private school: the Army – Arlington Hall in 

Virginia; the Navy – Mt. Vernon Seminary in the 

District of Columbia. This narrative treats Army 

(and Army Air Forces) SIGINT production in 

ETOUSA, leaving Navy SIGINT operations for separate consideration.

The interception and processing of most nonmilitary communications, on which both Army and 

Navy had largely trained their SIGINT specialists 

before Pearl Harbor was attacked, were relinquished by the Navy to the Army altogether for the 

duration of the war. The Navy devoted its growing 

resources to the war at sea. When the war began, 

the Army SIS had six intercept units at fixed stations; it added a seventh (Vint Hill Farms Station 

near Warrenton, Virginia) in 1942, and five others 

before the war ended. Until 1943 those stations 

were unable to produce enough raw traffic for analysts to reach early solutions. As more stations and 

positions were added, radio and wire links to the 

Washington center were unable to deliver the swollen quantities; much raw traffic came by mail, 

reaching Washington from one to three months 

after it had been collected. IBM runs at Arlington 

Hall had to be deferred until the mail brought messages missing from series that had been partly 

transmitted electrically. Whenever a cryptosystem 

became readable, much back traffic became subject 

to exploitation. By 1943 it became apparent that 

tactical SIGINT had to be produced, as in World 

War I, by mobile units along the front in combat 

areas, and by processing centers in the theaters.

The Signal Intelligence Service, ETOUSA, was 

an American counterpart to the British “Y” Service, 

a part of the U.S. Army Forces in the European 

Theater concerned with producing and distributing 

what the Army then called “radio intelligence.” Its 

origins and organizational history reflected the 

tumultuous circumstances of expansion and reorganization of the U.S. Army in 1942-43. An 

important contribution to its operations was made 

by the British participation in training Americans 

to cope with the methods of German communicators of World War II, methods that had not been 

used during the prewar period.

As early as May 1941, before the Japanese attack on Pearl Harbor, the U.S. Army established a 

Special Observers Group in the United Kingdom. 

After the United States had become a belligerent, 

the observers were succeeded on 3 January 1942 by 

a Headquarters, U.S. Army Forces, in the British 

Isles (USAFBI), with a broad staff. In the Signal 

Section of that staff, the SIGINT service officer was 

1st Lieutenant R. J. Doney. Besides Captain 

Solomon Kullback at Bletchley Park, four young officers were student observers concerned with 

interception methods at fixed and mobile British 

Army and Royal Air Force stations. The Air Ministry agreed to train some American officers in the 

analysis of machine ciphers. The War Office 

considered the ways in which American radio 

intelligence units brought to the area might be 

Chapter 9

The Forming of Signal Intelligence Service, ETOUSA
Page 114

assisted to engage in operational training in the 

light of British experience. At Carrickfergus, Northern Ireland, a platoon of the 122d RI Company, 

under 1st Lieutenant Shannon D. Brown and 2d 

Lieutenant James B. Hubbard, manned an intercept station beginning on 15 May 1942.1

As we saw in Chapter I, the Army SIGINT effort 

was supervised by and responded to the Military 

Intelligence Service. That relationship prevailed in 

the theaters. When other sources of military intelligence dried up or became ambivalent and vague, 

the intelligence requirements placed on SIGINT 

became the more urgent.

The relationship of the War Department to 

ETOUSA (or other theaters of operations) affected 

the ways in which SIS, ETOUSA, was able to function. General Eisenhower, as commanding general, 

ETOUSA, received missions from the chief of staff 

of the Army, missions for the execution of which 

his own staff determined requirements of men and 

material. If possible, “Washington” met the requirements, though not without considerable 

transatlantic negotiation and inevitable delay.

In Washington the Army SIS claimed personnel, got them trained, and assigned them to duty 

with Signal Corps units. Once these troops arrived 

in an overseas theater, they remained under the 

command and control of the theater commander as 

exercised through the theater chain of command. 

When the Army’s chief signal officer or his representative visited ETOUSA, he was primarily 

concerned with technical matters. If the solution of 

problems required a departure from ETOUSA orders and regulations, such exceptions had to be 

authorized by the theater command. If differences 

arose between SIGINT and non-SIGINT unit commanders, they were resolved at higher levels in the 

theater chain of command.

In ETOUSA, the commanding general allocated 

resources to Army and Army Group, or to the Services of Supply. The components of the theater SIS 

could, however, be attached for rations and supply 

rather than assigned to a field command and could 

thus remain under the operational control of the 

director, SIS, ETOUSA, who exercised that control 

in meeting the requirements of the theater military 

intelligence service.

Who was the director, SIS, ETOUSA? “Under 

another hat,” as the saying went, he was the director, Signal Intelligence Division, Office of the Chief 

Signal Officer, ETOUSA, namely, Colonel George 

A. Bicher. He was responsible for both SIGINT and 

COMSEC operations, including training, organization of units, production, and administration. He 

had operational control of all SIGINT producing 

units in ETOUSA and all SIGINT personnel engaged in training in the UK.2 He was advisor to the 

assistant chief of staff, G-2, ETOUSA, on all technical aspects of SIGINT production, but he exercised 

no supervision over personnel of the Special 

Branch, Military Intelligence Service (MIS) who 

were sent to the theater for detached service and 

grouped in the MIS, War Department, London 

Branch. Their duties were kept entirely separate 

and supervised by Lieutenant Colonel Telford Taylor. Colonel Bicher did have technical and 

administrative supervision of the work of the Signal Security Agency liaison officers, successively 

Captain John N. Seaman, Captain Walter J. Fried, 

and finally Mr. Albert W. Small.

From 1942 to 1944, SID, ETOUSA, had to plan 

for the future and to cope with problems of the 

present. While cryptanalysts and traffic analysts 

were being trained in Britain to deal with German 

cryptosystems, intercept operators were trained 

there also in techniques of major effectiveness 

against German military communications. Tables 

of organization and equipment appropriate for the 

theater had to be established by formulating recommendations to “Washington” for approval there.

In June 1942 the Army liaison officers concerned with SIS matters were engaged primarily 

dealing with branches of British Military Intelligence and the Air Ministry to arrange itineraries 

and assignments of American observers on
Page 115

temporary duty in the U.K. Exchanges of SIS 

reports with the British “Y” Service led to the formulation of American Signal Operating Instructions 

for the European Theater and to adoption of cryptographic security measures.3

Lieutenant Colonel George A. Bicher reached 

London to assume the duties of director, SIS, 

ETOUSA, in August 1942. The 124th Signal Radio 

Intelligence (SRI) Company, arriving directly from 

the U.S. in September, set up a training station at 

Tidworth in Hampshire at the end of November 

1942 with eighteen receiving sets; a little later it established a DF station.4 In the following March it 

began to use a direct teletypewriter circuit with 

Headquarters, SIS, ETOUSA, in London for intercept control and the transmission of live German 

Air Force traffic for cryptanalysis. Analysts who 

had been partly trained at Bletchley were at the 

London terminal to guide training in both Army 

and Air “Y” production.

On 20 March 1943, SID, ETOUSA was still only 

a provisional unit of thirty-four officers and fiftyeight enlisted men. The chief signal officer then 

recommended to the Operations Division (OPD) 

War Department that its authorized strength be 46 

officers and 207 enlisted men, using equipment 

SIGINT organization at Headquarters, ETOUSA, 1944
Page 116

prescribed by the CG, ETOUSA, and organized in 

conformity with a table of organization originating 

at SIS, ETOUSA, but reviewed and modified at 

Headquarters, Signal Security Service.5

The structure of SID, ETOUSA, consisted 

eventually of a Headquarters Section, a (communications) Security Branch, an Intelligence Branch, 

and a Training Section. The Security Branch contained sections concerned with the compilation, 

distribution, and accounting of field codes, with 

maintenance of cipher machines, and with the 

protection of communications security. The Intelligence Branch was divided in sections concerned, 

respectively, with identifying enemy equipment, 

with coordinating signal intelligence, and with performing traffic analysis, cryptanalysis, and 

laboratory work on secret inks.

A related, later activity of the Signal Security 

Agency was the conduct of radio-countermeasures 

(RCM), such as jamming and deceptive radio communications traffic. In January 1944, the 3103d 

Signal Service Battalion (31 officers and 708 enlisted men) crossed the Atlantic to the UK Aided 

there by an experienced British signals officer, the 

unit operated in its specialized way while attached 

to SHAEF.6

Until 1 February 1943, both the Security Branch 

(Major Paul E. Neff) and the Intelligence Branch 

(Major Charles L. Allen) of SID, ETOUSA, worked 

under the same roof at 20 Grosvenor Square, London. On that day, the Intelligence Branch began 

operating at 59 Weymouth Street. As mentioned 

above, in the following month the Intelligence 

Branch was directly connected by teletypewriter 

with the 124th SRI Company at Tidworth. Analysts 

working on live German traffic previously furnished by GCCS in time could use material attained 

from American interception and could develop the 

correlation of analysis with intercept control.

The Air Intelligence Section of the Intelligence 

Branch was drawn by the character of its target 

communications into closer association with RAF 

SIGINT operations. American officers who learned 

RAF methods at Newbold Revel, Rugby, as early as 

September 1942, and at the RAF intercept station 

at Cheadle, applied their experience in January 

1943 in organizing an Air Intelligence Section, and 

in training others to work on intercepted traffic 

provided by the RAF and by the American unit at 

Tidworth. In June 1943 the Air Intelligence Section 

began training in interception and analysis of 

“voice” (British term “R/T”) communications. At 

first they worked from taped recordings; then two 

men were accepted at an RAF intercept station at 

Kingsdown to learn from live German intercept.

From those beginnings, the Air Intelligence 

Section went on with the training of certain USAAF 

units that had been designated as the 926th RI 

Platoon, the 951st RI Company, and the RI Platoons of the 417th and 418th Signal Companies, 

Aviation. Those units obtained instruction not only 

in London but at a station of the U.S. Eighth Air 

Force at Tean, adjacent to Cheadle, where the Air 

Intelligence Section placed a detachment. 

Coordinating with the RAF unit at Cheadle, the 

Americans avoided duplication, sought production 

that was complementary, and eventually provided 

Brigadier General Telford Taylor, 1946

(Photograph courtesy of 

the Department of Army)
Page 117

a Cheadle-American broadcast of technical SIGINT.7

The steps by which USAAF SIGINT operations 

had diverged from those of U.S. Army ground 

forces became apparent by January 1944. In April 

1944, after a temporary designation as “American 

Central Organization, Section 3,” the 926th RI Platoon and 951st RI Company were reorganized with 

a table of organization and troop basis, as the 3d 

USAAF Radio Squadron, Mobile. In May that unit 

moved from Tean to Uxbridge to be near Headquarters, Ninth Air Force. The Air Intelligence 

Section, SID, ETOUSA ceased to control the 

USAAF Radio Intelligence Units.

From 1942 to 1944, the Signal Intelligence Service, ETOUSA, kept growing. Its activities consisted 

at first of beginning training while achieving efficient organization. Matters of liaison and 

administration led to the training of more and 

more individuals and units in interception, processing, and the derivation of intelligence. The 

need to train men for service in NATOUSA was 

for a time allowed to inhibit the production of current SIGINT in connection with the training. In 

October 1942, while the 3d Platoon, 122d SRI Company was at Tidworth, it was redesignated as the 

128th SRI Company and became a cadre of that 

new unit later sent to the Mediterranean. The 124th 

SRI Company arrived in England in September 

1942 for extended training; it also contributed to 

other units formed there in 1944.

Another group paused in the UK for training 

before continuing to Algiers to join the 849th 

SIGINT Service in the Mediterranean.

In February 1943 SIS ETOUSA began issuing 

SIGINT bulletins, summaries, and periodic ETORIG reports of T/A operations that went not only to 

CG, ETOUSA, but also to Allied Force Headquarters, GCHQ (Military Wing) and to Washington 

(SPSIS).8

The American Army SIGINT personnel stationed in ETOUSA and subject to the administrative 

responsibilities of Colonel Bicher as Director, SIS, 

ETOUSA, increased in the latter part of 1943 with 

the arrival of men assigned to the “Special Project 

Group” concerned with learning how to produce 

Ultra. Their status is treated in Chapter 11.

Planning in the Theater

Before the decision in July 1942 to invade 

Northwest Africa during the ensuing autumn, all 

planning by American SIGINT officers for operations in the West had looked toward the 

requirements of forces that would be attacking 

across the English Channel. A tentative plan called 

for training in the UK of more than twenty-three 

radio intelligence units. Any cross-Channel invasion was deferred in order to execute a series of 

campaigns in the Mediterranean area, but such an 

undertaking never ceased to be primary in American thinking. Although the opportunity to become 

capable of a successful invasion was hampered, it 

was not forfeited. When plans for limited attacks in 

1943 had been shelved and May 1944 had been set 

Lieutenant Paul E. Neff, 1941

(Photograph courtesy of 

the Department of Army)
Page 118

as the date for an all-out attack, planning entered a 

new phase.

Until General Eisenhower arrived in the U.K. in 

January 1944 to assume command, all planning 

and preparations had to remain tentative. Thereafter the pace of plans and preparations accelerated 

until the invasion began on 6 June 1944. The previous concepts were superseded by the judgments of 

those who would actually command. General Sir 

Bernard Montgomery was designated to command 

all Allied ground forces in the field during the assault landings and the subsequent acquisition of an 

Allied lodgment in France. He insisted, as he had 

before invading Sicily, that the initial landing forces 

should be more widely dispersed and thus gain a 

wider choice of areas for penetration. The resulting 

plan provided for simultaneous amphibious 

operations by the troops of four different corps 

under the control of two armies, with other corps to 

come ashore subsequently. The British Second 

Army (Dempsey) would attack on the left opposite 

Caen, and the U.S. First Army (Bradley) would land 

farther north (on Omaha and Utah Beaches) to cut 

off and then seize Cherbourg. Each corps would 

commit two divisions and special units on D-Day 

and reinforce them with a third division soon afterward. Then a third corps with stronger, armored 

elements would land.

As the bridgehead in Normandy expanded, the 

Canadian First Army (Crerar) and the U.S. Third 

Army (Patton) would cross to Normandy, there to 

control several more corps that would eventually 

be engaged in exploiting a break-out near the base 

of the Normandy peninsula. At the time the U.S. 

Third Army became active, General Bradley would 

activate a Headquarters, 12th Army Group, and relinquish his direct command of First Army to 

Lieutenant General Courtney Hodges. Similarly, 

General Montgomery’s command over the British 

and Canadian armies would be exercised through a 

Headquarters, 21 Army Group. He would continue 

to be responsible for coordinating the operations 

of the two army groups until General Eisenhower, 

as Supreme Commander, Allied Expeditionary 

Forces, assumed direct command of the army 

groups, as well as of the Allied air forces.

After the Normandy landings had succeeded, 

landing craft needed for an amphibious assault in 

southern France would be salvaged and transferred 

to the Mediterranean. That invasion (Operation 

DRAGOON) was to bring the U.S. Seventh Army 

(Patch) into southeastern France and to open a new 

line of supply from Marseilles and adjacent smaller 

ports to the combat zone. The Seventh Army would 

contain a French army corps. It was to be reinforced by another, and thereafter both would be 

controlled by Headquarters, French First Army (De 

Lattre de Tassigny). Both the U.S. and French 

armies would then come under a 6th Army Group 

(Devers), itself, like the other two army groups, 

under SHAEF (Eisenhower).

The planning in London for the invasion of 

Normandy recognized that additional corps headquarters and more American divisions would be 

provided by the U.S. and would be placed under 

command of the U.S. Ninth Army (Simpson) in 

time to participate in any prolonged campaign to 

effect unconditional surrender.

By the winter of 1943-1944, Anglo-American 

collaboration in SIGINT had progressed from tentative, pre-Pearl Harbor beginnings to solid 

cooperation. In respect to special intelligence, the 

U.S. remained more a client than a full partner, 

though it contributed to production. In the production of tactical SIGINT (British term “Y”), American 

determination to achieve parallel competence using 

American personnel was unmistakable. To get that 

far as quickly as possible, the benefits of British 

experience were pursued and freely offered. A Theater “Y” service thus developed within the general 

framework of collaboration between the SIGINT 

establishments of the two countries. The British accepted not only leading American analyst but a 

stream of trainees. Beginning on 10 January 1943, 

some of the trainee officers became in turn instructors of Americans more recently arrived in the UK, 
Page 119

either en route to the Mediterranean area or earmarked for SIS, ETOUSA.

The decisions concerning the chain of command among U.S. Army ground forces in the 

invasion seem to have been reached during the first 

weeks after Eisenhower’s arrival in the United 

Kingdom. On the scene were Bradley and Hodges. 

Bradley’s Headquarters, FUSA, had already been 

established on 20 October 1943 at Bristol, where 

it replaced Headquarters, U.S. V Corps. The latter 

went to Taunton. VII Corps at the same time 

settled at Braemore, near Salisbury. XIX Corps 

Headquarters arrived at Warminster on 14 January 

1944. Hodges was promoted to lieutenant general 

and officially transferred to FUSA as Bradley’s 

deputy on 26 March 1944. On that day, having been 

summoned from Sicily two months earlier, Patton 

became officially CG, Third U.S. Army (TUSA).

On the FUSA staff were thirty-eight officers 

who had served at one time under Bradley (as CG, 

U.S. II Corps) in the Mediterranean area, supplemented by many more who had come directly from 

the U.S.

Patton persuaded General Devers, as CG, NATOUSA, to release from the Seventh Army staff in 

Sicily fifteen officers who had served there with 

him, and who thus came to the new TUSA. Late in 

January 1944, the Queen Mary brought from the 

U.S. thirteen officers and twenty-six enlisted men 

for Headquarters, TUSA. The staff was located at 

Knutsford, near Chester, about five-hours’ drive 

from London, and grew to exceed 1,000 by the end 

of March.

While planning was being done in the London 

area, the Headquarters, SOS, under the Deputy, 

CG, ETOUSA (Major General John C. H. Lee) was 

at Cheltenham, near which many of the service 

units for the two U.S. Armies prepared for the invasion. In London a small 1st U.S. Army Group 

(FUSAG) headquarters engaged in planning and 

preparation that included the eventual use of SIGINT services provided by means that are described 

below.9

The Invasion Begins

For weeks representatives of both American 

Army staffs remained in London for detailed planning. On 2 June 1944, Bradley’s Advance CP was 

established aboard the USS Augusta, the same ship 

from which General Patton had gone ashore to take 

command of the Western Task Force in Morocco 

(on 8 November 1942). FUSA troops were then either already on the ships that would take them 

across the Channel, or en route to ports of 

embarkation. V Corps (Gerow), VII Corps (Collins), 

and after them XIX Corps (Corlett) – including two 

armored divisions – were FUSA’s principal subordinate commands. VIII Corps (Middleton) from 

TUSA was temporarily attached to FUSA, and 

would go into action in Normandy on 15 June to 

hold the western section of the American line while 

VII Corps invested and overcame Cherbourg. That 

city surrendered on 26 June, after which VII Corps 

(with extraordinary speed) came into the line east 

of VIII Corps, and the First Army’s push southward 

began.

TUSA’s other three corps – XV (Haislip), XX 

(Walker), and XII (Cook) – as well as many separate units that comprised Army troops, next moved 

to Normandy. They brought the total American 

strength ashore by the end of August 1944 to more 

than 1,000,000. An advance echelon of Headquarters, TUSA, opened south of Salisbury on 29 June 

and by 4 July began crossing to Normandy. There 

they set up near the road-center of Valognes. The 

rear echelon of Headquarters, FUSA, was not far 

away. Bradley moved his command echelon from 

Grandcamps-les-Bains near Omaha Beach to a 

point inland near Vouilly on 2 July. In Normandy, 

TUSA welcomed opportunities for its units to become seasoned in combat in operations being 

controlled by FUSA. When the time came for a 

breakout, their better performance would reflect 

the earlier combat experience.
Page 120

The First U.S. Army Group (FUSAG) had been 

first activated on 19 October 1943 in London in accordance with HQ, ETOUSA, General Order No. 

74, dated 16 October 1943.

The structure known as First U.S. Army Group 

was removed from that designation and transferred on 14 July 1944 by HQ, ETOUSA, General 

Order No. 73, to a new organization, the 12th Army 

Group. All units and personnel passed to the new 

command. The old command, FUSAG, supposedly 

under Patton, remained as a phantom in order to 

induce the enemy to believe that the main attacking 

forces, under FUSAG control, were still in the UK 

awaiting the favorable moment for what would be 

the primary assault across the channel. With the 

same purpose in mind, the presence of General 

Patton in Normandy and the fact that he commanded TUSA were kept as secret as he would 

allow until after TUSA had begun to fight as such.

On 1 August 1944 TUSA went into action. On 

that day, headquarters, 12th Army Group took 

command of both FUSA and TUSA, as authorized 

on 25 July by the Supreme Allied Commander. At 

the same time, 12th Army Group remained under 

the overall operational control of General Sir Bernard Montgomery until the Supreme Commander 

was ready to assume direct control of Allied ground 

forces. That occurred on 1 September 1944.

FUSAG was officially deactivated on 18 October 

1944. Back in 1943, when that headquarters began 

functioning as a planning group, its Signal Section 

contained a “Security and Countermeasure Branch” 

with the responsibility “to coordinate all signal security and signal intelligence matters within the 

First U.S. Army Group, including armies and the 

Zone of Communications. It will also coordinate 

these matters with SHAEF, SIS ETOUSA, Navy, 21 

Army Group, and other British Services...” The 

same individual officer represented FUSAG and 

SID, ETOUSA for SIGINT planning.

The Structure of SIS, ETOUSA

The initial concept on which planners in 

FUSAG, ETOUSA, and the War Department focused their concern called for providing each U.S. 

army with two signal construction battalions and 

one large signal information and monitoring 

(SIAM) company, and, for each of the seven corps, 

a signal service battalion that would contain one 

radio intelligence company. A program for issuing 

cipher machines and all other items of secure communications systems for the dissemination of 

SIGINT was also a feature of the planning. The 

planners contemplated establishing an army group 

SIGINT service as well as a SIGINT service in each 

army and corps. The War Department withheld approval from any project to create an army group 

SIS paralleling that at the theater headquarters, 

just as it objected to having the Headquarters, 

FUSAG, duplicate the scope of tasks performed at 

HQ, ETOUSA, and HQ, SOS, ETOUSA.

The 12th Army Group Headquarters was thus 

given instead an attached Signal Security Detachment “D” (SSD “D”) of the Signal Intelligence 

Division, Office of the Chief Signal Officer, SOS, 

ETOUSA. The Army Group staff itself had relatively small SIGINT and COMSEC groups, as well 

as two Signal Radio Intelligence Companies among 

its Special Troops.10

With which type of ground combat unit should 

tactical SIGINT units be placed? How self-sufficient should they be? How mobile? How large? 

What equipment would they need? What kinds of 

specialization, and in what proportions, would be 

required? The answers to such questions could be 

provided on the basis of certain known factors, but 

since the enemy’s communications and cryptographic, technologies would not remain static, 

even current experience might be insufficient. 

Adaptability might also become essential.

At first, after Pearl Harbor, the Signal Corps 

had planned to place radio intelligence (RI) platoons in each division’s signal company, and a 
Page 121

small RI company in each corps signal battalion. 

For armies, there would be large signal RI companies. Processing centers (in Washington and 

perhaps at a theater headquarters) would reinforce 

field processing at an army group level. By the time 

the SIS, ETOUSA, was being prepared, experience 

in the Mediterranean had given abundant demonstration that forward RI units were necessary but, 

if held at division level, were subject to excessively 

frequent displacement that curtailed their productiveness. If held near an army headquarters, they 

were too far in the rear for effective intercept of 

much important tactical traffic. The preferred level 

was therefore the corps.

The representatives of ETOUSA, 12th Army 

Group, FUSA and TUSA in the UK, and of the Signal Corps and OPD in Washington, participated in 

a prolonged effort to determine how SIS, ETOUSA, 

would be manned. The two armies (FUSA and 

TUSA) each intended to have an army SIS as well 

as an information service. As D-Day drew nearer 

without a decision, the theater commander authorized FUSA to establish three provisional signal 

service companies (RI) for the three corps: V 

(Gerow), VII (Collins), and XIX (Corlett). Then, in 

April 1944, the War Department gave final official 

approval to the activation of two successive groups 

of seven such units.11

SIS, ETOUSA, was therefore to provide one tactical SIGINT company for service with each corps. 

It would be assigned to an Army and attached to a 

corps but remain under the operational control of 

SID, ETOUSA. The unit would be mobile, moving 

when corps headquarters moved, and have its own 

communications, administration, mess, and maintenance elements. It should have its own 

direction-finding capabilities, technical library, and 

maps. It would include analysts who could read 

simple codes and ciphers, understand German, analyze traffic, recognize items of operational 

intelligence that deserved to be passed at once to a 

corps G-2, and provide good control of intercept 

operations in accordance with directions from 

Corps and Army.

The personnel for those companies were to be 

found, as far as possible, within ETOUSA. Cadres 

were taken from the larger SRI companies that had 

been activated earlier in the war, or even before it. 

To the cadres were added intercept operators from 

the RI platoons in division signal units and in the 

signal service battalions assigned to corps. Communicators came from the same sources. Men for 

nontechnical duties in SIGINT companies were 

found in a variety of other units – men to drive 

trucks and keep them operating, for example. Some 

came from Replacement Depots. Two types of SIS 

detachments (to perform traffic analysis) were attached to RI companies, after being trained at SID, 

ETOUSA. For the larger SRI companies – to be 

with Army, Army Group, and ETOUSA/SHAEF – 

the SIS detachments each contained three officers 

and twenty-nine enlisted men. For the corps signal 

service companies (RI), each such element consisted of one officer and fourteen enlisted men. 

Between March and 18 July 1944, five of the larger 

and seven of the smaller detachments had been 

provided.

The demand for intercept operators in ETOUSA 

extended to two other activities besides SIGINT. 

The first – security monitoring of friendly communications for the purpose of detecting vulnerabilities 

and disclosures – was to be provided by signal security detachments. The second – substantive 

monitoring of friendly communications as well as 

direct reporting from unit commanders by radio to 

provide current information to G-3 operations officers for purposes of control – was a task for which 

so-called SIAM (“Staff Information and Monitoring” or “Signal Intelligence [or information] and 

Monitoring”) companies were established. The 

British in the Mediterranean had developed what 

they termed a “J” service, performed by teams that 

kept forward friendly forces under close surveillance by radio monitoring and liaison. In Africa, 

Sicily, and Italy such operations had served a valid 

purpose. During a war of movement by a widely 

dispersed command, especially such as the U.S. 

Third Army was to conduct in Brittany and northern France, the exercise of control could be greatly 
Page 122

helped by thus keeping track of subordinate and 

flanking units.

When it learned that the War Department 

could not supply a SIAM company for several 

months, the Third Army, on its own, organized 

what it called its Army Information Service (AIS) 

before the break-out from Normandy. It obtained 

personnel for this effort from the 6th Cavalry 

Group (Mecz). As the U.S. Seventh Army moved 

into the southern segment of the Allied line, its 

SIAM company of numerous platoons was observed by several officers from First and Third 

Army and from 12th Army Group. The latter had 

proposed that a SIAM Company for each Army be 

established according to a table of organization and 

equipment (TO&E) that the War Department approved.

The SIAM companies (3322d, 3323d, and 

3325th), which totaled between 490 and 500 officers and enlisted men, were to operate with each 

corps in platoons of varying size. (The TO&E 11-

875, 10 May 1944, authorized up to 12 officers and 

700 enlisted men.) The 3324th SIAM Company 

was organized late in the war in the United States 

and did not see action. Its original complement 

consisted of personnel from a mechanized cavalry 

reconnaissance squadron. The three companies 

formed in the ETOUSA went into a three-month 

training program in the UK, after being drawn primarily from former cavalry squadrons.

During the first week of the invasion, SIAM reports from forward elements of Bradley’s U.S. First 

Army were intercepted by SRI companies working 

for Headquarters, ETOUSA, and were decrypted; it 

was beneficial practice for units soon to be in Normandy, working there on the radio communications 

of a stubborn foe.

Only traffic in plain text or low-grade cryptographic systems would be examined at the corps 

SIGINT company for intelligence; all messages in 

medium-grade systems were to be processed in 

units at army or army group headquarters. In 

March 1943 during training in the UK, SID, 

ETOUSA, London, began to analyze low- and medium-grade German systems in traffic copied by 

British intercept units, to be supplemented by similar material which American intercept operators in 

southern England were learning to collect. After 

the invasion, those units were to be moved to the 

continent for operations with the U.S. armies and 

army groups.

SIS, ETOUSA, intended to link the scattered 

tactical SIGINT units in at least one SIGINT communications net, by which technical SIGINT data 

would be pooled to an appropriate extent. In any 

event, RI companies were expected to cover enemy 

activities in areas adjacent to their respective corps 

zones and be responsible for giving and receiving 

technical SIGINT information wherever it had 

originated.

The standard large signal RI company under 

Table of Organization 11-77, dated 11 April 1942, as 

modified in January 1944, consisted of 13 officers, 

1 warrant officer, and 309 enlisted men. By TO&E 

11-500, of 11 September 1944, the authorized 

strength was reduced to 10 officers, 1 warrant officer, and 268 enlisted men. Experience in the 

Mediterranean Theater showed that the large SRI 

company might remain administratively a unit, but 

in operations would be split into detachments. In 

ETOUSA, the principal problem for the large companies was the loss by transfer of officers and men 

to serve as cadres for the new corps companies.

The standard signal service company (RI) to 

work with a corps headquarters consisted of 8 officers and 121 enlisted men, under TO&E 11-500, 

dated 1 July 1943. It was organized into one company and two platoon headquarters (an intercept 

platoon and an intelligence platoon), a T/A unit, 

and eight teams. Of the eight teams, two were for 

intercept, one for D/F, three for communications 

(message center, teletype, and mobile radio), one 

for motor maintenance, and one for the mess. That 

organization turned out to need adaptation to actual operating conditions. The three headquarters 
Page 123

elements were combined into one by several of the 

signal service companies (RI), who thus found a 

more prudent use for manpower. One serious deficiency was the absence of a guard unit. The corps 

companies were often far enough forward to be vulnerable to sabotage and, on occasion, as during the 

Ardennes offensive in December 1944-January 

1945, to being overrun. The two or three directionfinding teams of three men each kept a lonely vigil. 

Sabotage of wirelines in some areas was persistent, 

in one instance being attributed to “friendly agents 

(French cows),” but in another to the kind of enemy 

who booby-trapped each loose end of a severed 

wire.

The allocation of personnel under the TO&E, as 

amended on 22 September 1944, was as follows:

Company Headquarters 11

2 Platoon Headquarters 5 (each)

T/A Unit 14

2 Intercept Teams 31 (each)

D/F Team 4

Message Center Team 15

Teletypewriter Team 4

Mobile Radio Team 5

Motor Maintenance 2

Mess 6

SSD “D” was a provisional organization, an advance element of SIS, ETOUSA, attached for 

administrative purposes to Headquarters, 12th 

Army Group. The 114th and 118th SRI Companies, 

however, were assigned (not attached) to 12th 

Army Group. SSD “D” exercised direct operational 

control over the two companies, which were under 

administrative subordination to a 3900th Signal 

Service Battalion of a 3146th Signal Service Group, 

consisting of Special Troops, 12th Army Group. 

Whenever administrative requirements clashed 

with operational tasks, the usual compromise arrangements curtailed the SIGINT operations.

In addition to housekeeping chores and routine 

military activities, the men of the two intercept 

companies at HQ, 12th Army Group, were expected 

by the administrative officers to “sparkle” in all 

ways – uniforms, weapons, quarters, vehicles, 

equipment, and bearing – and to perform their 

military duties strictly according to regulations. 

Even when a tactical situation had the men working under great pressure in adverse field conditions, 

when the requirements of SIGINT production were 

simply incompatible with “sparkling” appearance, 

the former were obliged to yield to the latter.

In the Mediterranean, the 849th SIS also suffered from administrative vulnerabilities, primarily 

because it was converted from a theater headquarters unit to a field unit. At first it lacked a suitable 

table of equipment or other authorization for the 

means of meeting fundamental requirements. 

There, moreover, the SRI companies were broken 

into detachments, several of which lacked stable 

administrative support.

Signal Security Detachment “D” under Lieutenant Colonel C. L. Allen started in September 1944 

with 24 officers and 147 enlisted men. It arrived at 

the end of hostilities with a strength and organization largely unchanged. Its 25 officers and 133 

enlisted men were grouped as follows (as of 15 

April 1945):12

During the preinvasion period of preparations, 

SSD “D” briefed the SIGINT sections of the FUSA 

and TUSA staffs thoroughly on what was expected 

of them. They were to coordinate communications 

security and communications intelligence activities 

within their respective armies. They were to perform cryptanalysis on medium-grade traffic using 

keys ascertained by research at higher headquarters. They were to get intelligence information into 

the hands of intelligence sections through intelligence channels of 12th Army Group. From the 

corps RI units the Army SIS could expect spot reports by telephone until a COMINT communications 

network by secure radioteletype could be established. They could expect from corps units daily 

activity reports timed to fit into the production of 

intelligence summaries, and they could expect, by 

courier mail, copies of the raw material intercepted.13
Page 124

Final Stage of Training in the United Kingdom 

All the mobile field units of SIS, ETOUSA, realized during their organization and training in the 

UK that they must make certain essential preparations while there if they were to be properly 

equipped to operate successfully. They adapted the 

vehicles that were to serve as their operating vans, 

got their receivers, typewriters, and other equipment suitably mounted and stowed, and did what 

they could to be ready for action in any kind of 

weather.

Experience with live German military traffic developed their ability to pierce the veil of enemy 

COMSEC practices by search and surveillance and 

to identify the more fruitful nets, aided by DF. They 

found that there were few shortcuts to competence. 

Once they faced the enemy at closer ranges, they 

would have to accumulate more technical data pertaining to enemy units in the area and to use the 

assistance that could be derived from technical 

data pooled at higher levels of command. They 

would discover that interception of VHF voice communications in ample quantity came only during 

combat operations and from sites close to the front.

The training of SIGINT units in the UK was 

based on experience in NATOUSA. There it had 

been ascertained that the primary sources for 

meeting corps needs were enemy reports of air reconnaissance and of army-air cooperation, or from 

communications between enemy panzer units and 

armored reconnaissance, artillery, and other enemy 

units opposite the corps front. Intercept operations 

yielded logs and raw traffic in three-letter (T/L) 

code, jargon code, and a mixture of code with plain 

language. That material, as it stood, could not be 

used by G-2; it had to be processed by traffic analysts and interpreted by men who could recognize 

the significance of detailed items.

The SIS, ETOUSA, prepared an Intercept Operators’ Guide issued on 26 August 1943.14 It was a 

twenty-one-page document that dealt with both 

German and Italian communications procedures. 

It emphasized the dependence of a great number of 

highly trained personnel on the way in which an intercept operator performed his tasks and on the 

activities of a “trick chief” in getting results. As the 

men of the RI units settled down in the UK to practice for the first time on live German traffic, this 

guide was available to convey knowledge that earlier had been orally provided by British officers. 

The types of radio working were outlined: 

Point-to-point, in which double callsign procedure 

was used between two stations employing one frequency; “kreis,” or circle, in which three or more 

stations operated in the same fashion; “linie,” in 

which two important stations used the same callsign and the same frequency, thus concealing in 

which direction the traffic was flowing; and “netzverkehr,” in which the intercept operators’ task was 

rendered much more difficult because each station 

had its own receiving frequency, to which its set 

was always tuned, but a transmitter which could 

use the frequency of the station to which it wished 

to communicate. Intercommunication of such a net 

was therefore possible between several stations at 

the same time, and the same intercept operator 

could never hear traffic passing both ways between 

two stations. The last type of communications net 

Major Charles L. Allen, 1942

(Photograph courtesy of the

Department of Army)
Page 125

was the “stern” or star, found most common among 

German Air Force stations. In such nets, a control 

station worked with two or more outstations using 

the same frequency. Each outstation had its own 

callsign, but the control station had none, responding to calls from an outstation that used its own. 

Sometimes there was relaying by control, and 

sometimes direct communications between outstations. In the German Army, star nets were often 

used, especially by divisions and lower units.

In the interests of camouflaging their communications, the Germans had also contrived some 

variations on the five standard varieties of net. For 

American intercept operators, who had had little or 

no experience with such camouflage, the training 

experience in the UK was essential.

The value of the parallel material concerning 

Italian Army and Air Force communications was 

lessened by the Italian armistice after the Allied triumph in Sicily.

The training of traffic analysts in what the British called wireless telegraph intelligence was for 

some officers quite new as they began it in the UK. 

One such officer had never seen a radio log when he 

reached England in August 1943 for three months 

of training that would be spent, for the most part, 

at Bletchley Park. He learned how to reconstruct 

the nets of a German infantry division that was stationed in the vicinity of Le Havre, combining 

intercept data from operators’ logs 

with information gained from captured documents. Among his early 

discoveries was the inadequacy of 

American provision for DF of enemy 

signals. Unable to take cross-bearings for a “fix,” they had only line 

bearings and signal strength as 

guides to the enemy’s location. 

(Since goniometry had been so 

prominent a part of radio intelligence during World War I, the 

deficiency in 1943 seemed hard to 

explain.) He was also introduced to 

the methods by which his British instructors analyzed the changing callsign system of German 

Army and German Air Force communicators15 and 

thus anticipated the alterations.

Assignment of the SRI Companies

A month before the invasion of Normandy, 

eight of the larger signal RI companies were stationed in the United Kingdom. They had arrived 

over a considerable period by different routes. The 

two which were to work in behalf of SHAEF/HQ, 

ETOUSA, were the earliest. The 124th SRI Company (Captain William R. Dindinger) crossed the 

North Atlantic in September 1942 and moved at 

once to southern England, where it began learning 

how to collect live German traffic. In August 1943 it 

obtained an SIS Detachment of analysts (four officers and twenty-two enlisted men) and became a 

theater RI unit. The 121st SRI Company, commanded by Captain Alvin L. Burke, reached the UK 

in December 1943 after having been stationed for 

more than a year in Iceland. (Had it been assigned 

to XII Corps, it might have felt at home with the 

code designator of that headquarters, “Iceberg.”) It 

was assigned to HQ, ETOUSA, and controlled by 

SID, ETOUSA, like the 124th.

The 121st, under Captain Cletus Beard as its 

new CO, trained at Lymington, housed in a girls’ 

school called Elmer’s Court. There it had direct 

telephone connection with SIS, ETOUSA, in 

 Officers Enlisted

HQ and HQ Detachment 8 22

Intelligence Branch HQ 2 3

 Field Units Coordination Section - 2

 Intelligence Coordination Section 5 12

 Photographic Section 1 3

 Traffic Analysis and Control Section 2 24

 Cryptanalysis Section 4 33

 Mobile DF Section 1 28

Signal Security Detachment 2 6

 (at HQ, 12th AG) 2 6 

 25 133
Page 126

London as it began intercepting live traffic from the 

continent. It fitted out an intercept room with 

thirty-six positions, carefully organized and engineered, and connected with a good antenna system. 

Not scheduled to go to the continent until late in 

the autumn, it had plenty of time to make itself mobile. It prepared several 2-1/2-ton trucks to carry 

wooden huts high enough to permit standing under 

the roofs, equipped with windows along one side 

only so that they could be parked closely in pairs, 

under camouflage nets, with light in each. Entry 

was at the rear. The trucks were equipped with 

heaters, fans, lights, and accommodations for the 

equipment used by the various types of specialists. 

Seven huts each carried five intercept positions and 

seven “fishpole” antennas. Another hut housed the 

message center. Commercial power was used when 

available; at other times the unit’s own generators 

were put to work. A control truck contained a 

power distribution panel which was connected by 

cables to the different huts. Another was the T/A 

vehicle. Other trucks or semitrailers were adapted 

for signal supply, signal repair, and DF operations. 

Those vehicles were accompanied by many that 

were used for purposes less directly engaged in SIGINT operations.

Into Action

The 114th SRI Company (under Captain Lynnford S. Wilson), assigned to Headquarters, 12th 

Army Group, was not fully trained at the time of the 

invasion in June. Like the 116th SRI Company, it 

was scheduled for transit to France in August, 

when 12th Army Group could use it there. By that 

time the company would be ready. The 116th, commanded by Captain Edward S. Barley, rode to 

Omaha Beach on the SS Robert S. Peary and debarked with some difficulty via barge on 9-10 

August 1944. In its sixty vehicles, the unit moved to 

an assembly near Periers. The 114th arrived there 

on 19 August.

The 113th SRI Company, commanded by Captain Charles J. Schauers, was the first of the larger 

companies to reach the continent. It had arrived in 

the UK in December 1943 at a strength of 3 officers 

and 190 enlisted men and had begun its training at 

Perham Downs in Wiltshire. There it was joined by 

detachments from SID, ETOUSA, and from the 

124th SRI Company for training. Among the lectures heard by the unit was one given on 10 

February by an SID, ETOUSA, officer (Lieutenant 

Mendel) who had recently observed SIGINT operations in Italy. Late in March, assigned to FUSA, the 

113th moved to a station in Devon. By the time the 

113th went to Normandy, it had grown to 15 officers, 280 enlisted men, and 19 attached. Its SIS 

platoon (under 1st Lieutenant Bayard H. Hale) 

joined the unit the next day. With the 113th as a liaison unit were one officer and fourteen other 

ranks from the British 53 Wireless Intelligence Section, men who remained with the 113th until 17 

September 1944. In two echelons the 113th reached 

Cricqueville, Normandy, on 14 June 1944. Two officers and three enlisted men from SIS, FUSA, were 

attached to the 113th SRI Company at that time.

TUSA placed its Army SIS under Captain (later 

Major) Charles W. Flint as SIGINT officer. His 

SIGINT Section included Lieutenants E. A. Devine, 

Orsen A. Dalton, and Deverton Carpenter. In May 

the 118th SRI Company was assigned to TUSA. One 

Corps Signal Service Company (RI), the 3254th, 

had already been activated on 16 April and three 

more were later assembled to complete the first 

block of seven corps companies. Captain Flint was 

also concerned with forming the Third Army’s Information Service.

While HQ, TUSA waited for commitment in 

Normandy, Captain Flint obtained a large van and 

got it fitted out with desks, two teletypewriters, and 

other communications facilities to serve as the 

Third Army SIS operations center. To that van 

came intercept material from the 118th SRI Company (which reached Normandy on 15 July 1944), 

from the corps RI companies, and from the AIS. 

The van was therefore kept within the G-2/G-3 

area.
Page 127

The 137th SRI Company, commanded by Captain Michael F. Mishley, was assigned to HQ, U.S. 

Ninth Army (NUSA), on 17 April 1944. When the 

landings in Normandy began, the unit was not yet 

fully organized. The cadre was at Dartford, where, 

as men arrived and training proceeded, the intercept operators discovered how extensively they 

needed to adapt their earlier training if they were to 

cope successfully with actual conditions. In particular, they were impressed with the importance of 

good direction finding to production. Even though 

an SCR-291 was not on their authorized table of 

equipment, they managed to acquire one and to develop the techniques for its use. The 137th was an 

energetic unit which benefited from opportunity to 

salvage items of discarded equipment and take 

what it would need to France. In August, the analytic element (three officers and twenty-seven 

enlisted men) which had been training in London 

at SID, ETOUSA, reported for duty. Two more enlisted men came later.

Three SRI Companies followed Headquarters, 

12th Army Group to France: the 116th on 8 August, 

the 114th on 11 August, and the 137th (which later 

went to Ninth Army) on 3 September. All three operated near the advance tactical segment of HQ, 

12th AG. That meant successively near Periers, 

Laval, and Verdun.

By October 1944, SHAEF was ready to use on 

the continent the capabilities of the 121st and the 

124th SRI Companies. Their intercept targets were 

strategic traffic in high-grade cryptographic systems; with some initial trial and error they found 

good sites at Pont-au-Mousson and St. Quentin.

When Headquarters, 12th Army Group, became operational near Periers, Normandy, on 1 

August 1944, SSD “D” had not yet left the UK. It 

was not until 11 August that SSD “D” began 

working directly with the 114th and 116th SRI Companies at Periers, and started exercising technical 

control over other elements of SIS, ETOUSA. In the 

interval, U.S. SIGINT units obtained needed technical information from British 21 Army Group and 

by means of a special broadcast from the UK arranged by SID, ETOUSA.

By the time the pursuit across France was about 

to enter a “September pause,” SSD “D” had developed closer relations with G-2, 12th Army Group 

TAC, at Laval and had established satisfactory control of the American SRI units. It was in steady 

communication with First Army’s 113th SRI Company and Third Army”s 118th SRI Company. On 17 

September the 113th went “on its own” in Belgium, 

where a British SIGINT detachment (one officer 

and fourteen other ranks) that had been working 

with the company for the previous six months, returned to its parent organization. The 3254th 

Signal Service Company (RI) worked at Headquarters, Third Army, while VII Corps was in Brittany 

but in October left Verdun to rejoin the VII Corps 

at Houffalize in the Ardennes.

The last of the large SRI Companies of SIS, 

ETOUSA, to reach France in 1944 was the 117th. 

That unit, commanded by Captain Edward J. 

Heinen, had seen long service in the Mediterranean and, with a Detachment “A,” provided tactical 

SIGINT support to HQ, U.S. Seventh Army, and 

HQ, VI Corps, respectively, in Operation 

DRAGOON. The 117th and its Detachment “A” 

were reorganized at the end of 1944, months after 

6th Army Group had been activated, and after Seventh Army had chased a German command from 

the Riviera to the upper Moselle. The Detachment, 

still commanded by 1st Lieutenant Frederick V. 

Betts, became the 3260th Signal Service Company 

(RI) attached to VI Corps. The 117th SRI Company 

under Captain Heinen remained with HQ, Seventh 

Army, and both came within SIS, ETOUSA.

The 129th SRI Company had been earmarked 

for assignment to the U.S. Fifteenth Army where it 

might be activated at a much later date. Instead of 

gaining readiness during the wait, the 129th was 

depleted in order to obtain enough SIGINT personnel for the three Corps RI companies going to 

Ninth Army. Successive transfers left the 129th 
Page 128

much reduced before it had an opportunity to serve 

on the continent as a unit.

Early Days for the Corps Signal Service Companies (RI) 

The pattern of organization and training in the 

United Kingdom for the first corps RI companies, 

those that served with FUSA and TUSA, was common to them all but not identical. The new 3250th, 

3251st, 3252d, and 3254th were formed in 

southern England for duty with the V, VII, XIX, 

and VIII Corps, respectively. They were destined to 

participate in the struggle to gain a firm lodgment 

in Normandy and to break out of confinement 

there into other parts of France. After activation in 

April, the cadres were drawn from the older, larger 

SRI companies and stationed at Tidworth on the 

Wiltshire Downs, or at Lyme Regis, or Burton 

Bradstock, Dorsetshire, closer to the English Channel where the German communications on the 

continent could be better heard. There they received a stream of newly reassigned personnel, 

drew equipment, and exerted extraordinary energy 

in learning their jobs and reducing their discomforts.

Detached service or temporary duty enabled 

some personnel to benefit from training elsewhere 

with more experienced men whose units had in 

turn gained from instruction by certain American 

and British officers, who had had SIGINT 

experience in the Mediterranean Theater. The 

commanding officer and usually at least one other 

officer were taken from one of the larger SRI units. 

The team of traffic analysts were trained at SID, 

ETOUSA, before joining the unit near the end of 

the period preceding transfer to France. By that 

time, the intercept operators of the unit were presumably able to provide live traffic suitable for 

analysis.

Communicators who had been combed from 

other Signal Corps units worked at acquiring 

greater speed with accuracy. An extraordinary effort was devoted to scrounging lumber and other 

materials and in constructing and mounting huts 

on 2-1/2-ton trucks, as mobile operations rooms. 

Carpentry furnished them with counters, shelves, 

and chairs or benches at which to work. Engineering mounted sets, antenna connections, power 

lines, lights and fans. When the time came to move 

to France, the vehicles had to be prepared for 

shipment, and the sensitive equipment had to be 

stowed in ways that prevented damage from rough 

handling.

The SIGINT units of FUSA moved to Normandy early in the attack. The 3250th Signal 

Service Company (RI), commanded by Captain Lee 

Brownfield, followed V Corps Headquarters inland 

from Omaha Beach and set up shop with its twelve 

receivers in bivouac near the village of Bernesque. 

Closer to the front it placed two DF teams. For a 

while, two of the receivers were used to monitor V 

Corps’ own communications for security.

The 3251st divided into two detachments that 

went to Utah Beach by different routes. The first 

embarked at Cardiff in the Liberty ship Ezra 

Weston and sailed on 2 June in a convoy that drove 

off submarine attacks at sea only to be struck by 

coastal artillery while waiting for two days offshore. 

One man in the unit was killed, another seriously 

wounded, and a British liaison officer had to be 

hospitalized before returning to duty about three 

weeks later. When the detachment went ashore, 

the personnel were landed at one point and the 

vehicles – except for five that were unloaded and 

lost in deep water – came ashore far from the men. 

The men marched on foot to bivouac near St. Mére 

Eglise where the vehicles and equipment joined 

them the next day. The second detachment crossed 

from Weymouth to Utah Beach without misfortune, and the company, commanded by Captain 

Glenn E. Prahl, was in business on 13 June, serving 

VII Corps and FUSA.

At the same time, the 3252d company, under 

the command of Captain Alfred Jones,16 crossed 

the Channel to Omaha Beach and staged through a 

XIX Corps assembly area near Longeville to 
Page 129

bivouac near Castilly on 15 June. There it remained 

until 18 July, without much success for the first two 

weeks.

The 3254th company, commanded by Captain 

Robert L. Hord, Jr., crossed to Utah Beach from 29 

June to 2 July and began operations at a site near 

St. Sauveur le Vicomte in support of VIII Corps. It 

moved to La Haye du Puits on 11 July and to Coutances on 30 July as the campaign progressed. 

Attached were a British sergeant plus two officers 

and five enlisted men from SIS, ETOUSA, and representatives of the 118th SRI Company (with TUSA) 

and of SIS, FUSAG (soon to become 12th Army 

Group).

The 3254th Signal Service Company (RI) with 

VII corps was originally activated by TUSA, and 

like that corps expected to serve HQ, TUSA, in 

France. Circumstances altered that project, as we 

shall later see.

Another TUSA Corps was the XV, commanded 

by Major General Wade Haislip. Its Signal Service 

Company (RI) was the 3253d, commanded by Captain Emory L. Jones and organized on 25 April 

1944. It trained until 8 June at Wincham Hall, 

Cheshire and then moved to quarters at Burton 

Bradstock, Dorsetshire, just vacated by the 3251st. 

On 10 July the 3253d arrived, from Southampton, 

off Omaha Beach. It pushed inland to Senonville 

on 12-13 July. During the next week, the unit’s 5 

officers and 116 enlisted men got their equipment 

in working order, found their targets, and on 19 

July began twenty-four-hours-per-day coverage 

and daily reporting to SIS, ETOUSA.

At that juncture, HQ, TUSA was not yet “operational.” Operation COBRA by FUSA was about one 

week away from its overpowering start.

In England the XII Corps (Major General 

Gilbert Cook) and its 3255th Signal Service Company (RI) were scheduled to follow XV Corps and 

the 3253d. (XII Corps was inclined to emphasize at 

the end of the war that that was the only time 

they followed XV Corps; at other times they believed that XII Corps was parallel and slightly 

ahead until XV Corps had left TUSA altogether to 

come under HQ, Seventh Army, on 29 September 

1944.) The 3255th drew its commanding officer, 1st 

Lieutenant (later Captain) Walter M. Drozdiak, 

from the 121st SRI Company and other officers 

from that and the 118th SRI Company. Of the eight 

officers, one came from SID, ETOUSA, one from 

the 93d Signal Battalion that served XII Corps, and 

three from replacement units. Filling out the 

company’s authorized strength was a slow process. 

In order to expedite the acquisition of necessary 

skills, some of the intercept and DF operators were 

placed temporarily with other units – for example, 

the 124th SRI Company and the 3253d Signal 

Service Company (RI) – which had stations near 

the coast. For the last few weeks the 3255th was 

itself stationed with 121st SRI Company at Elmer’s 

Court near Lymington.

An advance party of HQ, XII Corps, reached 

Utah Beach on 23 July 1944 and procured a site in 

an apple orchard near Quettetot for the main body. 

The XII Corps had been made responsible for 

TUSA’s part in receiving from the United States 

and forwarding to Normandy the numerous elements (divisional and army troops) that were to 

serve under General Patton’s command. After 

TUSA was committed to battle at the end of July, 

XII Corps waited for the word to move. On 12 August 1944 General Patton ordered them to move to 

the vicinity of Le Mans, and there to regroup for attack to the eastward.

On that day also, the 3255th Signal Service 

Company (RI) reached Normandy and joined the 

thousands of American vehicles streaming through 

destroyed towns to its assembly area. On 15 August 

it went into bivouac four miles east of Le Mans and 

got in touch with the 118th SRI Company. With the 

code-designator “Sombrero,” the 3255th soon 

began galloping to the Meuse and Moselle Rivers 

in Lorraine.
Page 130

The 3256th Signal Service Company (RI), which 

was commanded by Captain Robert L. Braden, was 

being prepared for operational duty in England 

from 5 May to the end of July 1944. It was assigned 

to TUSA and attached to XX Corps (Major General 

Walton H. Walker) and stationed at Perham Downs, 

Wiltshire. Between 4 and 7 August, a few days 

ahead of the 3255th, the unit moved to Normandy 

in echelons. There it shifted several times before 

settling at Courville-sur-Eure to begin intercept 

and DF operations on 17 August. Three days later it 

filed its first Intelligence Summary (ISUM). The 

unit was able to produce quantities of order of battle information and to maintain continuous 

operations by leap-frogging echelons during the incessant advances by XX Corps.

As noted above, during the summer of 1944 the 

War Department authorized HQ, ETOUSA, to 

activate a second set of seven Signal Service Companies (RI) for duty with Corps. The 3257th was 

activated by Ninth Army and attached to the XVI 

Corps at Dartford on 25 August 1944; the 3258th, 

at the same time and place to XIII Corps, and the 

3259th, about two months later to III Corps.

The 3257th started out with a cadre of fifteen 

enlisted men taken from the 121st, 124th, and 129th 

SRI Companies. A first sergeant and thirty-four enlisted men from a replacement depot reported in 

on 27 August. A week later, five 2nd lieutenants, 

one of whom was to be the intercept and radiotelephone officer, arrived. More enlisted men reported 

during September. On 4 October the DF officer 

checked in. Not until 9 October was the CO, 1st 

Lieutenant Nicholas T. Lampos, assigned to the 

3257th. At the end of October the unit had reached 

the authorized strength of 8 officers and 120 enlisted men. During the first week of December 

1944, the 3257th moved up the Seine estuary to 

Rouen en route to an action station in Holland.

The 3258th Signal Service Company (RI) went 

through a somewhat similar experience. SIS, 

ETOUSA, assigned to it eight enlisted intercept operators from the 121st and 129th SRI Companies 

and, from its own staff, one officer and seven lessexperienced intercept men. The remainder of the 

company came for the most part from replacement 

depots. The lieutenant and enlisted men of the T/A 

unit were selected and trained at SID, ETOUSA. 

Traffic analysts (U.S. Seventh Army) working in a van in France, 1944

(Photograph from NSA History Collection)
Page 131

Familiarity with German language was the primary 

qualification. At Avon Tyrell, the bulk of the company accumulated vehicles and equipment and 

trained the men who straggled in.

The 3258th operated eighteen positions in vehicles and had two vans for analysts. The latter 

arrived from London in October and trained more 

of the company to work on traffic analysis, T/L 

codes, and “Fusion” work. The unit reached Rouen 

on 25 November 1944 and moved to Forges-lesEaux to await travel orders. Three weeks of further 

training there, including work in DF, helped to 

raise the level of competence before this unit, too, 

moved to Wijnansrade, Holland.

HQ, III Corps, commanded by Major General 

John Millikin, was ready for operations long before 

the 3259th Signal Service Company (RI), under 1st 

Lieutenant Harold McCannel, was in shape to perform in combat. The III Corps had gone under 

TUSA instead of Ninth Army before the Ardennes 

offensive; it transferred to First Army from Third 

Army in February 1945. During the operations in 

Luxembourg in January 1945, III Corps was given 

the 3253d, during its temporary release by XV 

Corps, but returned that unit to XV Corps and employed the 3259th instead, beginning on 26 

February 1945. The 3259th was at Mulartshoette, 

Germany, and III Corps was en route to the Remagen bridge.

The 3260th Signal Service Company (RI) was 

so constituted, as we have seen above in connection 

with the 117th SRI Company, while in the field with 

VI Corps in the Seventh Army zone. As Detachment 

“A,” 117th SRI Company, it had plenty of experienced men, and as the 3260th it had only to induct 

others into the kinds of work provided by the German forces opposing VI Corps.

Three other corps SIGINT units that had been 

formed in the UK, beginning in November were 

sent to the continent before the end of hostitilities. 

The 3261st Signal Service Company (RI) – activated on 9 November 1944 and trained at Dartford 

– crossed to Le Havre on 28 February 1945, and 

moved on 8 March 1945 to a site in Baronville, Lorraine to support the XXI Corps, U.S. Seventh Army. 

It was commanded by Captain Falk Schilling. During the same month, the 3262d (1st Lieutenant 

Fred T. O’Day) started working with HQ, FUSA, as 

it encircled the Ruhr, and served with the XVII 

(Airborne) Corps while it mopped up the encircled 

area. The 3263d, commanded by 1st Lieutenant Albert W. Litschgi, reached its authorized strength in 

January 1945. It had collected officers and men 

from the 121st and 124th SRI Companies, from HQ, 

ETOUSA, from the radio platoons of the 67th and 

94th Signal Battalions, and from replacement depots. Before hostilities ceased, it had reported to 

HQ, TUSA, for duty, and on 1 May 1945 was at 

Bammersdorf, Germany.

The relationship of corps to specific army commands resembled that of divisions to certain corps 

commands. While nothing was fixed, certain units 

tended to stay under the same commanders. The 

U.S. First Army, for example, at various times controlled seven different corps: III, V, VII, VIII, XV, 

XVIII, and XIX. Of them, V and VII Corps stayed 

throughout, from invasion to surrender – though 

the commanding general, V Corps (Gerow) moved 

up to command the Fifteenth Army.

The U.S. Third Army, before 5 May 1945, commanded five different corps: III, VIII, XII, XV, XX. 

It released XV Corps to Seventh Army, III Corps to 

First Army, and VII Corps (for three different periods) to First or Ninth Army. Third Army commanded 

XII and XX Corps throughout hostilities and got 

back III Corps. Fifth U.S. Army in Italy commanded II, IV, and VI Corps, but released VI Corps 

as the original American component of Seventh 

Army. When the French Corps in Seventh Army 

was reinforced by another French Corps and came 

under French First Army, the U.S. Seventh Army 

added the new XXI Corps to VI Corps and then on 

29 September 1944 added XV Corps from TUSA to 

the other two. The 3253d Signal Service Company 

(RI) moved with XV Corps to U.S. Seventh Army. 

Thus VI, XV, and XXI Corps remained under 
Page 132

Seventh Army until the surrender and acquired additional divisions for certain operations.

Ninth Army commanded VIII Corps for three 

weeks in October 1944 and then exchanged it for 

XIX Corps from First Army, and took command of 

the new XIII and XVI Corps. XIII, XVI, and XIX 

Corps remained under Ninth Army “for the 

duration.”

Fifteenth Army did not exist until 6 January 

1945, and its two corps (XXII and XXIII) began 

their service in April 1945 along the Rhine protecting the river crossing and rear areas. XVIII Corps 

served with First Army, and then with British Second Army at the end. Certain divisions tended to 

remain under one of the corps either on the line or 

in reserve, but the general experience provided a 

kaleidoscopic shifting of divisions.

In the field after August 1944, the structure of 

SIS, ETOUSA, was as follows:

3d Radio Squadron Mobile and Its Detachments

While SIS, ETOUSA, took form in the United 

Kingdom, the U.S. Ninth Air Force (Brereton) 

included a Signal Intelligence Service of its own in 

its preparations to conduct tactical air operations 

during the invasion. General Lewis Brereton’s 

headquarters moved to Ascot, England, during the 

autumn of 1943 from its location in Egypt, took 

over certain elements from the Eighth Air Force, 

and received a stream of reinforcements. By June 

1944 its strength was about 170,000. It included 

the IX and XIX Tactical Air Commands and later 

the XXIX (Provisional) as well as other components of a “numbered” air force.

Tactical support was to be provided by IX 

TAC (Brigadier General Elwood Quesada) to the 

U.S. First Army, XIX TAC (Brigadier General Otto 

Weyland) to the Third U.S. Army, and XXIX-TAC 

(Provisional), (Brigadier General Richard Nugent) 

to the Ninth U.S. Army. The tactical air commands 

placed their headquarters close to the army headquarters and during the invasion formed closely 

cooperative teams. Ninth Air Force came under 

General Carl Spaatz’s U.S. Strategic Air Forces for 

administration and under Headquarters, Allied Expeditionary Air Force, for operational control.

Officers of AEAF, USSTAF, and Ninth Air Force 

submitted to the War Department a program for 

building an SIS during the spring of 1944 by augmenting the basic unit in the UK. Specialists sent 

from the United States and other personnel already 

in the theater would provide the manpower. German linguists and communicators were in heavy 

demand. On 20 March 1944 the Ninth Air Force 

redesignated the 951st Signal Radio Intelligence 

Company (Aviation) as the 3d AAF Radio Squadron, Mobile (G). Major (later Lieutenant Colonel) 

Harry R. Turkel, at that time the SIGINT Officer on 

General Brereton’s staff, became also the 

commanding officer, 3d RSM. Like the large SRI 

Companies in the Mediterranean Theater, the 3d 

RSM (540 officers and men) was reorganized 

during April into three field detachments for “voice” 

and one for CW radio. They were to provide “Y” 

service based on the intercept of German Air 

Force radiotelegraph, radioteleprinter, and radiotelephone traffic to the A-2 and the Tactical Air 

Commands of the Ninth Air Force.

Detachment “A” under Captain Brinson dealt 

with intercepted traffic other than “voice” communications, kinds normal for heavy, multimotored 

German aircraft, and ground bases, and processed 

it primarily for intelligence of strategic quality: 

order of battle, the scale of enemy offensive operations (bombers, nightfighters, transports, and 

reconnaissance), condition of enemy airfields, flak 

units, and enemy reconnaissance reports. The output produced by Detachment “A” was used by A-2, 

Ninth Air Force, usually in twice-daily briefings of 

the commander.

Detachment “B” under Captain (later Major) H. 

T. Silverstein, a former PW Interrogation Officer 

(understood by his unit to be a product of Harvard 
Page 133

University’s graduate school) consisted of seven officers and seventy-two airmen when it was activated 

in April and attached to IX TAC. Most of the personnel had been working as a unit while on detached 

service from the 414th Signal Company (Aviation), 

and responded quickly to reorganization and 

training. IX TAC further attached Detach-ment “B” 

to the 70th Fighter Wing, near whose headquarters 

the unit soon moved and with which it landed in 

Normandy in June.

Detachment “C” was to work with XIX TAC. 

When it was activated on 20 April 1944, one officer 

(2d Lieutenant Kurt Heinrich) and three airmen 

were taken from Detachment “B” as the cadre; the 

remainder of the unit had to be constructed from 

the augmentation personnel obtained in May. 

Being attached to the 100th Fighter Wing, Detachment “C” moved near the headquarters of that 

command and scrounged for equipment, vehicles, 

supplies, and personnel.

Services of Supply ETOUSA

SIGNAL SECURITY DETACHMENT “D,” SIGNAL INTELLIGENCE DIVISION

Signal Radio Intelligence Company Assigned or Attached to:

 114th HQ, 12th Army Group

 116th HQ, 12th Army Group

 113th HQ, FUSA

 118th HQ, TUSA

 117th HQ, SUSA

 137th HQ, NUSA

 129th HQ, Fifteenth Army

 121st ETOUSA

 124th ETOUSA

 

Signal Service Company (RI) Assigned or Attached to: 

 3250th HQ, V Corps

 3251st HQ, VII Corps

 3252nd HQ, XIX Corps

 3253rd HQ, XV Corps

 3254th HQ, VIII Corps*

 3255th HQ, XII Corps

 3256th HQ, XX Corps17

 3257th HQ, XVI Corps

 3258th HQ, XIII Corps

 3259th HQ, III Corps

 3260th HQ, VI Corps

 3261st HQ, XXI Corps

 3262nd HQ, XVIII Corps (Airborne)*

 3263rd HQ, TUSA 

 3264th SSD “D”

*The SIGINT unit was attached at another time to a different corps.
Page 134

Detachments “B” and “C” were primarily 

trained to intercept “voice” traffic, translate and 

interpret it, and forward it to officers engaged in air 

operations. Partly trained men were placed in RAF 

schools, where they worked on live traffic. The RAF 

also helped find vehicles (trucks or vans) to make 

the detachments mobile. Each unit had a van for 

intercept operations, another for intelligence operations, a third for direction finding, another for 

electric power generation, and others for communications and storage, plus trucks for the transport 

of men and their housekeeping requirements. The 

intercept, direction finding, and intelligence vans 

were connected by telephones. The intelligence van 

had wire communications with the Wing A-2 and 

the Fighter Director Center. Its radio receiver monitored intelligence broadcasts from Cheadle or 

other rear area transmitters.

Detachment “D” was created somewhat later 

and crossed the English Channel to Utah Beach on 

an LST late in October 1944, en route to a site near 

Paris. After gaining experience while occupying a 

station recently evacuated by a German SIGINT 

unit, Detachment “D” moved through the 

Ardennes area to a location near the BelgiumNetherlands border, where it supported XXIX TAC 

(Provisional) in its operations with U.S. Ninth 

Army.

Meanwhile, Detachments “B” and “C” had participated in the assault operations in Normandy. 

The German Air Force fought energetically to resist 

the invasion. Detachment “B” landed on Omaha 

Beach on 9 June 1944 and was directed by an MP 

along the route of approach of an armored attacking force – an action which led, in part, to this unit 

suffering a fatal casualty there on its first day. It 

was extricated after some delay. That was an abrupt 

introduction to conditions often experienced later. 

The unit was soon able to pass to the Fighter 

Director Center of IX TAC the purport of orders 

given from German ground stations or from a formation leader’s plane to the other aircraft of a 

Luftwaffe formation as it approached an area of 

combat.

Detachments “B” and “C” were able to report 

the location and altitudes of German aircraft and 

their positions during times when they reported 

observing American planes. The units could alert 

the center to the situations of enemy aircraft that 

had been damaged or were experiencing other difficulties that made them vulnerable. The 

detachments could transmit the substance of 

intercepted enemy reports of damage from Allied 

attacks and give warnings of enemy maneuvers to 

attempt retaliation. Various German air attacks on 

the Normandy beachhead were thwarted by timely 

Allied countermeasures taken with benefit of foreknowledge from SIGINT. Unescorted American 

bombers (from bases in the UK) toward which 

enemy aircraft were moving to attack, were warned 

in time to avoid the impending contact, or were 

given fighter protection.

A Detachment “E” was primarily used for communications, for the exchange of information 

among the detachments, and for passing along 

information obtained from broadcasts from England. Its radioteletype channel to A-2, Ninth TAC, 

during the latter part of the Battle of the Bulge was 

to be of particular value, enhanced by the failure of 

landlines that would otherwise have carried much 

of that traffic.

SIGINT was used defensively when the German 

Air Force gained a reprieve from Allied offensive 

air operations during Operation COBRA. Exploitation of the breakthrough then involved the 

commitment of American fighters and fighterbombers to operations with American tanks and 

infantry against ground targets. In Normandy 

“armored column cover” was shown to be effective; 

an air-support party in an American tank in each 

column kept in touch by radiotelephone with 

pilots of aircraft overhead, whose observations 

could influence the action on the ground and who 

could themselves attack suitable targets instead of 

waiting for the tanks.

By 25 August 1944, as Paris was being liberated, 

air intelligence based on SIGINT enabled the Ninth 
Page 135

Air Force to plaster German air bases in two major 

areas.

The 3d RSM in France followed the pattern for 

which it had trained in England. At Headquarters, 

Ninth Air Force, Lieutenant Colonel Turkel and 

Major Edward Hitchcock conducted briefings twice 

daily. Their information was useful to the target 

intelligence and operations sections. A daily appreciation or situation report was sent to other Air 

headquarters, to SHAEF, and to the British Air 

Ministry. At the tactical air commands, the dual 

control over the RSM detachments by the intelligence and signals officers could create considerable 

friction, as at the IX TAC, or relatively little because 

of good teamwork, as at the XIX and XXIX TACS.

Colonel Turkel sought through interrogations 

of prisoners of war and alert searches of battlefield 

areas to gain cryptographic information that could 

be employed in producing “Y.” He had considerable 

success. Even before the liberation of Paris, he had 

learned that his counterpart, a German SIGINT 

unit whose target was the Ninth Air Force, was the 

third battalion of a SIGINT regiment commanded 

by a Colonel Von Eick, located at La Celie St. Cloud 

in a chateau. After the site had been evacuated by 

the Germans, Headquarters, 3d RSM, found it was 

just what they wanted until the unit shifted by 

stages into Germany at Nuremberg.

The detachments of the 3d RSM(G) kept a statistical score of the German aircraft destroyed, 

probably destroyed, or damaged in operations to 

which their SIGINT had contributed.18

When the U.S. Seventh Army invaded France 

from the south, supported by XII Tactical Air Command, the latter, as we have seen, obtained SIGINT 

“Y” Service from a detachment of the 849th SIS. As 

those units came under ETOUSA, the 3d RSM(G) 

contributed intelligence reports and daily “Y” summaries to A-2, XII TAC, and brought it into the 3d 

RSM communications net.

The Signal Intelligence Service, ETOUSA, thus 

consisted of several different kinds of field units: 

large signal radio intelligence companies, moderate signal service companies (radio intelligence), 

detachments of the 3d Radio Squadron, Mobile, 

operating under army, army group, and theater 

headquarters. They carried out operations in interception, traffic analysis, direction finding, and the 

production of signal intelligence from radio messages in cryptographic systems of low and medium 

grades, or plain text, or voice.

The American products were the equivalent of 

what the British ally called “Y” Intelligence; “U,” 

or Ultra, was separately produced and distributed. 

As described in Chapter XI, producing it was almost a British monopoly, shared with Americans 

when sharing became a necessity. Under Colonel 

Bicher’s administrative control, a select few Americans arrived in England for apprenticeship in 

interception, machine processing, and cryptanalysis of German Army and Air Force communications 

enciphered by the Enigma machine. More is said 

about them in Chapter XI.

Notes

1. Report in Folder 314.7 History, 1942-1945, USAFET 723/931 11048(6) NARC.

2. WD Ltr, AG 3113(3-20-43) OB-S-B-M, 20 Mar 

1943, Subj: “Intercept Directive”; HQ, ETOUSA Ltr, AG 

311.5 MSIG, 27 Jul 1943, Subj: “Operational Control of 

Signal Intelligence and Radio Intelligence Units.”

3. Quarterly Report on Signal Activities, USA-FBI, 

for the period 1 Mar 1942 to 31 May 1942; History of Signal Intelligence Division, HQ, ETOUSA.

4. The strength of the 124th SRI Company was then 

7 officers and 236 enlisted men under command of Captain William R. Dindinger.

5. Memo for A.C/S, Opns Div, WDGS, from Lieutenant Colonel J. E. Watters, Sig C, thru CG, ASF, 20 Mar 

1943, Subj: “Request for Approval of T/O, SIS, ETOUSA.” 

Copy in AHS Rec, Box 11558, S-1569.

6. History of the SSA in World War II, Vol. X, 63.

7. See Lieutenant Colonel Harry R. Turkel, USAF 

(Res.), The S.I.S. of the Ninth Air Force in World War II, 

Feb 1951. (NSA Hist. Coll.) Also, SIS HQ, SOS, ETOUSA, 
Page 136

“Report on Signal Intelligence Service, HQ, SOS, 

ETOUSA,” 17 Apr 1973. Ibid; History of the Air Intelligence Section, SID, OCSigO, HQ, ETOUSA, 14 Sep 

1942-8 May 1945.(AHS).

8. Issuance of those reports is recorded in the History of SID, ETOUSA, but the documents themselves 

have not been found in SIGINT archives.

9. History of SIS, ETOUSA, Items R-8040 AHS and 

8062 AHS; History of the Intelligence Branch, Signal 

Security Detachment “D,” G-2 Historical Section, Box 

6/33, AHS; History of SID, ETOUSA, 2 vols. Box 34/4 

AHS. See also 12th Army Group, Report of Operations 

(Final After Action Report, Vol. XI, Section 5 [Signal 

Sections]), 134ff.

10. 12th Army Group, Report of Operations (Final 

After Action Report), Vol. XI, Sec. 5 (Signal Section), 

134ff. NARC, Suitland, Md. Box 1750.

11. Cable, WAR-17502, 1 Apr 1944, and follow-up on 

10 Aug 1944.

12. SID, ETOUSA, had three other Signal Security 

Detachments stationed, early in 1944, at Hall Place, Bexley, Kent; Eastcote; and Bletchley, respectively. They 

were redesignated as the 6811, 6812, and 6813 Signal Security Detachments, and engaged in intercept, 

processing, and analysis, for a Special Project (producing Ultra). Signal Security Detachment “D” retained its 

name. Personnel of SID, ETOUSA in the UK stayed at 

slightly more than 30 officers and 310 enlisted men; SSD 

“D” at about 25 officers and under 150 enlisted men. 

When Lieutenant Colonel Allen took command of SSD 

“D,” Lieutenant Colonel Charles H. Hiser became Chief, 

Intelligence Branch, SID.

13. History of Signal Intelligence Division, ETOUSA, 

3 vols, in AHS A5-20 Records, Box 34/4; and “Plan for 

the Operation of the Signal Intelligence Service, HQ, 

SOS, ETOUSA,” 11 July 1943, in Folder 322 Sig 1 and 

Radio 1 Activities.

14. Intercept Operators’ Guide prepared by the Signal Intelligence Service ETOUSA Intelligence Branch 

(18S1S 277). Copy in NSAHC, Folder No. 2000-B.

15. Weekly Activity Reports from Lieutenant R. S. 

Harrison covering the period, 1 Aug-23 Oct 1943, Copy 

in NSAHC, Folder No. 1857-A.

16. Taped interview in NSA History Collection. 

17. See Summary of Opnl Activity of SSD “D,” 1 Sep 

1944 to 1 Apr 1945. AHS Box 34/4.

18. See, for example, Record of Accomplishments of 

3d Radio Squadron Mobile (G), 8 June – 26 Oct 1944. 

Records of the History Section, USAFSS.
Page 137

Chapter 10

A Summary Version of the Campaigns in ETOUSA

In broad outline, the chronology of the war in the European Theater ran as follows:

Invasion and Buildup in Normandy 6 June to 24 July 1944

Breakout 25 to 31 July 1944

Driving the Germans across the Seine 1 August to 25 August 1944

Liberation of Paris 25 August 1944

Pursuit to Belgium-Luxembourg-Lorraine 26 August to 14 September 1944

From French Riviera to Contact with TUSA 15 August to 11 September 1944

Liberation of Brittany 2 August to 28 September 1944

Through the Westwall to the Rhine 15 September to 21 March 1945

Enemy Counteroffensives in Ardennes

 and Northern Alsace 16 December 1944 to 25 January 1945

From the Rhine to the Surrenders 7 March to 11 May 1945

Within those broader subdivisions, certain key features deserve identification:

Surrender of Cherbourg 26 June 1944

Surrender of Brest 21 September 1944

Defeat at Arnhem 17-26 September 1944

Opening the Scheldt as far as Antwerp 8 November 1944

Railhead at Liege 18 September 1944

Surrender of Aachen 21 October 1944

Surrender of Metz 22 November 1944

Liberation of Strasbourg 23 November 1944

Crossing at Remagen (FUSA) 7 March 1945

French Forces Enter Germany 19 March 1945

Rhine Crossing Begun:

 TUSA 23 March 1945

 Seventh Army 26 March 1945

 Ninth Army and 21 AG 24 March 1945

Encirclement and Control of the Ruhr Area 28 March to 18 April 1945

Penetration and Overrunning of Germany 

 from Coast to Contacts with the Russians,

 and with Fifth Army, along the Elbe-Mulde 

 Rivers, in Czechoslovakia, Austria, and 

 the Brenner Pass 24 March to 7 May 1945
Page 138
Page 139

The cross-Channel attack that began on 6 June 

1944 consisted of amphibious landings on miles of 

beaches edging the Contentin peninsula of Normandy on its northern boundary and of airborne 

drops farther inland. The beaches for U.S. landings 

(Omaha and Utah) extended from the Orne River 

to the east of the vicinity of Quineville in the west. 

The British went in east of the Orne, heading for 

Caen. The Americans invaded on either side of the 

Vire River mouth, heading for St. Lo, Periers, and 

Cherbourg. Allied ground forces were heavily supported by air and sea bombardment. After getting a 

firm hold on the beaches and adjacent interior 

areas, the Allies constructed two artificial ports 

through which they poured in troops and material. 

Inland they pushed the enemy back from an area 

that became fairly congested with reinforcements, 

including headquarters of several army corps and 

of a third U.S. army, more and more divisions, 

Army and corps nondivisional units, small airstrips, and accumulations of vehicles and supplies 

for a push down the peninsula into France.

Cherbourg fell to the attacks of the U.S. VII 

Corps on 26 June. Caen and St. Lo were not taken 

for many more weeks. In Normandy the newer divisions got their first experience of bitter combat in 

terrain that enabled each side to exact heavy casualties from the other. The bocage (hedgerow) 

country and the wide stretches of marsh through 

which the Allies had to advance denied them the 

benefits expected from armored vehicles until new 

tactics were devised to make them effective in such 

terrain.

When the invasion began, plans called for the 

early capture of Caen and the employment of armored forces on suitable ground south and east of 

Caen. When Caen long eluded seizure and then fell, 

the plans were changed to make it a pivot on which 

the Allied line would swing until it was facing east. 

As the U.S. First Army (FUSA) swung, Third U.S. 

Army (TUSA) would emerge on the west to press 

into Brittany and seize its important ports, so that 

the Allies would not thereafter have to depend on 

artificial ports and beaches to bring in supplies. 

Part of TUSA romped through Brittany until German troops had concentrated in several ports, 

where they put up stubborn resistance. All TUSA 

except VIII Corps pivoted east and northeast along 

with FUSA. Partial encirclements in the ArgentanFalaise pocket and again east of the lower Seine 

followed exhausting battles, from which German 

units escaped in disarray too great to make a stand 

short of Belgium and Lorraine.

The Allies pursued a beaten enemy heading for 

his Westwall (Siegfried Line). But within Germany 

extraordinary efforts sent screening forces to positions in front of the Westwall. The Allies could not 

deliver enough gasoline to keep all four Allied 

armies going. Delays in September enabled the 

German screens to be strengthened and the retreating forces to be so deployed that, when 

advances were attempted again, the Allies found 

water barriers well manned and the going slow and 

costly. The Germans held onto ports along the 

Channel, but other troops that had been stationed 

near them to oppose an Allied invasion from the 

sea were able to pull back into Holland. While 

Antwerp fell to the Allies on 4 September, the 

Scheldt estuary remained under control by 

German troops until 8 November.

Allied strategy called for the main effort to penetrate Germany to be made north of the Ruhr in 

sufficient strength to bring about disruption of the 

German war effort. The absence of Antwerp as a 

supply port prevented execution of that plan before 

winter. At a time when the enemy's weakness 

might facilitate an entry farther south by Patton’s 

Third Army, or by Hodges’ First Army, striking at 

the Westwall en route to the Cologne plain, General 

Eisenhower directed that such attempts be made. 

In September the Allied Airborne Army, in 

conjunction with British ground troops, tried to 

seize bridges over the Waal and lower Rhine at Nijmegen and Arnhem. The paratroopers landed in 

some instances directly among an unsuspected 

German armored corps which was too strong to be 

overcome. The armored column trying to reach 
Page 140

Arnhem was stopped short of its goal. The operation failed. 

Neither FUSA nor TUSA gained enough ground 

in subsequent battles to occupy advantageous positions for renewed offensives, and the costs were 

very high. The Third Army’s operations in conjunction with the Seventh Army (newly arrived from 

the south) did arrest an attempted German counter-offensive that was intended to separate them 

and to force American westward withdrawal. The 

First Army’s losses were matched by those it inflicted on its opponents. Despite punishing air 

attacks, the Germans were able to shift divisions 

from one section of the front to another, and to 

bring up supplies and reinforcements from sources 

nearer than those of the American armies. Only the 

U.S. Seventh Army, supported from Marseilles, 

seemed relatively well provided during the winter.

Another German counteroffensive was being 

planned that autumn. Despite the known Russian 

preparations to renew their attack in the east (an 

operation that the Red Army actually started on 12 

January 1945), Hitler committed to a winter attack 

in the Ardennes much of the new manpower and 

equipment that the Eastern Front required. Because of the conditions for an enemy attack in the 

Ardennes were so unpromising, the Allies, running 

short of manpower, accepted the risk of defending 

there by a thin force. They concentrated stronger 

forces to attack east of Aachen. Hitler chose the Ardennes area in an attempt to penetrate beyond the 

Meuse River far enough to regain control at Antwerp. He lacked sufficient strength, and he 

succeeded only in stopping current Allied attacks 

elsewhere. It cost him irreplaceable men and weapons.

As the German Ardennes counteroffensive petered out, another but smaller German counterattack 

began in northern Alsace. Just as the Ardennes 

penetration put a strain on the Anglo-American association in arms, that in Alsace, with its threat to 

Strasbourg, brought about distrust and irritation 

between the Anglo-Americans and the French. 

Before the end of January, the German attack there 

had been contained. Next, the Allies eliminated a 

German salient at Colmar.

The Allied forces moving into Western Europe 

via Normandy included, as previously noted, the 

British Second and the U.S. First Armies, each with 

two corps at the outset and more immediately afterward. Commanding ground force operations 

during the landings and subsequent expansion inland was the commanding general, 21 Army Group, 

acting as Allied ground forces commander. In general control of the operations of ground, air, and 

naval forces was the supreme commander, AEF. 

On 1 September he assumed field command of 

ground troops. SHAEF Main stayed in England 

while both an advance CP and a forward CP went to 

France. SHAEF Forward, first organized near 

Portsmouth, crossed the Channel in successive segments beginning 28 August and occupied a school 

at Jullouville, near Granville, on Normandy’s 

western coast. Communications with the army 

groups were not good. Two weeks after opening 

there, SHAEF Forward began moving to Versailles, 

where it officially started operating on 20 September. On 19 September a SHAEF Advance opened at 

Gueux, about seven miles northwest of Reims, 

where it was ensconced on the grounds of an athletic club. By 5 October 1944 SHAEF Main had 

transferred to Versailles from Bushy Park, leaving a 

SHAEF Rear in London. In the following February, 

SHAEF Advance moved from Gueux into Reims, to 

which SHAEF Forward also moved from Versailles, 

opening there on 20 February. The supreme commander had places at which to confer with his 

commanders near the cities of Luxembourg and 

Spa, but they were places of convenience and security, not staffed for other purposes.

Before SHAEF Forward left Normandy for Versailles, the Headquarters, 12th Army Group had 

assembled in Normandy at Valognes and moved to 

Versailles. The 12th Army Group kept a tactical 

headquarters at Laval, forward of the main headquarters, one which displaced several times as the 

campaigns moved into Germany. Signal Security 
Page 141

Detachment “D,” SID, ETOUSA, operated in proximity to the 12th AG TAC Headquarters.

The SIGINT Division, OCSigO, ETOUSA sent 

a forward detachment to Valognes with Headquarters, Communications Zone, SOS, ETOUSA 

which remained there until 10 September. It then 

moved with Headquarters, COMZ to Paris, followed there in October by the rest of the staff. In 

Paris, Colonel Bicher and his staff of forty-one officers were quartered at 124, Boulevard 

Maurice-Barres.

In February 1945 the Allies began several attacks intended to reach the Rhine. Although the 

main Allied effort remained that to be undertaken 

in the north, where Field Marshal Montgomery was 

getting ready for a large set-piece attack to cross 

the Rhine north of Duisberg, all along the front Allied attacks began. The enemy kept many bridges 

intact across the Rhine for use in case he was 

driven back, but he remained to make his main defensive efforts west of the river. In consequence, 

the Allies maneuvered to cut off access to the 

bridges, and succeeded in destroying or capturing 

thousands upon thousands of Germans. Most 

bridges over the Rhine had been blown up by the 

time Allied ground reconnaissance could observe 

them. But on 7 March, while the mopping-up west 

of the Rhine was in full cry, a unit of III Corps, 

FUSA, found a boarded-over railroad bridge at 

Remagen that had not yet been blown. The defenders were barely prevented for several days from 

demolishing it. Vehicles, including light and medium tanks, antiaircraft and assault guns, and 

more and more infantry, kept crossing while the 

shaky bridge came under attack by artillery and aircraft. But other bridges and ferries were also put in 

operation near Remagen. When the bridge finally 

collapsed under shelling and bombing, the enemy 

had been pushed well back, and the supplementary 

bridges permitted building up a bridgehead large 

enough for FUSA to use as a base. When the other 

Allied armies were ready to cross the Rhine elsewhere, the enemy’s losses west of the river had 

deprived him of the means to maintain another line 

of defense between the Rhine and Berlin. One last 

major effort was made to protect the Ruhr; elsewhere the defenders were outnumbered and 

outmaneuvered.

A large force was encircled within the Ruhr and 

held there, separated and compressed, until over 

300,000 surrendered. Elsewhere, as various Allied 

corps fanned out from their bridgeheads, they met 

sharp opposition at many scattered points but no 

concerted resistance of a regional dimension. The 

enemy tried without important success to reorganize and set up rallying points. The Allies, 

discovering the hideous and disgraceful prison 

camps and capturing V-2 rockets not yet fired, saw 

also the enormous destruction inflicted by Allied 

bombers. As the guns ceased firing, the turmoil of 

war became quieter but no less disruptive. Violence 

lay close to the surface of a suffering Europe. 
Page 142

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Page 143

Beginnings

Anglo-American collaboration in special intelligence came somewhat later than that in other 

forms of SIGINT. All collaboration in intelligence 

was based, one must remember, on mutual advantage rather than on altruism. As it progressed, 

confidence grew, but neither country released anything to the other unless the action would benefit 

itself either directly or indirectly by the uses to 

which the other would put the assistance. When 

the likelihood of war applied primarily to the Japanese Empire, U.S.-British exchanges of information 

on Japan in the cryptologic field went further than 

in other areas. Benefits had always to be balanced 

against risks, and while the U.S. remained a nonbelligerent, Britain seemingly viewed U.S. security 

secondary to the protection required for special intelligence.

The United States moved toward belligerency 

by stages. Before the surrender by France in 1940, 

the U.S. was a neutral hoping to escape the conflict. 

Gradually it faced the prospect that not only France 

but Great Britain would succumb to Nazi German 

dominance unless the U.S. became an “arsenal of 

democracy” and furnished Churchill the tools 

which he needed to “finish the war.” Delivery of the 

material made in America led to protection of convoys by units of the U.S. Navy along with the Royal 

Canadian Navy as far as a “chop” line in mid-Atlantic. The formula for American action became “all 

aid short of war.” By 1941 the U.S. government had 

given the Nazi fuehrer occasion for declaring war 

against the U.S. had he needed an excuse. He 

would do so, though, only if more advantageous to 

him than refraining. Preparedness for war in the 

United States lagged far behind the requirements 

of readiness to meet such an action.

Steps in that direction included staff talks in the 

Washington area at which, in the supposition that 

the U.S. had gone to war, a grand strategy and certain major preparatory measures were agreed.

For the British, World War II had its phases 

too. While deprived of support by Belgium and 

France in 1940, and while acquiring Fascist Italy as 

a declared adversary, the British “stood alone,” 

awaiting a probable invasion by the Germans. By 

surviving German bombing attacks, the British discouraged the invaders and diverted them to a vast 

attack on the Soviet Union in June 1941. As the 

Germans became enmeshed in a winter offensive 

there, the Japanese seized an opportunity (that 

may have seemed to be fleeting) to benefit from the 

involvement of the British, French, and Dutch as 

well as the United States in the European conflict. 

Pearl Harbor was quickly followed by Japanese triumphs in a selected part of the British and Dutch 

empires and by Japanese threats to isolate Australia and New Zealand. When Hitler and Mussolini 

declared war against the United States – while 

Japan withheld parallel action against the Soviet 

Union – the alignments of World War II were established.

During the stages of change in the war situation 

of the future Anglo-American Allies, certain factors 

that affected collaboration in special intelligence 

appeared. The producers of SIGINT in both governments were contributors to general intelligence 

used in connection with foreign policy, ground, air, 

and sea operations of the armed services, and various forms of warfare included within the concept 

of “total war” that then prevailed. The army and air 

forces of the United States had one SIGINT 

organization, although the air components tended 

to become independent as the war continued. 

The U.S. Navy Department had a second SIGINT 

Chapter 11

Aspects of Collaboration in Special Intelligence
Page 144

organization. Among the British, the Foreign Office, Admiralty, War Office, and Air Ministry kept 

their principal SIGINT producers under one umbrella, the GCCS; the latter distinguished sharply 

between special intelligence and “Y” intelligence. 

Different authorities controlled the two.

In the United States the same authorities, divided between army and navy organizations, 

controlled production of SIGINT of all grades. The 

Army’s Signal Intelligence Service (later Signal Security Agency) tried to meet the requirements of 

the Military Intelligence Service. In the Navy, OP20-G became part of an extensive reorganization in 

the months after the Pearl Harbor attack. OP-20-G 

tried to enhance its services to those engaged in the 

Battle of the Atlantic, while devoting most of its 

growing resources to Japanese matters.

The initiative to effect Anglo-American collaboration in SIGINT was taken by the British 

government through its ambassador in Washington, Lord Lothian, who in July 1940 suggested to 

President Franklin Roosevelt certain exchanges of 

broad and general scope.1 Churchill, who had been 

prime minister for about two months of a country 

left alone to face grave danger, offered to exchange 

certain British scientific and technological accomplishments that had military application in return 

for access to American industrial productivity, particularly in the field of ultra-shortwave radio 

emitters. While not requiring any other quid pro 

quo, the proposal expressed a hope that the U.S. 

government would exchange scientific and technical information as well as allowing British 

procurement of military equipment.

On 11 July 1940 the cabinet adopted a position 

expressed by Secretary of War Henry L. Stimson 

(in which Secretary of the Navy Frank Knox concurred), that the U.S. government

Give all information possible to the 

British to aid them in their present 

struggle, and furnish them such material assistance as will not interfere 

seriously with our own defense preparations.2

Secretary Stimson advocated that any British 

procurement arising from the agreement to exchange information be subject to approval by the 

U.S. Army or Navy Departments, in order to insure 

that it would not interfere with American programs 

of procurement.

The exchanges began, after the arrival of a British technical mission headed by Sir Henry Tizard, 

at a session on 28 August 1940. The representatives 

of the U. S. Army had been authorized to furnish 

not only “technical information on munitions, devices, or processes of manufacture owned by the 

U.S. Government,” but also “cryptanalytic information,” not, however, to include any information 

about our own codes, ciphers, and methods of 

cryptography. Intelligence gained abroad could be 

given to the British, but U.S. patent rights and 

trade secrets were to be protected.3

The president sought to obtain American military assessment of the British ability to withstand 

the Axis powers in addition to the counsel being 

provided him by Colonel William D. Donovan. In 

August 1940 Brigadier General George V. Strong, 

chief, War Plans Division; Brigadier General Delos 

Emmons, USAAF; and Rear Admiral Robert Ghormley, assistant chief of Naval Operations, went to 

England (at about the same time that the Tizard 

mission was in Washington) to observe and to discuss ways of assisting each other. Their soundings 

continued while, at home, Army and Navy SIGINT 

officials considered the possibility of exchanging 

cryptologic technical information and SIGINT 

products with the British government.

From London, General Strong, by cable of 5 

September 1940, asked the chief of staff if the Army 

would agree to a full exchange with the British of 

German, Italian and Japanese code and 

cryptographic information. The U.S. Navy (Captain 

L. F. Safford, Chief, OP-20-G) was unwilling to 

exchange more than intercepts; the U.S. Army, on 
Page 145

the other hand, responded favorably to General 

Strong’s query, though not to a continuous exchange of intercepts. By January 1941 contacts 

between GCCS and both G-2, SIS and OP-20-G 

were in progress, under the canopy of the Tizard 

mission and by an authorization to the National 

Defense Research Committee to deal with cryptologic exchanges.

Actual exchanges of information with respect to 

cryptanalysis were somewhat gingerly approached. 

The British were then beginning to produce 

SIGINT from high-level communications of the 

German Air Force and Army, but their successes 

were limited, hard won, and often required amplification from other sources. German submarine 

communications enciphered by an Enigma machine presented analytic problems of immense 

difficulty, soon to be increased, on which the effort 

was intense. GCCS was working also on Abwehr 

(German Secret Intelligence) traffic and on intermediate cryptosystems of the German, Italian, 

Japanese, and other governments, and achieving 

important successes.

In the United States, while the navy worked on 

a Japanese naval attaché system, the Army SIS in 

the summer of 1940 was nearing the end of an 

arduous eighteen-month quest for an electromechanical analog device able to decipher the highest 

level cryptosystem used in Japanese diplomatic 

communications. Having in 1939 displaced a 

system previously known in Washington as RED, 

the new one was labeled PURPLE. Early in October 

1940 came the first deciphering successes with “the 

PURPLE machine.” A wiring diagram, technical 

data, and a considerable body of intercepted traffic 

were thereupon delivered by agreement to the navy 

cryptanalysts for use on work in progress on the 

same target. Secure navy engineering facilities then 

constructed six PURPLE machines, of which three 

went to the army, one to GCCS, and two to the 

navy.

As part of the exchanges in the cryptologic field, 

the British agreed to receive at GCCS two U.S. 

Army and two U.S. Navy cryptologists who would 

escort the PURPLE machine that the U. S. was 

giving to the British. They crossed the Atlantic from 

Halifax on a British warship. Representatives from 

each SIGINT organization, each a reserve officer, 

were designated. The Navy Department sent Lieutenant Robert Weeks and Ensign Prescott Currier; 

the Army had planned to send its leading expert, 

Lieutenant Colonel William F. Friedman, but 

illness caused his orders to be revoked, and Captain 

Abraham Sinkov thus became the senior Army officer, accompanied by Lieutenant Leo Rosen. At 

GCCS, where special machines to rapidly test analysts’ ideas were in use, the American gift could be 

Captain 

Laurance F. 

Safford, USN

(Photograph 

from the 

NSA History 

Collection)

Lieutenant Leo Rosen

(Photograph from the NSA History 

Collection)
Page 146

appreciated. Washington officials expected these 

officers to discover and learn all that they could to 

benefit the work to be done at home.

Captain Sinkov’s report described how GCCS 

was organized and how its output was facilitated by 

interception, direction finding (DF), and technical 

radio intelligence (called by the British, Wireless 

Technical Intelligence or WTI). Both Army and 

Navy officers had observed much that was outside 

the realm of special intelligence; they knew only of 

the existence of special intelligence and were 

pledged not to reveal its existence except to specifically named individuals.4

The ability of the analysts at GCCS to read German communications enciphered in some of the 

cryptosystems that used the Enigma machine was 

sufficient in 1940 to promise that the limited defenses of the United Kingdom would be used with 

maximum effectiveness against any invasion across 

the Channel. Broader successes in the coming 

months could be expected at GCCS. The products, 

special intelligence, were kept utterly secret by 

elaborate security precautions. Awareness by the 

Germans could deprive the British of what 

amounted to a “secret weapon” essential to their 

survival.

When OP-20-G started trying to read German 

naval Enigma traffic early in 1941, considerable 

progress would have been facilitated by sharing the 

lessons of experience already learned at Bletchley 

Park. Technical SIGINT collaboration then was 

confined to “Y” intelligence. Intelligence provided 

by the Admiralty to the Navy Department may have 

included some SI in a disguised form. As late as August 1941, when Commander A. G. Denniston, then 

head of GCCS, conferred in Washington with officers of the U.S. Navy and U.S. Army SIGINT 

organizations,5 he could not fail to observe how far 

from a consolidated, unrestricted commitment of 

American resources to preparedness still prevailed. 

The division of American public opinion over the 

right course of the United States concerning the 

war in Europe remained deep and emotional. 

Prominent were not only a “Committee to Defend 

America by Aiding the Allies” but also an “America 

First” committee.

Probably at the time of Commander Denniston’s visit if not earlier, OP-20-G received from 

GCCS diagrams of wirings and wheels of an Enigma 

machine and descriptions of the wheel movements 

during encipherments. Such material was subjected to preliminary research by Mrs. Agnes P. 

Driscoll and others, but was allowed to drop out of 

sight.6 Methods of solution that had worked on 

lower-grade systems could not be applied successfully. They were much too slow. Machine processing 

was required to cope effectively with such complex 

machine encipherings, a fact realized slowly at OP20-G.

Although the U.S. Navy had been participating 

with the Royal Canadian Navy and the Royal Navy 

in protecting transatlantic convoys long before the 

attack on Pearl Harbor, German submarines in 

January 1942 commenced a campaign of sinkings 

along the eastern seaboard which the U.S. Navy 

was not able to oppose effectively. When the means 

Captain Abraham Sinkov

(Photograph from the NSA History 

Collection)
Page 147

of retaliation had been sufficiently increased 

through better information about the enemy's situation and centralized control of our shipping and 

escorts, the Germans found the campaign too 

costly and returned to other areas of the Atlantic.

Commander Rodger Winn, a sagacious British 

barrister turned Royal Navy Reserve officer, visited 

the United States in the summer of 1942 and succeeded in persuading navy authorities to institute a 

system of escorted convoys from the Caribbean to 

northern ports and to link that system with the 

convoys to European destinations. He also convinced navy authorities that something akin to the 

Operational Intelligence Centre (OIC) in the Admiralty, would strengthen American anti-submarine 

operations. The British OIC was soon visited by 

Lieutenant Commander Kenneth Knowles, who 

was to become the officer-in-charge of parallel activities in Main Navy, Washington. His unit, under 

a successively modified administrative organization, was the Atlantic Section, Combat Intelligence 

Division, U.S. Fleet (F-21) and eventually, a unit of 

the Tenth Fleet (FX).7 Its submarine tracking room 

used intelligence from all sources, and could advise 

the convoy and routing unit of the submarine situation affecting a convoy’s course. 

U.S. Navy Attempts to Produce Special Intelligence

Collaboration in the production of special intelligence tends to be focused on the invention and 

manufacture of high-speed machines for use by 

army, navy, and GCCS analysts. Some of the books 

published about how Ultra intelligence was used to 

win the war leave the impression that, on both 

sides of the Atlantic, men of genius conceived of 

mechanisms that enabled decryption to be performed by tenders of machines analogous, perhaps, 

to the shift in textile manufacture from hand-weaving to factory output. Instead of being watchers of 

bobbins, the analysts acted more like musicians 

whose instruments provided music when properly 

played, but which otherwise yielded only noise.

Several types of a machine usually called a 

“bombe” emerged during the war from the work of 

men who applied electromechanical technology 

that was then novel. The British in 1939 acquired 

from Polish and French collaborating cryptologists 

the prototype of a bombe,8 and went on to devise 

their own. The Enigma in use from 1939 to 1941 

had three wheels, or rotors, and could be additionally elaborated so that the paths of a maze of wiring 

between the same plaintext letter and its final cipher equivalent could differ several thousand 

times. The bombe enabled the analysts to discover 

the way in which the controls of the sending and receiving Enigmas had been set for an enciphered 

message to be converted to plaintext German. 

It was possible for an enciphered message to be 

a reencipherment necessitating a second deciphering with special keys available to limited recipients.

The three-wheeled Enigma was partially replaced on 1 February 1942 by a fourth-wheel 

version for some German naval communications. 

When the four wheels were used, GCCS lost the 

ability to decipher most Atlantic submarine traffic 

Left to right: Alistair G. Denniston, Director, 

GCCS; Professor E. R. Vincent; and Brigadier 

John H. Tiltman in London, 1942

(Photograph from the NSA History 

Collection)
Page 148

for at least nine months in that year. The intelligence shared by the British Admiralty with the 

Navy Department with respect to protecting convoys and weakening the German submarine 

offensives abruptly declined in quality. Certain 

navy authorities, unaware of the reasons, concluded that the British were not meeting the 

obligations that they had assumed for full 

reciprocity in exchanges of cryptologic techniques. 

If the American cryptologists started as junior partners in producing SIGINT (other than Japanese), 

they intended to become equally competent by 

catching up. The material given to OP-20-G, 

including samples of plaintext messages with data 

about the Enigma, had been so quietly provided 

and so secretly retained there, that British action 

was probably unknown to the complainers.

The U.S. Army SIGINT organization in the 

throes of rapid growth, particularly in 1942, intended to acquire competence to produce SIGINT 

from all kinds of encrypted communications. It 

could not acquire German military traffic of sufficient quality and quantity for efficient processing 

from its own intercept stations, and it expected reciprocity – from GCCS for American contributions 

since 1940 concerning Japanese SIGINT – to include all kinds of material concerning German 

communications. Those expectations were for a 

time disappointed. The Military Intelligence Division, War Department, headed in 1942 by Major 

General George V. Strong, concluded that it was 

not being given all the SIGINT to which it was entitled and that it could not allow a condition 

of dependence on GCCS to persist indefinitely. No 

U. S. Army forces were even scheduled for operations against the Germans until the decision in July 

1942 to seize French North Africa as a base for future operations in the Mediterranean region. The 

first landings there could not be made until the following November. During Allied discussions in 

1942 of a cross-Channel attack to establish a second front in Western Europe to aid the Soviet 

struggle on the Eastern Front, and during 

Bombe deck at OP-20-G, May 1945

(Photograph from the NSA History Collection)
Page 149

the planning for Operation TORCH in Northwest 

Africa, the necessary intelligence was for the most 

part of British origin. During the Casablanca Conference in January 1943, the same situation 

persisted.

In 1942 the U.S. Navy Department’s pressure 

on the British authorities led, finally, to an accommodation. Colonel John Tiltman, BA, as a temporary 

representative of GCCS in Washington, convinced 

his superiors in the U.K. that the U.S. Navy’s “Y” 

authorities were determined to develop the ability 

to produce special intelligence to offset the British 

failure to furnish it. He was authorized to explain 

that the Royal Navy itself was being denied the 

kind of German naval intelligence that had 

once been available and that GCCS had not been 

able to produce it since the advent of the fourwheeled Enigma for Atlantic submarine 

communications. The closest possible collaboration by the British in producing and using “Y” 

intelligence could be expected, but recovery of special intelligence of first-rate quality, as before, 

seemed likely to depend upon a successful development of a high-speed bombe. GCCS had obtained 

authorization to exchange information about such 

a development, and would supply one bombe to 

OP-20-G.

By arrangement, two U.S. Navy officers, Lieutenant R. B. Ely and Lieutenant Junior Grade J. J. 

Eachus, went in June to GCCS in part to observe 

how the British made use of an expert analytical 

research group and, in part, to learn all that they 

could about the processing of naval Enigma traffic. 

Lieutenant Commander Howard T. Engstrom and 

others concerned with rapid analytical machines 

(RAMs) prepared the two visitors for their trip. Ely 

returned in August, Eachus in October, after having stayed to see tests of the British devices then 

under development. Those tests and others that 

followed were discouraging.

OP-20-G began a project, after Navy Department approval on 10 September 1942, to develop 

and then manufacture a device designed to operate 

at high speeds and to discover Enigma settings by 

testing possible cribs. That was to be the navy’s 

bombe for the four-wheeled Enigma. As outlined 

by Commander Joseph Wenger a week earlier, the 

project would cost $2,000,000 (already available 

at the Bureau of Ships) and take about five months 

from the first model to reach a production rate of 

about one per day. Operating them would eventually require 30,000 square feet of space and 500 

operators. (The exact total number to be fabricated 

was left for later determination. It was once set at 

96, then increased to 112, plus more to be shipped 

to the UK for GCCS.) The Navy’s contract with the 

National Cash Register Corporation of Dayton, 

Ohio, was surrounded by extraordinary security 

controls and given the highest priority and precedence in obtaining essential materials, after an 

appeal to President Roosevelt by Admiral Ernest 

King. Lieutenant Commander Ralph Meader, USN, 

was placed in charge of what was designated the 

Naval Computing Machine Laboratory at the Dayton plant. Joseph R. Desch of NCR Corporation 

was the contractor's principal engineer involved. 

Waves were sent to Dayton to assist in assembling 

and testing the first models. While the work there 

advanced, a special building for bombe operations 

was prepared at the Naval Communications Annex 

in Washington.

Commander Joseph Wenger

(Photograph from the NSA History 

Collection)
Page 150

By June 1943 production models were available 

for tests which they passed well. Output reached 

four or more per week, and analytic operations 

were maintained in Dayton until September. Commander B. F. Roeder, USN, was put in charge of a 

new special unit of OP-20-G to process Enigma 

traffic and to disseminate results. Quarters for the 

Waves who would run the bombes were constructed across the street from the compound of 

the Naval Communications Annex in Washington. 

In September the bombes began working there as 

the transfer from Dayton became gradually complete. When the daily keys in German naval traffic 

had been ascertained, the bombes became 

available for other tasks, some of which GCCS requested.

The terms of collaboration in special intelligence by OP-20-G and GCCS were recorded in a 

written agreement negotiated in Washington for 

GCCS by Sir Edward Travis, its head, and reported 

to his superior by Commander J. N. Wenger, USN, 

on 1 October 1942. It was signed the next day. The 

British consented to full exchange of intercepts, 

keys, “menus,” cribs, and all technical data applicable to German Navy and, in particular, German 

U-boat communications. The United States 

undertook to match the British primary responsibility for German naval SIGINT by assuming 

parallel responsibilities for the Japanese naval 

SIGINT problem. OP-20-G would send to GCCS 

the Japanese material intercepted at American stations and all American recoveries of cipher keys 

and codes to help GCCS retain its capabilities in 

Japanese SIGINT production.

In developing and using analytical equipment, 

GCCS would respond to requests for technical assistance and would send to OP-20-G certain 

technical personnel to obtain information about 

the American high-speed project. GCCS would also 

obtain certain items of special equipment that were 

manufactured in the United States.

By the collaboration thus defined, the intelligence needs of both the Navy Department and the 

Admiralty would be served. The arrangements 

might be expected to benefit the Allied protection 

of transatlantic convoys over the new sea lanes for 

supply and reinforcement of the Allied campaigns 

in the Mediteranean area.

U.S. Army Preparations to Produce Special 

Intelligence 

While the Navy bombe project was in the developing stage, the Army too became restive at what 

seemed to be a withholding of reciprocal assistance 

by the British at GCCS. In May 1942 Major Solomon Kullback began a visit of several months at 

GCCS. He studied the cryptanalytic methods used 

at GCCS for treating a wide range of enemy cryptographic systems. Though he was shown operations 

in progress on Enigma traffic, it was not done in a 

way that enabled him to become an expert at that 

as he did with other cryptosystems.

Probably before the navy actually launched its 

bombe project, the army SIS had decided to design 

a bombe that used relay switching instead of the rotary type to be employed in British and U.S. Navy 

versions. On 30 September 1942 the Army Signal 

Corps contracted with Bell Telephone Laboratories 

(BTL) to produce a test sample. Its subunits would 

be a single-frame apparatus analogous in its operations to those of a German three-wheeled Enigma. 

By November 1942 BTL could demonstrate successfully the sample model. BTL then undertook to 

complete 144 frames. To the uninitiated this bombe 

looked like metal shelving stocked with the insides 

of radio receiver sets in an orderly and interconnected arrangement.

In the winter of 1942-1943, GCCS had as a 

bombe building project one that involved ultimately choosing one of two methods for coping 

with encipherments from a four-wheeled Enigma. 

The U.S. Navy had another. The U.S. Army was 

well along on developing its bombe applicable to a 

three-wheeled Enigma. Officials of SIS and OP20-G conferred in January 1943 on the progress 

made thus far with the Army’s apparatus, and the 
Page 151

possibility of incorporating certain features in its 

further development. At that time, seventy-tw0 

frames (or half the total number) were expected to 

be ready early in April 1943.

Pursuant to the agreement with the Navy in 

October 1942, GCCS sent one of its leading cryptologists, Dr. Alan M. Turing, to the United States in 

December 1942. He had been closely concerned 

with the devices for machine processing that had 

been developed by GCCS. On 21 December he was 

escorted to the Naval Computing Machine Laboratory by several officials of OP-20-G and by Major 

Geoffrey Stevens, the British SIGINT Liaison Officer stationed by agreement at Arlington Hall 

Station.. The navy bombe as it then stood was of 

uncertain merit as he saw it, though he may have 

reconsidered and thought better of it later on.

When Dr. Turing’s authorization to visit the 

Bell Telephone Laboratories and observe Army 

cryptologic projects there was sought from a junior 

American officer, he was suspected of trying to slip 

in somewhat clandestinely. His request was 

refused until the issue of his eligibility had worked 

its way through official suspicion at various levels 

to become the subject of correspondence between 

General Marshall and Field Marshal Sir John 

Dill, the head of the British Joint Staff Mission in 

Washington. On 5 February 1943 he and Major 

Stevens were finally received at BTL and were 

shown the army bombe and other devices then 

under development.9

During the Anglo-American discussion preceding Dr. Turing’s visit to BTL, some U.S. Army 

SIGINT officials expressed doubt that the British 

had been exchanging cryptologic materials with 

complete reciprocity, as agreed. When the army 

identified materials allegedly withheld, the British 

insisted that they had all indeed been released 

to the American cryptanalysts who had come to 

GCCS. The British maintained that, to fulfill their 

part of a “full and free exchange,” they did not have 

to allow such materials to be used in Washington. 

The correspondence with Sir John Dill induced 

General Marshall’s deputy to acknowledge that 

sending “us” the Enigma materials wanted by the 

U.S. Army did indeed involve an increased hazard 

of compromise that need not be incurred. Instead, 

he conceded that arrangements should remain as 

they then were.10

The British concluded that at the Bell Telephone Laboratories the U.S. Army was 

experimenting with what they believed to be a 

more efficient development of the same “highspeed analyzer” that had been shown at GCCS to 

several American officers. The prime minister had 

authorized this disclosure during their visit to 

GCCS in April-May 1941, and at later dates to Brigadier General Frank Stoner and Lieutenant Colonel 

George Bicher of Headquarters, ETOUSA. Major 

Solomon Kullback and Captain Roy D. Johnson of 

the SIS had subsequently worked at GCCS on the 

Enigma cryptanalytic problem, and had learned of 

the more recent developments. In the eyes of the 

British, the experiments at BTL should have been 

disclosed to them without waiting for ultimate success.

Dr. Alan M. Turing, British cryptologist

(Photograph from the NSA History 

Collection)
Page 152

The Turing episode is important as an indicator 

of the U.S. Army’s degree of self-confidence and the 

British appraisal of a proper partnership. Dr. Turing was a young mathematical genius whose 

doctorate had been won at Princeton University in 

1938, after two years of leave from his Fellowship 

at King’s College, Cambridge University. He had 

then declined the opportunity to work with the famous mathematician, John von Neumann, at 

Princeton as an assistant in order to resume the 

role of a Cambridge don. He had already produced, 

before the war, a paper with ideas concerning an 

electronic machine which could calculate automatically – a paper read widely among mathematicians 

because of its demonstration that some problems 

were not mathematically solvable even though 

mathematically stated.

GCCS had recruited him very soon after the war 

began, and at Bletchley Park he was known as “the 

Prof.” because of his abstracted ways; he had 

shown various practical qualities too. They ranged 

from padlocking and chaining his tea mug to a radiator in his office to devising electromechanical 

means for sifting the cryptographic variables in 

enemy encipherments.

The records do not show whether the method 

by which his access to the Bell Telephone Laboratories as first sought was really intended to avoid 

drawing attention from those who ought to have 

been approached for approval. It was not the only 

time that Turing relied for necessary credentials on 

administrative channels which ignored requirements or took too much for granted. While the 

obstacles to his visit were being removed, he 

seemed to have found time to visit Princeton and to 

have enjoyed access to food more nourishing than 

Britain’s wartime rationing permitted at home.

The main consequence of the episode was undoubtedly the demonstration that, when taken to 

the highest army level, the specifics of collaboration in cryptologic matters would follow the view of 

GCCS and not of G-2. Moreover, in spite of the navy’s intention to protect its highest COMSEC 

system, the decision was made by the chief of staff 

of the Army to allow Turing to see such a cipher 

machine under development. In the discussion, 

General Marshall set a precedent for accepting the 

British view that all unnecessary risks of a compromise by transmitting SIGINT materials out of the 

United Kingdom should be avoided.

When, a few weeks later, the U.S. Army tried to 

obtain Ultra materials from the British comparable 

to what had already been released to the U.S. Navy’s OP-20-G, the British declined. GCCS, supported 

by the Chiefs of Staff Committee, then insisted that 

its SIGINT collaboration with the U.S. Navy, including some SI, had been necessary in order to 

fight the German Navy in the Atlantic.

The U.S. Army – GCCS Agreement in May 

1943 

The availability of enough of the new army’s 

rapid analytical machines (RAMs) for SIS work on 

German Army and Air Force Enigma communications could be foreseen in February 1943. Mr. 

Friedman on 8 February then advised Colonel W. 

P. Corderman, commanding officer at Arlington 

Hall, that the SIS could by 1 April 1943 begin assembling and installing “our E-solving machinery” 

and could expect to be operating soon afterward. 

Needed then would be trained operators, traffic, 

and traffic-intelligence materials, and certain special information and complex special procedures 

already developed at GCCS. Special cryptographic 

equipment for use in fully secure communications 

channels would also be required. While some German Army Enigma traffic was being intercepted in 

1942-43 at Vint Hill Farms Station, or at an Army 

intercept station in Newfoundland and another in 

Iceland, the amount was small and the reliability of 

interception was inadequate for regular work. British intercepts would be essential to the program at 

Arlington Hall Station.

The British position in January 1943 at the time 

of the “Turing affair” had been that there should be 

no “exploitation” in the U.S. of vitally Top Secret 
Page 153

traffic unless the British became convinced, as in 

the case of German submarine communications, 

that such exploitation in the United States was necessary. Colonel Tiltman persevered in upholding 

that position in conversations with Mr. Friedman. 

The latter insisted that the U.S. Army apparatus 

bore no external or internal resemblance to the 

British bombes or associated equipment and asserted that it was capable of solving several other 

types of cryptographic traffic problems. He proposed to expand U.S. interception of Enigma 

communications in Northwest Africa and to establish new Washington-Algiers telecommunications 

cryptochannels.11

The U.S. Army proposal to the British on 23 

February 1943 meant that a second center for producing some German Army and Air Force Ultra 

would be established in the Washington area. 

Enigma traffic that had been intercepted by American and British operators, and then analyzed and 

interpreted, would require transatlantic communications for delivery of special intelligence from the 

U.S. to destinations in the theaters of war.

At that time, the Allies controlled no part of the 

European continent, and neither partner was ready 

to risk an Allied attempt to invade across the English Channel for lack of sufficient strength to 

remain. The British could still consider the United 

States to be a junior partner whose potentialities 

remained uncertain in the light of current events in 

Tunisia. They quite naturally recoiled from the 

prospect of relinquishing control over an instrument of war that they had produced and on which 

they depended so heavily. U.S. Army authorities 

knew that special intelligence was available to 

Americans at Allied Force Headquarters at Algiers 

and at ETOUSA in England, and would continue to 

be available to them on the principle of the “needto-know.” It was the ability to decrypt Enigma 

traffic independently that, in the long run, they believed they must acquire. They appreciated that the 

security of Ultra was fragile but believed that the 

risk in producing it in the U.S. was not too great.

Earlier agreements to exchange traffic with the 

British (and, as of 15 January 1943, with the Canadians) were bringing material of solid benefit to the 

U.S. Army. The traffic was chiefly diplomatic and 

William F. 

Friedman at his 

desk at 

Arlington Hall 

Station

(Photograph 

from the 

NSA History 

Collection)
Page 154

Japanese Army communications. At British sites, 

communications originating in neutral and German-dominated countries in Europe could be 

copied when no American station could hear them. 

In Canada, Australia, and British India, Japanese 

Army material copied by the British and furnished 

in the exchanges amounted to about thirty percent 

of that available to American analysts. The amount 

of duplication did not exceed what was warranted 

in order to eliminate garbles and to verify doubtful 

information.12 

The attitudes of individuals at lower levels of 

the chain of command were more nationalistic 

than that of those near the top. When Captain Edward G. Hastings, RN, discussed the American 

request with Colonel Carter Clarke and Colonel 

Corderman, for example, his remarks could be 

treated as more or less an ultimatum – the Americans should withdraw their proposal or 

Anglo-American collaboration in SIGINT might 

cease. Cooler heads, in particular Lieutenant Colonel Telford Taylor of G-2, recognized that 

collaboration would not be allowed to founder if 

the issue were to be taken high enough. He also believed that the current British position would 

eventually soften so that American capabilities 

could later be expanded gradually under arrangements that would then be agreeable.

Consultations in London, in which the British 

Chiefs of Staff Committee was asked to consider a 

British reply to the U.S. Army proposal, and in 

which the U.S. military attaché and the principal 

U.S. SIGINT officer in London, Colonel George A. 

Bicher, participated, produced an “unshakable answer” from the British. American participation in 

the United Kingdom would be welcome; no exploitation of Enigma traffic performed in the United 

States would be accepted. The British were able to 

find support for their position in the words of General Marshall’s letter at the time of the “Turing 

affair.”

During the negotiations, the U.S. SIGINT 

officer at Allied Force Headquarters in Algiers, 

Lieutenant Colonel Harold G. Hayes, was asked to 

report whether SI went from GCCS to AFHQ in Algiers and, if so, whether it came to him. He replied 

that the “Y” Service in which he was engaged was 

quite separate, that SI went directly to General 

Eisenhower’s chief of intelligence at AFHQ via a 

special radio link and that Hayes himself could not 

prudently even inquire about SI until he knew the 

substance of any agreement about it between GCCS 

and the SIS, Washington.

The Americans wished to avoid an ultimatum 

from either ally to the other, but they insisted that 

the U.S. Army must become capable of producing 

SIGINT from German Army and German Air Force 

Enigma communications. Again the issue was 

resolved by negotiations in Washington in which 

Sir Edward Travis, head of GCCS, came to an 

understanding with Colonel W. P. Corderman, Sig 

C., in terms that were supplemented by arrangements satisfactory to the Special Branch, G-2, War 

Department. The agreement was signed by Travis 

and Corderman on 17 May 1943. It conformed 

closely to a draft approved by the British Chiefs of 

Staff Committee and offered to General Marshall 

by Sir John Dill. General Marshall thus overruled 

General Strong's insistence on terms enabling the 

U.S. Army, forthwith, to start developing at home 

Brigadier General Harold G. Hayes, 1955

(Photograph from the NSA History 

Collection)
Page 155

(with the assistance of GCCS) its own ability to produce SI. He acceded instead to the British agreement 

to receive a U.S. Army unit in the UK for training 

and production there that would be supervised by 

GCCS and for delivery of SI to the War Department 

by secure Britsh communications channels.

The new agreement distinguished between the 

American and the British names for the same 

things as follows: 

 U. S. British

Special Intelligence A Special Intelligence

Special Intelligence B “Y” Intelligence

TA Intelligence “Y” Intelligence

The two organizations, GCCS and SIS, agreed 

to exchange completely all information concerning 

the detection, identification, and interception of 

signals from, and the solution of codes and ciphers 

used by, the military and air forces of the Axis powers, including the German Abwehr. The U.S. Army 

assumed as its main responsibility the reading of 

Japanese Army and Air Force codes and ciphers. 

The British assumed as their main responsibility 

the reading of the codes and ciphers of German and 

Italian Army and Air Forces. Both countries 

agreed that special security regulations should 

apply to intelligence derived from enemy highgrade codes and ciphers. In that connection, both 

agreed to use their most secure cryptographic 

systems for the transmission of decodes and technical cryptanalytic data.

British or U.S. military or air commanders in 

chief would receive all the special intelligence 

necessary for the conduct of operations – obtaining 

it from either British or U.S. centers as mutually 

agreed. To insure dissemination of that sort, liaison 

officers were to be appointed and authorized to see 

all decodes. Distribution of SI would be held to a 

minimum and would be confined to those who 

needed the intelligence for the proper discharge of 

their duties. The same security regulations would 

govern all recipients of Special Intelligence A. 

Until modified by mutual agreement, the 

regulations in force in theaters of war where British 

forces were already operating would govern. Special Intelligence A was not to be intermingled with 

general intelligence from other sources unless that 

became imperative, and then all must be handled 

as if it were special intelligence A. Under no 

circumstances could special intelligence be 

transmitted in a cryptographic system that could be 

read by anyone except an authorized recipient. 

Special intelligence B was to become the basis for 

action, documents, or telegrams only when a 

different source could be presumed, and transmissions were to be in “absolutely secure” cryptosystems.

In Washington and London intelligence liaison 

officers of the two allies were to have access to all 

special intelligence and were to be free to select and 

forward whatever they deemed necessary.

Cooperation and coordination in “Y” between 

the U.S. Signal Intelligence Service and the British 

“Y” Service, at all levels, were also to prevail. Each 

was obligated to inform the other of the employment and scope of its “Y” effort in Allied theaters.

Brigadier General W. Preston Corderman, 

1954

(Photograph from the NSA History Collection)
Page 156

It was agreed that research into new technical 

methods of attack on German Enigma communications would continue to be conducted in 

Washington.

U.S. liaison officers at GCCS would select messages and summaries that they believed should be 

sent over existing British secure channels, either to 

G-2, Washington or to theater commanders.13 U.S. 

liaison officers in the War Office and Air Ministry 

would continue, as in the past, to handle SIGINT 

relevant to order of battle.

A U.S. party in Great Britain would work at independently solving Enigma keys but would avoid 

duplication of effort. They would be furnished with 

British machines and be given instruction in all 

processing and would conduct complete processing 

to the extent they desired. Their decodes would be 

passed to Bletchley Park for emendation, 

translation, and distribution. Members of that 

American party would not be transferred elsewhere 

except for urgent reasons. Distribution of Allied 

special intelligence would be through specially 

trained British units at the headquarters of commanders-in-chief. If the commander-in-chief was 

an American, an American liaison officer would be 

attached to the unit “to overcome difficulties that 

may arise in regard to a difference in language.” 

Ultimate control over matters of security and all 

dissemination of special intelligence was to be retained by the Director, GCCS.14

The 17 May 1943 agreement was forwarded to 

the chief of staff, U.S. Army, by General Strong on 

10 June 1943 with a recommendation that it be approved. On 15 June 1943 it was approved by the 

secretary of war.

On 23 July 1943 Colonel Bicher, the chief, SIS, 

ETOUSA, received from Washington the program 

for executing that part of the 17 May agreement 

that provided for a U.S. Army SIS contingent to 

learn how to produce SI in the UK.

After resolving matters with the Army, Commanders Travis and Wenger, along with other 

officers of OP-20-G, discussed the progress made 

on the two types of bombe for the four-wheeled 

Enigma that GCCS had under development and 

testing, and the situation in the United States, 

where the Naval Computing Machine Laboratory at 

Dayton, Ohio, already had a production model 

soon to be manufactured. On 18 May 1943 the 

British faced an uncertain performance by 

their new bombes in either version, while the 

Americans were confident that their machines 

worked well and would be in full production before 

the end of June.

In those circumstances it was agreed that 

the British would allocate tasks and provide materials to OP-20-G in the form previously shown, and 

that the Americans would keep GCCS informed of 

the number of operative bombes available and 

would, of course, return to the British all results as 

soon as possible.15

Sir Edward Travis

(Photograph courtesy of William F. Friedman 

Collection, George C. Marshall Library)
Page 157

The Friedman, McCormack, and Taylor Mission – April to June 1943

Even before the agreement had been concluded, Mr. William F. Friedman of SIS, now 

recovered in health but no longer in uniform, made 

a long visit to GCCS and to London. Lieutenant 

Colonel Alfred McCormack and Major Telford Taylor, from the Special Branch, G-2, accompanied 

him to England, arriving on 25 April 1943. 

In London they began by consulting Lieutenant 

Colonel George Bicher at Headquarters, ETOUSA, 

before he left for consultations in Washington. 

The dual nature of their positions in Army organization was reflected in courtesy calls on the 

assistant chief of staff, G-2, and the chief signal 

officer, ETOUSA. Their professional interest led 

them quickly to sessions with the deputy 

director, GCCS (Travis), and his superior officer 

(Sir Stewart Menzies), the chief, Secret Intelligence 

Service at the latter’s office. There they learned that 

the British authorities expected them to proceed 

with their mission of observation without regard to 

the current controversy.

The three men often stayed together during 

their seven-week visit, but occasionally separated 

and compared notes afterward. Their movements 

took them not only to SIGINT stations in London 

and GCCS at Bletchley Park (BP) but to several 

outstations. Almost at once they went to Tidworth 

to see a U.S. Army SIGINT company in training. 

They sampled the SIGINT establishments at 

“Berkeley Street” and “BP,” then devoted several 

weeks to thorough examinations of the systematic 

operations at each. It was soon apparent to 

them that U.S. intelligence officials in Washington 

had an inadequate understanding of the 

complexities of the British effort. Reports by earlier 

American visitors had not been studied widely 

enough. The British liaison officer may have 

been supposed to provide a full and intelligible picture to the responsible U.S. intelligence officials but 

had not. Whatever the reasons, Colonel McCormack set out to rectify deficiencies by 

industrious recording of observations on his own 

visits. All three tried to convey to their superiors 

(Colonel Carter Clarke of the Special Branch and 

Colonel W. Preston Corderman, CO, Arlington 

Hall) by carefully drafted messages, facts that they 

were convinced those officials at home should be 

taking into account in the negotiations over an 

GCCS agreement.

The main problems to be met in accordance 

with the terms of agreement would be

(1) how could the the U.S. Army improve its 

ability to produce special intelligence; 

(2) how could Anglo-American technical collaboration in producing SIGINT be enhanced; 

(3) how could intelligence liaison officers stationed in the United Kingdom satisfy the 

intelli-gence requirements of the army; and 

(4) how should American participation in disseminating special intelligence to field commands 

be established?

All Americans who were “in the Ultra picture” 

agreed that the U.S. Army must ultimately learn 

how to produce special intelligence for its own 

needs but in doing so ought not to hamper current 

production.

The three visitors were amazed by what the 

British had accomplished in the way of 

organization and expansion. Comparing their views 

of British production one evening, McCormack 

said: “It's not good. It’s superb But it isn’t 

military.” The others agreed that at BP considerations of rank and grade were ignored in favor of 

“the best man for the job,” of candor in technical 

cooperation, and of acceptance of personal eccentricities.

To Colonel Carter Clarke, Colonel McCormack 

cabled (in the spirit of BP):16
Page 158

If Corderman wants his people to 

learn what makes this operation tick 

he had better send them over to learn 

it, because they never on God’s green 

earth will learn it from anything that 

Arlington will be able to do in any 

foreseeable future.

The visitors discovered from the questions and 

instructions that came back to them while in London that their painstaking cabled reports were not 

convincing in Washington. Their superiors might 

not have been impressed by figures such as the 

many receiving sets within the United Kingdom 

alone by which Enigma intercept material was obtained, or the sixty-seven bombes already in 

operation of which forty-six were running twentyfour-hours per day on German Army and Air Force 

(three-wheeled Enigma) traffic. They might not 

have found noteworthy the estimate in May 1943 

that 1,650 to 1,700 persons were at work on cryptanalysis and intelligence analysis of Enigma traffic, 

in addition to many more concerned with interception, special communications, and delivery. But if 

they ever understood the steps involved in processing Enigma, producing cribs, setting up machines 

for operations to verify the correspondence of letters, testing the arrangements, studying possibilities 

indicated by the machines, and deriving an understandable text from possible combinations, 

translating the text into intelligence, feeding the intelligence back into the general pot in order to 

relate it to logs and other data from traffic analysis 

in a search for more cribs, and other actions – then 

they might have been more agreeable with the conclusion of Colonel McCormack’s message cited 

above. They might also have accepted his opinion 

that there was no likelihood that Arlington Hall 

soon could provide any significant amount of timely 

intelligence by working on the problems of Enigma 

keys that GCCS would define each day.

As McCormack noted, GCCS was both a producer of SIGINT information and an organization 

directly involved in supplying combat intelligence 

to field commanders. Although watch officers of 

each armed service selected items to go to their 

ministries (Admiralty, War Office, and Air Ministry) for treatment in the output of finished 

intelligence, GCCS itself sent any Ultra item relevant to a field commander’s current operations to 

that commander by a direct communications system which GCCS controlled for that purpose. It 

sent appropriate items directly to Brigadier Sir 

Stewart Menzies, who quickly passed deserving 

items on to the prime minister.

Among the features of the British SIGINT operation that Colonel McCormack found of primary 

interest was the effort, within the security framework, to disseminate to that person all SIGINT 

affecting an individual’s duty performance. Availability of SIGINT was not confined to the service 

with the greatest interest but extended to all three 

whenever their representatives in the Watch Room 

wished to have an item. Moreover, he could find no 

reason to believe that any items just went to British 

commanders when U.S./UK commanders were 

jointly involved. General Eisenhower, for example, 

was receiving anything pertinent to his area of 

command, and that information went also to General Sir Harold Alexander, his principal field 

commander.

Next in size to GCCS at Bletchley Park was CDR 

Denniston’s station in London known as “Berkeley 

Street,” where almost 250 persons were engaged in 

producing diplomatic intelligence. Everything released from Berkeley Street went to the Foreign 

Office and to the service ministries, while liaison 

officials from other government agencies selected 

what their chiefs might want. Items for Washington, New Delhi, Melbourne, and Cairo were 

distributed through GCCS; diplomatic intelligence 

based on SIGINT went to British diplomatic recipients through a system controlled by the Chief, SIS, 

rather than over standard diplomatic communications channels.

McCormack’s visits included the MI6’s establishment at St. Albans devoted to training men and 

managing counterintelligence operations. There he 
Page 159

found a small party (largely recruited from American academic faculties) from the U.S. Office of 

Strategic Services. They were apparently at an early 

stage, of their preparations for the eventual invasion of the continent across the Channel.

Mr. Friedman, Colonel McCormack, and Major 

Taylor saw at Berkeley Street the PURPLE machine 

that had crossed the Atlantic in 1941 and another 

one – bigger and not so dependable – that British 

engineers had since fabricated. From the point of 

view of U.S. intelligence, Berkeley Street might in 

the long run prove to be a source of greater value 

than Bletchley Park’s.

While Mr. Friedman was at Bletchley Park, 

news came by radio of the Allied captures of Bizerte 

and Tunis on 8 May 1943, and on 18 May came 

word of the Corderman-Travis agreement reached 

in Washington. On 20 May he was for the first time 

shown Bletchley Park’s bombe operations.

The visit to the U.K. by Mr. Friedman and Colonel McCormack ended on 12 June 1943 but Major 

Taylor remained to execute certain terms of the 17 

May agreement that were of great concern to the 

Special Branch, MIS. He was to be the first of the 

intelligence (as distinguished from SIGINT technical) liaison officers at Bletchley Park. He was also 

to be officer-in-charge of others to come from the 

U.S. for similar G-2 duties, or to be inducted into 

one of the Special Liaison Units (SLU) for distribution of SI to commanders in the field.

Collaboration under the Army’s 17 May 

Agreement

Under the terms of the new agreement, one or 

more U.S. representatives would review the daily 

output of Ultra material at Berkeley Street, another 

station at Ryder Street, and Bletchley Park in order 

to select items of value for American intelligence.

The “Yellow Project,” as Arlington Hall’s early 

work on Enigma had been called, was transformed 

by the new agreement. Captain (later Major) Roy 

D. Johnson, who prepared from November to April 

at GCCS17 to meet the responsibilities of operations officer of an Enigma analytic unit under 

Lieutenant Colonel Frank W. Rowlett, instead went 

back to England in October as officer in charge of 

an overseas Signal Security Detachment. The new 

“Operation BEECHNUT,” as authorized in July, 

sent officers and enlisted men from Arlington Hall 

and Vint Hill Farms Stations for duty in three such 

detachments plus one headquarters unit that together became the Special Project Branch of the 

Signal Intelligence Division, ETOUSA. They included intercept operators, machine processors, 

and cryptanalysts. Major William P. Bundy became 

the operations officer of the Branch. The three Signal Security Detachments were numbered 6811, 

6812, and 6813 and were separated of necessity.18

The intercept unit went to a site on the heath near 

Bexley in Kent and set up a station known as “Santa 

Fe.” By dint of hard work they responded to training that enabled them before June 1944 to count 

about 100 reliable operators in the unit. In the latter part of 1944 they were the subject of a 

commendatory letter from a British consumer. The 

second detachment had working quarters at Eastcote but were housed at Harrow-on-the Hill, seven 

miles away, until they could get a camp built, in 

part by their own labor. The analytical group began 

arriving in September and were taken in at Bletchley Park, where an individual’s progress determined 

his transfer from training to operational work. The 

branch was slow in grasping the opportunity 

opened for it in July, largely because of the necessity of obtaining G-2 clearances before shipment 

from the U.S. and also because of the unexpected 

amount of transportation and housekeeping duties 

that their separate sites required. It was in March 

1944 or later that the Special Project Branch could 

begin to look confidently toward its objective. At its 

peak strength, it numbered about 36 officers and 

400 enlisted men, of whom some had been found 

in the theater.

The intercept operators of the 6811th Signal Security Detachment were at first inattentive to the 

wisdom of fully recording German communicators’ 
Page 160

chatter. An example of what could result from 

alertness was reported later by Albert Small,19 the 

SSA liaison officer at Bletchley Park. A traffic analyst noted in a log that one German operator, at a 

time of callsign changes, had asked another if a certain callsign was that of an individual with a 

well-known long and distinctive name. The man 

had been a sergeant, and could have been promoted to lieutenant. Trying his name as a crib in a 

signature, Bletchley Park soon broke the key for 

that day’s transmissions.

U.S. cryptanalysts who went to GCCS to learn 

the ways in which work was organized and the 

methods by which results were attained found 

themselves engulfed in British nicknames and 

slang by which cryptosystems, analytic operations, 

processes, and units were identified. It illustrated 

the epigram about the British and the Americans as 

peoples who were separated by the same language. 

Foreign cryptographic systems, for example, were 

classified for identification in categories named by 

fish, flowers, animals, birds and insects, rather 

than by letter-and-number symbols, as they were at 

home. Colors were also used, as they had been in 

Washington.

Rapid analytical machines and auxiliary processing devices acquired distinctive names on 

which much ingenuity was expanded. The “bombe” 

– for which the Poles are credited with providing 

the name that the British and Americans retained – 

was made more efficient by using a “Duenna” in the 

latter part of the war. Resort to electronics rather 

than electromechanical operations produced for 

GCCS both a “Giant” and ultimately a “Colossus.”

American visitors had to recognize the meanings of “blist,” “cillies,” and “Uncle Dudley,” as well 

as “Duddery,” and scores of other terms that served 

as oral shorthand. Such inventiveness was inherent, apparently, in the mental equipment needed 

in producing SIGINT. Machines devised by the 

Americans at home accumulated a roster of esoteric designators.

One comprehends the extent to which the use 

of special terms at GCCS amounted in effect to a 

code upon reading the following sample: 

The only Air key still defying us is 

GNAT (Fliegerkorps X). LILY, which 

has no Uncle, is difficult enough 

without one; for FIREFLY we are 

largely dependent upon cillies, and 

for GLOWWORM on re-encodements 

from FIREFLY. FIREFLY does not 

seem to be using his large store of Uncles but we do not know yet about 

GLOWWORM. There is fairly good 

evidence since the fifth that WASP, 

who started without his, has now put 

it on his best crib frequencies, and we 

may be in for trouble. JAGUAR, a 

heavy user of D and of Uhr, has got 

stuck for the last day or two At the 

end of the month most of the [Army] 

keys in use were compromised, with 

the result that PEEWIT, the Supply 

key, decoded a lot of operational 

traffic as well, and also PULLET, the 

Y key.... 

At “Berkeley Street,” Taylor served until relieved late in July 1943 by a civilian, Mr. Roger 

Randolph. Captain Bancroft Littlefield followed 

Mr. Randolph in December, and about one year 

later, Captain Lewis T. Stone, Jr., took over from 

Captain Littlefield. At “Ryder Street,” Major W. L. 

Calfee acted as U.S. SIGINT Liaison Officer.

The American Ultra officers who came to 

Bletchley Park for similar duties were the nucleus 

of a unit in Hut 3 that came to be designated at 

Bletchley Park as “3-US.” Major Samuel McKee 

joined Taylor in selecting the first of a stream of 

“CX/MSS items” (Ultra) for transmission to Washington, always via British secure communications 

channels. The first messages were sent on 27 August 1943.
Page 161

Principles of selection rested more on trial and 

error than on doctrine. Guidance from Washington 

was minimal. Almost at once, Taylor and McKee 

recognized that Ultra messages provided far better 

data on German Army and Air Force order of battle 

than the materials two U.S. liaison officers, assigned to duty at the War Office and the Air 

Ministry, had been obtaining from other types of 

SIGINT material. Their selections in Hut 3 soon 

overloaded the available British secure communication circuits and had to be restricted.

In Washington, where the MAGIC Daily Summary became so important to the conduct of the 

war, a narrowly distributed Military and Naval 

Supplement was used as the vehicle for SI. On 1 

July 1944 it was replaced by a daily MAGIC European Summary prepared by the German Military 

Reports Branch of MIS. About ninety percent was 

based on special intelligence.

The five or more U.S. officers in Hut 3 were led 

by Major F. W. Hilles, while Taylor (promoted to 

lieutenant colonel) and McKee worked on arrangements for training American Special Security 

Officers in disseminating Ultra to U.S. commanders. The recruitment was done in Washington 

where the training there was preliminary; training 

at GCCS was the main, final stage, and chiefly 

accomplished in “3-US." All personnel were 

accounted for as the strength of “MIS, War Department, London Branch.”20

Several of the future Special Security Representatives completed their training by visits to the 

Mediterranean area commands where Special Liaison Units (SLUs) were functioning. The first visitor, 

Captain John F. B. Runnals, went to Algiers, La 

Marsa, Bari, and Caserta in November-December 

1943 not long after the liberation of Naples. At 

AFHQ in Algiers he found the principal British 

Special Security Officer (SSO) in the theater, Lieutenant Colonel Robert Gore-Brown, from whom he 

obtained an explanation of the functions of nine 

SLUs in NATOUSA, six others in Egypt and the 

Near East, and a special communications network 

extending from “Windy Ridge” in the United Kingdom to Gibraltar, Algiers, La Marsa, Taranto, Bari, 

Foggia, Caserta, and Bastia. Further forward he ascertained the organization of SLU activities.

In April, when Major Lewis F. Powell, Jr., 

began his trip to the Mediterranean area, he carried 

instructions (from the chief of staff, Army) for certain U.S. air and army officers governing the 

protection and use of special intelligence. He was 

also to observe the SLU system as employed by the 

Mediterranean Allied Air Force and constituent 

commands.

The personnel of MIS, War Department, London Branch were of three categories: Advisors, 

Special Security Representatives (SSRs), and Special Security Officers (SSOs). The first type worked 

in Hut 3, Bletchley Park, or in a London British 

SIGINT station. The second and third types were to 

be assigned to the headquarters of U.S. commanders, as members of Special Liaison Units controlled 

by the British. They would work in offices, vans, or 

possibly briefly in tents, near a Special Communications Unit (SCU) of British RAF noncommissioned 

and enlisted communicators. The SCU in its own 

vehicle would be using a “Type X” machine – a 

cryptographic system that was reserved for the protection of special intelligence, in radio (or undersea 

cable) channels.

The SSRs were expected to be closely associated 

with the chief of intelligence, chief of staff, and 

commanding officer of a headquarters. The SSOs, 

depending on the preference of the SSR, would 

work for him, or with him. The SCUs kept in touch 

with the central station in the UK and delivered deciphered messages to an SSO. If the message was 

urgent, it would be taken at once to the SSR for action; otherwise, it would be handled as the others 

delivered at stated times, or used in daily briefings 

and summaries. The SSO office or van could be 

used as an Ultra library where officers “on the list” 

could consult files and maps showing information 

from SI. The maps not only presented enemy order 
Page 162

of battle but the enemy’s beliefs concerning the disposition of Allied forces.

During the planning to invade Normandy, the 

planners benefited from available special intelligence. The Eighth and Ninth Air Forces, then 

engaged in preinvasion bombing, also found Ultra 

useful in choosing targets and escorting the bombers. The tactical air commands that would support 

the armies prepared to make use of SI. Later fortythree American officers were assigned to Special 

Liaison Units. U.S. Army officers who served as 

special security representatives in the European 

Theater are listed below opposite the command 

headquarters to which they were accredited.

Future SSRs visiting in Algiers saw the segregated operational areas of the SLV and the SCV on 

the top floor of a hotel used as Allied Headquarters. 

They observed the receipt of Ultra messages from 

GCCS, their conversion into plain text, and the 

making of copies for delivery to persons on the 

Ultra list. They learned that record copies were 

filed and retained for certain periods, while others 

were recovered and destroyed after being read. 

SSRs read the messages and observed how they 

were used as sources of strategic or tactical 

intelligence. The pattern of briefings, mapping, 

summaries, and spot alerting was noted. They were 

told of the variety of security problems, including 

those arising from the association of officers 

Special Security Representatives, USA, European Theater

ETOUSA Captain Edmund H. Kellogg

SHAEF Lieutenant Colonel Edward K. Thompson (A-2)

U.S. 13th Army Group Lieutenant Colonel Charles R. Murname,

 Lieutenant Colonel Samuel I. Orr, Jr.

 U.S. First Army Lieutenant Colonel Adolph G. Rosengarten

 Major William D. Hobenthal

U.S. Third Army Lieutenant Colonel Melvin Helfers

 Captain George C. Church

U.S. Seventh Army Major Donald S. Bussey

U.S. Ninth Army Major Loftus E. Becker

U.S. Fifteenth Army Captain W. T. Carnahan

6th Army Group and 1st TACAF (Prov.) Major Warner W. Gardener

U.S. Strategic Air Force Major Lewis F. Powell, Jr.

Eighth Air Force Major Anselm E. M. Talbert

Ninth Air Force Lieutenant Colonel John W. Griggs,

 Major Edward C. Hitchkock

 1st Lieutenant Robert S. Whitlow

 1st Lieutenant Frank B. Coffman

 Major Lucius A. Buck

IX Tactical Air Command Lieutenant Colonel James D. Fellers

 1st Lieutenant Robert S. Morris, Jr.

XII Tactical Air Command Major Leo J. Nelson

XIX Tactical Air Command Major Harry M. Grove

XXIX Tactical Air Command Lieutenant Colonel John W. Griggs

 Captain Langdon van Norden

1st Technical Air Force Lieutenant Colonel Leslie E. Rood

 Major Warrack Wallace
Page 163

uninformed about “Y,” or unaware of SI, with those 

on the Ultra list, and the necessity of persuading 

commanders not to take military action traceable 

only to special intelligence. Those who visited in 

early 1944, or after the liberation of Rome, were 

able to note the circumstances and methods of SI 

service at 15th Army Group (Allied Armies in Italy), 

Mediterranean Allied Air Force, and U.S. Fifth 

Army.

Before the invasion of Normandy and while still 

in the UK, many SSRs had learned their way 

around the headquarters with which they would be 

associated in France. At the headquarters of U.S. 

Army or Air Force commands to which SLUs were 

provided, the presence of officers and enlisted men 

in British uniforms naturally aroused some attention, for they were conspicuously different from 

others. Their places of work were usually less 

prominent. Curiosity about them was deflected in 

some cases by imaginative titles for their units or, 

in the case of individuals, by the nature of their 

supposed specializations. On an intelligence staff a 

man would have had to be dull indeed not to recognize that a colleague with seemingly superlative 

powers of deduction might possibly have a special 

source of information. Awareness irritated some of 

the intelligence staff who were not on the SI list, 

and aroused envy in others, but most shelved their 

concern.

The term “special intelligence” was inclusive. 

Codewords like MAGIC and Ultra were preceded 

and followed by others. The War Department issued several successive Secret security directives 

for the protection of SIGINT with the titles: “Security of Radio Intercept Intelligence,” then “Security 

of RABID Intelligence,” then “Security of ULTRA 

DEXTER Intelligence within the European, North 

African, and Middle East Theaters of Operations.”21

On 24 August 1944 SHAEF issued revised instructions for protecting SIGINT of all grades. 

Besides specifying that American and British security practices were to be uniform and to follow 

certain methods, those instructions distinguished 

between crypt intelligence and traffic intelligence 

and assigned codewords as follows:

CIRO-PEARL – for medium-grade codes and ciphers.

PEARL – for low-grade codes and ciphers.

THUMB 1 – for traffic analysis, excluding direction finding.

THUMB 2 – for DF and other technical aids.

The regulation covered handling, and defined 

the recipients of different types of SIGINT.22

To quote from a study prepared after the war, 

“Synthesis of Experiences in the Use of Ultra Intelligence by U.S. Army Field Commands in the 

European Theater of Operations,”23 concerning security measures:

Most of the representatives found 

that substantial security was rather 

easily attained and that perfect security was an impossibility. The 

representative’s most difficult job 

was to make certain that recipients 

did not make direct operational use 

of Ultra without appropriate cover. 

Charged with responsibility for success or failure in battle, any 

commander would find that the temptation to employ Ultra improperly 

was well-nigh irresistible at times. 

Even daily security reminders by the 

representative and periodic directives from higher authority were 

tried and found somewhat inadequate... 

There was no method by which the 

representative could censor all tactical orders and discussions, but, by 

monitoring summaries, appreciations, and publications based on 
Page 164

other intelligence sources, he could 

largely safeguard against a written 

break of Ultra security. Physical security and the protection of Ultra 

signals presented no serious problems... 

The reliable guiding influence of 

Ultra in working with other intelligence outweighed its value as a 

separate and distinct source of operational information. Its normal 

function was to enable the representative and his recipients to select the 

correct information from the huge 

mass of prisoner of war, agent, 

(ground) reconnaissance “Y,” and 

photographic (reconnaissance) reports. Ultra was the guide and censor 

to conclusions arrived at by other intelligence: at the same time the latter 

was a secure vehicle by which U1tra 

could be disseminated under cover.24

The representatives, who worked and lived with 

Ultra in the field, were aware that it often had a direct operational value; one stated:

It was important to protect Source, 

but it was also important to get the 

last bit of exploitation, the ultimate, 

from Ultra consistent with Security.

U.S. officers in Hut 3 selected the items to be 

passed directly to any of the U.S. commanders or to 

be used by the Intelligence Division of his staff in 

preparing briefings and summaries. At the commands, the way in which the items were used 

depended on the commander's attitude and the 

personalities of those directly involved. An intelligence briefing early each day could be considered 

normal. Ultra, if its role as the source could be 

masked, might furnish some of the information. If 

not, or perhaps in any case, a separate briefing to 

officers “on the list” could precede or follow 

the regular intelligence briefing. At some 

headquarters, such as that of General Jacob Devers, CG, 6th Army Group, it was given in the SSO’s 

own small office with maps that showed Ultra data. 

At General Bradley’s 12th Army Group the Ultra 

unit, disguised by the title “Estimates and Appreciation Group,” gave its own separate briefing in a 

trailer adjacent to that of the G-2.

Some SSRs served also as the “Y” officer in a 

staff SIGINT unit. Their knowledge of current Ultra 

enabled them to guide the work on “Y” material 

and in reports or oral briefings to avoid whatever 

had to be treated separately.

Not all commanders held Ultra in the same regard, at least when first apprised. General Mark 

Clark’s disdain in 1942, during the planning for Operation TORCH, has been described in books by 

Winterbotham and Lewin.25 General Patton’s dislike of the restraints for security reasons on his 

movement into advanced areas, such as his flight as 

a passenger (with his dog, Willie) on a bombing 

raid over Germany, cooled his interest.

Later Collaboration between OP-20-G and 

GCCS

The basic agreement covering the respective responsibilities of OP-20-G and GCCS mentioned 

above had been signed in October 1942. It was a 

preface to assumption by OP-20-G of a positive 

role in producing SI. During December 1942 GCCS 

recovered the ability to read submarine Enigma 

traffic, now enciphered by the four-wheeled version of the machine. While having SI again 

applicable to U-boat activities was a great advantage, the German Navy’s counterpart to GCCS, 

known as the B-Dienst, was able in the spring of 

1943 to read enough of the Allied communications 

pertaining to the convoys so that German sinkings 

were disastrous. The Allies executed a communications change, the submarines then lost that 

advantage, and in May 1943 so many more of the 

U-boats were sunk as to induce a transfer of submarine offensive efforts to a different area of the 

Atlantic.
Page 165

The German Navy renewed the submarine offensive in August 1943. The new U-boats with fresh 

crews were expected to score heavily with their recently developed, acoustically guided torpe- does. 

SI had alerted the Allies to the plans and to the new 

weapon. Allied ships nullified the torpedo by towing a device that drew a torpedo away from the 

target ship. On occasion, when more than one Uboat was engaged in an attack, one was probably 

struck by an acoustic torpedo fired by the other. 

The Allies at that time were enabled by SI to direct 

allied aircraft to rendezvous points assigned to German submarines refueling at sea from surface or 

underwater tankers. Destruction of such supply 

ships greatly restricted the range of a submarine’s 

voyage or obliged it to deplete the fuel of a sister 

ship. Aircraft from small escort carriers which protected a convoy often were able to drive attacking 

submarines underwater, or to damage them with 

depth charges.

By 1944 OP-20-G was feeding SIGINT to F-21 

(Atlantic Section, Combat Intelligence Division, 

U.S. Fleet) the Operational Intelligence Center, Admiralty, and to Ottawa. Eventually the British 

would agree that the Americans were bearing the 

major share of the SI load in the Atlantic and carrying it satisfactorily.

Special Intelligence in the Invasion of Normandy, June 1944

Special intelligence relating to the probable opposition to the Allied invasion of Normandy enabled 

the planners to know that the enemy had a fair idea 

of the general region but not of the exact places 

where the attacks would be made. The Germans 

had diverse calculations of time as well as place, so 

that the Allies could expect them to remain deployed to meet a wide range of possibilities. The 

enemy was generous enough to provide data two 

weeks before the invasion in messages showing the 

disposition of German forces in the Cotentin peninsula, including recent strengthening there, and the 

chain of command under Field Marshal Erwin 

Rommel as commander-in-chief, Army Group B. 

Special intelligence afforded the Allied command a 

good understanding of what the enemy expected. 

As early as 10 January 1944, German Army Intelligence was aware of the First U.S. Army Group 

(FUSAG) and connected it with the expectation of a 

cross-Channel attack in the vicinity of Calais.

The Allies, partly from special intelligence and 

partly from other sources, knew that at the time of 

the invasion OB West controlled Army Group B 

and Army Group H; that is, four Armies and a 

Panzer Group West, comprising sixteen operational corps in all.

The Allies knew that Rommel’s intention was to 

defeat the invasion at the beachheads and that his 

panzer divisions were to be held in readiness to 

move to the actual beachheads as soon as each was 

disclosed. Only one panzer division’s location was 

not established; the 2d Panzer Division in Brittany 

might be near enough to reach the battlefield in 

Normandy during the critical early days. Allied air 

plans to “isolate the battlefield” by bombing were 

intended to keep out of the battle any German armored unit from Rommel’s mobile reserve.

The strategic plans of the enemy were supplemented by what was learned on the eve of the 

invasion, for on 30 May 1944 the main cryptosystem in use by Rommel’s Army Group B in an area 

extending from the Netherlands to southwestern 

France became readable at GCCS.26

During the week of the invasion, the volume of 

traffic encrypted on relatively few keys enabled the 

analysts at GCCS to recover three of the four main 

army keys for 9 June 1944. On that day, intercepts 

at British stations alone were about 17,000 in numbers, but the successes gave no promise of reading 

current German Army traffic; German Air Force 

traffic was more available. An early illustration of 

the operational use of special intelligence by the 

Ninth Tactical Air Command, supporting U.S. First 

Army (FUSA) in Normandy, can be mentioned 

here.
Page 166

A German FW-190 pilot was captured and interrogated at a wing headquarters of the Ninth 

TAC. He stated that his unit was based near a town 

which he called Essay. The Wing A-2, who knew of 

an enemy airfield at Lessay but not of a place called 

Essay, recommended the bombing of Lessay.

At Headquarters, Ninth TAC, where special intelligence was received, the SSO recalled a German 

message that had mentioned fighter-group landing 

grounds at Essay and Lonrai, information not yet 

included in general intelligence. He also knew from 

other special intelligence that the field at Lessay 

had been trenched, ploughed, and abandoned. So 

he advised that the wing not bomb Lessay and that 

the area described by the PW be reconnoitered. 

That mission yielded photographs of three landing 

strips – Essay, Lonrai, and a previously unknown 

one at Barville. The next day all three fields were 

successfully struck. 27

As Major Taylor had foreseen during the negotiations early in 1943, U.S. acceptance then of 

British restrictive conditions governing the production of Ultra was followed by gradual British 

accommodation to U.S. needs. Before the Nazi surrender ended hostilities in Europe, the Signal 

Security Agency had sent enough persons for prolonged training in production of SI at GCCS to 

operate independently elsewhere. When the war 

shifted to the Pacific and to Japanese communications, where the U.S. had the primary responsibility 

for SIGINT, U.S. production of relevant special intelligence reflected the prowess of Arlington Hall 

and OP-20-G and their forward centers. Aware of 

the situations of Japanese forces on various islands 

and atolls, Admiral Nimitz and General MacArthur 

advanced upon the home islands leaving thousands 

of Japanese soldiers and airmen stranded and far 

from the battle zone.

In this general chapter concerning BritishAmerican collaboration in special intelligence, we 

have anticipated the conclusion in Europe of a conflict that we now again consider in somewhat 

greater detail. We have been describing Ultra 

matters and now return to PEARL and THUMB; 

that is, we leave special intelligence to resume attention to tactical SIGINT.

Notes

1. Memo for Sec/War from Actg Sec/State, 19 July 

1940, covering Lord Lothian’s Aide Memoire to the 

President as an enclosure.

2. Memo from CSA (General George C. Marshall) to 

Brigadier General George V. Strong, Asst CIS, War 

Plans, 19 July 1940, Subj: General Interchange of Secret 

Technical Information between the U.S. and British 

Governments.

3. A joint letter from the Sec/War and Sect Navy to 

the National Defense Research Committee, quoted in 

Memo for Chiefs of Arms and Services from AG, WD, 4 

Nov 1940, Subj: Interchange of Technical Information 

with British Representatives. Ibid.

4. “Report of Technical Mission to England by Captain Sinkov and Lieutenant Rosen,” 11 April 1941.

5. At that time he arranged for assignment of a 

GCCS Technical Liaison Officer to duty with SIS as observer of work done on Japanese cryptosystems. Mins. 

of a Conference held on 16 Aug 1941 with leading cryptanalysts of SIS.

6. Memo from OP-20-G-A to OP-2O-G-I, 7 July 

1944, Subj: American Cryptanalysis of German Naval 

Systems, signed by RB. Ely, LCDR, VSNR. Interview 

with Mr. Frank Raven, 24 Jan 1980.

7. Had the U. S. Navy unit been called the Operational Intelligence Center, he might have qualified as 

OIC, OIC, for the abbreviated title “OIC2.”

8. See Ronald Lewin, ULTRA Goes to War, (N. Y. , 

1978), 4off.

9. History of the Signal Security Agency, Vol. II, 257 

If. A copy of Dr. Turing’s report, “Visit to National Cash 

Register Corporation of Dayton, Ohio,” is in NSA Hist. 

Coll.

10. Memo for Sir John Dill from General George C. 

Marshall, 6 Jan 1943. Copy in NSA Hist. Coll. 

11. Memo for Colonel Corderman, 8 Feb 1943 

(SPSIS-7/SPSIS 311.5-General). General Strong later 

called the U.S. machine “analogus [sic] but not identical.”
Page 167

12. Memo for Colonel Corderman from Major H. 

McD. Brown, 17 Mar 1943, Subj: Traffic Exchange with 

B.S.C. Copy in NSA Hist. Coli.

13. The Liaison Officers from the Signal Intelligence 

Service who were assigned to duty at GCCS were Captain 

John N. Seaman, August 1943 to Mar 1944; Captain 

Walter Fried, April to October 1944; and Mr. Albert 

Small, from October 1944 to May 1945. Their reports 

primarily concerned technical cryptologic operations 

rather than the products of concern to the Special 

Branch, G-2.

14. Photocopy of signed document in NSA Hist. Coll.

15. On 4 June 1943, OP-2o-G broke the Atlantic Uboat key for 28 May – their first success with the new 

bombe using traffic from GCCS on test models in Dayton.

16. Cable V 4772, 13 May 1943. Copy in “Colonel McCormack’s trip to London.” Books No.9 and 35. In NSA 

Hist. Coll. Colonel Corderman later visited GCCS in October 1943 and arranged for Captain Seaman to stay on 

as a technical liaison officer.

17. Captain Johnson’s report to CO, Arlington Hall 

Station, 16 May 1943, summarized his work on German 

military cryptosystems, including Double Playfair and 

three cipher machines. One cryptosystem was a teletypewriter with tone transmissions, he said.

18. HQ, ETOUSA Order of 28 Jan 1944, cited in History of Signal Intelligence Division, ETOUSA, Vol. I. 

They were attached to the Base Section for supply and 

administration.

19. Small Report G-8, 17 Dec 1944. NSA Hist. Coli.

20. Memo for Colonel Clarke from Lieutenant Colonel McCormack, 8 Feb 1944, Subj: SLU Personnel. 

General Bissell, G-2, approved. (Copy in ACSI Book No. 

21.) Although duty in Europe was paramount in 1944, 

their qualifications for subsequent service in the Far 

East were kept in mind.

21. See AG Ltr to Supreme Commander, AEF..., 15 

Mar 1944 (AG 312.1, 11 Mar 44); OB-S-B-M, Copy No. 

105 is in History of S.S. Opns Overseas, Vol. I, NSA Hist. 

Coll.

22. Memo AG 380.01-1 GBI-AGM, Subj: Security of 

Special Intelligence, 24 August 1944. Seen in archives at 

Arlington Hall Station, in the History of the Intelligence 

Branch, Signal Security Detachment “D,” SID, ETOUSA, 

Box 6/33.

23. USA SSG, History Files (Book No. 53), 24-25.

24. The italics are my own and emphasize the role of 

SI at Army and Army Group headquarters.

25. F.W. Winterbotham, The ULTRA Secret (NY, 

1974), 90-91: Lewin, Ultra Goes to War.

26. Report by Captain Walter Fried, No. 45, 4 June 

1944. NSA Hist. Coll.

27. Synthesis of Experiences in the use of Ultra Intelligence by U.S. Army Field Commanders in the 

European Theater of Operations. USA SSG, History 

Files (Book No. 53) 27.
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Page 169

General Considerations

The SIGINT material presented in the following 

pages illustrates the way in which SIS, ETOUSA, 

contributed to the victory over Germany in Western Europe. The samples are illustrative; they are 

far from being comprehensive. To indicate the degree of reliability of terms of intelligence, those 

from SIGINT included in the daily intelligence 

summary (ISUM) by G-2, 12th Army Group, were 

tagged as CIRO-PEARL, PEARL, or THUMB. Most 

messages were not disseminated intact except as 

technical material; their significance for operations 

was ex-tracted and reported. Signal Security Detachment “D” (SSD “D”) received an average of 

almost 900 intercepted messages per month in medium-grade crytographic systems, from which it 

derived timely intelligence information. Many 

more messages in lower-grade systems swelled the 

voluminous total. When a verbatim translated 

message was supplied to G-2, its form might overcome an American com- mander’s skepticism, but 

most “Y” SIGINT came from combinations of 

several enemy messages which required interpretation of their meanings in light of information from 

other sources. Though the value of SIGINT is not 

now demonstrable by quantitative analysis alone, 

certain important types of SIGINT information 

may be recognized.

SIGINT in medium-grade cryptographic systems (CIRO-PEARL) provided information that, 

within a few hours after interception, yielded order 

of battle intelligence. Enemy reports showed the locations of command posts, main lines of resistance, 

outerguard lines of resistance during retreats, 

boundaries of unit areas, identifications of neighboring units and of the points of contact between 

them. From rear areas came data on the locations 

of dumps of fuel, rations and supplies, medical 

dressing stations, repair shops, replacement and 

training units, billeting areas, and unit lines of 

communications. Large-scale movements of troops 

for substantial distances could be followed in 

SIGINT. From enemy divisions in combat zones 

came standard periodic situation reports and field 

orders from operations officers, standard situation 

reports by German intelligence officers, and 

reconnaissance reports by air, ground, or artillery 

units – the latter concerned both Allied expenditures of artillery ammunition and targets for 

German guns. The bulk of reconnaissance reporting was done in low-grade PEARL systems rather 

than in CIRO-PEARL, but sometimes a report was 

encrypted in the latter.

On 9 August 1944 Signal Security Detachment 

“D” arrived for duty at Headquarters, 12th Army 

Group, in Normandy, which it assumed on the 11th, 

working directly with the 114th and 116th SRI Companies. Until much later, communications with SIS 

units had to be by radio. A radio broadcast of technical matters was established. Conferences with 

SIGINT representatives of 21st Army Group and 

Ninth Army coordinated intercept and communications arrangements.

Beginning on 1 September 1944, the Intelligence Branch, SSD “D,” began publishing what 

were labeled SIGINT Summaries (SIGISUMs) and 

SIGINT Technical Summaries (SIGITSUMs) – the 

latter separately disseminating cryptologic technical intelligence. On 1 November 1944 the technical 

summaries were redesignated as “WHAMs” and 

245 “WHAMs” were published. (The meaning of 

the acronym “WHAM” is unknown to the author.) 

The SIGISUMs contained medium-grade items 

(CIRO-PEARL) and appeared only as often as the 

material warranted – 157 of them were published.1

Chapter 12

From Normandy to the Seine
Page 170

The two series from SSD “D” at Army Group 

level were based on the material intercepted near 

the front by the RI companies of the Corps, farther 

back by SIGINT units near Army and 12th Army 

Group Headquarters. The RI companies each produced a Daily Activity Report (DAR) containing an 

intelligence summary, decodes and translations, 

technical summary of nets heard, a message count 

and allocation of positions, DF bearings, code 

“idents,” and cipher values.

The 12th Army Group G-2’s daily intelligence 

summary was distributed by teletype with operational priority to the following headquarters:

SHAEF Main

6th Army Group

21 Army Group (Main)

Eighth Air Force

FUSA (Command)

TUSA (Main)

U.S. Ninth Army (Main)

U.S. Fifteenth Army (Forward)

12th Army Group (Main)

12th Army Group TAC

First Allied Airborne Army

Com[munications] Z[one]

ASCZ

Ninth Air Force (Advance)

Static combat operations along defensive lines 

with patrols, skirmishes, artillery harassment, and 

air bombings were reflected in SIGINT production 

and enemy signal security. Wire traffic became proportionately much higher than radio traffic. 

COMSEC practices were observed more carefully 

by the communicators. Tactical radio intercepts, 

however, yielded “Y” of solid merit in establishing 

order of battle and in warning of incoming artillery 

fire or air bombing. Radio intelligence on both 

sides reflected static combat conditions; what was 

sauce for the goose was sauce for the gander.

In fast-changing situations, radio was necessarily used in greater proportion. Radiotelephone was 

used more and more frequently in all situations as 

the war continued. The need to use codes and ciphers increased, and certainly applied to “voice” 

communications. The greater volume of traffic assisted the analysts. Lapses in COMSEC practices by 

one side benefited the other. Voice codes required 

a special vocabulary around which messages could 

be framed. Unfamiliarity with the vocabulary 

caused much spelling out and resorting to plain 

text in messages of otherwise unnecessary length. 

Sinners in that type of communications were 

mainly controllers of road traffic, the MPs, and 

high-ranking officers who used radio as a direct, 

personal means of communication, disregarding 

the adverse possibilities. Messages that should 

have been classified Top Secret were thus transmitted not only to the intended recipient but also to an 

enemy who could understand them. At the end of 

the war, captured documents showed that the 

enemy gained his most valuable tactical intelligence from the violation of regulations by Allied 

communicators and commanders.

Tactical SIGINT was welcomed by commanders especially when it disclosed in time that the 

enemy was preparing an artillery mission or an attack on any given area. It was highly valued if it 

revealed that an enemy unit within reach lacked either fuel for its vehicles or important types of 

ammunition, so that it could be attacked in the 

most effective manner. Such SIGINT information 

was produced often enough to justify great effort. 

But by far the bulk of SIGINT that mattered to 

ground forces consisted of identifications and DF 

fixes. Data from interrogating prisoners of war or 

from captured documents about enemy order of 

battle and the fighting status of enemy units were 

checked against tactical SIGINT.

Air and ground reconnaissance spotted assembly or movement by enemy forces; SIGINT often 

identified them and sometimes learned the effects 

of artillery fire or air attacks upon them. Although 

SIGINT remained limited by the enemy’s resort to 

wire communications or radio silence and was subject to radio deception practices, the range of radio 

collection extended to rear areas and thus to sources 
Page 171

out of reach by ground, and often by air, reconnaissance.

On a static front, American “Y” units were subject to certain disadvantages in serving the corps 

commands. Unless they could use wire communications between a forward intercept unit and a 

processing center, all medium-grade enemy traffic 

had to be carried back by courier and then analyzed; the resulting intelligence reached forward 

fighting units after a delay which often deprived 

that intelligence of any usefulness. Protecting 

retransmission via radio by hand-operated cryptosystems among numerous communicators was not 

a practical method.

The prohibition against cryptanalysis on medium-grade intercepts at a corps RI unit (even 

though the unit held in its files pertinent, captured 

medium-grade cipher documents) meant that such 

intercepted material had to go back to an army or 

army group headquarters for analysis. When intercepted material contained intelligence information 

pertinent to the situation of units of the very corps 

whose RI company did the intercepting, and the 

products came back after a lapse of twenty-four to 

forty-eight hours, the opportunity within that corps 

and its neighbors to know and to act in time had 

usually vanished.

The exploitation of captured cipher keys that 

were used in medium-grade systems by the 9th 

Panzer Division, was so beneficial to Third Army 

that the 3254th Signal Service Company (RI) could 

not be reconciled to the wisdom of the prevailing 

arrangements. That unit was able, from intercepted 

medium-grade traffic, to trace the 9th Panzer Division during the pursuit across central France. The 

SIGINT identified adjacent German units, located 

command posts, supply dumps, roads being used, 

and revealed which units were suffering shortages 

of fuel and ammunition.

The 3250th Signal Service Company (RI) supporting V Corps in Normandy was asked on 2 July 

1944 by corps staff to request the Germans to 

accept a brief cease-fire in order to return to the 

German lines six captured German nurses. It took 

only about fifteen minutes calling on 2743 kilocycles to get an answer. A conversation first in 

German and then in English ensued. After overcoming much suspicion and obstinacy, Captain 

Brownfield and Captain Jetter of the intercept unit 

induced the Germans to meet and escort the nurses 

across No-Man’s Land.

That unit was able in Normandy to give to the 

corps G-2 data on the enemy’s planned main line of 

resistance (MLR), approximate sites of headquarters, movements of enemy units, probable sites of 

observation posts, and enemy reports on the combat efficiency of various German units facing V 

Corps.

Like others bivouacked in woods and villages in 

Normandy, the 3250th came under air bombing 

and artillery bombardment that encouraged the 

digging of slit trenches, the camouflaging of worn 

paths visible from the air, and attention to other 

measures of security. The men collected abandoned weapons from the beaches or other places to 

be able to defend themselves if necessary, for they 

then had no organic security guards or regular 

stock of weapons and ammunition.

In those first weeks, the SIGINT units had to 

improvise and adapt ways to keep their radios and 

other equipment working because of the lack of replacement parts and in order to raise their level of 

comfort a few millimeters. When a few men were 

caught by an air raid while bathing, they were described as unbelievably incongruous, peering out of 

slit trenches while wearing helmets and nothing 

else.

The Breakout

The U.S. VIII Corps headquarters became operational in Normandy under command of First U.S. 

Army on 15 June 1944. It first cleared German 

troops out of an area extending to the western 

coast. It then faced the German main line 
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of defense across Normandy in its westernmost 

segment while VIII Corps was capturing Cherbourg. An Allied attack along that line from 4 to 19 

July 1944 quickly demonstrated the skill and 

strength of the enemy in the hedgerow country. 

Later operations further educated the VIII Corps 

divisions (79th, 82d, and 90th).

After the XIX Corps occupied St. Lo on 18 July, 

and after the British attack of 18-21 July got 

possession of Caen and absorbed the reserves of 

Panzer Group West, the initiative passed to U.S. 

First Army. In an attempt (Operation COBRA) to 

break through the enemy line near the center and 

to open the way down the west coast of Normandy, 

First Army committed the V, XIX, VII, and VIII 

Corps. The first stage was a colossal carpet bombing south of St. Lo. Next an infantry push by part of 

VII Corps, followed by armored and motorized 

forces also under VII Corps, smashed the scattered 

parts of German formations before they could be 

reorganized. Additional offensive efforts prevented 

the German Seventh Army from ever reestablishing a solid defense line to stop a deep penetration. 

The enemy reinforcements brought from elsewhere 

had to be committed piecemeal. They were chewed 

up.

At the same time, the attempt to cut off withdrawal by Germans being pushed southward by 

VIII Corps did not succeed. On 28 July, however, 

when retreating Germans turned eastward rather 

than southward, the U.S. 2d Armored Division 

awaited them in blocking positions. In the battles 

that night, the Americans killed perhaps 1,000 and 

captured about 4,000. Some German troops 

slipped through, others veered off to the south and 

escaped. The latter included General Choltitz and 

his headquarters, LXXXIV Corps. He was thus 

saved to be in command in Paris a few weeks later, 

and possibly to have been instrumental in its being 

undestroyed when liberated.

How did the 2d Armored Division command 

know that they could expect the enemy to turn 

east?

Even earlier, on the afternoon of Operation COBRA’s first day, when the VII Corps infantry had 

moved well into the bombed area and had begun to 

meet serious resistance, and when the VIII Corps 

armored divisions were poised for commitment, 

how was it possible to decide whether the enemy 

had been smashed or had simply withdrawn his 

own armored forces into positions from which to 

fall on the flanks of any deep American thrusts? 

Had the panzer units been bombed or were they 

biding their time? Major General J. Lawton Collins, 

CG, VIII Corps, took the risk – in the absence of 

intelligence from SIGINT or other sources – that 

the Germans were able to pounce; he ordered his 

own armor to attack before the enemy might reorganize. American combat commands found a 

complete gap through which attacking forces could 

enlarge the breakthrough. Although VIII Corps was 

not able to cut off the enemy’s western flank in time 

to encircle the defending units there, it did threaten 

such an operation. The enemy chose to strike 

southeastward rather than to go south along the 

western coast of Normandy far enough to slip 

around the American spearheads. His southeastward movement enabled superior U.S. forces to 

defeat him in meeting engagements.

The 3254th Signal Service Company (RI) served 

with VIII Corps in July and early August 1944. Before the American attack (COBRA) opened with the 

tremendous carpet bombing of 25 July 1944 near 

St. Lo, the volume of enemy traffic facing VIII 

Corps in the northwestern segment of the Allied 

line was low. On 27 July, as ground forces pushed 

through the bomb-torn area, and while armored 

spearheads with tactical air cover exploited the 

openings made by infantry-artillery operations, 

enemy traffic increased greatly. The enemy’s zone 

of defense had been ripped apart. The German II 

Parachute Corps and LXXXIV Corps were separated. Wire lines had been broken. Radio 

communications between the disorganized elements of enemy divisions and corps furnished 

abundant material for U.S. SIGINT operations.
Page 173

Highly useful to VIII Corps were intercepted reports from reconnaissance patrols and artillery 

units of the 2d SS Panzer Division (“Das Reich”). As 

those reports described American gains, such as 

the occupation of Cambernon by the 1st Infantry 

Division and the advance on Cerences by Combat 

Command “B” (CCB), 2d Armored Division from 

the northeast on 28 July, and by CCB, 4th Armored 

Division from the north (Coutances) the next day, 

Allied seizure of the route southward along the 

coast to Avranches began to seem imminent to 

both American and German commands.

By 31 July remnants of the 2d SS Panzer Division were heard and located, while that division’s 

headquarters was placed at Montbray. The enemy 

was apparently drifting away from VIII Corps. 

Other intercepted messages spotted the locations 

of dumps of mines, mortar shells, and fuel. On 1 
Page 174

August enemy shortages of ammunition were reported.

VIII Corps passed to control by General Patton 

as commander of Third Army (instead of deputy 

commander, First Army), officially on 1 August. On 

that day Avranches fell to the Allies. The breakout 

would next be exploited.

Circling the Enemy’s Southern Flank

For the next four days, while the Allies widened 

the western corridor and secured their avenue into 

Brittany from attacks from any direction, the enemy 

groped for means of closing the original gap that 

had been opened by VII Corps on 26 July, and had 

been held open since then by the ever-increasing 

strength of the Allies in that area. At the same time, 

the enemy swung the separate parts of a line of resistance away from the west coast southeastward 

rather than trying to restore control at Avranches, 

and thus risking another breakthrough farther east. 

The Third Army, instead of being used wholly in 

Brittany, sent VII Corps there and directed XV 

Corps southward to outflank the enemy in Normandy, and then eastward in large bounds to 

Laval. Northwest of XV Corps, the 1st Infantry Division and 3d Armored Division moved against the 

stronger German forces facing them to close a gap 

between VII Corps and the columns of XV Corps 

racing east of Mayenne.

At that juncture the enemy tried to push an armored counterattack from the vicinity of Mortain, 

which First Army had occupied on 3 August, westward to Avranches. On the very evening that the 

Allies finally took the town of Vire, farther north, 

the Germans barely managed under Allied pressure to mount a counterattack that took Mortain 

and pressed a few miles west on either side of it. 

Some evidence that an attack was impending had 

come through tactical SIGINT. The 2d SS Panzer 

Division showed interest on 5 August in obtaining 

data about the area surrounding Le Mesnil Tove, a 

village held by the VIII Corps. That division also set 

up liaison with the 2d Panzer Division, whose 

artillery regiment was described as moving by road 

toward Mortain.

The German attack began about midnight and 

hit elements of the 9th and 30th Divisions. The latter had barely arrived, after days of hard battle 

north of Vire and a long march to Mortain, when 

the enemy overran them. Not all of them, for the 

120th Infantry’s 2d Battalion held out for several 

days atop a critical hill, remaining there until the 

enemy withdrew. And others also fought back 

stub-bornly. The attack ran out of steam as VIII 

Corps contained it with reinforcements on the 

ground and especially in the air.

Regimental and division commanders seem to 

have been surprised by the attack. Perhaps General 

Collins, CG, VIII Corps, and General Courtney 

Hodges, CG, First Army, were surprised. At 12th 

Army Group, even though that headquarters was 

newly operational and its tactical SIGINT units 

were not yet well established, the attack should 

have been no surprise. Radio communications 

from which special intelligence was being derived 

passed daily between Hitler’s headquarters and 

Field Marshal von Kluge, C-in-C, West. Hitler 

ordered the attack on 2 August. Kluge’s staff 

prepared the plans, which required further 

exchanges between OKW and OB West. The fact 

that Kluge started the attack on 6 August, despite 

Hitler’s wish that it be postponed until it could be 

much heavier, might have surprised 12th Army 

Group enough to prevent it from alerting subordinate commanders. Kluge and his principal 

commanders were convinced that they could never 

assemble the necessary attacking units under the 

kind of pressure already being exerted by American 

ground and air forces, unless they did so by the 

night of 6/7 August. Indeed, the 116th Panzer Division was then so engaged that its commander failed 

to pull out of line the elements that he was expected 

to provide for the initial attack. Panzer Group 

Eberbach was sent through rough hilly country because of its forest cover from air attacks rather than 

farther south through flat, open plains. Movement 

was all but suspended by day in order to minimize 
Page 175

the consequences of Allied domination of the air. 

Even had the Germans regained Avranches, their 

ability to retain it, and by further attacks to exploit 

a breakthrough separating the Americans on the 

south from their base in the north, was doubted by 

some enemy commanders, who favored prompt 

withdrawal across the Seine River.

General Hodges probably got the warning; 

General Patton certainly did.

The XV Corps (Haislip) under Third Army had 

started moving eastward along the enemy’s southern flank in Normandy. During the night of 6/7 

August 1944, Patton noted in his diary the receipt 

from “a secret source”2 of a “rumor” that the enemy 

intended to counterattack toward Avranches. He 

was inclined to credit other indications, perhaps 

from the same type of source, that the real purpose 

of a counterattack would be to cover a general German retreat beyond the Seine River. But he held 

two divisions in positions where they could, if 

necessary, contribute to containing a German counterattack.

The actual fighting in Normandy during the 

second week of August departed from the original 

expectations. Instead of sending the Third Army 
Page 176

into Brittany and building up forces west of the 

Seine for perhaps a conclusive campaign to be 

fought in northern France, the Allied command 

employed the larger part of Third Army in a sudden 

encircling movement around the enemy's southern 

flank. The revised objective was to prevent him 

from retreating across the Seine, or if not successful in that, to drive him across northern France into 

his Fatherland.

Allied maneuvers risked enemy concentration 

and counterattacks that could separate the Third 

Army and part of the First Army from their bases in 

northern Normandy. Allied superiority in numbers 

and weapons, and particularly Allied mastery of the 

air, enabled the Allies to forestall such a concentration. The German attack toward Avranches near 

Mortain on 6/7 August was meant to have been followed by a second and much stronger thrust which 

the German High Command (OKW) would have 

preferred to begin on 11 August. Its designated 

commander wanted to wait until 20 August so that 

certain preparations could be completed.

The proposed operation had to be abandoned 

before 20 August because of a more pressing need 

to hit the western flank of the XV Corps, near Alencon, where the American line had temporarily left a 

gap of about twenty-five miles. But that attack in 

turn could not be adequately manned because of 

Canadian penetrations of the German line near 

Falaise – an intrusion that had to be contained by 

switching German forces from Alencon. Pressure 

on many other parts of the enemy line around the 

pocket was unremitting. Shortening the line could 

not provide enough troops for a strong counterattack.

Apparently 12th Army Group believed that the 

enemy had started to withdraw across the Seine 

when only some of the mere shards of destroyed 

German units were being sent there. Actually, 

though German commanders in the field grew 

deeply apprehensive about being kept in the Falaise pocket too long to save their commands from 

capture or annihilation, Hitler would not authorize 

withdrawal until several days later.

SIGINT from the 2d SS Panzer Division and 

from remnants of the Panzer Lehr Division disclosed that they had moved east of Falaise on 11 

August. The 21st Panzer Division, another fruitful 

source of tactical SIGINT, was one of the main 

enemy units covering retreat to the Seine. Its reconnaissance patrols on 16 August reported in 

detail the situation observed at the southern edge 

of the all-important opening. The division set up a 

defensive line among wooden hills east of the Argentan-Falaise road through which marching 

German columns could move at night.

During the battles to hold the pocket open at its 

eastern end, the 9th Panzer Division was overrun 

west of Argentan. By 27 August, captured cryptographic material was being used by the Allies to 

read the communications of that headquarters as it 

escaped across northern France.3

SIGINT from the 9th Panzer Division disclosed 

the composition of that command, successive locations of supply headquarters, data on successive 

main lines of resistance, and times when artillery 

support was unavailable to one of its major elements, so that the pursuers could readily force a 

further retreat.

SIGINT and the Capture of Brest

The Ninth Army took from Third Army the mission of reducing Brest and at least containing the 

other French coastal fortresses in Brittany held by 

the Germans. When a Special Security Representative (SSR) joined Headquarters, Ninth Army near 

Rennes, he soon realized from special intelligence 

that estimates of enemy strength in Brest, based on 

other sources of intelligence, were seriously lower 

(perhaps as much as 50 percent) than they should 

be. Within a week, having captured Brest, the 

Ninth Army’s count of prisoners of war confirmed 

those SIGINT calculations. Thereafter, General 

Simpson was most receptive to Ultra.4
Page 177

At another juncture, when the “Colmar pocket” 

was to be reduced, special intelligence (as we shall 

see) corrected exaggerated estimates of the strength 

of the defenders. SIGINT worked both ways.

Notes

1. History of the Intelligence Branch, SSD “D,” 15-16. 

2. Blumenson, ed., Patton Papers, II, 503.

3. Tech Hist. 3254th SigServCo (RI).

4. Synthesis of Experiences in the Use of Ultra Intelligence by U.S. Army Field Commands in the European 

Theater of Operations. USA SSG, History Files (Book 

No. 53), 28.
Page 178
Page 179

Pursuit in the North

The complete defeat of the enemy in Normandy 

produced a situation in which the questions became: how much could he extricate from the 

so-called “pocket” west of the gap between 

Argentan and Falaise; and having saved what he 

could, where would he cross the Seine River; and 

where would he be able to establish a new line of 

defense? Haislip’s XV Corps went to the Seine and 

wrested a bridgehead on the far side at MantesGassicourt. Corlett’s XIX Corps joined in an attempt 

to establish a second encirclement along the Seine, 

but most of the enemy was able to shift northward 

toward the Seine estuary and to cross there to the 

eastern bank. Once across, they moved along the 

coast. Other shattered German forces crossed the 

upper Seine and for a time may have thought that 

they could defend along such a river line as the 

Aisne-Marne or the Somme in conjunction with the 

German units that had crossed the lower Seine.

On 15 August 1944 the Seventh Army’s invasion 

of southern France began, and during the remainder of the month, German occupation troops as 

well as combat forces withdrew from most of 

France. They continued to defend German possession of ports in Brittany and along the Channel. 

Unable to withstand Allied pursuit, the enemy appeared to be fleeing into the shelter of his fortified 

Westwall – that zone of pillboxes, obstacles, and 

barriers near the German border.

U.S. First Army moved along the Seine on the 

right of 21 Army Group and sped through northern 

France into Belgium and Luxembourg. XIX Corps 

on the left was next to the British. VII Corps was on 

the right, passing through places with names 

familiar to veterans of World War I. V Corps was 

involved in the liberation of Paris and then moved 

through the city and toward that part of the Westwall south of Aachen. The columns moved rapidly 

in long daily jumps, with skirmishes and small encounters but few substantial battles. As they 

reached Belgium, the VII Corps and V Corps then 

shifted so that the latter came up beside the XIX 

Corps, while the VII Corps crossed the Meuse and 

passed eastward in country that, in late December 

1944, became the northern edge of the German Ardennes salient. The enemy’s hasty retreat across 

France led to overconfidence among the Allies. 

They believed that the Germans were so demoralized and so weakened that they would not fight 

until within the Westwall, and that even there they 

would be readily overcome.

The pursuit in the north enabled American 

troops to head off and to capture or destroy 

thousands of the enemy and their vehicles in the renowned “Mons pocket,” where bitter fighting in 

World War I had also taken place. Yet along the 

Scheldt, the Albert Canal, and the Meuse River, 

forces sent from Germany manned a line through 

which the retreating enemy passed to reorganize 

in its shelter, or along which they were able to take 

up positions because of the carelessness of Allied 

com-manders. Weary but exultant over the rapid 

advance that brought about the seizure of Brussels 

and Antwerp, those commanders neglected to control the bridges over the Albert Canal. All crossings 

were then blown up by the Germans. That costly 

mistake could have been attributed to inadvertence 

but another, of greater proportion, was the failure 

to interrupt the escape of enemy troops across the 

watery area between Antwerp and the coast. In a 

ferrying operation that took several days, thousands of the enemy slipped across the Scheldt and 

kept on behind the German line to join its defenders. At the same time, the enemy in effect extended 

his defense line onto Walcheren Island, and denied 

Chapter 13

To the Westwall
Page 180

the use of the captured port of Antwerp to the Allies 

until they could gain control of the banks along the 

lengthy channel so that Allied ships could pass. It 

took until 8 November 1944 to clear the enemy 

from the sites menacing the Scheldt.

The enemy was able to thwart an Allied airborne and ground operation to gain the Rhine 

bridge at Arnhem. While the plan was risky almost 

to the point of being foolhardy, it was apparently 

bad luck that brought German panzer forces into 

the area where Allied gliders and parachute troops 

later descended, and inflexibility that caused the 

operation to proceed in spite of SIGINT warnings 

of the German forces there. German forces were 

able to oppose Allied movements and thus to overcome the men who had succeeded in seizing the 

Arnhem bridge and to regain control of it before Allied reinforcements could arrive to consolidate a 

defense and retain possession. German Air Force 

units also struck Allied troops concentrated at the 

nearby Driel railroad station to whom, for lack of 

any communications, no warning could be conveyed by a SIGINT detachment that had learned of 

the impending operation about three hours before 

it began.

In the end, the enemy’s new main line of defense could be neither outflanked nor swiftly 

pierced. It took months more to reach the Rhine.

Although the main effort by the Allies remained 

that of breaching or circumventing the Westwall 

for a crossing of the lower Rhine, followed by the 

capture of the Ruhr’s industrial complex, and then 

by a drive eastward across Germany’s northern 

plains and northward to seize her ports, no such attempts could be made until Antwerp was operating 

as an Allied supply base. That could not begin until 

the port was rehabilitated and made accessible 

from the sea, conditions achieved during November 1944. Though Field Marshal Montgomery (as 

he became by promotion on 1 September 1944) believed that under his command the Allied ground 

forces could accomplish the early defeat of Germany by a relatively narrow invasion that carried to 

Berlin (and others supported that view), General 

Eisenhower believed that the enemy must be kept 

under strong pressure at many points without waiting for the mounting of such a spearhead attack as 

Montgomery advocated.

In October and November 1944, therefore, the 

U.S. Ninth Army moved its headquarters to Maastricht, Holland, and, as part of Bradley’s 12th Army 

Group, launched attacks to push through the Westwall toward Cologne. With U.S. First Army (FUSA), 

it shared some the the hardest combat of World 

War II in reaching the Roor River valley trying to 

control the dams that could flood the area, and to 

break through to the east. Those efforts were not 

successful. The city of Aachen was captured. The 

Westwall zone was thus entered without being 

pierced. The battles inflicted heavy losses on both 

sides.

The detachment of the 3d RSM with the Ninth 

TAC became so alert to the sounds of radio telephones in German aircraft that they were able to 

recognize the noise of carrier waves when a pilot 

turned on his set even though he refrained from 

speaking. Their direction finders could pinpoint 

the aircraft and fighter-controllers were thus enabled to vector aircraft to vantage points for attacks. 

Claims to twelve victories were based on radio intelligence of this sort. 

The enemy was known to have an uncommitted 

reserve from which a counterattack could be expected unless these divisions were used instead to 

stop the Allies in a resumed offensive. Preliminaries to a renewed U.S. effort to get control of the 

Roer dams, and thus to be able to retain bridging 

over the Roor once it had been crossed, began during the first week in December. U.S. First Army was 

about to strike again when on 16 December 1944 

the enemy launched what Allied reporters called 

the “Battle of the Bulge.”

During the pursuit, the Corps RI companies 

had found their arrangements for mobility put to a 

test that showed them to be generally effective. 
Page 181

They moved by echelon so that intercept coverage 

could be continuous even during a move, and they 

were able to spot some of the enemy units, the temporary locations of CPs and supply or ammunition 

dumps, and the state of potential opponents. To 

achieve good direction finding usually required 

stops longer than proved practicable. The arrangements for consulting maps within a truckborne hut 

left something to be desired.

When a gasoline shortage required interruption 

of the Allied pursuit, FUSA was aware that enemy 

opposition was not far away. Their delaying road 

blocks and mines, blown bridges, and other harassing actions were about to be superseded by a firmer 

defense. The enemy was not going to rely on the 

shelter of the Westwall’s semifortified positions as 

the site of his first shift from retreat to static defense operations. He was going to oppose the Allies 

in all approaches to the Westwall.

By 16 September 1944 the 3251st Signal Service 

Company (RI) with VII Corps was able to occupy a 

site across the German border at Kornelimuenster, where it worked for the next month. 

The 3252d company with XIX Corps, which moved 

eight times in September, settled at the end of the 

month at St. Pieter and remained there until 13 

October. It then moved to Heerlen, east of 

Maastricht, where it remained for more than two 

months.

Haislip’s XV Corps, which had gained and held 

the bridgehead over the Seine at Mantes- Gassicourt through which part of FUSA crossed in 

pursuit, was transferred temporarily from Third to 

First Army. When it reverted to Third Army and 

moved toward the Moselle, its RI company, the 

3253d, moved on 9 September to Lusigny, southeast of Troyes, and shortly afterward, in a series of 

shorter moves, went another 150 miles to the upper 

Moselle valley. On 29 September 1944, when XV 

Corps left Patton’s Third Army for General Alexander Patch’s Seventh Army, the 3253d entered the 

Seventh Army’s SIS together with the 117th SRI 

Company and its Detachment “A,” which later 

became the basis of the 3260th Signal Service 

Company (RI) while operating with VI Corps.

The 3254th, attached to VIII Corps, Third 

Army, left that command temporarily in Brittany 

and worked directly under Signal Security Detachment “D” (SSD “D”) at Mangiennes near Verdun. 

Early in October VIII Corps turned its responsibility in Brittany over to others and moved to plug a 

gap in the Allied line in the Ardennes area. The 

3254th left Verdun and found a site at Houffalize 

from which to serve VIII Corps under FUSA until, 

on 20 December, it moved with VIII Corps to Third 

Army control during the Ardennes campaign.

The 113th Signal Radio Intelligence Company 

with FUSA moved successively to Huy on the 

Meuse, to Jalhay, Limbourg, and Battice, Belgium, 

while Headquarters, FUSA set up at Spa. The 118th 

SRI Company with Third Army stayed near Verdun 

as long as the campaign toward the Saar was restrained by supply problems and by the departure 

of XV Corps to join Seventh Army farther south. 

The 117th SRI Company, already with Seventh 

Army, reached a site near Vesoul on 20 September 

and moved to the Epinal area on 2 October. In September 1944 the 137th SRI Company, which had 

been assigned to HQ, Ninth Army, moved to the vicinity of Verdun and operated there and at 

Hollenfells, Luxembourg, under direction of SSD 

“D” until the Ninth Army was in a position to use its 

capabilities. When HQ, Ninth Army, opened at 

Maastricht on 15 October 1944, the 137th SRI Company set up at Valkenberg, Holland.

The Ninth Army was originally scheduled to 

control the XIII, XVI, and XII Corps. On 25 November 1944 the 3258th, attached to XIII Corps, 

began its move to Kerkrade, Holland, and a week 

later, the 3257th took a similar route to join XVI 

Corps at Heerlen the III Corps, however, went to 

Third Army without a SIGINT company of its own. 

The XIX Corps then came under Ninth Army, taking the 3252d with it. XII Corps had to borrow the 

3256th from XX Corps during the Ardennes cam-
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paign, and only late in February 1945 got the 

3259th to keep.

The 114th and 116th SRI Companies, assigned 

to 12th Army Group, were among the units using 

the Verdun area early in September. On 10 October 

1944 the 116th shifted from Verdun to Bettembourg, Luxembourg, where it stayed until 20 

February 1945. It did not pull back during the enemy’s thrust through the Ardennes. On 8 November 

the 114th – after a month at Walferdange, Luxembourg – moved to Verviers, Belgium.

The 121st and 124th SRI Companies, trained for 

higher grade interception and analysis in the direct 

service of SID, ETOUSA, and SHAEF, came from 

England later. As we have seen above, the 121st operated at St. Quentin, France, from December to 

March, and the 124th at a site near Congy, France, 

through the winter. It was sent to Pont-a-Mousson, 

under HQ, 6th Army Group, on 4 March 1945 for 

the remainder of the war.

Pursuit to the Moselle River

The speed of the Allied pursuit to the edge of 

Holland was surpassed by that of the Allied drive 

farther south across the Meuse to the Moselle River 

en route to the Saar basin. The opposition there 

was weak. But neither Allied advance could maintain the pace as distances from the supply ports 

lengthened. By 4 September a condition that, at 

various times in World War II, would affect armies 

and air forces on both sides brought the advance 

toward the Moselle to a temporary stop. Shortage 

of motor fuel obliged the Supreme Command to resort to allocations. To give enough to 21 Army 

Group, supported by FUSA on its flank, none at all 

was given to Third Army (TUSA) for a few days and 

after that only reduced amounts which restricted 

TUSA’s operations. The enforced pause in September allowed the enemy to bring forward important 

strength, so that crossing the Moselle became 

much more difficult than it might have been a few 

days earlier. The enemy even tried to launch a 

strong counterattack that would forestall the 

linking up of Seventh Army with Third Army. He 

was frustrated by conditions that had induced him 

to make successive commitments piecemeal rather 

than to deploy overwhelming strength. His intentions were observed in SIGINT, as well as in other 

sources of intelligence, enabling the Allies to take 

effective countermeasures.

Two major developments changed the situation. Allied strategy for the future made the 

campaign toward the Saar a secondary effort. The 

main drive was to be that bound for the Ruhr, conducted by Montgomery’s 21 Army Group, to which 

the U.S. First Army would provide flank protection. 

The Ninth Army was to come in between First and 

Third Armies. Since supplies were still brought to 

both Montgomery’s 21 and Bradley’s 12th Army 

Groups from ports far to the rear, the resources for 

delivery were insufficient to keep all offensives 

going. The pause from 1 to 5 September was repeated at the Moselle bridgehead from about 9 

October to 8 November, though it was more a slowdown than a complete stoppage. The enemy was 

subjected to limited attacks instead of being given 

the usual indications that an opponent had gone 

over to defense, such as barbed wire, mines, and 

entrenchments, lest he release a portion of his 

forces from that part of the front to strengthen another. Patton instructed his corps commanders to 

continue making limited attacks, to keep a good 

line of departure for a renewal of the offensive, and 

to set up outposts and mobile reserves. Artillery 

batteries were to be ready to strike all roads likely 

to be used by the enemy.

As XX Corps headed toward Metz, running out 

of gasoline before its first objectives at the Moselle 

were attained, the 3256th Signal Service Company 

(RI), during the night of 3/4 September 1944, 

picked up an order from an enemy commander to 

a Reconnaissance Patrol Schellwitz to keep Highway 18 under observation. Later, by DF operations, 

the section of the road being patrolled was ascertained to be northeast of Longuyon and north of 

Longwy. XX Corps sent its own armored reconnais-
Page 183

sance unit there and captured several prisoners 

from Patrol Schellwitz.

By September 1944 the 3256th Signal Service 

Company (RI), working with XII Corps, was at 

Nancy after completing a drive across France from 

Orleans. There Third Army traded blows with 

strengthened German forces until, after hard fighting east of Nancy, it could resume its advance in 

November.

While XII and XX Corps had been moving from 

the Meuse to the Moselle, XV Corps returned to 

Third Army command, after a period under U.S. 

First Army. The French and American divisions 

that were to be under XV Corps control moved to 

the southern flank of Third Army and fought their 

way to the Moselle at Epinal and south of it. General Patton noted in his papers on 16 September:

I sent XV Corps against Epinal yesterday. On a corpse we found an 

order to attack Eddy [XII Corps] in 

the flank today. They won’t do it 

now... 

XV Corps crossed near Epinal and prepared to continue generally northeastward as Third Army’s 

southern wing.

He noted in his diary on 18 September:

We got a message that two columns 

of infantry and tanks were attacking 

Luneville. . . . I told XV Corps to move 

out on its objective.

Luneville was on the northeastern edge of a great 

bend in the upper Moselle. XV Corps contributed 

to quelling the German counterattack that was intended to move on Nancy from Luneville as a base. 

Twice XV Corps had been in position to frustrate 

the enemy’s main expectation of stopping the Third 

Army. But he persisted.

On 21 September Patton wrote:

For the last three days we have had 

as bitter and protracted fighting as I 

have ever encountered. . . . The Huns 

are desperate and are attacking at 

half a dozen places....

The enemy was trying by counterattacks to reestablish firm connection between the German 

First and Fifth Panzer Armies in the Nancy area. 

He pressed hardest at one stage against the twelvemile front of the 35th Division in XII Corps, which 

on 30 September was overextended after four days 

of seesaw combat. Perhaps through German SIGINT, enemy artillery was led that afternoon to 

drop a shell just outside the command post of the 

320th Infantry at Bioncourt, where the XII Corps 

commander, the Third Army Chief of Staff, two division commanders, and three regimental 

commanders had begun a conference on the situation. Should the line be shortened or should the 

armored reserve be used? Several men were killed 

or wounded by the shell, including aides who had 

begun serving with General Eddy during the campaign in North Africa. After doing what they could 

to bring relief to the wounded, the XII Corps conferees agreed to pull the 35th Division back to 

shorter lines.

General Patton flew up from his headquarters 

at Verdun to Nancy in forty-five minutes and reversed the decision; instead, he committed elements 

of the 6th Armored Division available to XII Corps 

and arranged for release of another infantry regiment from XX Corps if necessary. The attack next 

morning found the enemy even worse off than the 

Americans; the German counterattack against the 

35th Division was thrown back from ground previously taken. By noon the 6th Armored Division 

held Chateau Salins; the 35th Division held the 

Foret de Gemecy. On 15 November the 3255th Signal Service Company (RI) moved into Chateau 

Salins.

Crossing the Moselle began with sharp battles, 

either on the western side where the terrain was favorable or at the river itself, where high ground on 
Page 184

the east bank dominated the crossing site. XII 

Corps crossed both north and south of Nancy and 

sent armored forces to envelop a considerable area 

east of it. Enemy forces within the hilly, often forested, area of envelopment were reinforced. 

German counterattacks continued for many days, 

even after Nancy itself had been vacated, so that 

possession of the crossings was insecure for a period much longer than might have been foreseen.

Near Metz, XX Corps had to overcome strongly 

fortified positions in areas outlying the city on all 

sides. It also had to cope with mobile and armored 

defenders, so that even after gaining and enlarging 
Page 185

a bridgehead, it was found necessary to meet repeated German counterattacks. Wooded heights 

and forested areas interspersed by rolling farm 

land on clay soil provided opportunities for limited 

maneuver. The rains that autumn were so heavy 

and prolonged that rivers flooded their banks. The 

defense of the city of Metz persisted until surrender 

of the city on 22 November 1944. Isolated outlying 

forts remained in the possession of their garrisons 

until, one after another, they decided to quit. The 

last surrender came on 13 December.

Improvement in Enemy Cryptography

Before the invasion of Normandy, the German 

system of assigning callsigns was known. It had 

been learned partly from a captured callsign book 

and partly from reconstruction based on traffic 

analysis. Identifications of terminals were then 

easy and dependable.

The medium-grade cryptosystems in 1943-44 

were either non-Indicator or Playfair, while lowgrade systems were usually three-letter (T/L) using 

the HeeresSignalTafel (HST) as either a one-part 

or two-part code. Abundant experience with such 

systems in the Mediterranean had been turned to 

account in the training of ETOUSA SIGINT analysts. Some enemy divisions, like the 21st Panzer 

Division, introduced complicating features in the 

use of T/L codes. That command inserted for all 

place-names a frequently changing monoalphabetic substitution system.

As German defense of the approaches to the 

Rhineland stiffened in September, the reorganization and rehabilitation of German Army units 

brought with it the resort to new methods of insuring security of their communications. The Allies 

learned well in advance that on 1 November 1944, 

callsigns would no longer be assigned by older 

systems. In fact, they then became randomized. 

The use of German “E” and “F” callsign books 

continued, but much less systematically. The new 

variations, however, tended to become habitual 

with different units, which could thus be identified. 

Examples were the 10th SS Panzer Division, 130th 

Panzer Lehr Division, and the 3d Panzer Grenadier 

Division.

In February 1945, before the Rhine had been 

crossed by Allied forces, the German communicators began replacing their non-Indicator 

cryptosystems with a much more secure 

“Rasterschluessel.” Presumably as control documents could be provided, the new system displaced 

Playfair systems and thus materially altered the 

work of reading medium-grade traffic. Captured 

“Raster” grilles were occasionally available for use 

in decipherment.

German communications nets had to be identified after 1 November 1944 by scattered bits of 

typical procedure, references in plain language to 

known persons or places, types of code used, negligent resort to fixed callsigns, patterns discovered 

(over a period) in the use of frequencies, and by decrypts. Traffic intelligence of that description 

required much more recording and detailed analysis of data than had been necessary before the 

randomizing of callsigns. During operations of 

such fluidity as the pursuit across France and the 

ebb and flow of forces in the Ardennes, it became 

necessary to collect and analyze data not only on 

units being faced but also on others likely to be in 

opposition because of sudden moves. Wanted were 

maps, means of understanding references in traffic 

to German map grids, and data gathered by other 

corps or armies. That caused Third Army’s SIS to 

establish a research section to act in liaison with 

counterparts at corps, other armies, and army 

group levels.

When the boundaries of Allied army zones or 

corps areas were shifted, a corps signal service 

company (RI) was likely to begin covering an 

enemy command that, while new to it, had previously been covered by another U.S. RI company. 

From army or army group SIGINT units, the 

needed collateral could thereupon be sought and 

quickly applied.
Page 186

In August 1944 the movements of the 9th Panzer Division were followed by U.S. SIGINT units 

because the non-Indicator cipher keys used by that 

command had been captured. Other captured documents expedited the processing of intercepted 

traffic, especially when code names for persons, 

units, and even some types of war material were 

copied for the first time. When enemy communicators changed frequencies every three days, captured 

tables of frequency allocations proved highly useful 

to the SIGINT analysts. Captured prisoners from 

time to time helped to identify the most useful frequencies and links.

The communications changes adopted after 1 

November 1944 by the German Army on the Western Front produced so much difficulty for U.S. 

tactical radio intelligence units that, first at the 

SHAEF level and then on 10 December 1944 at 12th 

Army Group, conferences of SIGINT representatives sought to pool their experiences. Attending 

the SSD “D” conference were representatives from 

G-2, 12th Army Group; SSD “D”; the Signal Intelligence Services of First, Third, and Ninth U.S. 

Armies; each SRI company, and each signal service 

company (RI). The conferees on 10 December 1944 

agreed to use various methods developed among 

the units for meeting certain problems. These included methods of approach in traffic analysis, of 

exchanging results of T/A, and of reporting 

continuities discovered in the enemy’s allocation of 

frequency groups. Captured signal documents were 

to be speedily reported and disseminated. Ways of 

controlling DF securely by radio – since wire lines 

had been found vulnerable to enemy artillery and 

even to friendly agents – were adopted. An 

acceptable approach to VHF intercept was tentatively reached, while the methods being used on 

three-letter codes were judged worth continuing. 

In view of the enemy’s changes, and because SID, 

ETOUSA, had an advance detachment operating 

on the continent, the routing and processing of raw 

intercept was modified. Only non-Indicator traffic 

was to be considered medium-grade henceforth. 

Decoded medium-grade material would in the 

future be sent to First, Third, and Ninth Army SIS 

officers instead of G-2, ETOUSA.

Early in October 1944, while Third Army was 

gathering strength and awaiting the signal to resume the offensive, the 3256th Signal Service 

Company (RI) heard an unidentified artillery net 

for the first time. It was given a serial number and 

passed a series of “routine” reports from 15 to 23 

October that were associated with that number. 

The reports mentioned personalities, gave mileages 

covered, fuel consumed each day – nothing that 

seemed striking. But on 24 October all that changed. 

First the net transmitted a series of coordinates. 

Then it exchanged visibility reports. About two 

hours later, at 0040 hours, came the following: 

Ready. First shot. Time and percussion fuze. . . . 

Then a long dash. About thirty seconds later the 

first round of a monster 280-mm shell could be 

heard passing overhead. It landed near the XX 

Corps CP in Conflans-Jarny. The mystery was 

solved.2

The huge railroad gun became as famous as 

“Anzio Annie” had become. Radio surveillance enabled the SIGINT unit to give a report of almost 

every firing and to warn when the gun was being 

loaded. XX Corps artillery, alerted by direct wire, 

could correlate its sound-flash data. Direction finding on the enemy observers' reports, and a study of 

the coordinates, helped locate the gun. Its target 

became predictable – whether Conflans-Jarny, 

Nancy, Pont-a-Mousson, or elsewhere within its 

great range. The two-hour interval to load and aim 

provided time to take suitable protective measures. 

It had not yet been destroyed when the enemy 

resorted to his new, randomized callsign allocations and began using “Rasterschluessel.” The last 

intercepted traffic from the enemy net came on 20 

November 1944.

It was not the only such gun employed by the 

enemy but the first in Northern Europe in World 

War II. Another hit near Headquarters, SSD “D,” 

in Luxembourg City on 28 October. The veterans of 

World War I could remember “Big Bertha,” the 
Page 187

weapon that struck Paris, including a church filled 

with people at prayer.

Seventh Army

The invasion of southern France, Operation 

DRAGOON, succeeded so well during the first two 

days of landings that the enemy appeared to be 

pulling back. From special intelligence, the Allies 

learned that German ground troops were abandoning southern and southwestern France and were 

returning to defend the Fatherland. The Ninth Air 

Force’s Signal Intelligence Service soon detected so 

much radio traffic at airdromes near Bordeaux, 

Dijon, and Bourges that they concluded the Germans were evacuating their upper-grade officers by 

air from those places. In three days’ time, successive Allied air sweeps found it possible to destroy 

thirty German transport aircraft.3

General Patch had to decide whether to push 

steadily after the enemy’s rear units or to attempt 

to outflank his main body and try to cut off the retreat. If he tried the latter maneuver, he risked an 

attack on his own right flank from enemy forces in 

the Maritime Alps. His own line of communications to the beaches might thus be cut.

From SIGINT there was no indication of anything but a defensive attitude on his flank. The 

Seventh Army’s unloading plans were modified to 

rush vehicles and fuel ashore in order to reinforce 

the pursuing “Task Force Butler” by sending the 

36th Division deep in the enemy’s rear.

Knowing from SIGINT that the enemy was unaware of the character of the U.S. forces there, and 

that he believed that only guerrilla forces were 

gnawing at German lines of communication, Seventh Army withheld from the war correspondents 

any information about “Task Force Butler” – its existence or its operation.4

At Montelimar Seventh Army established a 

strong road block across the German XIX Army’s 

route of escape. Only by abandoning their heavy 

equipment could the Germans extricate personnel 

from the trap after a hard and costly battle.

The U.S. Seventh Army moved into the front 

south of Third Army, sealing off the area east of Besancon as far as the Franco-Swiss border. Under 

6th Army Group (Devers), both U. S. Seventh Army 

and French First Army prepared to push into 

Alsace and southern Germany. Effective 29 September 1944, XV Corps was transferred from Third 

to Seventh Army, from 12th to 6th Army Group. In 

part, that action was based on the fact that Seventh 

Army was being well supplied through Marseilles 

instead of being short of men and ammunition like 

Third Army, which was supplied from Normandy. 

The transfer of XV Corps seemed to make a renewed offensive by Third Army less likely to succeed 

in seizing Sarreguemines.

Third Army Reaches the Westwall

On 2 November 1944 Third Army was authorized to resume its offensive of about sixty miles 

across Lorraine to the Westwall, starting a week 

later, at a time when the U.S. First and Ninth 

Armies would be attacking, too. When the ten-division attack opened on 8 November, with fire from 

more than 400 guns, the data gleaned by special intelligence and other sources enabled the shelling 

and supporting air (later in the day) to strike at all 

known enemy command posts. Enemy radio soon 

confirmed that the enemy’s loss of control before 

the ground attack began had been drastic. The 

weather cleared enough in mid-morning to let the 

supporting planes see the targets and work ahead 

of the advancing ground troops. For the next few 

weeks it rained almost every day, and often all day 

and night. There were many streams between the 

Moselle valley and the Saar basin-the Meurthe, the 

Seille, the Nied, and the Saar Rivers – so that any 

repetition of the far-ranging armored columns of 

the previous August were rendered wholly 

impossible. The Saar River, normally about fifty 

feet wide, was swollen to 300. Tributaries backed 

up and overflowed their banks. As at Anzio a year 

earlier, even tracked vehicles struggled with the 
Page 188

mud, and heavy ones, like the tanks, were held to 

the roads.

XX Corps and XII Corps slugged their way 

nonetheless to the edge of the Westwall and by 14 

December had begun to penetrate it. Discouragement then became widespread. All things 

considered, Third Army was probably not strong 

enough for the mission. Although its commander 

was able to drive about in Saarlautern on the 14th, 

that city was not behind the fortified zone but 

within it. A few days later, on 20 December, Third 

Army was being drawn away to the Ardennes sector, about 100 miles to the north.

To reinforce the Germans facing the Third and 

Seventh Armies, the veteran 3d Panzer Grenadier 

Division, in almost full strength, was shifted from 

the Italian front. It became for Third Army the 

principal source of low-grade traffic conveying tactical intelligence. Three other divisions shared that 

function: the 116th Panzer Division, the 2d SS Panzer Division, and the 15th Panzer Grenadier 

Division. The 1st Panzer Artillery Corps supplemented the intercepted material from these four 

divisions. When Third Army was attacking near 

Nancy and Metz, reconnaissance units of the 3rd 

Panzer Grenadier Division not only reported their 

observations of American movements but also gave 

away the identities and locations of opposing German units.

Some SIGINT indicated that in November three 

German divisions were pulling out of the line facing 

Third Army. They were the 130th Panzer Lehr, 11th 

Panzer, and 21st Panzer Divisions. When the Third 

Army turned north in December to take command 

of operations along the south limits of the German 

salient in the Ardennes, they soon picked up reports there by the 130th Panzer Lehr Division's 

reconnaissance units. The 116th Panzer Division, 

another familiar enemy unit, also turned out to be 

west of Bastogne. A great battle lay ahead.

Notes

1 Harry R. Turkel, Lieutenant Colonel (Res), The 

Signal Intelligence Service of the Ninth Air Force in 

World War II, written by the former Chief, SIS, Ninth 

Air Force from memory in 1951. NSA Hist. Coll.

2 SGCO-3256.0.1, 3256th SS Co (RI) Opnl and Intell 

Hist for Period 5 May 1944 to 31 May 1945. Box 23223, 

WNRC.

3 Turkel, The Signal Intelligence Service.

4 Synthesis of Experiences in the Use of Ultra Intelligence by U.S. Army Field Commanders in the 

European Theater of Operations. USA SSG, History 

Files (Book No. 53), 26.
Page 189

Situation at the Outset

On 15 December 1944 the Allies were still trying 

to reach the Rhine below Cologne. East of Jilich 

and Duren the U.S. Ninth and First Armies had just 

renewed their efforts. Farther south, the Third 

Army had established bridgeheads across the Saar 

River and was preparing to exploit them in penetrating the Westwall there. The Seventh Army and 

the French First Army of the Allied 6th Army 

Group had reached the French bank of the upper 

Rhine, and had liberated Strasbourg and other portions of Alsace.

At one wide segment of its front, First Army 

had assigned responsibility to VIII Corps, which 

lacked the troops for continuous close coverage. 

Outposts, artillery units, and mobile infantry and 

tanks were so disposed that an enemy incursion 

would be observed, resisted, and contained. That 

segment of the front was in the Ardennes facing a 

mountainous area of Germany known as the Eifel.

The Ardennes area, mostly in Belgium and Luxembourg, but extending also to the fringes of 

France, lay between the Our River, a tributary of 

the Moselle on the east, and the Meuse River on the 

west. It was a region of hills, plateaus, and steepsided river valleys, strewn with forests. Among 

innumerable hamlets and villages were a few small 

towns. A network of paved roads, supplemented by 

many dirt roads, connected the towns. During rain 

or melting snow, heavy vehicles – even if tracked – 

had to use the roads, which had to be endlessly 

repaired. In some villages, the roads narrowed to a 

single lane between rows of buildings. In many, 

they descended into ravines, crossed bridges, and 

climbed up fairly steep grades on the far side.

In general the good roads were more readily 

used when going north or south. For movement 

east or west, impediments were more frequent. Although the German invasion of France in 1940 

came through the Ardennes, that had been done in 

the spring. An offensive across that area in winter 

was bound to be so much more difficult that the 

likelihood was discredited by the Allies. The heights 

could be expected to receive the first inhibiting 

snows in December. Yet before daylight on 16 December 1944, a heavy artillery and rocket 

bombardment ushered in just such a German attack. For several hours the dimensions of the 

offensive forces were not recognized locally.1 It was 

thought probable that the attack was intended to 

draw off U. S. divisions attacking farther north 

rather than to continue far into the rear of the Allied Western Front.

The German attack was a surprise as to both 

place and strength, though the Sixth Panzer Army 

was known to be available for a blow somewhere. 

That German troops had been withdrawn from 

their counterattacks against Third Army, east of 

Metz and Nancy, and moved northward was known. 

SIGINT had identified some of those movements. 

But the assembly east of the Ardennes of some 20 

divisions, of which 5 were panzer divisions, armed 

with about 500 medium tanks and 1,900 guns and 

rocket-throwers, was unsuspected. Drastic security 

measures and perhaps radio deception had brought 

about the surprise. It enabled the attack to begin 

against an unreinforced VIII Corps and part of the 

VI Corps, although at the cost of inadequate reconnaissance and preparation by German battalion 

commanders, who began with probing tactics.

Chapter 14

The Ardennes Offensive,

16 December 1944 – 20 January 1945
Page 190

The surprise was, by definition, an “intelligence 

failure,” so that besides subjecting Allied strategy 

to assessment, it prompted investigation of evidence that the attack had been coming, and a 

review of the way that that evidence had been interpreted. The surprise in the Ardennes was believed 

to resemble – though on a far greater scale – the 

failure to foresee the German offensive that in February 1943 had carried Rommel’s command 

through Kasserine Pass. On 13 December 1944 

SHAEF had warned that unless the concentration 

of German Army divisions opposite U.S. First Army 

soon dispersed, a relieving attack should be expected. Special intelligence from the German Air 

Force indicated that an operation was in preparation but not where it would be delivered, and it 

gave no indication that German air units would be 

used except, in accordance with known Luftwaffe

policy, to defend Germany from Allied invasion by 

counterattack rather than to furnish close support 

in a ground offensive.
Page 191

In August, September, and November, the Japanese ambassador in Berlin had reported to Tokyo 

that Hitler intended to return to the offensive before the end of November – and SIGINT had so 

informed SHAEF. The Allies watched for indications that the necessary forces were being organized 

and made ready. Such evidence was inconclusive, 

in part because the use of new covernames for 

major German commands prevented firm interpretation. Reviews of special intelligence that were 

made when hindsight enabled an analyst to discard 

irrelevant material exonerated the interpreters 

while revealing certain limitations to which special 

intelligence itself was subject.2

The German offensive consisted of three armies, 

the Sixth Panzer Army on the north, the Fifth Panzer Army in the middle, and the Seventh Army on 

the south. The last was to widen the area brought 

under German control but not to go beyond the 

Meuse River. The other two armies were expected 

to strike out for the Meuse, which so angled northeastward across their paths as to make the distance 

to be covered by the Sixth Panzer Army to reach 

Liege considerably shorter than that to be traversed 

by the Fifth Panzer Army in reaching Dinant and 

Namur. Huy was at the boundary between the two 

army zones. In 1940 German screening task forces 

had reached the bridges at the Meuse in about 

twenty-four hours. In 1944 a spearhead armored 

force got only part way there before it ran out of 

fuel, then was cut off from its resupply, and had to 

be rescued. The whole pace of the attack fell so far 

behind plans that the Allies were able to quickly 

bring in enough reinforcements to confine the 

enemy within a narrowing salient that never quite 

got to the Meuse.

The northern part of the seventy-mile front at 

the start overlapped from VIII Corps’ area into part 

of V Corps’ area – both in FUSA’s zone. Around 

Monschau and Elsenborn, in the Schnee Eifel, V 

Corps stalled the attack. That caused the Sixth Panzer Army, which was expected to make the main 

effort on the shorter axis of attack, to lose access to 

some needed west routes and thus to clutter the 

roads farther south. One characteristic of the Ardennes campaign was the monumental traffic 

jams. While the bad weather precluded Allied air 

support, the stalled columns simply lost time, but 

in good weather Allied air attacks cost the enemy 

men and vehicles as well. The offensive had been 

timed to start under several successive days of bad 

weather, but sunny skies intervened at critical 

stages, and Allied planes risked low ceilings on 

other days. The rain provided morning fogs and 

wet ground. Then snow covered the ground and 

froze briefly before thawing into seas of mire.

The stalwart protection of the northern 

shoulder of the salient had its counterpart at the 

south, where Seventh Army had only limited 

success. In the Fifth Panzer Army’s zone, St. Vith 

and especially Bastogne, were important road centers. The U.S. 7th Armored Division was sent 

southward from Ninth Army in time to stiffen the 

defense around St. Vith, which parried enemy efforts for a week. Though St. Vith eventually fell to 

the Germans, Bastogne was reinforced by armor 

and the 101st Airborne Infantry Division. Although 

the town was gradually encircled, its screen of defenders held until a corridor was opened on 26 

December 1944 to connect it with Patton’s approaching Third Army on the south. The roads 

radiating from Bastogne could be connected by detours around the perimeter defenses, but only with 

severe disadvantage to the Germans. Though Fifth 

Panzer Army did make better progress than its 

northern associate, the Sixth, it could not cross the 

Meuse.

The Enemy Is Contained and Pushed Back

While the reinforced U.S. First Army built up a 

firm barrier against northward penetration and 

expansion of the German-held salient, the Third 

Army was making a spectacular ninety-degree shift 

of its axis of attack in Lorraine. Two corps (XII and 

III) left the Saar River front to others and moved 

north in fierce combat into the flank of the German 

Seventh Army and, beyond that, of the Fifth Panzer 

Army. As noted above, one armored column opened 
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a corridor into Bastogne’s defensive perimeter, a 

corridor that was never closed thereafter in spite of 

assiduous and costly German attempts.

At the outset the enemy committed about 

200,000 men, including paratroops dropped on 17 

December, and as the attack broke through and 

moved westward, he used three more armored and 

eight more infantry divisions. The Americans facing the initial attack numbered about 83,000 and 

had 240 tanks, 180 tank destroyers, and 390 guns. 

The Allied forces used to contain the enemy and to 

drive him out of the salient rose, however, to 26 divisions (of which 8 were armored) and to more 

than 4,000 guns. Later it was calculated that 

1,255,000 Allied artillery rounds had been fired in 

the campaign. The air support provided by Allied 

and German air forces was substantial. Occasionally, the Luftwaffe harrassed Bastogne and other 

battlefields. The Allies provided vital air transport 

not only to the beleaguered defenders there but 

also at other points, and achieved even greater success in eliminating their Luftwaffe opponents. The 

enemy did make an air raid on airfields in Belgium 

on 1 January 1945 that destroyed many Allied aircraft on the ground.

Before the German attack (Operation Jeremy), 

special intelligence indicated that airfields used by 

the Ninth TAC would be subjected to heavy attack. 

When other sources also provided such indications, 

the commanding general, Ninth TAC, maintained 

his purely offensive policy, protecting his units by 

launching Allied neutralizing attacks on enemy airfields. In this instance, the warnings from SI 

persuaded him to send up alert flights at dawn, and 

to assign combat pilots to antiaircraft units around 

his airfields in order to aid in enemy aircraft recognition in case the Germans attacked.

At two of the Ninth TAC airfields, early on New 

Year’s Day when the German aircraft did come 

over, they found Allied planes already in the air 

ready to engage them while other planes took off to 

join the fray. American casualties there were small; 

German losses were sizeable.

SIGINT Coverage during the Ardennes Campaign 

The SIGINT units of SIS, ETOUSA, that contributed military intelligence during the battles in 

the Ardennes were numerous and well placed. The 

121st Signal RI Company, one of the units serving 

HQ, 12th Army Group, had more than twenty-five 

positions at St. Quentin, France, trained on links 

between the battle area and various points in Germany. The 113th SRI Company with First Army, the 

118th with Third Army, and the Signal Service 

Companies with the various corps found ample 

traffic from which they derived extremely valuable 

data on order of battle and on the locations of the 

mobile enemy formations.

VIII Corps and First Army (at Spa) had been 

served by the 3254th Signal Service Company (RI) 

from a site near Houffalize. The static nature of the 

front there had allowed the enemy before his attack 

to rely on wire communications rather than radio, 

but enough radio had been heard to identify various German divisions and artillery commands in 

the Westwall and in rear areas east of the Eifel. On 

18 December, with other means of communications unavailable, Captain Robert L. Hord, the 

unit’s commander, went to the Corps’ CP for orders 

and found that he had about two hours to pack up 

and get out. As the unit started for Neufchateau, 

the sound of small arms firing could be heard close 

behind. From Neufchateau the unit was sent farther southwest and settled at Villiers from 21 

December to 7 January.

It then moved to Les Fosses, near Namur, and 

on 22 January began a shift eastward that brought 

it to Hachiville in northern Luxembourg for several 

weeks.

The 3251st with VII Corps had moved in a series of bounds across France and Belgium, reaching 

Kornelimunster, Germany, on 16 September. The 

site there was vulnerable to enemy air attack and 

artillery bombardment, which drove the unit back 

to Raeren, Belgium, on 17 October after losing 
Page 193

several vehicles, some equipment, and personal 

possessions. On 2 December, however, the 3251st 

occupied a hill at Stolberg, Germany, east of 

Aachen. When VII Corps prepared to counterattack from the northern side of the Ardennes salient, 

the 3251st moved via Havelenge, Belgium, and Villers le Bouillet, west of Liége, to Lee Avins. As 

VII Corps progressed, the unit moved with it and 

by 5 February was again at Stolberg. 

Captain Lee Brownsfield’s 3250th Signal Service Company (RI), with V Corps in the Monschau 

area, kept its twelve positions and three direction 

finders covering the communications of Sixth 

SS Panzer Army units facing V Corps but sent a detachment (one officer, six enlisted intercept 

operators, and one traffic analyst) to cooperate in 

covering the spearheads penetrating westward toward the First Army’s rear area. A second special 

team tested the desirability of placing a VHF intercept unit where it could cover German voice traffic, 

but concluded that the volume would not justify 

that action.

When the Third Army, with its XII Corps on the 

east and III Corps on the west, started its dramatic 

northward thrust into the southern flank of the Ardennes salient to relieve the eastern elements of 

VIII Corps, the Third Army SIS with the 118th SRI 

Company and two corps SIGINT companies formed 

part of the forces so deployed. On 23 December 

1944 Captain Walter Drozdiak’s 3255th Signal Service Company (RI) moved north on a long, cold 

night for 140 miles from Saaralbe to Luxemborg 

City in support of XII Corps. There the unit found 

such pressure upon the signal units that its own 

men put in the wire connections between the operating vans and the Corps and Army G-2 Sections.

On 30-31 December 1944, the 3256th Company 

(Captain Robert L. Braden), normally supporting 

XX Corps, moved to the aid of III Corps, whose SIGINT company had not yet been sufficiently trained 

to be sent over from the UK. The 3256th occupied 

a site at Eischen, Luxembourg, and got its first satisfactory intelligence data on 5 January 1945. It 

identified and located various enemy divisions.

The volume of enemy radio traffic swelled rapidly during the first incursion and during the 

ensuing battles. German reconnaissance units reported what they were observing, naming hamlets 

and villages among which they were moving. Battle 

groups identified their positions and named adjacent units. The locations of command posts, dumps 

of supplies and ammunition, and even lines of attack were spelled out or were indicated by DF. 

During periods in which air reconnaissance was restricted by weather conditions, tactical SIGINT was 

often the only reliable instrument for determining 

what forces faced an U.S. command. Reports of 

their condition enabled U.S. commanders to know 

how those forces stood with respect to strength, 

mobility, and ammunition. As the westward movement slowed down and innumerable engagements 

occurred behind the leading divisions, and during 

the turmoil surrounding the slow withdrawal, the 

usual sources of intelligence became more 

plentiful: contact, prisoners, deserters, captured 

documents, and photographic reconnaissance. Yet 

SIGINT traced the retreating enemy divisions and 

clarified the enemy's intentions.3

Three detachments of the 3d Radio Squadron, 

Mobile (RSM), were caught up by the ebb and flow 

of combat in the Ardennes campaign. Detachment 

“B” under Major H. T. Silverstein was supplying 

SIGINT service to the Ninth Tactical Air Force 

from a site near Verviers and west of Monschau, in 

the direct path of the German Sixth Panzer Army. 

When Detachment “B” withdrew a few miles southward to Jalhay on 17 December, it entered a scene 

of great confusion as some troops pulled back and 

reinforcements came up, while German planes 

dropped flares and bombs. The next day it was sent 

to join Detachment “D” at Fouron-St. Pierre near 

the Belgium-Netherlands border. For a few days 

the two units jointly supported the IX and XIX Tactical Air Commands and U.S. Eighth Air Force. 

While the operational echelon of Detachment “B” 

stayed with Detachment “D,” the rest of 
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Detachment “B” moved over the icy roads via 

Charleroi to Thuin near the Belgium-France border.

During the Ardennes attack, SIGINT provided 

important intelligence in both quantity and quality. 

Messages for thirteen enemy commands of divisional strength and armored and mobile units were 

read by U.S. SIGINT units. They provided G-2 with 

reliable information at a time when other sources 

of intelligence were either lacking or relatively 

slight.

On 16 December 1944 CIRO-PEARL messages 

originating at the headquarters of Wehrkreis VI, in 

Muenster, provided information concerning the replacements and supply services to Sixth Panzer 

Army. They gave the positions of the Abteilung II 

(MOT), Headquarters, VI A.K., one regiment and 

three battalions of Panzer Grenadier replacements, 

a field battalion, and a reconnaissance unit.

A few items may be noted here. In ISUM No. 

136 for the period ending at 1800 hours, 17 December 1944, the German 116th Reconnaissance 

Battalion mentioned three small communities – 

hamlets or villages – west of Dasburg, where the 

116th Panzer Division went after crossing the Our 

River via a usable bridge. The report indicated that 

the enemy would be trying to cross the high, northsouth ridge that separated the Our and Clerf Rivers, 

slipping between two defensive positions manned 

by the U.S. 28th Division. By the next afternoon, as 

shown in ISUM No. 137, that same German reconnaissance unit was reporting on an area nearer 

Houffalize, at Sassel and Tavigny, rather than 

heading toward Bastogne.

The enemy got heavy bridging across the Our 

River very late on 16 December and could then 

send Mark V Panther tanks, stronger than the 

American Shermans, to reinforce the spearheads. 

The SIGINT pertaining to the 17th Panzer Grenadier Division and the 10th SS Panzer Division 

showed that both were out of the operation at first, 

although perhaps available for later commitment 

to exploit hoped-for early successes. The latter unit 

was held near Bonn in OKW reserve.

The 10th SS Panzer Division had eluded encirclement west of the Seine in August and was largely 

responsible for defeating the Allied airborne operation near Arnhem in September. Its infantry units 

had participated in the defense against Ninth Army’s November attacks north of Aachen while the 

rest of the division went back to Ruurlo, Holland, 

for refitting. A succession of messages beginning 

on 13 December 1944 disclosed that part of the division would be moved by railroad from Elten to 

Rheindahlen, would then be reunited with the rest, 

and would be committed to battle farther south 

than Aachen. From 17 December on, the loadings 

and dispatches from Elten were heard, concluding 

with:

Everything with the exception of Flak 

(IV/SS PZ AR 10) rear echelon has entrained. To depart during the evening:

SS PZ Regt 10 (Less 8 Co)

SS PZ AA 10

1 Kp/SS BZ Pi Btl 10

1,2 Batt/IV/SS PZ AR 10

13 Kp/SS PGR 21

13, 14 Kpn/SS PGR 22

III/SS PGR 22

Three trains have already left. The remainder loading tonight and leaving 

early 19 Dec.

But lack of fuel then made impossible the employment of the 100th Panzer Division in a way 

that had been envisaged earlier.

At the outset of the Ardennes attack, the inexperienced U.S. 106th Division, with the 14th Cavalry 

Group attached, held a key section of the American 

front in the Schnee Eifel northeast of St. Vith. 

Among the small villages, enemy reconnaissance 

had discovered not only that the defenses were 

lightly manned by green troops but also 
Page 195

that a certain gap could be used to penetrate to a 

crossroads in the rear. On the morning of 16 December two regiments of the 18th Volksgrenadier 

Division, reinforced by a tank destroyer battalion 

and 40 mobile assault guns, pushed into an area 

held by a very much smaller force. At the village of 

Weckerath, fewer than two troops of the U.S. 14th 

Cavalry Group stood in the path. While they held 

their positions against attack, enemy units also bypassed them. Shortly before noon it was obvious 

that they must pull back or be overrun. Colonel 

Mark Devine, CO, 14th Cavalry Group, authorized 

immediate withdrawal, and they came back in various vehicles, with guns blazing, through a gauntlet 

of enemy riflemen on both sides of the road. Behind them violent artillery shelling suddenly 

dropped on Weckerath. They had moved not a 

minute too soon to avoid it. Records of the 106th 

Division and the 14th Cavalry Group for that period 

did not survive to explain the timing of their move.

At the southern end of the attacking front, the 

U.S. 28th Division was overpowered more slowly, 

while the 4th Infantry and 9th Armored Divisions 

fell back but still contained the attacking German

Seventh Army.

Examples of SIGINT during the Enemy’s Advance 

Upon recognizing that the attack was a major 

offensive, the Allied Supreme Command and the 

U.S. First Army Command reinforced the defenders. At the northern shoulder, V Corps was able 

quickly to strengthen the 9th Infantry Division by 

elements of the 1st Infantry Division. First Army 

later sent the whole 1st and 2d Infantry Divisions to 

hold the shoulder west of the 9th Division. Ninth 

Army on 17 December released from its reserve the 

7th Armored Division, which headed for St. Vith, 

and the 30th Infantry Division, which moved to an 

area farther west. There the latter joined the 82d 

Airborne and 3d Armored Divisions under Headquarters XVIII (Airborne) Corps – released from 

SHAEF Reserve. Major General Matthew Ridgway 

took command of an XVIII Corps sector on the 

north rim on 19 December.

From the south, the 4th Armored Division, the 

6th Armored Division, and the 35th Infantry Division in Third Army’s III Corps began pressing from 

Arlon toward Bastogne, while the XIII Corps came 

up via Luxemborg City between the XII Corps and 

the Our River. More reserves were put at Third Army’s disposal. Into the Bastogne perimeter, the 

101st Airborne Division moved during the night of 

18 December.

While the enemy was trying to get to the Meuse 

by making the main effort along the northern zone 

of attack, his advance units were contending with 

road blocks, blown bridges, and traffic congestion 

as well as with U.S. forces that made movement 

costly and slow. Occasionally Allied aircraft slipped 

below the clouds and verified the location and nature of enemy columns on the roads or strafed and 

bombed in close tactical support of ground troops.

The attacking and the containing forces both 

operated in a large area and were subject to considerable uncertainty about their military situations. 

By 21 December small armored task forces from 

the U.S. 3d Armored Division were moving in the 

area along the northern bank of the Ourthe River, 

northwest of Houffalize. One of them was “Task 

Force Hogan,” which on that day was cut off from 

the 3d Armored Division by enemy forces at Samree, Beffe, and along the roads between Dochamps 

and Hotton. Isolated for several days, the men disarmed their vehicles and escaped on foot during 

the night of 24/25 December.

Reconnaissance elements of the German 116th 

Panzer Division were heard reporting during 23 

December 1944 as follows:

1200: Apparently 20 tanks at Marcouray (P4482), possibly out of gas... 

Bridge at Marcourt (P4285) blown. 

Locality free of the enemy. The Regt 

is to block the road Beffe (P4385) 
Page 196

Marcourt in the area of 560 (Inf Div); 

blocking had already been begun by 

8/GR 1130/560 Inf. Diu.

1245: Strong enemy infantry attack 

with tanks from NY (P3990) repulsed. 

Enemy is attacking Melines.

1310: Enemy attack on Melines 

re-pulsed. Further strong enemy 

pressure.

1340: Relief of PGR 60 will be taken 

care of by I/GR (560 Inf Div). CO to 

report personally at PGR 60.

1400: Marcourt free of the enemy. 

Bridge blown at Marcourt. Ostensibly 20 to 30 enemy tanks are there. 

Roads have been blocked, tanks have 

been ordered to surrender.

4

Among the corps SIGINT units newly arrived 

within effective range of interceptions from the 

battle area was the 3258th Signal Service Company 

(RI) attached to XIII Corps, Ninth Army. From a 

site in Holland (Kerkrade on 29 December 1944), it 

tied in with the Ninth Army’s 137th SRI Company 

and with the XIX Corps’ 325d Signal Service Company (RI) in covering the Ardennes area as well as 

that area north of Aachen within the Ninth Army’s 

zone. The 3258th produced SIGINT from the communications of the 103d Reconnaissance Battalion 

of the 3d Panzer Grenadier Division, the 146th 

Panzer Artillery Regiment of the 116th Panzer Division, and the 130th Panzer Lehr Division.

The 103d Panzer Lehr Division, whose low and 

medium-grade traffic was readable, had been ordered on 22 December (ISUM No. 142) by von 

Manteuffel, Fifth Panzer Army commander, to 

hurry its advance elements on beyond Bastogne to 

St. Hubert. The Third Army’s attack against the 

southern flank of the salient was beginning that 

day, and St. Hubert must be held. ISUM No. 144 

shows that it was in German hands by 1400 hours 

on 23 December.

On 23 December, with General von Manteuffel 

himself in the van, the 130th Panzer Lehr Division 

moved upon Rochefort via St. Hubert, south of it. 

As a major road center, control of Rochefort was 

essential to the successful support of the forces carrying the German offensive farther west to Dinant 

and Namur. It had been occupied by the U. S. 84th 

Division about one day earlier, and the enemy’s approach was expected in view of the SIGINT given 

below:

1308: Div Ia to CG, 130 PZ Lehr Diu: 

The Oberbefehlshaber AOK 5 [CG, 

Fifth Panzer Army] has again ordered a quick thrust to St. Hubert 

(GSGS 4042/P 3161).

OFENROHR is to proceed to Gerimont (P4258).

1725: Div la to CG, 130 PZ Lehr Div:

Fourth U.S. Armored Division is advancing along line: Remagne (P3956) 

— St. Hubert (P3161). Schluesselblime 

[codename for IV/pz AR 130] to take 

up the line: Remagne (P3936)-Moircy 

(P3858)-Vesqueville (P3259)-St. Hubert (P3161), leaving protection on 

the flank. From there advance toward Rochefort (P2<Y76) with 

advance Bn.

On 23 December 1944, farther north, another 

generous German source of SIGINT, the 116th Panzer Division, provided its intentions and dispositions 

for an approach march to attack Hotton:

The Division is to launch an attack on 

Hotton (GSGS 4042/P3687) and will 

pull out during the night of 23/24 December leaving protecting forces.
Page 197

As protecting forces the following 

will remain in the present MLR:

a Bn of PGR 156

a Bn of GR 1130 (560 Inf Div)

2 Assault Gun companies

1 Heavy Howitzer Battery with sufficient ammo all to be under command 

of CO Bn/PGR 156.

The following will pull out at last 

light: 

PZ Regt 16

PGR 60

PGR 156

3/PZ PI Bn 675

I/PZ AR 146 (less Heavy How Battery)

Distribution of these units in the convoy to be:

A. Gruppe Bayer (Oberst.)

PZ Regt 16

PGR 60

PZ AR 146

3/PZ PI Bn 675

B. Gruppe Gro/lman (Maj. PGR 156)

PGR 156 (less 1/PGR 156)

III/PZ AR 146 (Less 1 Heavy How 

Battery)

 Route of March:

Beffe (P4385)-Dochamps (P4984)-

Samree (P5082)-Laroche (P4580). 

Further orders to be issued there.

Order of March:

Gruppe BAYER

Gruppe GROLLMAN

CO is at fwd Div CPo

On 21 December 1944, the 116th Panzer Division with infantry from the 560th Volks-grenadier 

Division had been unable to take Hotton against a 

stubborn American defense of the bridge there. The 

piece of SIGINT given above cannot be reconciled 

with other records showing what actually occurred 

there.

The route of march given in this intercepted 

order leads away from Hotton, to a river crossing at 

Laroche. The 116th Panzer Division was already 

across the Ourthe River the day indicated in the 

SIGINT for its movement across. The division did 

not turn up the southwestern bank of the Ourthe at 

Laroche to attack Hotton for a second time. Perhaps the discrepancy is one of dating the order; 

perhaps it is a case also of reversing the order of villages on the route of march.

On 24 December 1944, reconnoitering elements of the 130th Panzer Lehr Division sent in the 

following reports: 

0925: Attack toward Rochefort 

(P2177) gaining slowly on the ground.

1000: Send vehicles only north of 

Bastogne (P5558). Roads south of 

Bastogne may be impassable.

1045: Bridge at Rochefort blown.

1(x)5: Main dressing station in St. 

Hubert at cathedral.

1110: Fighting against strong enemy 

resistance. Rochefort is taken; the existing bridges have been blown. Send 

bridging column forward.

1147: Set up advanced PW cage at Rochefort.

13(X): Our own bombing attack on 

Bastogne was observed today at 0930 

hours.

1550: About 1530 hours our own 

bombing attack and low flying attack 

took place at Bastogne.
Page 198

1635: Large formation of Air Force 

observed over Bastogne.

178 enemy [Allied] transport planes 

are dropping supplies of all kinds.

On 24 December, the 116th Panzer Division had 

orders to pierce the American line east of Marche, 

to press through that gap, to take Marche, and then 

to make contact with the 2d Panzer Division in the 

vicinity of Ciney. Ciney was near the western edge 

of the Allied forces containing the German salient 

on the north. Elements of the U.S. 2d Armored Division were drawn there on 24 December by reports 

that enemy tanks had been seen in the area. The 

116th Panzer Division did break through the American line by stealth and threatened to cut the 

highway between Botton and Marche, but could 

not join the 2d Panzer Division in operations to extend the apex of the German salient.

Tactical SIGINT production developed with experience. During December 1944 and January 

1945, DF benefited from various modifications of 

means and methods. A better apparatus became 

available. Mobile DF units could be operated in 

truck-borne huts. DF operations could be 

controlled by radio instead of wire lines subject to 

endless breakage or outage for other reasons. But 

the use of one-time pads impeded the speed needed 

if many DF operations were to succeed. Aside from 

that, which was not an insuperable difficulty, units 

found that their radios had to be set at a different 

frequency for DF links than for other communications, and that the changeover took as much as half 

an hour.

The lonely DF outstations were sometimes 

shelled or bombed and could not be secured against 

an enemy infiltrating patrol. Some of the main sites 

needed guards. One of the units welcomed the assignment of several Belgian soliders to that duty. 

Police guard dogs gave some DF units a greater 

sense of security. Keeping the DF teams supplied 

became a drain when vehicles were scarce.

Several SIGINT units contributed personnel to 

teams testing the productivity of VHF monitoring. 

For ground forces, the tests usually disclosed that 

the results were not worth the effort. For SIGINT 

production among air units, intercepted VHF 

(“voice”) traffic was prevalent and useful in 

ETOUSA as in Italy.

Air-ground cooperation was highly valued in 

both First and Third Armies. The latter had been 

obliged at first to share its own needs with those of 

the forces investing Brest, but eventually it received 

ample attention by the Nineteenth TAC. FUSA 

learned to appreciate the Ninth TAC under General 

Quesada long before December 1944 and owed its 

escape from having the army’s headquarters at Spa 

overrun, to the willingness of Ninth TAC fighterbombers to follow an American artillery spotter 

plane down through the cloud ceiling where they 

then knocked out an armored column only two 

miles from Spa. Other supporting aircraft flew improvised support when the skies were closed above 

all airfields except those at the outer limits of fuel 

ranges.

In air-ground support, U.S. voice traffic enabled tankers on the ground and crews of supporting 

aircraft to cope jointly with enemy targets by calling on or alerting each other.

Special Intelligence

On the fifth day of the offensive, SI provided a 

message (from a German Air Force headquarters) 

reporting that the Ardennes drive would continue 

with the Sixth Panzer Army heading for the Meuse 

sector while the Fifth Panzer Army pushed on toward Marche. One element of the Sixth Panzer 

Army would advance northwestward via Elsenborn 

and another would continue its operation to capture St. Vith. The German Seventh Army, at first 

moving in a southwesterly direction, would continue its attack toward Arlon.5

By then the radio silence and the cover and deception plans by which the preparations for the 
Page 199

attack had been so well masked had been replaced 

by the standard system of unit periodic reports and 

daily air liaison officer reports. Since radio had replaced wire communications and since Allied 

intercept units were well placed for audibility, they 

collected large volumes of messages. Special intelligence provided much more detailed and accurate 

deductions about order of battle, aided by identifications from prisoners taken in combat.

Allied bombers kept striking at choke points in 

the road and railroad systems by which the Germans were resupplied with fuel, ammunition, and 

other required items. Stores, accumulated in the 

area from which the operation was launched, had 

to be drawn down because of the delays in transportation from points farther within Germany. 

Bomb damage to communications systems interfered with arranging detours or other adjustments 

after a destructive raid. Special intelligence not 

only helped determine the best targets but also 

made known the effects of Allied attacks upon the 

stocks held by tactical units facing battle with Allied forces.6

Some of the special intelligence took a long 

time to decrypt, especially when it was transmitted 

not by Enigma but by nonmorse radio teletypewriter links. The enemy had quickly recognized 

that his offensive had achieved surprise and that its 

dimensions had been successfully concealed from 

the Allies until they analyzed the events of the second day. The enemy had concluded correctly that, 

as local Allied reserves were being used up, the Allies would have to weaken their forces adjacent to 

the zone of attack in order to find other reserves of 

any strength. Some SI showed the Allies what the 

Germans believed to be Allied intentions as well as 

what the Germans themselves planned to do to oppose Allied maneuvers. Thus the 12th Army Group 

was not surprised by the German Air Force attempts on 17/18 December to strike columns of 

Allied reinforcements moving from the Aachen and 

Maastricht areas toward the northern flank of the 

German Sixth Panzer Army. Similarly, the Allies 

early became aware that the Germans knew that a 

U.S. force (the U.S. Third Army) was concentrating 

with a view towards approaching Bastogne from 

the south, and that the German Fifth Panzer or 

Seventh Army intended to get there first. Also in 

January after the German advance had stalled, the 

Allied command learned from SI that the Germans 

interpreted Allied measures as showing no intention of creating another Falaise, or Mons Pocket, in 

which the bulk of the German forces might be 

caught. When the offensive was abandoned, the 

panzer divisions were indeed pulled out successfully with only some rear-guard fighting; they were 

being preserved for subsequent availability elsewhere.

The Allied commanders knew in advance, 

through SI that on 22 January 1945 the Sixth Panzer Army would be withdrawn and that the Fifth 

Panzer Army would remain in command of the 

whole sector. Sixth Panzer Army took under command certain additional armored corps and 

divisions.7

The Allied command was naturally interested 

in knowing as soon as possible where the withdrawn troops were again to be committed. Would 

they join the counteroffensive then being attempted 

in the Saar area; would they reinforce the Aachen 

sector; or would they perhaps be transferred to the 

Eastern Front? The latter proved to be the case.

Examples of “Y” SIGINT as the Attackers 

Withdrew

As the attack from the south by Third Army advanced toward the southern perimeter around 

Bastogne, despite fierce resistance from 23 to 26 

December 1944, SIGINT noted the collapse of elements of the 5 Parachute Division which were in its 

path. That force reported on 25 December that 

lacking reserves, bazooka and antitank ammunition, and contact with neighboring German units 

on the left, it was going to withdraw. It requested 

support from German artillery and from a bicycle 

platoon. (ISUM No. 144)
Page 200

After the relief of Bastogne on 26 December 

1944, the 1st SS Panzer Division attempted to close 

the corridor into the perimeter by attacking westward. On 6 January 1945 its intelligence officer 

submitted a situation report as the day began: 

Enemy picture in front of our sector: 

Last night there was no prevailing security. Firm enemy strongpoints 

established as far as 500 meters south 

of church at Lutrebois (GSGS 4042/

P564529) and from sector near Latannerie Mill (P572508) around Villers 

La Bonne Eau (P574503). 

Presumably enemy has no intentions 

of attacking for the present in front of 

our sector. Our reconnaissance unit 

was able to advance through a break 

in the line west of PT 475 (unl) to the 

south on road “T” at PT 406 (unl) and 

from there to the west via Schloss 

Losange (P556526) without making 

direct contact with the enemy. To the 

east and west of the road there were 

several unguarded vehicles with 

heavy machine guns and large calibre machine guns.

At the present there is enemy rifle 

and arty fire as heretofore. The western edge of Villers La Bonne Eau was 

found to be mined. Query: How is situation at Ischpelt (P65)-Donkholz 

(P6453)?

During the first week of January, radio intelligence on enemy reconnaissance near Flamierge 

and Flamizoulle alerted the defenders of Bastogne 

to the German intention to attack the city soon 

from the west. One enemy attack there was struck 

on the flank at the very outset by an armored force 

from Third Army – more by luck than intention according to General Patton – so that it failed. 

By 7 January 1945 indications, even though 

slight, that the enemy was about to retreat were 

recognized (ISUM No. 157). Soon more evidence 

appeared, though all German divisions were 

ordered to maintain radio silence beginning 8 January (ISUM No. 160). On 19 January Panzer Lehr 

Division was heard ordering all its mobile supply 

columns to return to Germany, and on 20 January 

it became evident that the division would try to 

establish itself along the skyline ridge west of the 

Our River that it had crossed in the first stage of the 

attack (ISUMs No. 170-174).

These selections from CIRO-PEARL SIGINT 

produced at Army and more particularly at 12th 

Army Group (by SSD “D”) were greatly outnumbered by the voluminous PEARL and THUMB 

messages read at the lower echelons.8

One of the tank regiments of the 1st SS Panzer 

Division filed a typical report on fuel and ammunition on 12 January 1945, as the Ardennes offensive 

was slowly going into reverse. It included the following:

Otto fuel allocation:

Received from Army 10 cubic meters

Consumption 10 cbm.

Supply on hand 1 cbm.

Supply of diesel fuel 0.5 cbm.

Motor oil 3.8 cbm.

Utility oil 0.4 cbm.

Grease 400 kgms.

Ammo expenditure, 8-12 January:

Pistol cartridges (SMK) 4,500 rounds

Pistol cartridges (7.65 rom) 200 rds.

Flare cartridges (type 41) 20 rds.

Signal cartridges (red) 10 rds.

Signal cartridges (green) 10 rds.

Smoke cartridges (orange) 
Page 201

Urgent need for repaired tank and for salvage missions:

Otto (required):

1 Abt cbm.

501 (Heavy Tiger) bn 8 cbm.

Diesel (required):

1 SS PGR 3 cbm.

Per order: GRUHLE (Hstuf)

As the enemy began to withdraw farther east, 

the 3255th Signal Service Company (RI) adopted a 

practice that it maintained almost to the end of the 

war, that of installing a forward intercept team at a 

site where it could be protected by a division CP, 

and might use a divisional communications line for 

wire traffic. Lieutenant Blaine Heinzelman, the 

unit’s intercept officer, with twelve intercept operators and one teletype operator, on 13 January 

1945 moved to the vicinity of Merzig near the CP of 

the 80th Infantry Division; there he found audibility much improved. A direct teletype link connected 

the forward van with the T/A Section. Two daily 

courier runs made it possible for the intercept material to appear in the Daily Activity Report. On 25 

January 1945 the forward unit shifted from Merzig 

to Wiltz.

The “Battle of the Bulge” was over.

Notes

1. That situation in the Ardennes was in some respects to be paralleled in North Korea as described by 

S.L.A. Marshall, The River and the Gauntlet (New York: 

William Morrow, 1953), 385.

2. That seems to be the import of an unofficial appreciation prepared by GCCS and called “Indications of 

German Offensive,” 13 Jan 1945, which was sent to G-2, 

and A-2, War Department. Copy in NSA Hist. Coll.

3. Two series of SIGINT reports produced by SSD 

“D” illustrate the form of SIGINT items originating during the Ardennes campaign. Some overlapping appears, 

as one shows what items HQ, 12th AG used in its Intelligence Summaries after receipt from SSD “D,” and the 

other indicates what SSD “D” sent as SIGINT technical 

data to the SRI Companies with the First, Third, and 

Ninth U.S. Armies. (The record copy is an archive of the 

USASA, seen by the author at Arlington Hall Station in 

1974.)

4. That message was believed to report the tactical 

envelopment of “Task Force Hogan,” part of the 33d Armored Regiment, U.S. 3d Armored Division. The tanks 

had to be wrecked and abandoned, but the personnel got 

back to American lines.

5. CX/MSS (Series 2) 405/T86.

6. CX/MSS (Series 2) 416/T58 and T34; CX/MSS 

(Series 2) 419/T89 and 420/T16; CX/MSS (Series 2) 

429/T100 and T113.

7. CX/MSS (Series 2) 436/T60; 437/T100.

8. SSD “D” described radio intelligence operations 

during the Ardennes campaign as reaching an all-time 

high volume of intercept and fruitful output.
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Page 203

Through the Westwall to the Rhine

The U.S. Ninth Army remained under control 

of 21 Army Group from the end of the operations in 

the Ardennes until the encirclement of the Ruhr 

the following April. Until the main Allied crossing 

of the Rhine in March 1945, the Ninth Army’s 137th 

SRI Company stayed at Valkenberg, Holland. The 

XII Corps moved to the Ninth Army zone and was 

joined by the 3258th Signal Service Company (RI) 

which came from Forges les Eaux near Rouen. It 

was stationed at Kerkrade on 29 December 1944. 

On 24 December the XVI Corps’ 3257th Signal 

Service Company put its main station where the 

3252d had been at Heerlen, northwest of Aachen. 

The 137th SRI Company with Headquarters, Ninth 

Army, and the experienced 3252d Signal Service 

Company (RI) at Muensterbusch serving the XIX 

Corps (now commanded by Major General R. S. 

McLain) were able to help the newly arrived 3258th 

and 3257th get into production quickly despite the 

enemy’s new cryptic callsign system and the 

previously unfamiliar enemy units facing the Ninth 

Army. On 27 January 1945, the 3257th sent a VHF 

detachment to work with British SIGINT personnel 

(104 WI Section) at Beek, closer to the front.

In Third Army, the 3256th Signal Service 

Company (RI) had served temporarily with Millikin’s III Corps during the Ardennes battles. When 

III Corps was transferred to First U.S. Army, the 

3259th Signal Service Company (RI) came to III 

Corps, and took up work at Muhlartshuette; the 

3256th went back to Major General Walton Walker’s XX Corps in Third Army, in accordance with 

preinvasion plans.

First Army’s 113th SRI Company had been in 

Limbourg when the Ardennes attack began, and on 

18 December 1944 had moved westward ahead of 

the German offensive. By 18 January 1945 it was 

back at the old stand in Limbourg. The 3262d Signal Service Company (RI), destined for support of 

the XIII Corps in U.S. Fifteenth Army, went to the 

113th SRI Company for field training in the area 

west of the Rhine where Fifteenth Army would 

eventually take over from First Army. The 3262d 

therefore was available when FUSA crossed the 

Rhine and built its bridgehead to keep the bridgehead’s northern flank under radio surveillance.

Even before the enemy had been forced to 

abandon his offensive in the Ardennes, he commenced on 1 January 1945 a smaller drive in 

northern Alsace. When that thrust between the U.S 

Seventh Army and French First Army had been 

contained, the Allied Supreme Command insisted 

that the enemy’s large new bridgehead on the western bank of the Rhine – the so-called “Colmar 

pocket” – had to be eliminated. To accomplish that, 

General Eisenhower was prepared to strengthen 

the 6th Army Group by various divisions from a 

new SHAEF Reserve, and to have both the U.S. 

Seventh Army and the French First Army committed to the operation.

Persistent reports by agents persuaded 6th 

Army Group that the enemy kept large German 

forces either there or across the Rhine available for 

reinforcement. SHAEF, on the other hand, received 

contradictory reports from SI. In the end, that 

SIGINT induced 6th Army Group to commit only 

one Corps, the XXI (Milburn), from U.S. Seventh 

Army along with the French. The salient was 

eliminated expeditiously. The Seventh Army was 

thus free in January to make better preparations 

for and to expedite its next operation in the Saar 

area. That offensive went well.

Chapter 15

Winter and Spring Battles, 1944-1945
Page 204

Initially overcautious, 6th Army Group then became overconfident. Justifiably exulting over its 

victories in March, it concluded that the German 

First and Seventh Armies had been decimated and 

practically eliminated from the war. SI offset the 

intelligence sources on which such overoptimism 

was founded. SIGINT indicated that the two German armies would live to fight again. In fact, new 

German lines of resistance were organized rather 

quickly in the path of 6th Army Group’s advance, 

which was deterred but not stopped.

After the enemy had been checked and pushed 

back in the Ardennes and after the smaller attempt 

in Alsace had also failed, the Allies faced the rigors 

of a winter more severe than most. The Seventh 

Army, as the northern command under 6th Army 

Group, had taken over part of the front previously 

held by Third Army when that command switched 

to the Ardennes. In February Third Army did not 

return to its former zone but remained east of Luxembourg. While it cleared a triangle between the 

Saar River and the Moselle, captured Trier, and 

drove the enemy from the Prum River valley and 

Bitburg, it found the going hard and slow until 

March.

The German units that faced U.S. Third Army 

in the Moselle-Saar triangle in March 1945 seemed 

to be deficient in secure radio communications, for 

lack of either radio equipment or trained communicators. Frequent intercepts consisted of reports 

in plain language by units that felt obliged to retreat in order to escape encirclement. The reports 

often specified the route to be taken in withdrawal. 

The tactical situation became fluid enough for 

radio intelligence companies with one of the American armies to collect traffic from German units 

opposing one of the other U.S. armies along the 

west bank of the Rhine.

Farther north, the U.S. First Army resumed its 

advance toward the Cologne plain, while 21 Army 

Group, with U.S. Ninth Army protecting its right 

flank, prepared an elaborate operation to cross the 

Rhine, as the main Allied offensive effort. There the 

Allies planned to acquire a bridgehead large enough 

to become the base for a subsequent drive across 

Germany.

Rather suddenly, the Allied operation farther 

south gained complete control over the Rhineland 

and the Palatinate and reached the western bank 

of the Rhine River. The First Army near Bonn, the 

Third Army near Coblenz, and the Seventh Army 

near Worms pierced German defenses and enveloped great numbers of the enemy before they could 

retire across Rhine bridges that were being preserved for such use. Once the Westwall had been 

penetrated, the enemy might have withdrawn to 

the far bank of the Rhine and there deployed for a 

stalwart defense behind that helpful barrier. Instead, large numbers were caught before they could 

cross, thus making the defense of the Ruhr and the 

main areas of Germany that much weaker.

The Bridge at Remagen

SIGINT kept FUSA aware that the enemy expected to use some bridges for withdrawal and then 

to demolish them. On the morning of 7 March 

1945, elements of Millikin’s III Corps were able to 

cross a tributary of the Rhine, the Ahr River, and to 

move down its valley to the great, historic stream. 

Early in the afternoon they found that the Remagen 

railroad bridge, which had been boarded over for 

motor vehicles and marching troops, was intact. 

American troops seized the bridge in a sharp 

skirmish before it could be blown. By nightfall 

American tanks and armored infantry had rushed 

across. During the night, tank destroyers, more infantry, artillery, and antiaircraft units hurried over 

to take positions in the bridgehead. Thereafter, 

despite successive counterattacks, observed artillery fire, and repeated air attacks, they held the 

whole bridgehead, and the bridge itself survived for 

a week. Supplementary ferries and pontoon bridges 

were available when the railroad bridge collapsed, 

and the enemy was eventually pushed back until 

out of artillery range.
Page 205

Before the main Allied crossing by 21 Army 

Group had begun, the First Army’s Remagen 

bridgehead had been extended along the Rhine 

about forty miles opposite an area also controlled 

by FUSA. The bridgehead enclosed a section of the 

autobahn between Frankfurt and Cologne and provided an ample base area for a major attack against 

the Ruhr.

During the defense and expansion of the Remagen bridgehead, SIGINT identified approaching 

German units and alerted the Americans to their 

impending counterattacks. At one point, on 12 

March, SIGINT intercepted a communication to 

the U.S. commander from the German commander 

near Honnef, where U.S. artillery fire was falling on 

a monastery. The Germans obtained a suspension 

of two hours in order to evacuate some 300 children who had been sheltered there.1

Samples of Special Intelligence in March 1945 

As Allied columns pressed northward along the 

Lohn River toward Marburg, retreating enemy 

forces gathered to form centers of opposition farther north.

It was still dark one night when word came to 

one of the forward airfields from Headquarters, 

Ninth TAC, to send an observer at daylight to check 

the area near Marburg. The pilot returned from 

that flight with a report that in the woods there was 

a huge concentration of German motor vehicles. A 

squadron of Allied fighter-bombers in the vicinity 

was redirected to the target; before darkness returned, perhaps as many as 400 tanks, armored 

cars, and trucks had been demolished.

What had triggered the action? SIGINT! A German message reported the fact that the vehicles 

were there awaiting fuel for their next move. Decrypted quickly, the word was passed to the chief of 

staff and A-2, Ninth TAC. An air reconnaissance 

flight had, as usual, masked the actual source of the 

intelligence.2

 Special intelligence disclosed that the German 

OB West one day in March 1945 had refused a request from Army Group H to allocate to him all the 

ammunition being produced by two specified factories in the northern sector of the German defensive 

front. In declining, he explained that all the medium caliber field howitzer ammunition for the 

Western Front came from those two producers. Although their existence had been known to Allied 

intelligence, their importance had gone unrecognized. They had never been struck.

When the SSO, Headquarters, Ninth Air Force 

called the message to the attention of the director 

of operations, he decided at once that the factories 

should be bombed without delay. Within a few 

hours, they had been destroyed in a bombing attack 

that also hit two or more similar targets near 

them.3

German Collapse

The Third and Seventh Armies crossed the 

Rhine much farther south than the First Army. By 

24 March 1945, with the river behind them, Allied 

forces broke through all defenders and encircled 

the Ruhr. The Allied high command adjusted to the 

circumstances by switching the main effort from 21 

Army Group to 12th Army Group. The Ninth Army 

on the north and First Army on the south pressed 

enemy forces back into the Ruhr and extended 

their efforts to the east until, at Lippstadt, they 

were in contact. At that stage, Ninth Army reverted 

from 21 Army Group’s to 12th Army Group’s control and completed the reduction of the Ruhr’s 

defenses until a dispirited German force, estimated 

at about 300,000 – unable either to break out or to 

be relieved from outside – surrendered.

Meanwhile the several corps of First Army and 

Third Army under General Bradley’s command and 

of U.S. Seventh and French First Army under General Devers’ 6th Army Group command, suppressed 

uncoordinated German resistance as they overran 

much of Germany.
Page 206

Once they had crossed the Rhine, U.S SIGINT 

companies began hearing transmissions from German units that were facing the Russians on the 

Eastern Front. Since such mobile units might shift 

to face the Allies – in the end some of them did so 

shift – it seemed important to keep tabs on their 

whereabouts.

In southern Germany a “Bavarian Freedom 

Movement” arose as an organized resistance to the 

Nazi structure which had dominated that region. 

They got control of a radio broadcasting transmitter by which they could inform the U.S. Third 

Army, as it approached, of both political and military conditions. They seized control of some towns, 

which they reported were ready for Allied occupation, and they informed listeners that the citizens 

and some of the armed forces at Linz were ready to 

surrender. They alerted the invaders to the fact that 

military control of the area had been assumed by 

the German Air Force. They described the removal 

of roadblocks on Bavarian highways. They even 

broadcast instructions to the distant German garrisons that had been holding French Atlantic coastal 

ports to surrender them to the Allies.

To some SIGINT units, conditions in Germany 

seemed to resemble those encountered in France 

during the previous summer, except that there 

were no cheering civilian throngs. Moreover, there 

were many sharp contrasts between wrecked German towns or disheartening prison camps, on the 

one hand, and other seemingly untouched areas of 

Germany that reflected the promise of spring in radiant April weather.

Some U.S. SIGINT units with the armies and 

corps moved across Germany to Austria or Czechoslovakia. In southwestern Germany, north of 

Switzerland, the French began to express their nationalism in relations with the Anglo-American 

Allies. From Italy, radio traffic brought word of the 

earlier surrenders there and of contacts between 

Fifth Army and Third Army patrols in Alpine 

passes.

After the German surrender, SIGINT units 

were used to monitor communications for evidence 

of resistance to Allied occupation. Such evidence 

was lacking. Other army SIGINT units started preparing to participate in the campaigns to effect 

surrender by Japan. Before that could occur, the 

Japanese joined the Germans in accepting defeat.

Notes

1. HQ, FUSA, Sitreps No. 550 (071200A to (072400A 

March 1945) to No. 560; G-2 Jnl and File, SENECA 

DAR’s; III Corps G-2 Periodic Reports, especially Annex 

1 to No. 92, 12 March 1945.

2. Synthesis of Experiences in the Use of Ultra Intelligence by U.S. Army Field Commanders in the 

European Theater of Operations. USA SSG, History 

Files (Book No. 53), 25

3. Ibid., 27.
Page 207
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Page 209

The end of hostilities in Europe and the Far 

East brought on a period of speedy demobilization. 

Overseas theaters of operations engaged in the 

transitional activities of shrinkage in numbers and 

planning for a future dominated by considerations 

of relief and rehabilitation, on the one hand, and 

political reorganization, on the other. The Signal 

Intelligence Service, ETOUSA, ceased to exist. On 

15 September 1945, the Signal Security Agency 

passed administratively from the Signal Corps to 

become part of the Military Intelligence Service, 

War Department. It became the Army Security 

Agency. The resources for producing radio intelligence for the army in Europe were soon placed 

under command of a regional authority, Army Security Agency, Europe (ASAE). 

Colonel George Bicher returned to the United 

States and Colonel Earl F. Cooke became the first 

chief, ASAE. His headquarters were not in London 

or Paris, but in the American Zone of occupied Germany, at Frankfurt. The numerous SIGINT units 

that had served in the Army in the North African, 

Mediterranean, or European Theaters of Operations, U.S. Army, were either disbanded or reduced 

as part of the general demobilization. Personnel 

that had started from Europe through the United 

States en route to service against Japan were soon 

out of uniform.

Through all the months before some degree of 

stability could prevail, one of the principal efforts 

was to ascertain from the experience in the West 

whatever lessons it provided for the future.

After hostilities in Europe had ceased, and 

while the lessons learned were under study, G-2, 

12th Army Group, tried by questionnaire to discover the relative value to commanders of different 

kinds of intelligence. Divisions and corps staffs 

were not asked about signal intelligence as such, 

though if they had been asked they might well have 

answered as they did. Their most fruitful source, 

they all agreed, was interrogation of prisoners of 

war. Corps officers gave the “Phantom” (or SIAM) 

teams high credit for swift transmission of 

important, current information which could be 

used in preparing G-2 operational reports. At the 

army level, the most constant, profitable sources of 

information about the enemy were declared to be 

prisoners, tactical reconnaissance, and photographic reconnaissance. Next in value came 

SIGINT, supplemented by agents’ reports and captured enemy documents.

This judgment corresponded with that of British forces in the Mediterranean, where field 

commanders had remained for a long time skeptical of SIGINT’s validity, let alone its relative value. 

Disdain for special intelligence may have been 

great among other commanders; for example, Admiral Kelly Turner, testifying in the postwar 

investigation of the Pearl Harbor attack, referred to 

“droppings from these despatches” marked Magic 

or Ultra.1 In part the failure of SIGINT to attain 

prestige arose from the masking (for security 

reasons) of its actual yield, i.e., the requirement 

that some other explanation be available to the 

enemy for any action taken by an Allied commander. That policy insured another explanation 

also for all Allied commanders who were not 

sufficiently “in the know.”

But until ground operations at night became 

preponderant, air reconnaissance and photographic interpretation (assuming adequate air 

strength) were bound to be the preferred sources of 

intelligence for activities behind the enemy lines. 

Tactical reconnaissance and prisoners taken by 

patrols (if sufficient in numbers and sufficiently 

Chapter 16

Some General Considerations
Page 210

dispersed) could well exceed the information about 

the enemy’s front that emerged from radio interception in advance combat areas.

None of the published judgments applied to 

strategic SIGINT – to SI – whose dissemination 

was so carefully restricted and whose existence was 

so well concealed that any questionnaire was not 

practicable.

Commanders in the field (as we have seen in 

chapter 12) received special intelligence through 

the Special Security Representative (or Officer) system. The Special Liaison Units (SLU) consisted of 

intelligence officers and enlisted communicators 

who followed strict security rules in using a special 

SIGINT communications cryptosystem that connected them with London. To quote from a study2

prepared after the war concerning security measures:

Most of the representatives found 

that substantial security was rather 

easily attained and that perfect security was an impossibility. The 

representative’s most difficult job 

was to make certain that recipients 

did not make direct operational use 

of Ultra without appropriate cover. 

Charged with responsibility for 

success or failure in battle, any commander would find the temptation to 

employ Ultra improperly was wellnigh irresistable [sic] at times. Even 

daily security reminders by the representative and periodic directives 

from higher authority were tried and 

found somewhat inadequate...

There was no method by which the 

representative could censor all tactical orders and discussions, but, by 

monitoring summaries, appreciations, and publications based on 

other intelligence sources, he could 

largely safeguard against a written 

break of Ultra security. Pbysical security and the protection of Ultra 

signals presented no serious problems 

The reliable guiding influence of 

Ultra in working with other intelligence outweighed its value as a 

separate and distinct source of operational information. Its normal 

function was to enable the representative and his recipients to select the 

correct information from the huge 

mass of P/W, agent, [ground] reconnaissance, “Y,” and photographic 

[reconnaissance] reports. Ultra was 

the guide and censor to conclusions 

arrived at by other intelligence; at 

the same time the latter was a secure 

vehicle by wbich Ultra could be disseminated under cover.

The representatives, who worked and 

lived with Ultra in the field, were 

aware tbat it often had a direct operational value; one stated: ‘It was 

important to protect Source, but it 

was also important to get the last bit 

of exploitation, the ultimate, from 

Ultra consistent with security.’3

The 12th Army Group’s official, final, after-action report (Vol. III, 119, 157) said of signal 

intelligence that it had been

 . . . of material value to the Armies 

and at times has provided them with 

very vital information. The existing 

arrangements for providing signal 

intelligence have been adequate and 

satisfactory.... While not directly a 

part of the G-2 Section, the signal intelligence service largely functioned 

as such. This agency was of invaluable service in not only producing a 

steady flow of combat intelligence 
Page 211

but also in its effective dissemination 

of such information. Through its 

radio intelligence activities the unit 

repeatedly produced enemy information at critical periods that was not 

obtainable from other sources, and 

often of decisive moment tactically.

In Italy captured German intelligence officers 

responded to interrogations with an approximation 

of the relative value to them of different sources of 

intelligence. They distinguished between two 

periods – first, the more or less static situations in 

the North Apennines before the final Allied spring 

offensive in 1945, and, second, the maneuvering 

after that attack began. During the first situation, 

they attributed their indebtedness to Allied prisoners of war at fifty to sixty percent, to radio 

intelligence at twenty-five to thirty percent, to air 

reconnaissance, ten percent, and to agents at five to 

ten percent. Once the attack began, the reliance on 

SIGINT rose to a level between sixty-five and 

ninety percent, on prisoners to twenty percent or 

less, and on air reconnaissance, much less. Information from agents dried up as defeat impended.

In Western Europe, where Allied command of 

the air persisted, the enemy fell back into the 

Fatherland. While he was being driven from occupied countries, the Allies could gain important 

tactical information from friendly civilians either 

directly or through their assistance to Allied agents 

and escapees. The enemy, on the contrary, had to 

depend as he did in Italy on his signal intelligence 

operations to a greater and greater degree. Once he 

was in Germany, the relations with the populace 

were reversed, but the enemy’s failure to reestablish a line of defense and stabilize operations there 

deprived him of much benefit. He remained in 

great need of SIGINT, as did the Allied forces.

The SIGINT that came to the Pentagon from 

GCCS or SID, ETOUSA, was valued according to 

its relevance to matters of Allied strategy. The 

Magic European Summary seems not to have been 

analyzed for its bearing on impending problems of 

manpower and supply. Shortages of artillery ammunition of certain types occurred. Preparations 

for the winter campaigning in 1944-1945 were not 

begun until too late to escape serious consequences. 

The Army reserves available to SHAEF during that 

winter were barely adequate for the wide front 

strategy. To reinforce some understrength units 

both Americans and British “cannibalized” other 

units.

The British forces in Western Europe and the 

Mediterranean area were more closely supervised 

from London by the British War Cabinet and ministries than were U.S. forces from Washington. 

There the prevailing doctrine was the primary 

discretionary authority and responsibility of General Eisenhower and his main American 

subordinates. That policy was reflected in the use 

made of SIGINT. Advisory information from 

Washington was relevant to strategic rather than 

tactical matters. Setbacks brought about reviews of 

events and searches for explanations, but in 

general, operations were designed by those responsible for execution.

The German attack beginning 16 December 

1944 in the Ardennes caught the Allies by surprise. 

As soon as the size of the operation was understood 

and the material intercepted in recent weeks was 

reexamined, many indications in SIGINT could be 

recognized. But they were not conclusive. With 

them was related material that could be construed, 

like SIGINT prefiguring the threat that was indeed 

executed, as a threat to attack elsewhere. The 

evidence as to time was more compelling than that 

concerning place. One conclusion to be drawn from 

the situation was the inadvisability of deducing 

anything from the mere absence of SIGINT, for the 

enemy’s elaborate methods of cloaking his 

concentration of forces as an extensive rest and refitting operation, and his imposition of radio 

silence, had deprived the Allies of a basis for accurate appraisal.

The preparations observed during the previous 

three months suggested that the enemy could 
Page 212

counterattack, but the recent depletion of both 

FUSA and TUSA made an enemy operation of that 

sort obviously unnecessary to stop either of them. 

The logic of the situation had seemed to favor the 

erroneous conclusion that the Germans were getting ready to apply maximum power against a 

renewed Allied drive toward the Rhine.

Allied air reconnaissance over the area in which 

the Germans concentrated forces and supplies preparatory to the attack yielded numerous indicators 

of a prospective attack. It is possible that the reports were retained by air intelligence, and not 

included in what 12th Army Group or First Army 

intelligence was digesting, but at SHAEF their purport was not unavailable, nor was it ignored. The 

interpretation of such material by G-2, First Army, 

was clear the enemy had the ability to counterattack but need not be expected to hit the weakly held 

line in the Ardennes in December because that 

would be so illogical.

The enemy’s SIGINT gave him – in view of the 

insecurity of U.S. communications – a far better 

appreciation of the status of Allied forces and plans 

than the Allies had obtained about the Germans. 

But once the offensive toward the Meuse had 

begun, special intelligence kept the Allied command informed of what the Germans knew about 

Allied deployment, movements, and intentions, 

and of what the Germans were planning to do.

On 29 December 1944 special intelligence from 

an estimate by German Military Intelligence, Foreign Armies West, of 21 December went to top 

Allied commanders. It stated that

There is no discernible systematic 

formation of major groups of Allied 

offensive forces against the flank of 

the German salient. On the contrary 

the Allies are endeavoring along the 

whole front to contain the German 

attacks and halt them east of the 

Meuse.

By 12 January 1945 the Allies learned through 

SI that the same German intelligence organization 

had by 6 January concluded that in the Ardennes

Eisenhower now considers the destruction of Army Group B to be his 

sole task. To this end he is bringing 

up every formation that can possibly 

be spared, while shelving completely 

all other plans.

The enemy noted, as SI reported, that the Allies 

did not feel strong enough to try to cut across the 

base of the Ardennes salient to trap the Germans to 

the west of it, but instead attacked from the flanks 

much farther east, toward Houffalize. The Germans had evidently expected that effort to occur 

earlier than it did.

Special intelligence showed that German Air 

Force units were moving to airfields from which to 

oppose the main Allied Rhine crossing, north of the 

Ruhr, and to curtail Allied air operations farther 

east. SI revealed to the Allies the German efforts to 

retaliate against American capture of the Remagen 

bridge and the adjacent bridgehead that developed 

immediately after the seizure on 7 March. Each 

step by the German Air Force to bomb the bridge, 

the bridgehead, or the pontoon bridges in the area, 

was known in advance through special intelligence.

As these illustrations show, SI often had immediate value for tactical air operations, but it 

remained primarily significant for its bearing on 

strategy.

The number of Americans involved in producing and disseminating SIGINT in the West 

eventually could be counted in thousands. At the 

centers in the Washington area, in England, and on 

the European continent as well as in the mobile 

SIGINT companies and detachments in the field 

with combat commands, the total grew with each 

year of the war. It took considerable time for them 

to attain a satisfactory level of performance, a fact 

that exerted no little influence on officials 
Page 213

responsible for preparedness in the postwar years. 

It had been about two years after the Japanese attack on Pearl Harbor before the U.S. Army and 

Army Air Forces began to produce efficiently their 

own SIGINT of the types known as “Y.”

The lessons of World War I had not been turned 

to account. It took prodigious efforts to catch up to 

the requirements for SIGINT. Without the shelter 

of the British and the benefit of their experience in 

World War II, American attempts to build a 

SIGINT service in the West could not have gone as 

far as they did during the two years that it took to 

get under way. The U.S. Navy had, at most, a kernel 

of its wartime SIGINT organization when Pearl 

Harbor occurred. Thus the subsequent innovations 

and performance of Op-20-G showed what it might 

do again if an enemy could be held off, perhaps for 

less than two years but nonetheless for a 

substantial period.

One lesson learned in World War II was the 

necessity of technical continuity in producing 

SIGINT – a necessity which grew even greater as 

the technology of communications continued to 

evolve new forms in profusion.

The ignorance and skepticism about SIGINT 

among commanders early in the war – a condition 

observed in British as well as U.S. commanders – 

diminished with respect to radio intelligence before 

hostilities ended. Except at very high levels of 

command, officers were unaware of the contributions made by special intelligence. Even among top 

commanders, occasional overreliance on SIGINT 

may have been responsible for adverse consequences. If SIGINT as a source has high value, it 

also has limitations, particularly when the absence 

of SIGINT about a subject could be interpreted as 

showing the nonexistence of the subject. Moreover, 

the need to protect SIGINT from disclosure kept it 

from receiving credit to which it was entitled. In 

fact, considerations of security were responsible 

not only for barriers to compromise but also for 

conditions unfavorable to efficient production.

A history of SIGINT in the European and Mediterranean Theaters in World War II needs to be 

considered in full awareness of what was happening at the same time in other theaters. Presumably 

the part played by SIGINT in the deliberations, 

positions, negotiations, and decisions of AngloAmerican planners and the Combined Chiefs of 

Staff will clarify the existing accounts of Allied strategic agreements.

There is a temptation to believe that SIGINT 

provided the best intelligence, especially strategic 

intelligence, and that intelligence controlled the 

course of combat. Surprise helps the side which 

attains it to win battles, either as defenders, like the 

U.S. at Midway, or as the German attackers at the 

outset of the Ardennes campaign in December 

1944. But that offensive failed to reach its objective; 

it squandered resources to no avail. SIGINT may 

permit surprise, but the ultimate outcome depends 

on relative strengths and tactics.

For subsequent wars, the experience gained 

during World War II may be less applicable with 

every year that passes, but one may assume that 

parallel problems in modified forms will arise. 

Success in meeting them will be more likely if those 

who must cope with them know what happened 

“the last time.”

Notes

1. Vice Admiral George C. Dyer, The Amphibians 

Came to Conquer.... 2 vols, Washington, D.C.: Supt of 

Docs., 1969, I, 187.

2. Synthesis of Experiences in the Use of ULTRA Intelligence by U.S. Army Field Commands in the 

European Theater of Operations, USA SSG History 

Files (Book No. 53), 24-5.

3. The italics are my own and emphasize the role of 

SI at Army and Army Group headquarters.
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Page 215

May 17, 1943

Agreement between British Government Code and Cipher School and U.S. War Department 

concerning cooperation in matters relating to:

 U.S. British

 Special Intelligence A Special Intelligence

 Special Intelligence B Y Intelligence

 T A Intelligence Y Inference

A distinction is made in nomenclature and procedure in handling intelligence derived from the 

solution of enemy high grade and that obtained from low grade codes and ciphers. The preservation of 

secrecy in regard to either category is a matter of great concern to both countries and if the highest 

degree of security is to be maintained, it is essential that the same methods should be pursued by both 

countries at every level and in every area concerned, since a leakage at any one point would jeopardize 

intelligence from these sources not in one area only but in all theaters of war and for all services.

This agreement is limited to the traffic specifically designated herein. It does not cover traffic 

emanating from non-service enemy or neutral sources. These subjects will be covered by future negotiations between Director, G.C.&C.S. and A. C. of S., G-2, War Department.

(1) Both the U.S. and British agree to exchange completely all information concerning the detection, identification and interception of signals from, and the solution of codes and ciphers used by, the 

Military and Air forces of the Axis powers, including secret services (Abwehr).

(2) The U.S. will assume as a main responsibility the reading of Japanese Military and Air codes 

and ciphers.

(3) The British will assume as a main responsibility the reading of German and Italian Military and 

Air codes and ciphers.

(4) Both countries agree that special security regulations shall apply to Intelligence obtained from 

decoding telegrams in enemy high grade codes and ciphers.

(5) Both countries agree to use their most secure codes and ciphers for transmission of the decodes 

of enemy signals and transmission of technical cryptanalytic data.

(6) British or U.S. Commanders-in-Chief, Military or Air, will receive all Special Intelligence necessary to them for the conduct of their operations from either British or U.S. centers as may be mutually 

Appendix A

Agreement between the War Department and G.C.&C.S.
Page 216

agreed. Liaison officers will be appointed as desired for facilitating this. They will be given full access 

to all decodes.

(7) The distribution of intelligence from the sources in question will be governed by the fundamental principle that distribution will be restricted to the minimum and will therefore be confined solely to 

those who require to receive the intelligence for the proper discharge of their duties.

(8) All recipients of Special Intelligence A, whether British or American officers, shall be bound by 

the same regulations, the regulations [Appendix (B)] now in force in the theaters of war where British 

forces are operating to be accepted at the present time. If at a later date either country wishes to modify them in the light of further experience then this may be done by mutual agreement.

(9) The extension to officers of a knowledge of the existence of such intelligence shall be confined 

to as limited a number as possible and restricted to the levels of command in conformity with the above 

mentioned regulations. Great stress is laid on the principle that Special Intelligence A should not be 

intermingled in reports with general intelligence from other sources. If, however, it becomes imperative to do so, the whole must be treated as Special Intelligence A and given the same strictly limited 

distribution. Under no circumstances is it permissible to pass Special Intelligence A in a code or cipher 

which can be read by other than the authorized recipients.

(10) Although Special Intelligence B is not subject to the same stringent regulations as Special 

Intelligence A, since the two are closely connected, it is essential to maintain a high degree of secrecy 

in the handling of Special Intelligence B also. In any action taken upon such intelligence and in any 

documents or telegrams based upon it, it is essential that its origin be disguised and that the codes or 

ciphers used for its dissemination be absolutely secure.

(11) All intelligence available from decodes shall be made available to Liaison Officers, and if they 

deem necessary it will be exchanged between London and Washington. These Liaison Officers will be 

specially appointed and given full facilities for this purpose.

(12) British and U.S. will notify one another without delay, giving full particulars, when either has 

information from any source indicating the compromise of any code or cipher used by the other. Action on such information will be most carefully considered in order not to compromise the source and 

if possible mutual agreement in such action will be sought. 

(13) Cooperation between and coordination of U.S. Signal Intelligence Service and British “Y” 

Service must take place at all levels, technical information being exchanged mutually at the same level 

and each country to agree not to lower the classification of such information or the intelligence derived 

from it below that level without mutual agreement.

(14) Each country shall inform the other of the employment and scope in each joint theater of war 

of their Signal Intelligence (Y) units in the field.
Page 217

(15) This agreement or the appendices thereto may be supplemented or modified from time to time 

governing any special feature for which either party wishes to make special provision.

(16) Definitions:

(a) Y Service or Signal Intelligence Service. The British, U.S. Army, and the U.S. Navy 

services concerned with intercepting, decoding, interpreting, classifying and dissemination of enemy 

(and neutral) communications, and the use of D/F and other specialized apparatus for establishing locations and identities of enemy transmitters.

(b) Special Intelligence A. Certain ciphers are placed in a special category, owing to their 

importance and difficulty of solution. The intelligence derived from these ciphers is known as Special 

Intelligence A. Such material is treated with most stringent security measures. Special Intelligence A is 

confined to a very strictly limited number of the most highly placed officers and is mainly of strategical importance.

(c) Special Intelligence B. Intelligence derived from the solution of lower grade ciphers. 

Such ciphers may under certain circumstances be upgraded to the “Special A” class. The dissemination 

of Special Intelligence B is wider though always treated as British Most Secret-U.S. Secret. Special 

Intelligence B may be used tactically.

Appendix (A) 

Special Provisions Regarding Work on German Machine Ciphers 

(U) Since it is believed unnecessary and impracticable to duplicate work on German machine 

ciphers and in view of the large number of personnel required and the unavoidable extra risk to the 

security of the source involved, agreement which follows has been arrived at. This agreement provides 

that:

(a) All desired intelligence from this source will be made available to the War Department in Washington.

(b) U.S. personnel will obtain experience by engaging in the solution of this type of cipher in Great 

Britain.

(c) Research into new methods of attack will be made in Washington.

(d) Transmission of Intelligence to Commanders-in-Chief in the field will be accomplished by 

special routes and staffs who will maintain a watch over the use of the intelligence to guard against 

compromise of the source.

(1) U.S. liaison officers will be appointed at G.C.&C.S. to examine messages and summaries and 

select those desired for transmittal to Washington for G-2 or the Theater Commanders. All decoded 

material will be made available to those officers. Decodes giving information regarding Order of Battle 
Page 218

will be handled as at present, i.e., through U.S. liaison officers in War Office and Air Ministry, respectively.

(2) Decodes or summaries to be passed to Washington through existing British channels.

(3) U. S. party to effect independent solution of keys will be established in Great Britain, but so 

coordinated by mutual agreement to avoid duplication. This party will cooperate with the British in 

regard to tasks and will be given every assistance for instruction of personnel. They will be furnished 

with British machines. Decodes from this section will be passed to Bletchley Park for emendation, 

translation and distribution, but U.S. party will conduct complete processing, including emendation 

and translation to such an extent as they desire.

(4) Formulas will be supplied by Great Britain for use on machines now at Arlington Hall.

(5) U.S. to undertake research for finding a new method for solution and to be rendered every 

assistance by the British for this purpose.

(6) In conformity with British policy, U.S. personnel engaged in solution work in Great Britain 

will not be transferred elsewhere except for very urgent reasons.

(7) Special Intelligence from this source will be passed to Commanders-in-Chief in the field 

through the Special British units provided for this purpose. The officer in command of these units will 

have direct access to the Commander-in-Chief and advise as necessary on the security aspect of 

handling and using this intelligence. Where an American officer is Commander-in-Chief, an American 

officer, properly trained and indoctrinated at Bletchley Park, will be attached to the unit to advise and 

act as liaison officer to overcome difficulties that may arise in regard to differences in language.

(8) The Director of the G.C.&C.S. will have the final decision when matters of security are involved in intelligence items (gossip) and as to what is passed to Commander-in-Chief in the field.

Appendix (B) British Security Regulations for Special Intelligence

Part I Coordination of Routing, Security and Use of Special Intelligence 

1) SPECIAL INTELLIGENCE is the agreed name for the highly secret information obtained by 

cryptographic means from enemy high grade ciphers.

2) Lower grade cryptographic material classed in general as “Y” Intelligence, is not included in the 

definition of SPECIAL INTELLIGENCE.

Part I to be Destroyed by Fire when Read

Part II

1) ALL SPECIAL INTELLIGENCE emanating from the United Kingdom and transmitted to Commands abroad will receive the prefix “Ultra.”
Page 219

ALL SPECIAL INTELLIGENCE emanating from centres other than the United Kingdom and transmitted either to United Kingdom or to another Command abroad, is to receive the prefix specially 

allotted to each producing centre as follows:

 DELHI Prefix SIRDAR

 WASHINGTON Prefix ZYMOTIC

 MELBOURNE Prefix ZYMOTIC

 KILINDINI Prefix ZYMOTIC

 MIDDLE EAST Prefix SWELL

3) SPECIAL INTELLIGENCE produced by U.S.A. centres either in U.S.A. or elsewhere if transmitted over British routes either to the United Kingdom or to the British Commands overseas, is to receive 

the prefix of the Command or centre through which it is distributed.

4) Where it is necessary for SPECIAL INTELLIGENCE to be transmitted between Commands or 

centres other than the United Kingdom, special routes and ciphers are to be arranged and approved by 

London.

Part III

ULTRA (see Para. 1) above) information can be regarded as reliable and action can be taken on 

it, but experience has shown that the following security regulations are vital to the preservation of this 

source. The Commander-in-Chief is held personally responsible for ensuring that they are scrupulously 

adhered to:

(1) The utmost secrecy is to be used in dealing with ULTRA information. Attention is called to 

the fact that if from any document that might fall into the hands of the enemy or from any message 

that the enemy might intercept, from any word that might be revealed by a prisoner of war, or from 

any ill-considered notion based upon it, the enemy were to suspect the existence of the ULTRA source, 

that source would probably forever be lost to our cause.

(2) This loss would vitally affect operations on all fronts, not only the particular front on which 

the source had been compromised.

(3) Commanding Officers of those Commands authorized to receive ULTRA information, i.e., 

normally only General and Air Officers commanding Armies and Air Forces, are to be instructed that 

ULTRA messages are for them, their personal representative, and their Senior Intelligence and 

Operations Staff Officer only, and are not to be seen by, read to, or discussed with any other person. 

ULTRA messages are to be destroyed by fire immediately [once] action has been taken on them. No 

records of Intelligence based on ULTRA information may be kept except at the H.Q. of the Commander-in-Chief.

(4) When ULTRA information is to be used by the Commander of an Army or an Air Force as 

a basis for action to be taken by a subordinate command, the information must be translated, when 

passed to the subordinate command, into terms of an operational order, so worded that if captured or 
Page 220

intercepted by the enemy the origin of the information could not be traced back to the ULTRA source, 

e.g., orders must never contain the precise time, date or place of an enemy operation revealed by 

ULTRA. Such orders based on ULTRA information if transmitted by WIT must be encoded only in authorized ciphers. Under no circumstances whatever is it permissible to transmit ULTRA information 

as such to lower formations.

(5) In general, if any action is to be taken based upon ULTRA information, the local 

Commander is to ensure that such action cannot be traced back by the enemy to the reception of 

ULTRA intelligence alone. A momentary tactical advantage is not sufficient ground for taking any risk 

of compromising the source. No action may be taken against specific sea or land targets revealed by 

ULTRA unless appropriate air or land reconnaissance has also been undertaken. Names of enemy 

ships revealed by ULTRA sources may never be quoted.

(6) The utmost care is to be taken in briefing pilots for an operation based on ULTRA information that only such details are given them as might have been obtained by other means, such as air 

reconnaissance, and only such as are essential to the success of the operations.

(7) No reference to ULTRA information is to be made in any summary whatsoever, however 

limited the circulation. No discussion of it is permissible except between the senior officers who are immediately concerned with the action to be taken upon it.

(8) If it is necessary to ask questions, or make comments on ULTRA material, whether on matters 

of Intelligence, Operations, Routing or Security, such messages are to be transmitted only over the 

special channel and in the special ciphers provided for ULTRA traffic. 

(9) Recipients of ULTRA may not under any circumstances carry on their persons outside their 

Headquarters, ULTRA messages which have been delivered to them.

1st March 1943

(Sgd.) GEO V. STRONG 

 Major General

A.C. of S., G-2

(Sgd.) E. W. TRAVIS

D.D.(S)

G.C.&C.S.

15 June 1943

Approved for the U.S. War Department.

By order of the Secretary of War.

(Sgd) JOSEPH T. McNARNEY,

Lieutenant General, U.S. Army,

Deputy Chief of Staff
Page 221

AG 311.23 (320-43)OB-S-B-M CJM/reh-2B 939 Pentagon

 March 26, 1943

SUBJECT: I intercept Directive

TO: Commander-in-Chief,

 Southwestern Pacific Area;

 Commanding Generals,

 North African Theater of Operations;

 European Theater of Operations.

1. In order to coordinate within the War Department the intercept of certain foreign radio 

transmissions it is essential that the signal radio intelligence companies and detachments now under 

your Command, and those that may come under your Command in the future, receive through the 

Signal Intelligence Service of your headquarters such directives as may be issued by the War 

Department. The detailed assignment of specific missions to those units will be made by your Signal 

Intelligence Service and may be changed from time to time by them, as changing circumstances may 

dictate. In addition to the above, a reasonable number of monitoring missions for security purposes 

may be assigned at your discretion.

2. The Chief Signal Officer, acting for the War Department, is authorized to communicate directly 

with the Signal Intelligence Service at your headquarters on matters pertaining to the specific mission, 

circuits to be covered, known frequencies, form of recording material, copying of station logs, methods 

of forwarding traffic, etc. The Chief Signal Officer is also authorized to furnish directly to the Signal 

Intelligence Service such manuals and pertinent literature as will assist these units in accomplishing 

their missions.

3. To meet the requirements of actual or impending hostile action within your theater, you are 

authorized to modify this directive. However, in the interest of overall coordination of radio and signal 

intelligence operations, you will promptly advise the War Department of your general plan of 

operation involving the interception of foreign radio transmissions. The Chief Signal Officer is authorized to communicate directly with you and with the Signal Intelligence Service regarding these plans.

4. Copies of all material intercepted by these units will be forwarded as soon as practicable and by 

the most expeditious means direct to the Chief Signal Officer, SPSIS, War Department, Washington, 

D.C. An important mission of these units is to intercept material desired by the War Department and 

to forward it to the Chief Signal Officer by the most expeditious means available.

Appendix B

War Department 

The Adjutant General’s Office

Washington
Page 222

5. You will furnish the officer in charge of your Signal Intelligence Service with a copy of this 

directive.

By order of the Secretary of War:

(Sgd) L.M. Banknight

Adjutant General

Copy Furnished:

 Chief Signal Officer
Page 223

RFP/RFL/fls

 AG 311.5 MSIG 27 July 1943

SUBJECT: Operational Control of Signal Intelligence and Radio Intelligence Units.

TO: Commanding Generals

SOS, ETOUSA;

Eighth Air Force;

V Corps;

Iceland Base Command

1. In order to coordinate the interception of enemy radio transmissions within this theater, authoritative operational control of all Signal Intelligence and Radio Intelligence units and activities in this 

command is vested in the Chief Signal Officer, SOS, ETOUSA, who will detail the assignment of 

specific missions to such units in accordance with War Department letter AG 311.3 (3-20-43) OB-S-BM, dated 26 March 1943, subject: “Intercept Directive.”

2. Air Force and Ground Force Signal Intelligence and Radio Intelligence units normally will be 

assigned missions of paramount importance to their respective services. All missions will be

 coordinated by the Chief Signal Officer, SOS, ETOUSA, to avoid duplication, insofar as it is possible, 

by units of our own forces and those of our allies.

3. For security reasons, intelligence resulting from such intercept activities will be given special 

handling in accordance with directives subsequently issued by this headquarters.

4. Monitoring of friendly radio traffic to detect violations of signal security, and the initiation of 

corrective measures, is a function of the Signal Intelligence Service (par 6f, FM 11-35). The activities of 

the various signal intelligence services in this respect will be coordinated by directives issued by the 

Chief Signal Officer, SOS, ETOUSA. This does not preclude the use of any regularly authorized T/BA 

equipment, or personnel, by any unit to monitor its own networks as an additional supervisory 

measure.

5. Personnel assigned to Signal Intelligence or Radio Intelligence units or detachments have been 

specially trained for the duties to which they are assigned. This training includes the imparting of 

considerable secret information to assist in the accomplishment of their mission. Due to this 

specialized training, and for security reasons, such personnel will not be assigned without prior 

reference to the Chief, Signal Officer, SOS, ETOUSA, and without the specific approval of the Theater 

Commander. Unit commanders desiring reassignment of Signal Intelligence or Radio Intelligence perAppendix C

Headquarters

European Theater of Operations

United States Army
Page 224

sonnel will submit requests, through channels, to this headquarters and will clearly indicate the 

reasons for requesting reassignment.

6. It is desired that the contents of this directive be published to such of your subordinate units as 

may be concerned.

By command of Lieutenant General Devers

RICHARD P. FISK,

Lt. Colonel, AGD,

Assistant Adjutant General

DISTRIBUTION:

Each Addressee (2)

CIS, ETOUSA (1)

G-2, ETOUSA (1)

G-3, ETOUSA (1)

AG Personnel (2)

AG Records (1)

Signal (2)
Page 225

AG320.2(9Jul 1948)PO-M-SPCAS 29 July 1943

SUBJECT: Special Cryptanalytic Project in Signal Intelligence Service,

European Theater of Operations, United States Army

TO: Commanding General

European Theater of Operations.

United States Army,

c/o Postmaster, New York, NY

1. The authorized grades and strengths, Signal Intelligence Service, European Theater of 

Operations, United States Army are rescinded effective at once and the following allotment is 

substituted therefor:

a. Officers: SIS ETOUSA (Signal Corps)

Col. Lt. Col. Major Capt. 1st Lt. 2nd Lt. Total 

 1 4 10 19 25 26 85

b. SIS ETOUSA

Signal Corps

Grades

 Mstr 1st Tech Staff Tech Sgt Tech Cpl Tech PFC Pvt Total

 12 -- 22 2 43 13 90 5 114 75 78 454

c. The above allottment includes an increase for a Special Cryptanalytic Section as follows:

(1) Officers: Signal Corps

Lt. Col. Maj. Capt. 1st Lt 2nd Lt Total

 1 2 5 15 36 591

(2) Signal Corps

Grades

 1 2 3 4 5 6 7

Mstr 1st Tech Staff Tech Sgt Tech Cpl Tech PFC Pvt Total

 3 -- 8 2 18 2 31 4 76 60 45 247

Appendix D

War Department 

The Adjutant General’s Office

Washington
Page 226

d. Personnel will be requisitioned and assigned as indicated in attached Table of Distribution, Tab 

B. Personnel selected need not hold the grades indicated but must be able to perform the duties 

indicated by the Specification Serial Number. Personnel selected will be shipped in their present grades 

and ratings. No attempt will be made to promote personnel merely to fill a vacancy.

e. A minimum of twenty-five percent of the officer personnel and ten percent of the enlisted 

personnel will be furnished from 2nd Signal Service Battalion, Arlington Hall Station and will be highly 

qualified technicians. The remaining percentages will be procured by the Chief Signal Officer and given 

initial training in the Signal Security Service at Vint Hill Station, Warrenton, Virginia.

f. A group of key personnel consisting of about ten officers and ten enlisted men will be shipped to 

arrive at ETOUSA not later than 1 August 1943. Fifty percent of the cryptanalytic group should arrive 

not later than 1 September 1943, and the remainder in suitable increments so that the full strength will 

be reached by 1 December 1943.

g. None of the personnel assigned to this unit will be reassigned to duties which will take them into 

the combat zone.

h. All personnel provided will be investigated and cleared by G-2 prior to assignment to such 

duties.

i. It will be the responsibility of the Chief Signal Officer to implement this authorization by requisitioning for the necessary personnel from the Adjutant General under the priorities assigned ETOUSA 

and providing necessary housing and training prior to shipment and to coordinate all activities in the 

preparation of this unit with Assignment Chief of Staff, G-2, War Department General Staff; Movement 

Branch, Mobilization Division, Army Service Forces, and Director, Stock Control Division, Army 

Service Forces.

j. Equipment and facilities for this Cryptanalytic Unit will be provided as indicated in the attached 

Special Table of Equipment, Tab C.

2. The following allotment of authorized grades and strengths is made to Headquarters, European 

Theater of Operations, United States Army, for a Special Intercept Detachment:

a. Officers: (Signal Corps)

Capt 1st Lt 2nd Lt Total

 1 2 3 6

b. Headquarters, ETOUSA Intercept Detachment

Signal Corps

Grades

 1 2 3 4 5 6 7

Mstr 1st Tech Staff Tech Sgt Tech Cpl Tech PFC Pvt Total

 2 1 3 3 10 – 35 2 62 34 28 180
Page 227

c. Personnel will be requisitioned and assigned as indicated in the attached Table of Distribution, 

Tab D. Personnel selected need not hold the grades indicated but must be qualified to perform the 

duties indicated by the Specification Serial Number. Personnel selected will be shipped in their present grades and ratings. No attempt will be made to promote personnel merely to fill a vacancy.

d. An advance party of the special Radio Intercept Unit consisting of two officers and four enlisted 

men, will be shipped to arrive at ETOUSA not later than 1 August 1943, to assist in the details of 

obtaining and preparing a suitable location for the radio reception site.

e. None of the personnel assigned to this unit will be reassigned to duties which will take them into 

the combat zone.

f. Equipment for this Special Intercept Unit will be provided as indicated in the attached Special 

Table of Equipment, Tab E.

g. This Unit will operate directly under SIS ETOUSA in accordance with directives issued by the 

War Department.

h. See sub-paragraph h, paragraph 1 above.

i. See sub-paragraph i, paragraph 1 above.

By Order of the Secretary of War

 (s) A. C. KELLY

Adjutant General
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Page 229

APO887

AG 322.88 OPGC AP0887 8 Feb 1944

Subject: Organization of Field Detachments for Signal Intelligence Division

To: Commanding General, CBS, SOS, ETOUSA, APO 887

Commanding Officer, EBS, SOS, ETOUSA, APO 517.

1. Letter this headquarters, AG 322/88 OPA, subject: “Formation of Field Detachments for Sig Intelligence Div,” 28 Jan 1944, is rescinded.

2. The following units are provisionally organized, effective 1 Feb 1944, at stations indicated:

Unit Location APO

6811th Signal Security Detachment Hall Place, Bexley, Kent. 887

6812th Signal Security Detachment Eastcote, Middlesex. 517

6813th Signal Security Detachment Bletchley, Bucks. 128

3. Personnel for units will be furnished by the Chief Signal Officer, this headquarters.

a. 6811th Sig Security Det will have an authorized strength of six (6) officers and one-hundredeighty enlisted men.

b. 6812th Sig Security Det will have an authorized strength of five officers and one-hundredtwenty enlisted men.

c. 6813th Sig Security Det will have an authorized strength of twenty five (25) officers and 

one- hundred-twenty enlisted men.

d. No additional grades are authorized for overhead of units.

4. Units will be assigned to HQ ETOUSA, and will be attached to Base Section wherein they are stationed for supply and administration.

5. Necessary equipment will be requisitioned through normal channels.

6. Final and initial rosters and reports of change, as required by AR 345-800 and AR 345-900 will 

be submitted to the CG SOS, APO 871, for the 91st MRU.

By command of General Eisenhower:

RICHARD P. FISK,

Lt. Colonel, A.G.D.,

Assistant Adjutant General

DISTRIBUTION: D plus Progress, SOS, APO 871

Appendix E

Headquarters

European Theater of Operations 

United States Army
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Page 231

RBL/CRH/cwh

APO 887

AG 322 OpSC 7 February 1945

SUBJECT: Operational Control and Technical Direction of Signal Intelligence and Signal Radio

 Intelligence Units.

TO: Commanding Generals:

US Strategic Air Forces in Europe

Each Army Group

Each Army

1. Letter, this headquarters, file AG 322 OpSIG, subject as above, dated 5 April 1944, is rescinded 

and will be destroyed in accordance with the provisions of AR 380-5, dated 15 March 1944. A 

certificate of destruction will be rendered thereon and submitted to this headquarters.

2. In order to coordinate the interception of enemy radio transmissions, authoritative operational 

control of all signal intelligence and signal radio intelligence units and activities in this theater, other 

than those specifically assigned to function with 6th Army Group, 12th Army Group or Air Staff, 

Supreme Headquarters, Allied Expeditionary Force, is vested in the Chief Signal Officer, this headquarters, who will detail the assignment of specific missions to such units in accordance with War 

Department letter, file AG 311.3 (3-30-43)OB-S-B-M, subject: “Intercept Directive,” dated 26 March 

1943.

3. Operational control of units within 6th Army Group, 12th Army Group or Air Staff, Supreme 

Headquarters, Allied Expeditionary Force, will be decentralized to the headquarters to which the 

various signal intelligence and signal radio intelligence units are assigned. The Chief Signal Officer, this 

headquarters, will exercise technical direction of these units through signal intelligence channels, i.e., 

determine general US policy with respect to methods of procedure, principles of operation and use of 

these units, and effect coordination including the exchange between these various units of technical 

information required to assist the accomplishment of their missions at their respective levels. For this 

purpose, the Chief Signal Officer, this headquarters, is authorized to communicate directly through 

signal intelligence channels with the various units concerned. 

4. For security reasons, intelligence resulting from such intercept activities will be given special 

handling in accordance with current directives.

5. Monitoring of friendly radio traffic to detect violations of signal security, and the initiation of 

correct measures, is a function of the Signal Intelligence Service (par 6f, FM 11-35). The activities of the 

Appendix F

Headquarters

European Theater of Operations

United States Army
Page 232

various signal intelligence services in this respect will be coordinated by directives issued by the Chief 

Signal Officer, this headquarters. This does not preclude the use of any regularly authorized T/BA 

equipment, or personnel, by any unit to monitor its own networks as an additional supervisory 

measure.

6. Personnel assigned to signal intelligence or signal radio intelligence units or detachments have 

been specifically trained for the duties to which they are assigned. This training includes the imparting 

of considerable secret information to assist in the accomplishment of their mission. Due to this 

specialized training, and for security reasons, such personnel will not be reassigned without prior 

reference to the Chief Signal Officer, this headquarters, and without specific approval of the Theater 

Commander. Under no conditions will such personnel be reassigned to jobs in which there is any 

possibility of capture. Unit commanders desiring reassignment of signal intelligence or signal radio 

intelligence personnel will submit requests, through channels, to this headquarters and will clearly 

indicate the reasons for requesting reassignment.

7. It is desired that the contents of this directive be published to such of your subordinate units as 

may be concerned.

By command of General Eisenhower:

R. B. LOVETT

Brigadier General, USA

Adjutant General

DISTRIBUTION:

Each addressee (2)

Deputy Supreme Comdr, Air Staff,

 Supreme Hq, AEF (2)

Supreme Hq, AEF (2)

Each Air Force (2)

G1 (1)

G-2 (1)

G-3 (OPO-AGH) (1) 

AAO (1)

C/Sig 0 (SID) (50) 

AG Mil Pers (1) 

AG ReInforcement (1) 

AG Opns (1) 

AG Records (1 )
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Op-20-G/jac October 1, 1942

MEMORANDUM FOR OP-20:

Subject: Collaboration of U.S. and British Radio Intelligence Organizations on Japanese 

 and German Projects.

1. After thorough discussion of U.S. and British radio intelligence problems in the Pacific and in the 

Atlantic, Commander Travis, R.N., has made the following proposals which, I understand, have the 

approval of the Admiralty:

Japanese 

(a) The British to abandon naval cryptanalysis at Kilindini and retain there only an exploitation 

unit which will read traffic from recoveries supplied by other units, and supply to these other units any 

code or other recoveries obtained in the course of this reading.

(b) The British to disband the British-Australian naval unit at Melbourne and turn over to the 

U.S. unit there such personnel as the U.S. may desire, except Commander Nave, who is to be recalled. 

Requests by the U.S. for any particular individuals from Kilindini or Melbourne will be entertained by 

the British. The future status of the diplomatic party at Melbourne will depend upon wishes of the 

Australian Government and the senior naval and military authorities in that area which the Admiralty 

will ascertain.

(c) Upon execution of the foregoing, OPNAV to assume responsibility for passing naval recoveries and pertinent naval information to the Admiralty (G.C.& C.S.) for transmittal to C.inC. Eastern 

Fleet and Kilindini.

(d) Pursuant to (c) above, OPNAV to pass to the Admiralty (G.C. & C.S.) (1) radio intelligence 

from Japanese naval communications, indicating major strategic moves in any area and any details 

bearing upon operations in the Indian Ocean Area; (2) all Japanese naval code and cipher key recoveries.

(e) In addition to the foregoing, OPNAV to pass to G.C. & C.S., by pouch, as much Japanese 

intercepted raw naval traffic as practicable.

German 

(a) The British to provide technical assistance, if desired, in the development of analytical 

machinery required.

(b) The British agree in principle to full collaboration upon the German submarine and naval 

cryptanalysis problems, including exchange of intercepted traffic, keys, menus, cribs, and such other 

pertinent technical information as may be necessary.

Appendix G

U. S. Navy Department Agreement with the Admiralty
Page 234

Miscellaneous 

(a) The U.S. to undertake certain work on Italian naval systems; traffic, and such pertinent information as may be available to be supplied by the British.

(b) The British to obtain certain items of special analytical equipment developed by the U.S.

(c) The British to send certain technical personnel to OP-20-G to obtain information concerning new U.S. high-speed analytical equipment and the technique employed in certain phases of U.S. 

work.

2. The result of the foregoing will be that the British will withdraw from active work in the Pacific 

Area and leave to the U.S. the general direction and control of the combined effort against Japanese. 

They plan to maintain a research unit at G.C. & C.S. so as not to lose touch with the Japanese problem. 

They have acceded to U.S. desires with regard to work on the German submarine and naval problem 

but, in effect, will be the coordinating head in the Atlantic theatre as the U.S. will be in the Pacific.

3. The foregoing appears to be a logical set-up for the reason that the U.S. has the primary facilities 

and experience in the Pacific, and the traffic is much more accessible to the U.S. there; whereas, the 

British occupy the corresponding position in the Atlantic. While providing for a logical division of labor 

on this basis, this plan will, at the same time, provide the necessary backup for the safety of each party 

concerned.

4. The primary concern of the British over U.S. entry into the German field is on the question of 

security. The British treat German material on a far higher plane than any other which they handle. 

The situation with regard to German communications is quite different from that which is found in the 

Japanese, in that the ramifications of the major system used are very great, and any disclosures which 

are made will affect the entire effort in every field. It must be realized that since the outbreak of war 

the British success has literally been their life blood. Before going into the work, the U.S. must be 

prepared to accept their standards of security and do everything within its power to insure compliance 

therewith. Not only will the safety of the British empire be at stake but, as U.S. efforts in the European 

theatre become more active, the future of the U.S. may also be at stake.

5. In concluding the discussions it was pointed out to Commander Travis that any agreement made 

by the U.S. must be subject to such change as circumstances and developments require in the interest 

of national safety.

Respectfully,

/s/J. N. Wenger

10/1/42

Seen by D. N. C.

CAPT. Zacharias

ADM Cooke

 /s/J. N. W.

Approved and accepted

by D. N. C., CAPT. Holden 10/2/42
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23 May 1945

MEMORANDUM FOR COLONEL TAYLOR:

Subject: Report of Lt. Col. Murnane and Lt. Col. Orr on Use of Ultra at 12th Army Group

...3. At 12th Army Group, a special section was established for the handling of Ultra which was 

designated as the Estimates and Appreciations Group with a staff consisting of the attached officers 

and one senior member of the G-2 Section. The function of this group was to collate Ultra intelligence 

with intelligence from all other sources and to formulate, under the direction of the A.C. of S., G-2, 

estimates of the enemy situation and capabilities. The specific duties of the attached officers were to 

receive and register all Ultra messages from the SLU, post a current situation map, conduct two daily 

briefings for the Commanding General and other staff members, dispatch signals to subordinate 

armies, record all order of battle information, and maintain a topical reference index of more generalized Ultra information.

4. The functions of the Estimates and Appreciations Group were performed entirely within one 

room to which admittance was limited to indoctrinated personnel only. Such personnel had full access 

to all Ultra messages which were divided into folders according to content, such as Order of Battle, 

Supply, Operations and Intentions, Air, Enemy Estimates of Allied Intentions, etc. Removal of Ultra 

material from this room was strictly forbidden. A large scale map of the western front was maintained 

showing the complete Allied and enemy situation. The posting of this map was the responsibility of the 

attached officers. Because of its constant use by the A. C. of S., G-2, it was found desirable to locate this 

room adjoining his office. Under strict field conditions a special trailer was used for Ultra material and 

served in substantially the same manner as the above described room.

5. In the early phases of the campaign, one daily briefing on Ultra was conducted at which the 

Commanding General, his staff, and all other indoctrinated personnel were briefed in the Ultra room 

or trailer. However, it became apparent that the presence of a large group at this briefing tended to 

limit discussion by the Commanding General and his staff. To alleviate this problem, the system of 

conducting two daily briefings was adopted, the first for general officers only, and the second for all 

other indoctrinated personnel.

Appendix H

Part 1

American Embassy

Office of the Military Attaché

1, Grosvenor Square, W. 1,

London, England
Page 236

6. The General Officer’s briefing was conducted at 0945 hours, immediately following the G-2, G-3 

open briefing in the War Room, and was regularly attended by the following officers of 12th Army 

Group:

 General Bradley, CG

Major General Allen, C of S

Brigadier General O'Hare, G-1

Brigadier General Sibert, G-2

Brigadier General Kibler, G-3

Brigadier General Moses, G-4

Colonel Standish, Chief Intelligence Branch

 and of the 9th Air Force:

 Lieutenant General Vandenberg, CG

Brigadier General Lee, Deputy to CG for Ops.

Colonel Hughes, Director of Intelligence

The presentation of Ultra material was made in the Ultra room by the attached officers and was based 

on information received during the previous twenty-four-hour period. Upon conclusion of the presentation the A.C. of S., G-2 or the Chief of Intelligence Branch highlighted enemy intentions or capabilities 

as revealed by Ultra or open sources, such as tactical reconnaissance, P/W interrogation, etc. Upon 

conclusion of the presentation a discussion customarily followed in which the CG expressed his views 

on the current situation and reviewed operational plans under consideration, and invited discussion 

from his staff. The briefing normally covered all pertinent information on the GAF, its operations and 

intentions, and in the discussion following, General Vandenberg and his staff consulted with General 

Bradley on plans for tactical air support, or target programs such as lines of interdiction or enemy supply installations. Thereupon the needs of the ground forces were announced and appropriate air 

support or tactical bombing agreed upon.

7. The second briefing conducted at 1130 hours for all other indoctrinated personnel was less 

formal and more in the nature of a discussion or forum. Present at this briefing were: G-2 air, G-3 air, 

Deputy G-2, Deputy G-3, Chief Order of Battle Branch, Chief Terrain and Defense Branch, Chief Supply and Transportation Branch, personnel from G-3 Special Plans (Cover plan), and the signal 

intelligence officer. Ultra information was again presented by the attached officers, and comments 

invited as to interpretation placed on particular messages. On this occasion the chief of the Intelligence 

Branch reviewed the current G-2 estimate of the enemy situation and capabilities and invited 

comments from the branch chiefs on matters pertaining to their special interests.

8. In addition to attending the 1130 briefing the branch chiefs frequently visited the room throughout the day to review the messages in detail and to discuss with the Ultra staff messages of special 

interest. For example, the Chief of the Order of Battle Branch daily reviewed all messages and 

discussed with the Ultra staff new open identifications, P/W interrogation, troop movements, strengths 

of units, etc. Thus the chief, OB was in a position to guide the interpretation of open sources, control 

of the tenor of periodic intelligence summaries, and safeguard against dissemination of reports contrary to Ultra information. His close association with both sources permitted prompt blending of Ultra 
Page 237

into open intelligence as soon as sufficient evidence from non-Ultra sources justified release of Ultra. 

Conversely, the Ultra staff was in constant touch with all relevant open sources.

9. Within the Ultra room a special map was posted portraying the disposition of Allied forces as 

known to the enemy and revealed by Ultra in enemy estimates of Allied dispositions and intentions. 

This map was posted by officers of G-3 Special Plans. In addition to aiding them in formulating cover 

plans it provided a ready means of determining which Allied units had been identified by the enemy 

and consequently which units could be released to the press.

10. All order of battle information as revealed by Ultra was recorded under appropriate unit headings such as Army Group, Army, Corps, Division or smaller units. This index was absolutely essential 

in correctly evaluating the Ultra material, in preparation of estimates, in servicing the army commands, and as a ready reference for the chief of the OB Branch. In addition to this, a topical index was 

maintained of such other messages as appeared to require subsequent reference.

11. Another principal function of the attached officers was to provide regular signals to the Armies 

of such information received at Army Group which had not been directly dispatched to Armies. Normally, routing from War Station provided armies with the essential information in their spheres of 

interest; but, it is highly desirable that Army Group send signals to Armies containing extracts from 

various messages of general interest not bearing directly on a given army front. The volume of traffic 

to Armies from Army Group must be tempered by the capacity of the signals unit at Army level, otherwise the Army channels might easily become overtaxed with this material to the impairment of the flow 

of current information from War Station.

12. Weekly Ultra summaries were dispatched to the Armies over the SLU link expressing the current opinion of G-2 based on Ultra and open sources. The summaries were prepared by the Chief of the 

Intelligence Branch with the assistance of the attached officers in formulating the views contained 

therein.

13. With the exception of one or two isolated instances of minor security violations which in no way 

impaired the source, the security record at 12th Army Group was excellent. This, in a large measure, 

can be attributed to the method employed for handling Ultra. As previously stated, all Ultra material 

was confined to a single room or trailer where all briefings, conferences involving Ultra, or preparation 

of Ultra documents were accomplished, an indoctrinated officer was present in this room 24 hours a 

day. As messages were received they were listed by date and number in a register and fastened in the 

appropriate folder according to subject matter, where it remained for forty-eight hours. After a 

message had remained in a folder for 48 hours it was removed, checked against the register, and 

burned. By this means an accurate check was made on the receipt and destruction of each individual 

message. The personnel of the 12th Army Group were keenly sensitive to the security necessary for 

safeguarding this source. The prevalence of this attitude is the best safeguard against security violations and undoubtedly accounts for the record achieved.
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Page 239

21 May 1945

MEMORANDUM FOR COLONEL TAYLOR

Subject: Report on Ultra Intelligence at First U.S. Army

1. The undersigned reported to the C.G. of First U.S. Army at Bristol, England on 15 May 1944 and 

remained with the command as a member of the G-2 Section during the campaigns of Normandy, 

North France and Germany. D.S. terminated at Weimar on 11 May 1945, when the undersigned returned to his parent organization. This report is based upon his experiences during that period...

....4. Preinvasion. Most of the information which formed the intelligence for Operation “Neptune” was gathered and evaluated by the British. It involved terrain, hydrography and enemy defenses. 

In order of battle alone Ultra made possible correct evaluation of agents’ reports. We knew what we 

would meet and that our cover plan was working.

The main job at Army level was, therefore, (1) organizing and training for the campaign, (2) dissemination of intelligence and advising the commander and the troops by estimates of the enemy’s 

capabilities to react to our attack.

In connection with the latter, much work went into the preparation of charts showing just when 

and where and in what strength the known enemy armored divisions could, under the most favorable 

conditions, launch coordinated and piecemeal attacks against our beachheads. Fortunately, the predictions proved false but the charts had sufficient verisimilitude to make the writer believe his chances of 

surviving the invasion were about nil.

5. The Battle of Normandy. (6 June to 24 July 1944). Our operations were in two phases; first, 

to land and secure the beachhead and secondly to expand it to support the build-up of troops, supplies 

and air facilities for the break-out, which marked the beginning of the Battle of Northern France. 

Intelligence for the landing was, in effect, done before D-Day. In an amphibious operation control 

must be decentralized so far that all the commander can do is to start it in motion and hope for the 

best. While it had originally been estimated that certainly piecemeal and possibly coordinated attacks 

to destroy the beachhead could be made late on D-Day by two enemy armored divisions, and by an infantry and four armored divisions on D plus 6, with corresponding variations between these dates, 

actually by D plus 9 (15 June 1944) only fourteen nominal divisions were in the “Neptune” area. No 

Appendix H

Part 2

American Embassy

Office of the Military Attaché

1, Grosvenor Square, W.1,

London, England
Page 240

piecemeal or coordinated counterattack had materialized but it was estimated that ten more divisions 

could arrive by 22 June 1944.

What had happened was that (a) air cooperation had restricted large scale enemy movement to 

darkness, (b) the airborne troops had ruptured his chain of command, and (c) the courage and dash of 

our assault troops prevented the enemy from “getting set” and compelled a piecemeal commitment of 

his reserves as they arrived on the battle field.

Therefore, the essentials of intelligence were (1) to watch for the movement of the expected divisions, (2) explain the untidy enemy O.B. map based on identifications resulting from piecemeal 

commitment, and (3) explain the evolution of the chain of command into an orderly pattern. These 

tasks remained the same throughout the battle but the details varied with each phase. They were directed to the sole question when and where would the enemy counterattack.

By 19 June 1944, the Cotentin Peninsula was cut. The immediate problem was, therefore, the defense plans for Cherbourg and the extent of its supplies. There were not many Allied divisions ashore 

then, and the balance between the troops needed for a quick reduction of the port and those to hold the 

lines against the expected German counterattack was as delicate as it was important.

By 29 June Cherbourg was ours and the peninsula was cleared. We had a major, though damaged, 

port and our beachhead was reasonably secure. The occasion was signalized by your reporter changing 

his socks, shirt and underclothes for the first time since 6 June. The first phase had ended.

The second phase is associated with “hedgerow” fighting. Opposing First Army was Seventh German Army with LXXXIV Corps of five divisions and II Para Corps of four divisions. In the rear areas 

were known to be four infantry and one armored division, while Pz Gruppe West, with II SS Pz Corps 

and 9 and 10 SS Pz Divs, was known to be moving west and was expected momentarily against the British on our left. Still remaining in Brittany were three divisions. First German Army in SW France could 

spare the 11 Pz Div and Nineteenth Army on the Mediterranean, the 9 Pz Div, but neither was believed 

capable of sending up more infantry divisions. Only in the Pas de Calais, Holland and Germany itself 

were reserves available.

Here, then, was the issue. While we were slowly and gradually fighting our way out of the “Bocage” 

into terrain favorable for armor, would the enemy bring in enough forces either successfully to rope off 

the beachhead or even to mount a counterattack, thus setting us back indefinitely, if not destroying us? 

Equally effective were two quite different factors. First was [the deception] Operation “Fortitude,” 

and the second was the American divisions who got their battle training and the American soldiers who 

died in the hedgerows of Normandy. The G-2 estimate of 10 July 1944 said “No sooner do his reinforcements arrive than they are thrown into combat, not through choice but immediate necessity.” The 

search for information was obviously directed to points throwing light on the issue.

6. The Battle of Northern France. (25 July to 14 September 1944). After an intense bombardment by heavy bombers, on 25 July, VII Corps, with three divisions abreast, attacked in a SW direction 
Page 241

between St. Lo and Perriers. The purpose initially was to pocket the German LXXXIV Corps which was 

defending on the western portion of the Cotentin Peninsula. The larger mission was to destroy the German Armies west of the Seine and secure the “lodgement area.” The attack had been postponed several 

days on account of the weather and we had helplessly watched II Para and LXXXIV Corps get prepared for it by bringing in pz Lehr from the east, 5 Para Div from Brittany and pull 353 Division out 

of line into reserve.

By the 28th it was apparent that LXXXIV Corps was in pretty much of a rout. On that day, we spoke 

of the La See or the Selune Rivers as lines behind which the enemy would defend. On 1 August the general line, not connected with an obstacle, of Trouville-Falaise-Mortain-Rennes was suggested. Our 

armor had shaken loose.

It was obvious that the enemy needed two things: (1) an obstacle to get behind and (2) fresh forces. 

It was mobile warfare, and so our problem was to ascertain how the enemy would meet these two requirements and, of course, to watch above all things the flanks of our spearheads. For the first time, 

two other factors appeared: morale, for it was hoped that the July “putsch” would have repercussions 

among the troops, and secondly, supply, for fuel and ammunition are the critical items of mobile warfare.

Of obstacles, there were none short of a line through Dreux, Chartres and Orleans, with the flanks 

anchored on the Seine and the Loire. For troops there was, in whole or in part, the Fifteenth Army in 

the Pas de Calais. While “Fortitude” was still “selling,” its appeal had dropped off and five divisions 

came down between 25 July and 8 August. Therefore, the Germans took the very long chance of attempting to push us back into the beachhead by attacking from Mortain westward toward Avranche. 

With all the forces he could muster under XLVII Pz (2 Pz, 2 SS and 17 SS, Lehr and 116) he made the 

attempt between the 8-11 August, while LXXXIV Corps tried to extend and stabilize the line southward. The effort failed and the east flank of our spearhead was secure. The stage was set for the debacle 

which followed.

No useful purpose will be served by elaborating on the Argentan-Falaise Pocket, the fall of Paris 

and the Mons Pocket. They were great victories but credit for them must go to the commanders and 

the troops. Of the enemy it may be said, to quote from the After-Action Report (which I wrote, so it’s 

no plagiarism) that the weight and speed of our attacks were appreciated “too little and too late” and, 

therefore, the divisions the enemy sent to stop us only became engulfed in our offensive. It mattered 

not what we did, provided we did something. As was stated before, intelligence is unimportant when 

you are winning and even though we were reading the enemy’s mind, it mattered not for he did not 

have the means to carry out his intentions. The Battle of North France ended on 14 September when, 

reaching the Siegfried Line, we ran out of gas.

7. The Battle of Germany. (15 September 1944 to 9 May 1945). In the current perspective, the 

highwater mark of the campaign is the Ardennes offensive, for had it not occurred we might be still 

fighting on the Rhine River. I shall, therefore, divide it into three phases: first, events leading up to the 

Ardennes; second, the Ardennes offensive; and finally, its aftermath.
Page 242

By 15 September it was apparent that the enemy would attempt, at any rate, to defend the West 

Wall, using remnants of the battered divisions from France, L. of C. [line of communications] and administrative troops. For our part, the problem was to get up fuel, ammo, and supplies. It was not until 

early October that we were able to undertake even limited objective offensives to breach the West Wall, 

while the German had well used the time to set his own house in order. By the middle of October, we 

had expended our offensive powers and surrounded Aachen, but achieved no great breakthrough. After 

the fall of Aachen, the German remained on the passive defense on our front, but in later October he 

was capable of launching a medium scale diversionary attack on the exposed east flank of Second British Army NW of Venlo. The wave of optimism of September was gone; the seventy battalions that he 

combed out after the fall of France had made themselves felt. On 12 November, G-2 estimate said, in 

part, “It is now a race against time. Can the enemy complete his dispositions for his offensive prior to 

the launching of our attack? With the approach of winter in the east, it is believed the enemy will stake 

all on an offensive in the west.”

I have recited the events historically as being the easiest means of showing in what direction our intelligence efforts were bent. We reached the West Wall, optimistic but logistically broke. We watched 

the enemy recuperate at a slightly faster rate than we could get up our supplies. We watched the master hand of von Rundstedt deftly deploy his forces and his reserves, bringing up battalions from the 

replacment army, giving some ground on the south, but always keeping in balance.

On 16 November, First Army launched a large scale attack which it was hoped would carry through 

to the Rhine. The fighting that followed was probably as bitter, as long drawn out, and on as large a 

scale as has occurred in this war. On 10 December 1944, the perhaps too famous and certainly much 

discussed Estimate No. 37 was published. The real intent of it was to warn that, despite the fighting 

that had taken place during the previous three weeks, Sixth PZ Army west of the Rhine was uncommitted and, therefore, available for a counteroffensive. This counteroffensive, it predicted, would most 

probably occur after our major forces had crossed the Roor River. It is beyond the scope of this report 

to examine the validity of the “ex post facto” constructions placed on it, that it intended to warn against 

the large scale offensive that actually occurred.

That the Ardennes Offensive, which was very costly, could have been foreseen is submitted for the 

following reasons: (a) the enemy was defending on an artificial line with a major obstacle, the Rhine, 

astride his supply lines, (b) the German doctrine is an active defense, (c) the German situation, in the 

big picture, was so desperate that he could afford to take the longest chances and, (d) finally, the effect 

of our overwhelming air superiority was minimized by choosing a time when daylight was shortest, and 

the weather most likely to be bad. While the enemy had no cover plan to mislead us, his counterintelligence was superb and merits very careful study. Some clues came from open sources but were not 

heeded as no clue came from Ultra. Once it was appreciated that a real offensive with strategic objectives like Antwerp and Liege was under way, the tide swung precipitously from general optimism based 

on the long-term hopelessness of Germany's strategic position to calamity and woe, involving the imminent arrival of divisions believed to be in the East (as well as invented ones), and new secret 

weapons. The problem was to keep the record accurate and straight.
Page 243

The details of the offensive I need not go into. Suffice it to say that it was an unpleasant experience. 

I cannot pass without remarking on the superb courage and fortitude of the American soldier. Between 

19 December 1944 and 11 January, we published twenty-three G-2 estimates of the situation, the last 

one stating that the enemy’s offensive power on First Army’s front was spent and, in fact, he had barely 

sufficient divisions for a counterattacking reserve.

By the beginning of February, it was becoming more and more apparent that the enemy had shot 

his bolt. With a major disaster in the East and Southeast requiring the transfer there of 6 SS Pz Army, 

and with his reserves of manpower and his stocks of material gone, particularly his fuel, it was doubted 

if he could put up more, than a strained defense of the West Wall. 

With what little there was the enemy did a magnificent job of regrouping and regaining his balance, 

and his intelligence was aided by his excellent “Y.” However, while the plans were good, there was very 

little with which to execute them, and the enemy, in effect, wilted before the drives of all the Allied 

Armies in the West, and by the end of the first week of March his forces west of the Rhine were split 

into bridgeheads defending the critical crossings.

The Remagen Bridge (7 March 1945) was a piece of luck, to be sure, but it required a skillful and 

well-trained army to exploit it. That it was a matter of life and death to the enemy was self-evident and 

the intelligence effort was directed to the question of where, when and with what would he counterattack, and by what other means would he attempt to destroy it. For the remainder of the month our 

efforts were directed to expanding the bridgehead and to building up within it sufficient supplies to be 

able to exploit it.

The Ruhr Pocket was created 1 April and has been described by captured German generals as the 

greatest single defeat that the German Army has ever suffered. The burning question, of course, was to 

determine the when, where, and the with-what of the German plan to open it up. Had we actually 

known how many enemy troops (315,000 PW’s were taken) were contained in the pocket, we might 

well have left more troops to reduce it at the expense of the corps which turned east (about the middle 

of April) and started to work-over the Hartz Mountains.

With the Ruhr pocket closed, the end was obvious. River lines there were to the east, such as the 

Weser-Werra line, the Saale and the Elbe. But the German was then beaten. He was totally lacking the 

means of executing any plan.

The end came as an anti-climax. We (First Army) had lost our three corps, and were in the process 

of turning over the army and service troops, preparatory to return to the U.S.A. for probable employment in the Orient. The Isum of 062400 B May 1945 read: “For the first time in eleven months there 

is no contact with the enemy. The victory which was won on Omaha and Utah Beaches reached its climax. Today belongs to the men of this Army who fought and conquered the enemy from Normandy to 

the Elbe. There is no enemy situation to report, for there is no longer an enemy to defeat.”

8. In the three preceding sections I have sketched at strategic level the actions of First U.S. Army 

and the German reactions. It was required because intelligence is important only as it bears on the 
Page 244

success of our operations. Without this history, it would be impossible to explain or determine the use 

and effect of Ultra, for the test is: did the signals sent out at the time resolve or confuse the issues as 

we saw them?

The most important question in combat intelligence is where. In the main, Ultra furnished the answer. Certainly it was invaluable in separating the true from the false out of all the information that 

came in. Without it, we would have been pretty much in the dark and our actions might have been determined by the caution or aggressiveness of the commander. But to have relied on it alone would have 

been foolhardy, not only because by blending the intelligence from all agencies can the real picture be 

obtained, but also because at Army level the tactical is frequently more important than the strategic, 

which is the proper field of Ultra. Therefore, the answer to . . . [what] effect ... Ultra had on the operations of First U.S. Army is to be found in the history of Ultra, rather than in this report. In the main, 

Ultra did resolve the issues.

9. The first objective of my job, as I see it now, was to be able to present to the commander a clear 

and accurate picture of the enemy situation as it affected his command. It is therefore, a matter of record keeping and presentation. But both the G-2 and I “grew with the job” and the record of my trials 

may prove helpful to someone else at some other time.

Initially, the G-2 presented the signals, unsorted, unedited and without comment, to the C.G. and 

the CIS twice daily. Later I was permitted to see them after everyone else. By keeping records and by 

plotting a map, I was able to show the G-2 that a good deal of valuable intelligence had been overlooked. Gradually I was allowed first to sort and then to edit and by the beginning of the Ardennes 

offensive, the material was assembled and written up twice daily with a summary of whether the situation had changed and why. This write-up was then read to the C.G. by the G-2 and, of course, the maps 

in the general’s office were kept posted. No briefing was ever done directly by the Ultra representative.

The equally important objective of informing the troops was accomplished by G-2 estimates of the 

situation. As the situation changed, I would write “appreciations” based on Ultra for the G-2 and, as 

time passed and the information was covered by other sources, the intelligence would be put out in the 

open estimate.

At tactical level a more difficult situation arises as the desire to take immediate action on a target 

disclosed by source can so easily result in a breach of security. This tendency increased toward the end, 

possibly due to the indifference of the commander to intelligence generally. It was also found to be very 

dangerous even to hint to the corps to expect enemy action, where the only knowledge of it came from 

Ultra, for the Corps’ G-2s [were]... insistent on the source of the information.

A further difficulty is the tendency to highlight the dramatic, particularly as, when there is no real 

change in the situation, the G-2 feels he must say something at the daily conference. Another was the 

fact that other readers, for lack of something better to do, would frequently grab a seemingly important signal and rush it to the G-2 without giving it the thought and study it required. Ultra is something 

which must be “read, marked, learned and inwardly digested.” If a signal is not understandable, it must 
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not be dismissed as unimportant. Ultra must be presented not for what it says but for what it means to 

the command which receives it.

10. Security. The security of Ultra at First U.S. Army was not good. Initially there was much curiosity as to the nature of SLUs work and my connection with it, particularly as two of the assigned 

members of the G-2 Section had the inevitable curiosity of all professional newspapermen. It is submitted that the situation created by having an SLU present in the section should be faced, and it be 

explained that its work is secret, rather than to pretend that it is not there...

11. Conclusion. Throughout the job I have felt great discomfort over the fact that I was serving 

two masters: one was the C.G. of First U.S. Army through his G-2 by reason of my detached service 

there, and the other was my parent organization. An example of this difficulty is clearly presented in 

the problem of security. Is Ultra given to the command subject to the rules and regulations;... or is it 

the responsibility of the command of which I am a part to see that the rules are obeyed; am I not part 

of the command and Special Branch’s watchdog?

Again, is it my responsibility and duty to see that the best use is being made of Ultra and that the 

greatest advantage is being taken of the intelligence derived from it. When I raised this point, I was told 

I was criticizing the command.

If I have learnt anything in the Army it is that the first duty of a superior (whether it be a supreme 

commander or a squad leader) to a subordinate is to give clear orders. When all the major circumstances cannot be foreseen, then the duty of the superior is to find them out and make his will known, 

just as it is ultimately, by imposing his will on the enemy, that the commander defeats him.

 ADOLPH G. ROSENGARTEN, JR.

 Lieutentant Colonel, Info
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Page 247

28 May 1945

MEMORANDUM FOR COLONEL TAYLOR

Subject: Ultra and the Third Army

1. Ultra Specialists

Major (later Lt. Col.) Melvin C. Helfers was Ultra specialist with 3rd Army from 6 June 1944 until 

he was hospitalized about 12 March 1945.

Major Warrack Wallace assisted Lt. Col. Helfers for a month in 1944, leaving the UK for France on 

16 June and returning to the UK on 20 September.

Lt. Col. Samuel M. Orr, Jr., of the Ultra staff at 12th U.S. Army Group served as temporary replacement for Lt. Col. Helfers when the latter was hospitalized, and remained there for about a week until 

relieved by the undersigned.

The undersigned officer (Capt. George C. Church) reported to 3rd Army on 18 March and remained 

there until the SLU received orders to close on 15 May 1945.

2. Officers in Ultra Picture

General George S. Patton, Jr., Commanding General

Major General Hobart R. Gay, Chief of Staff

Colonel Paul D. Harkens, Deputy Chief of Staff

Brigadier General Halley G. Maddox, G-3

Colonel Oscar W. Koch, G-2

Colonel Harold M. Forde, G-2 Executive Officer

Colonel Robert S. Allen, Assistant G-2

Major Charles W. Flint, Signals Security Officer

3. Duties of Ultra Specialist

The interpretation of Ultra to the staff officers as listed above involved the keeping of a situation 

map combining Ultra and open sources, a regular morning briefing of these officers, and conferences 

with Colonel Koch and other staff officers at irregular times with the arrival of operationally important items of Ultra. 

Appendix H

Part 3

American Embassy

Office of the Military Attaché

1, Grosvenor Square, W.1,

London, England
Page 248

The Ultra briefing took place every morning (except when cancelled for lack of material) at approximately 0900 hours, immediately preceding the open briefing in the War Room. The special briefing 

was held either in General Gay’s or Colonel Harkens’ office, and was regularly attended by all officers 

in the Ultra picture, with the exception of Colonel Forde, who never attended during the term of duty 

of the undersigned, and Major Flint, whose interest was limited to items involving Signals Security.

Close contact was kept with the G-2 situation room, and situation reports from open sources were 

constantly checked for supporting and expanding information.

Since the Special Briefing was not held in the office of the Ultra specialist, the situation map was 

necessarily portable and was kept by the undersigned on a large folding map board.

Officer billets for 3rd Army HQ staff were often located at a considerable distance from the HQ. To 

facilitate the handling of high priority items arriving during the night and the preparation of the map 

with current items for the special briefing, the undersigned found it necessary to live in the office, 

rather than in the billet provided.

The special briefing was also always attended either by General Weyland and/or Colonel Brown of 

XIX TAC. It had been customary during the campaign for Major Grove (Ultra recipient at XIX TAC) to 

give occasional talks on the GAF at the special briefing, in addition to his work at his own command. 

During these last two months, however, the XIX TAC HQ was usually located at some distance from 

the 3rd Army, and it was possible only once for him to attend.

4. Role of Ultra in 3rd Army

(a) General: The undersigned arrived at the 3rd Army when the liquidation of the German 

forces west of the Rhine had already reached an advanced stage. The Rhine was crossed within a week, 

and at no time during these last two months of the war was the 3rd Army front stabilized for more than 

a few days. The German generals were conducting a war with means that were hopelessly inadequate, 

and many of their orders were only in effect “for the record.” Orders for the preparation of defense lines 

were usually outdated by the time they reached us, with the line already pierced at many points or completely overrun. Orders for the commitment of new divisions were shorn of their normal significance 

because the divisions at best were ill provided with heavy weapons, and the piecemeal employment of 

units as they arrived at various points of the rapidly moving front led to a speedy frittering away of such 

new divisions as actually did arrive. German order of battle had become a tangle of miscellaneous replacement and training units, whose command relationships were no sooner established than they 

were destroyed by our farther advances. German resistance had degenerated into sporadic, if fanatic, 

defense of individual towns or strong points, and such counterattacks as were actually mounted never 

assumed serious proportions.

Under these conditions, the value of Ultra (as of intelligence generally) had undoubtedly suffered 

a decline from the time when the enemy had sufficient forces at his disposal to make his intentions of 

decisive importance.
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During this period, however, Ultra continued to be of great value in foreshadowing or confirming 

the identifications made by actual contact and in providing an insight into the intentions and operations of the German commanders.

During the previous period (from D-Day until his own term of duty) the undersigned can give only 

general impressions based on conversations with Lt. Col. Helfers, which were necessarily very limited 

because they were held in the ward room of the hospital at Luxembourg, and discussions with members of SLU. It appears that initially no special briefing was held, and that Ultra information was passed 

only to the G-2, orally or by written report. The German attack towards Avranches seems to have been 

the time when the value of Ultra became apparent and the custom of holding a special briefing each 

morning was instituted. Relations with members of the G-2 section not in the Ultra picture were also 

a problem at the start, but these straightened themselves out once the positions of the SLU and the 

Ultra recipient were thoroughly established with the Commanding General and his staff.

By the time the undersigned arrived at 3rd Army, these problems had all been smoothed out. There 

were no administrative difficulties, our position was accepted without question if not without curiosity, and all G-2 agencies including the situation room, the photo interpretation section, the order of 

battle section, and the prisoner of war section, were extremely cooperative in providing information 

without receiving anything in direct return.

(b) Detailed: The fact that the special briefing from Ultra each morning was attended and carefully followed by the Commanding General and his staff ensured that Ultra intelligence was fully 

considered in the operational plans of the 3rd Army. It is beside the point that German capabilities at 

the end were not of sufficient seriousness to cause any change in these plans.

There was only one considerable German counterattack on 3rd Army front during the undersigned 

officer’s term of duty. It occurred when the German 11th Army attempted to concentrate forces in the 

vicinity of Muehlhausen for a thrust to the southeast, at a time when the 3rd Army extended well to the 

east. Ultra provided valuable indications and identifications of this build-up, completing information 

from open sources. No change of 3rd Army plans was involved, since sufficient forces were available 

on the spot to cope with the threat. The Germans also planned a build-up for the Passau-Linz area, but 

this never fully developed owing to immobility of German formations and the complete collapse of German resistance.

One of the most valuable single contributions from Ultra during the two month period witnessed 

by the undersigned was provided during the closing days of the war, when we were notified by the 7th 

US Army that Army Group G had surrendered. The line specified in the surrender negotiations ran well 

up into Czechoslovakia, and therefore seemed to indicate that a considerable sector of the 3rd Army 

front was concerned in the surrender. From Ultra information, however, we were able to determine 

that Army Group G included only the German 19th and 1st Armies, that the right boundary of the German 1st Army lay in the area just east of Linz, and that the line specified in the surrender negotiations 

was apparently the boundary reported in Ultra between C-in-C West and Army Group South, rather 

than an Army Group G boundary. We therefore concluded that the surrender affected only a small sector of our front, which proved to be the case.
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Operational aspects of Ultra were fully considered. The same cannot, however, be said for the order 

of battle information provided by Ultra. Most of the detailed work on German order of battle was done 

by a Captain Gerber who headed the order of battle team at 3rd U.S. Army. Ultra was not available to 

Captain Gerber. The issue of his indoctrination was raised with Colonel Koch by the undersigned, as it 

had been by Lt. Col. Helfers and Lt. Col. Orr, but Col. Koch felt that it was inadvisable and insecure to 

increase the list of those in the Ultra picture, and that our information should be reserved for use as a 

check on information produced and compiled exclusively from open sources. The situation in this respect must have varied at different headquarters, depending on the officers who produced the detailed 

analyses of German OlE, but it seems clear that if any considerable use is to be made of Ultra O/B at 

Army level (even though only as a guide and check), the officer producing the detailed analyses of O/B 

should be in the Ultra picture.

There was no real necessity for the indoctrination of Col. Forde, the G-2 Executive Officer, whose 

activities were almost exclusively administrative and who never attended the special briefings.

5. Security

Physical security at 3rd Army was satisfactory for the period during which the undersigned was on 

duty there. The SLU was invariably provided with two office rooms, one for the WT section and one for 

the decyphering and encyphering, and if there was no lock on the door of the latter, it was fitted with 

hasp and padlock. The Ultra specialist was assigned to a separate office near the G-2, was provided with 

a safe, and the map kept from Ultra sources was fitted with hasp and padlock. Ultra papers were handled very carefully by the entire staff and no reports based on Ultra were retained by anyone other than 

SLU or the Ultra recipient for more than a few hours.

Material received by the undersigned called in few cases for any direct action. During the German 

build-up in the Muehlhausen area already referred to, Colonel Allen occasionally talked in general 

terms to the G-2 of the US Corps concerned, and was able to base his interest in the area on information provided by open sources. In one instance, during the Battle of France, there had been some 

indiscretion. On that occasion, a warning of German air attack on the HQ area provided by Ultra was 

passed on to AA and other units without sufficient cover.

One serious instance involving Ultra security arose while the undersigned was with 3rd Army. Col. 

Allen was captured by the enemy on 7 April, while on a mission which involved the investigation of captured German installations. The circumstances were not entirely clear. In the opinion of the 

undersigned, the episode resulted from a succession of slight errors in judgment which added up to a 

tragedy involving loss of life and limb. The mission originally assigned to Colonel Allen, while fairly far 

forward, was in an area behind our lines and the mission was not in itself dangerous. Colonel Allen 

after completing this mission seems to have entrusted himself and his party to another officer who was 

presumably familiar with the situation, and this officer led the entire group further forward than was 

safe. It is, however, certain that the security of Ultra was preserved, since Col. Allen was safely installed 

in a hospital located immediately in the path of our advance and, with the cooperation of a helpful Austrian doctor, was held there until the arrival of our troops. He was never subjected to interrogation.
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In general, all officers in the Ultra picture at 3rd Army were conscious of their responsibilities in 

connection with security. General Patton expressed his complete agreement with the reasons underlining the need for Ultra security, as set forth in the memorandum circulated by Group Captain 

Winterbotham.

6. Summary

The undersigned officer received complete cooperation and every consideration while on duty at 

the 3rd Army, both from those in the Ultra picture and others with whom daily contact was necessary. 

Material presented at the briefing was followed with interest and appreciation, and as indicated above, 

the only respect in which improvement could have been desired was in the greater use of order of battle information.

 GEORGE C. CHURCH

 Captain, CAC
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27 May 1945

MEMORANDUM FOR COLONEL TAYLOR

Subject: Use of Ultra by Ninth U.S. Army 

....2. Method of Using Ultra. 

Within the G-2 Section, Ninth Army, the undersigned was known as SLU Liaison Officer. At all 

times he maintained a separate office, entrance to which was restricted to indoctrinated personnel. The 

method of operation was as follows:

a. SLU deliveries were made four times daily, at approximately 0730, 1030, 1630 and 2230. At 

all times during operations, ZZZZ and ZZZZZ signals were delivered as soon as ready. In addition, during certain phases, the undersigned would instruct the SLU on certain types of messages (e.g., relating 

to a particular area) to be delivered immediately regardless of priority.

b. Briefing notes were prepared early in the morning and about 0845, the G-2 was briefed. The 

undersigned attended the open briefing at 0015, and thereafter went to the Commanding General’s office where he briefed the General and the indoctrinated members of his staff. A portable Ultra map was 

used for this purpose. Capt. Van Norden, Ultra recipient at XXIX Tactical Air Command, attended both 

briefings and briefed on the air situation at the latter.

c. During the remainder of the day, Ultra material was processed as received (i. e., read by the 

undersigned and appropriate notes made). In addition, the undersigned read all papers passing 

through the situation room (where a special box was maintained for him) and consulted with all members of the G-2 Section on the current situation.

d. The undersigned participated in the writing of all G-2 estimates and usually wrote or outlined the “Reserves” paragraph of the daily periodic.

e. Daily liaison was maintained with Capt. Van Norden of XXIX TAC, and more frequent meetings were held when the situation required. A number of visits were exchanged with the Ultra recipients 

at First U.S. Army and IX TAC, as well as with Twelfth and Twenty-First Army Groups, depending 

upon Ninth Army's subordination.

Appendix H

Part 4

American Embassy

Office of the Military Attaché

1, Grosvenor Square, W. 1,

London, England
Page 254

f. The undersigned also consulted daily with the “Y” group at Ninth Army (none of whom were 

indoctrinated) and the IPW personnel attached to the Army.

g. The objectives sought to be accomplished were as follows:

(1) To give the Commanding General and all indoctrinated members of the staff a clear picture 

of the open situation as it was affected by Ultra, together with a clear understanding of how each item 

could be used without loss of security.

(2) To give unindoctrinated members of the staff and the corps staffs as much of the situation 

in the light of Ultra as could be accomplished with appropriate cover, and to kill, so far as possible, 

open items of information known through the Ultra source to be in error. It was not always possible to 

“float” Ultra items, but it was possible to minimize errors from open sources.

3. Security.

The security consciousness of indoctrinated members of the command was in general good. This 

was due in part to the fact that following the first Ultra briefing, the Commanding General, of his own 

accord, made a brief talk emphasizing the need for such security in the strongest terms.

There were no breaches of security which the undersigned regarded as appropriate for reporting to 

Col. Taylor. On two or three occasions it was necessary to reprimand the G-2, (Col. Bixel) for indiscrete 

questions. It was also necessary on three occasions to speak in the strongest terms to Lt. Col. Abbott 

(head of Operational Intelligence for the greater part of the time) because of his attempts to include 

Ultra material in estimates without appropriate cover. In no case were these items seen by unauthorized persons, and the talks ultimately accomplished their purpose. Each incident was fully discussed 

with Capt. Vineyard, who commanded the SLU unit at Ninth Army.

4. Factors Found to be Helpful.

Ninth Army went into the field with a G-2 Section which had had no prior operational experience. 

In addition, there were personnel difficulties within the organization that led to inefficiency. These 

were solved in part, as late as 23 February 1945, by the relief and replacement of the G-2. In the various situations arising from these facts, the small degree of independence retained by the undersigned 

by reason of the fact that he was on DS and not assigned was invaluable. This status was also valuable 

in dealing with security problems. It is doubted whether an assigned officer could adequately handle 

such problems.

The unfailing accuracy and helpfulness of the staff at Bletchley Park was of immeasurable value in 

the field, since it enabled the Ultra recipient to speak with confidence and authority. This was supplemented in practice by signals and personal conferences with indoctrinated personnel at Twelfth and 

Twenty-First Army Group (depending upon Ninth Army’s subordination) who were untiring in complying with requests and volunteering additional material. Thanks to this high degree of cooperation, 

the undersigned experienced no difficulty with the general principles of selection which denied certain 
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types of material to Armies. It is believed that in general, where such items were material to the mission of Ninth Army, they were passed on at the request of, or by, one of the Army Groups.

The training received at Bletchley Park and the experience gained from a visit to the Mediterranean 

Theater proved fully adequate.

5. Principal Difficulties and Recommendations.

The primary difficulty experienced in the field was in no way attributable to any deficiencies in the 

Ultra organization. In order to piece Ultra into the open picture, it is necessary to have a relatively accurate open picture. It was found that an inexperienced G-2 Section was unable to provide such a 

picture, and consequently it was necessary to build up the open picture from basic open sources, persuade the G-2 Section to recognize the validity of this open picture, and finally to float Ultra against 

this perspective.

It is relatively easy to keep indoctrinated personnel advised on the enemy situation as it appears 

from all sources, including Ultra. It is more difficult to accomplish the same end with respect to nonindoctrinated personnel at one’s own headquarters and still more difficult to do so with respect to 

Corps staffs. In order to accomplish the last, the Ultra recipient must establish his position within the 

G-2 Section so that he can (a) veto or amend incorrect passages in publications sent to Corps prepared 

by unindoctrinated members of the staff, and (b) publish appreciations or estimates to advise the 

Corps of the true picture, with appropriate cover. Forms of appreciations and periodic reports prescribed by American manuals are not as well adapted to this task as the more informal type of 

discussion used by the British. The task is basically simple: to review the enemy situation using all bits 

of open information known to be correct (from Ultra, or otherwise) and filling in bits of Ultra information by way of speculation or reasoning. At Ninth Army, experience gained from work with Twenty 

First Army Group led to the publication of a series of so-called “Notes on the Enemy” prepared by the 

Ultra recipient. These were published as annexes to Periodic Reports or as Spot Intelligence Reports, 

and by means of them the Corps were kept currently advised of the enemy situation, including such 

Ultra items as would be “floated” by this means. There is attached to the ribbon copy as an example the 

series of these “Notes” published in this manner by Ninth U.S. Army during preparations for the Rhine 

crossing and the advance toward Berlin 

6. Conclusion.

Ninth Army relied heavily upon Ultra intelligence, and, when the service was withdrawn, all indoctrinated personnel expressed complete confidence in the material and appreciation of its value to the 

Army's operations. Although there are details that can be improved, one may say that the Ultra organization as a whole was of material assistance to the Army throughout the period of its operation.

 LOFTUS E. BECKER

 Major, F.A.
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30 May 1945

MEMORANDUM FOR COLONEL TAYLOR

Subject: Ultra and Its Use by XIX TAC

The following is a report of this officer’s service as Ultra recipient with XIX TAC, from 16 June 1944 

to 16 May 1945.

1. Historical.

Upon completion of training at the Park the undersigned was assigned to XIX TAC and reported 

on 16 June 1944 to Col. Joseph Cella, A-2, at Aldermaston...

On 1 Aug 44, XIX TAC commenced active air operations in cooperation with 3rd Army. Shortly 

after this, demands on General Weyland’s time made it necessary to brief him periodically but not at a 

given hour daily. He continued to be kept up to date on Ultra, but gave added responsibility to his staff 

with regard to operational details. Col. Cella continued with his daily briefings and studies, and took 

whatever action was necessary as a result of Ultra information. Both continued to receive immediately 

any Ultra signal (and its interpretation by the writer) which had operational significance and where 

time was a factor.

At the time of the formation of the 1st Allied Airborne Army, Col. Cella left to become its director 

of intelligence, and was succeeded by Col. Charles Hallett as A-2 of XIX TAC. He was immediately indoctrinated and continued to receive Ultra in the same manner and made the same studies as Col. 

Cella. Shortly after that, his executive A-2, Lt. Col. Walter E. Bligh, was indoctrinated and was briefed 

with Col. Hallett. The last officer to be indoctrinated was Col. Roger E. Browne, Chief of Staff, at Etain 

in the latter part of October 1944. Indoctrination in the field was given either by Lt. Col. McKee, or the 

Senior SLU officer, and the writer.

The two A-2 officers continued to receive daily Ultra intelligence, and the General and his Chief of 

Staff, to receive periodic briefings, plus all Ultra intelligence of immediate operational significance. 

This service was continued until the writer left the Command on 16 May 1945.

2. Methods of Handling Ultra.

A. Service to Indoctrinated Officers.

Appendix H

Part 5

American Embassy

Office of the Military Attaché

1, Grosvenor Square, W. 1,

London, England
Page 258

At the beginning of service as Ultra recipient at XIX TAC the writer adopted a standard form of presentation in which the information was arranged under the following headings:

1. GAF Intentions

2. GAF Operations

3. Indications of GAF Capabilities

4. Damage Reports

5. Potential Targets

6. GAF Order of Battle and Changes

7. Special Information (Japanese Military Attaché reports when received, German appreciations of Allied activities, GAF reports and descriptions of new aircraft, compilations by higher 

commands, etc.)

8. Ground Force Information

This sequence was found satisfactory to all customers, and was continued, although the method of 

presentation varied with circumstances.

In the beginning, a written report, as above, was presented to General Weyland, preceded by a brief 

of one page, when possible, covering the significant information in any or all of the above categories.

This was accomplished by a portable map, and any questions developing from the information were 

answered. The same method was followed for Col. Cella.

After active air operations commenced and Gen. Weyland was briefed at irregular but frequent intervals, the briefing became more and more a verbal one, but the writer continued to make a written 

report, both because Col. Cella and Col. Hallett preferred it, and because the writer desired to be sure 

of including all items of significance in an overall briefing.

In addition to the daily reports, the writer offered, during the middle of the move across France, a 

resumé of Ultra information, showing the recent changes in the enemy picture, and concluding with an 

estimate of GAF capabilities.

This was well received, with a request that the same type of report be submitted periodically, at 

least as often as significant changes in the GAF situation occurred.

About the same time, a request from Gen. Patton’s Chief of Staff came through Lt. Col. Melvin Helfers, Ultra recipient at 3rd Army, that a verbal presentation of Ultra information on the GAF be given 

to Gen. Patton and his staff at the regular Ultra briefing, along the same lines as the written resume. 

This request was complied with, and was continued periodically whenever the 3rd Army and XIX TAC 

Headquarters were together. It was the custom of Gen. Weyland and Col. Browne to attend the regular morning Ultra briefing of Gen. Patton and his staff, given by Lt. Col. Helfers and his successor, Capt. 

Church, during these times. It should be stated here that both generals and staffs were extremely attentive listeners, and gave the most serious consideration to Ultra information. This interest was 

indicated by the concentration of attention during the briefing, as it was the rule to ask no questions 

during the verbal presentation, but afterward many intelligent questions were asked and opinions 
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requested, based on the material at hand. It afforded the writer the greatest satisfaction to observe the 

influence of source information on the conduct of operations.

B. Field Conditions Affecting Handling of Ultra.

During the summer campaign and until October, when the Command moved into buildings in 

Etain, the Headquarters was in the field, in tents. The writer was assigned a command post tent for 

working, and later it was used also as living quarters, largely to maintain security and facilitate delivery of signals at odd hours. Working space and facilities were at a premium under these conditions, 

making it necessary to prepare portable maps and other presentation aids that would be at the same 

time effective and secure. During these times both generals and the A-2 were briefed in the privacy of 

their office vans. Supplies were not plentiful, and it was necessary to make use of expedients which fell 

short of being completely satisfactory to the writer.

When the command moved into buildings, this recipient was assigned an office which could be securely locked, and from then on much better presentations could be made. A permanent situation map, 

order of battle charts and maps, potential targets charts, and other displays were set up. These visual 

aids were effective in building up intelligence from Ultra signals. It then became the habit of the indoctrinated officers to come to these offices, and a much clearer picture could be given.

Under these conditions the daily written report was no longer necessary, and the signals were divided into the categories, and in the same sequence as before mentioned. Interpretive comments were 

written on the signals themselves.

It became the habit of Col. Hallett in particular to come in daily, and digest the information, with 

the maps and charts before him, prior to the staff conference, when operational plans were laid. At all 

times, signals having possible immediate operational significance were brought to all of the indoctrinated officers available as soon as they were received; most often to Col. Hallett, who was responsible 

for either tying in, or developing Ultra intelligence into open source intelligence.

As to important messages received at night, a working procedure with Gen. Weyland was agreed on 

at the beginning. Gen. Weyland stated that he wanted to be awakened at once for any information that 

he could DO something about, and it was left to the writer's judgment and experience.

It was the same for Col. Hallett, and the procedure was satisfactory and became standard.

C. SLU-Recipient Procedure.

The XIX TAC used the 3rd Army SLU as long as the two headquarters were together. Depending 

on varying conditions, receipts of signals averaged twice daily, with high priority messages being delivered as received. With the breakthrough from St. Lo, 3rd Army HQ, and its SLU moved ahead to 

maintain communications with its forward elements, and XIX T AC HQ was forced to separate from 

them for the same reason; fighter groups could not have advance fields prepared as fast as the army 

moved forward, and there was the same necessity for maintaining communications with them. Therefore it was necessary for the writer to go by road to the nearest SLU. During this period the writer was 

serviced by various other SLU’s, those with IX TAC, IX Air Force, 12th Army Group. For one period, 
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when XIX TAC HQ was in the Foret de Marchenoir south of Chateaudun, the nearest SLU was at Versailles. The writer moved from the HQ to Versailles where he could prepare the information, and made 

a daily trip of 96 miles, and return, to present the Ultra picture.

This necessitated 8 hours on the road, in addition to a full-time period of preparing and interpreting Ultra receipts. Use of Ultra information under these conditions was limited.

When the Command rejoined the 3rd Army HQ at Etein in October, normal relations with its SLU 

were resumed.

Except for very brief and infrequent intervals, when 3rd Army moved forward a day or so in advance of XIX TAC, the necessary time element on delivery of signals was observed. XIX TAC received 

its own SLU in March 1945 at Luxembourg; the SLU and this recipient were given adjoining offices. 

This is the ideal situation, messages being delivered frequently during the day, and any corruptions 

could be straightened out at once by consultation with the recipient.

All SLUs were highly cooperative. Relations were cordial, and every effort was made to render special assistance to this recipient under the special circumstances related.

3. Security.

Maintenance of security at XIX TAC was not a problem. The writer secured permission to have his 

presence explained at the outset in the following manner: Col. Cella called the officers of the A-2 Section together and stated that the writer had had special training with British Intelligence; that they had 

developed through longer experience in the war many sources and methods of interpretation; that 

their results were excellent. They had agreed to share them with our Army and Air Forces by training 

American officers for assignment to various commands. But they maintained a higher security standard, and this officer therefore would work directly with the A.C. of A.S., A-2. His work would be Top 

Secret and would not be discussed.

This statement satisfied the natural curiosity, and the writer's direct contact with the A-2 as intelligence liaison with the British was accepted without further comment.

4. Operational Use of Ultra.

Use of Ultra signals at XIX TAC are indicated by the headings under which the writer presented the 

material. They are so obvious that detailed discussion is not believed necessary. A comparison of intentions with the enemy scope of operations proved very useful in establishment of actual capabilities.

Damage reports were scanned for confirmation of results and claims, and were more than once the 

deciding factor in determining whether a repeat operation was necessary. When Patton’s open flank 

was along the Loire River, and XIX T AC was assigned the job of protecting that extended open flank, 

Ultra knowledge of enemy locations and movements was of great value.

Order of battle information was of equal value in determining enemy capabilities.
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At all times, Ultra proved an excellent means of confirming or completing intelligence from other 

sources, influencing the decision to take operational action. There were times when Ultra information 

was of such immediate value that the shortest possible steps were taken to translate it into open source 

intelligence so that operational action could be taken at once. A good example was the signal received 

early one morning (late March or early April) that the enemy had a strong concentration of M/T in a 

woods near Marburg. This was immediately passed to the Chief of Staff and the A-2, who ordered a visual reconnaissance to include this area. The recce pilot returned immediately with a report that a huge 

concentration was there; a squadron of fighter-bombers was in the vicinity and was redirected to the 

attack. They achieved excellent results, and throughout that day, as the enemy attempted to get out, 

successive waves were directed against them. At the close of the day, claims amounted to some 400 

plus M/T, tanks and armored vehicles destroyed.

Another example of direct results obtained through Ultra information was at the time Gen. Patton 

was preparing to attack through the Siegfried Line. Air-Ground plans included an attack on enemy Battle HQ at the proper moment in advance, to disrupt communications and direction of defense.

A careful collection of Battle HQ locations was made, confirmation and pinpoint locations were 

confirmed by photo and P/W interrogation. The attacks were successfully made. Enemy signals citing 

damages were received, confirming the decisive influence of the information.

 HARRY M. GROVE

 Major, AC
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General Histories of the Second World War

Craven, W.F., and Cate, J.M., Editors, The U.S. 

Army Air Forces in World War II. 7 vols. Chicago, 

1950-1958.

Esposito, Vincent J., Brigadier General, USA 

(Ret.), Chief Editor, The West Point Atlas of American Wars, 2 vols. N.Y., 1959.

Greenfield; Roberts, Kent and others, General 

Editors, The United States Army in World War II. 

Several series, 1948 ff. Of particular value for this 

history are the three volumes about The Signal 

Corps, and those relating to the Northwest African/

Mediterranean and European Theaters of Operations.

Hart; Liddell, Basil H., History of the Second 

World War, N. Y., 1970.

Morison, Samuel E., RADM, USNR, History of 

United States Naval Operations in World War II. 

15 vols. Boston, 1947-1975.

General Cryptologic Histories

Army Security Agency, European Axis Signal 

Intelligence in World War II as Revealed by 

“TICOM” Investigations, and by Other Prisoner of 

War Interrogations, and by Captured Material, 

Principally German, 9 vols.

Army Security Agency, History of the Signal 

Security Agency. Numerous volumes describing 

organization and operations for the most part in 

the Washington area.

Government Code and Cypher School, G.C.&C.S. 

History. Several series, including narratives of 

campaigns as shown in SIGINT produced at the 

time.

U.S. Navy OP-20-G, German Naval Communications Intelligence. 1946. IF 210.

U.S. Strategic Air Forces, History of U.S.S.T.A.F., 

Europe vs. the German Air Force, June 1945. 

Based on files of Special Intelligence at the British 

Air Ministry, London.

Historical Studies

Hayes, Harold G., Colonel, SigC, “Lessons 

Learned from the Operations of Signal Intelligence 

in NATOUSA,” 1 December 1943.

Humphreys, R. H., Group Captain, RAF, “The 

Use of ’U[ltra]’ in the Mediterranean and Northwest African Theaters.”

McCormack, Alfred C., Lieutenant Colonel, 

GSC, “The Use of CX/MSS Ultra by the U.S. War 

Department, 1943-1945.” SRH-OO5.

Williams, E. T., Brigadier, “Ultra at Eighth 

Army and 21 Army Group.”

Reports of Visits and Temporary Duty at 

GCCS

Fried, Walter J., Captain; Seaman, John S., 

Captain; and Small, Albert W., Liaison Officer Reports from GCCS to Commanding Officer, Arlington 

Hall Station. 

Friedman, William F., “Cryptanalysis of German Army and German Air Force Enigma Traffic,” 

12 August 1943.

Bibliography
Page 264

Friedman, William F., Personal Diary of Trip to 

England, 23 April to 13 June 1943.

Friedman, William F., “Preliminary Report,” 8 

July 1943.

Johnson, Roy D., Captain, SigC, “Cryptanalytic 

Reports,” 1943.

Kullback, Solomon, Captain, SigC, “The British 

G.C.&C.S.,” 2 June 1943.

McCormack, Alfred, Lieutenant Colonel, GSC, 

“Report of Trip to England, April-June 1943,” and 

appended documents. 2 vols.

Seaman, John N., Captain, SigC, “Report of 

Visit from 31 July 1943 to 14 March 1944.”

Sinkov, Abraham, Captain, SigC, and Rosen, 

Leo, First Lieutenant, SigC, “Report of Technical 

Mission to England,” 11 April 1942.

Trip reports concerning the use of Ultra in the 

Mediterranean Theater, 1943-1944. SRH-031.

Histories of SIGINT Units

Operational History of the 849th Signal Intelligence Service, July 1945. History of the Signal 

Intelligence Division, Office of the Chief Signal Officer, Services of Supply, European Theater of 

Operations, U.S. Army, 1942-1945. 3 vols.

Monthly Status Reports, 1 Dec 1942 to 1 Dec 

1944..

Administrative History and Chronology, June 

1942 to July 1945.

History of the Intelligence Branch.

History of the Air Intelligence Branch.

History of Signal Security Detachment “D,” attached to 12th Army Group.

History of the Special Branch, Military Intelligence Service.

History of Special Security Operations Overseas. Vol. II, European Theater.

If all Army Group/Army Signal Radio Intelligence Companies and Corps Signal Service 

Companies (Radio Intelligence) submitted periodic 

administrative reports and technical histories, 

many have been destroyed or so misplaced as to be 

lost. The others are uneven in value as historical 

sources. The best is the “Third Army Radio Intelligence History in the Campaign of Western Europe.”

Other Sources

Histories of Allied Force Headquarters and NATOUSA and of the Fifth Army have minor use for a 

cryptologic history. The archives of Allied Force 

Headquarters went to the British after microfilm 

copies had been made for the United States. The 

Mediterranean Allied Air Force records were similarly preserved. A guide of the microfilm and the 

reels themselves are at the NARC, Suitland, Maryland. In the MAAF records is a surprising amount 

of SIGINT matter.

The intelligence journals of various commands 

contain SIGINT items either attributed to a “reliable source” or identified as “Y” material.

Both the 6th Army Group (Devers) and the 12th 

Army Group (Bradley) produced after-action reports that paid attention to SIGINT.

The author has seen no CX/MSS messages: all 

references to them are from citations in the 

G.C.&C.S. History.