REF ID:A68389 • 

mrr SERVICE M)Jl.CES 

SIGNAL CORPS ENGINEFRING LABORATORIES 

COLES SIGNAL LABORATORY 

RFD BANK, NEW J!.RSEY ~ 

/) ' 11 October 1945 

REPORT O.tr WIRE EQUIPMENT CpMMITTEE 

I.. STATEMENT OF PROBT..Jffit. It is the objective of this committee to outline a 

progr&1r1 for the development of racili ties for transmission of taler.hone and 

telegr~ph signals and other forms of intelligence over wire lines in the 

.Army communication network. In this connection, there is s further requirement that the signals transmitted over the wire lines shall be capable of 

retrenem:lssion by other transmission mediums, particularly radio without 

add1t1onel complicated equipment or operating proced'l.R'es. The following 

general types of equipment and facilities a.re required for solution of this 

problem: · 

A. Wires and cables to serve as a transmiesion medium. 

D~ Equip111ent and tools for installation and maintenence of the wire 

lines. 

c. Stat~.on equipment for converdon of intelligence to and from 

elect.ricai energy. 

D. Switching equipment suitable for interconnecting all similar com.~unication channels. 

E. Transm5.ssion equipment tor greater utilization of the tra.nsmiss:l.on 

medium •. 

II. -DJlVANCES :QURING WOP*D W.Af!. ix. DU!."ing the time between the opening of the 

l'lll'opean W&.r in l.939 and the United States• en.try in 1941, many significant 

developments were made in the Arrq wire communications equipment. The e»-

ploitation of mobile warfare by the Cermans with the greatJ.7 inc~eased 

distances ro~ which communications were required placed great emphasis on 

the need fc,r better transmission. During this period, all presently avail.-

able carrier telephone and telegraph equipment, ep1ra.l-four cable, the twowire Repeater EE-89. and the four-wire Repeater FE-99 were developed. Improved 

construction methods such as rapid pole line construction and the development 

of the cable plow were also consummated, but •ere nevor generally accepted 

for use in the f1eld. Subsequent to the Unit.ed States' entry in the war, no 

general advance in the art of wire communication was i.iade, most of the effort 

bel ng expended i..wi a eearch tor aubsti tutes for cr1 ti cal materials, improve.. ... ment of the performance of the equipment by changes in mechanical and 

electrical design,, and the moisture and fungiproofing of equipment for use 

in the tropice. Prior to the cessation 0£ hostilities, a number of new 

I r. I ~- Q' (. ~ @'pp roved for Release by NSA on O 1-16-2014 pursuantto E .0. 1352a 
REF ID:A68389 

pro3ects were authorized, some of which are ap•,roaching completion, such 

aa high speed coils, lightweight field wire, a new field switchboard, and 

a lightweight teletypewriter. Other projects have more recently been 

authorized, and no significant progress has ~een made to date. These 

projects are included in the general discussion of required research 

and development outlined in other parts of this report. 

III. PRESENT STATUS. . 

A. Gepers.1. There are a good many items which comprise the list of 

wire communication equipments. Many of these are adapted from the commercial 

field with little or no change in design, either because of War Dep8.l!'tment 

polic;r, lack of development funds or lack or time to prosecute development. 

This ha.s resulted in some equipment being extremely heavy and bulky for 

military use, particularly when man-packed or used by parachute troops, 

and has aegravated the supply problem because of the necessity for using 

non-interchangeable parts made by dift'erent manufacturers for the same 

piece of equipment when expansion of the sources of supDly became necessary 

in wartime. In add.1 tion, a great. many wire equipments of various designs 

and makes were bought for use in the f'1xed plant. All this equipment was 

handled by the same supply organizationste.nd as a result, the number of 

parts which were kept in stock was enormous. It is believed that this 

trend has been recognized and in the future, development of equipment which 

ie suitable for both fixed plant and tactical use will be made wherever 

possible. Discussion of the present etatus or the various classes of wire 

communications equipment follows. 

B. Wire and Cable. 

1. The ma3or standard 1tems of equipment are aa followa1 

a. Wire W-130-( ) , lightweight a.ssaul t wire for forward use. 

b.. Wire W-110-B, general purpose field wire. 

c. Wire w-143, long distance field wire. 

d. Cable Assembly CC-.358, spiral-four cable. 

e. Cable W0-534 and WC-535, five and ten-pair cable used as an 

entrance cable for £ield wire lines at command posts, and other concentratio?UJo 

2. The dEflrelopment of lightweight field Wires WD-1( )/T'r. and 

WD-14( )/TT ia r~pialy approach!~ completion. These wires employ new 

insulating and protractive materials and have the range 0£ present field wire 

with about 2/3 of' the strength and 1/3 of the weight. 

2 
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REF ID:A6838 • 

3. It i,s significant that all wires listed are sui.table only for 

voice-frequency transmission, except sp~.ral-four cable which is se.tie.faet-0ry 

for transmission of frequencies up to 16 kc or 4 or 5 voice che.nnels. 

C. ~migpi_on Eauipmen,t. 

l. The following me.jor items of equipment are nov1 standard in 

this category1 

a. Carrier telephone and telegraph equipment of the CJ.t' eeries. 

This equipment provides four tele~hone channels for transmission over spiraltour cable on a. four-wire basis or over ope..n-wire lir1es on a two-wire basis 

a1'ld is capable of utilizing any voice channel to derive six carrier telegraph 

channels. 

b,. F.epeater EE-89, two-\vire, be.ttery operated, 21-type voice 

repeater for field lines. 

c. Repeater EE-99, four-wire battery operated, iroice repeater 

for field lines. 

d. Hepeater TP-14, two-wire, battery or pol'ler operated, 22-type 

repeater for general use. 

e.. Telegraph Terminal lf·H-1( )/TCC-1, equipment which provides ore 

carrier telegraph channel 1n the middle of a:ny voice c!-le.nnel while retaining 

the use of the latter. 

f. Telephone TP-9, telephone set l'1i th vacuum tube empl.ifiers for 

both talking and llatening uee on extended field lines for point-to-point com-· 

mum.ca ti on. 

2. It is significant that a 111s.ximum of four voice channels can be 

placed on field facilities w! th these equipments. Voice-trequency comsaunica.-

tion is still 1JSed exclusively in the lower echelons. · 

D. Li:nP ~uipment. A large number of items are inclu:ied in this cle.sa 

of equipment including• reels, reel units, cable hangers,, poles, pole hardware, crossarms, insulators, linemen's personal equipment, etc. For tact:f.cal 

line construction in forward areas, Axle RL-27 and .Reel Units RL-26 and EL-JJ.. 

are the main items of equipment used. Field wire is extensively used for 

ties. In pole line construction, the methods and equipment used for rural 

telephone tines in this country, such as Class 9 poles and Truck K-44 pole 

setting equipment, are s'l.111 in use b.r the Army. Trucks !C-43 r:s.nd K-44 are 

still listed as standard items on Tables of Equipment. However, experience 

in the European Theater indicated that these trucks wsre not satisfactory, 

either as a motor vehicle or as a piece of Signal Corps equipment. At the 

close of the war in that theater, one Field Army had discarded both vehicles 

referred to in favor of the standard 2-1/2 ton, 6 x 6. !:S.pid pole line and 

multi-airline construction methods using etructUI·al. timber have been used to 

a limited extent. Plow-in ~ethods using Plow LC-61 or a modified plow, 1ere 
... 

REF ID:A68389 

employed largely on an experimental scale. However, it is felt that there ia 

a very definite oppcrtunity for development in this respect. Overall trunk 

line construction equipment remains too bulky and heavy, and trunk line conatruction methods are cunberaome and far too slow. 

E. 'Ielephone Switchbo&rdf yd Statipn Egμ1pment. 

l. Telephone @!itqh'boa.rd•• 

a. ill present standard telephone switchboards are of the 

manl.llll type. The maJor telephone central office aets and switchboards now 

standard are liated belows 

(1) TeleoJ.wne Central Office Set TC-10. Major component 

Switchboard BD-110. Capacity a maxi.mm of 6 position& 

with 4 trunks, 60 common battery and 30 cagneto lines 

per position. Uaed at Army and Army Group. 

(2) Tele.phone Central Office §et TC-2. Major component 

Switchboard BD-89. Capacity a maximum. of 2 position• 

(non-multiple) \Iii.th 40 common battery, 20 magneto 

llnea and 4 trunks per position. Used at Corps. 

(Thia set was recently replaced by Telephone Central 

Office Set. .AN/TTC-3. hin component SWitchboard BD-120. 

Capacity of 3 positions with 30 co!llJllOn battery and 30 

magneto lines and 8 trtmks per position.) 

(3) T9lephone Central O!f'ice Set TC-4. i{ajor component 

Switchboard :SD-96. Capacity one position with JJJ 

magneto lines. Used at Division. 

(4) 'l'elephone Central Qffice Set TC-μ. ilajor component 

Switchboard nn..91. Capacity one position with 20 , magneto lines. Used in echelons below Division and 

in ilJ.r uni ts. 

(5} Swijchbgarde BD-71 apg. BD-7,S. Six or 12 11.ne monocord 

field switchboards used at P.egim.ent and Battal.i~n 

levels. 

(6) Switchboard SB-18/GT. Very sma.ll.,, emergency, &i:x 

line field awitchboard, using Adapter Plug U-4/GT aa 

line un.it. Telephone liE-8 is used as the operator'• 

set. 

b. It will be noted that there are folr c!i.fferent typea of 

the larger teleohone central oi'fice sets. Most of these types are made.by 

at least three tiii'i'erent ma.n~ao'turera. Compon.e:nt pa.rte of the switchboard 

made by one manufacturer are rarely interchangeable with those ude by 

another. As a. result, the component parts of all manutacturers muet be 

4 
,• REF ID:A6838. 

kept in stock separately. It will also be noted that the heavy, bulky field 

Switchboards BD-71 and BD-72 were designed about revamped World War I swi~chboard units in what was thought to be an economy move at the time because of 

the large stock on hand* Fortunately this board will soon be replaced by 

Switchboard SB-.22/PT, an eight-line lightweight field switchboard of the 

patch cord type which is less than l/2 or the weight or the present 1Witchboard. 

2. Telephone Stattgn Sets. 

a. The major items or equipment now standard and in use in 

this category follow. 

(1) Telephone EE-8, standard field set with leather or 

canvas case, capable of being operated on either 

local blttery or common battery lines, emplo;ya 

Handset Tl:l-9 and derives power from two Batteries 

BA-30. 

(2) Telephone TP-3, this telephone is similar to Telephone 

EE-8 except that it uses Handset TS-10, sound-powered 

type. 

(3) Telephone TP-6, a atands.rd commercial desk telephone, 

with certain minor changes to make it adaptable for 

Army use. 

b. The performance of this category ot equipment has been 

generally satisfactory, except that tbe handsets in general do r£Ot fit well 

under the rl-l battle helm.et. 

F. Telegram ~tch!>gardg arid station Famment. One of the ma-for 

advancee in wire communications during this 1f&1!' was the greatly expanded 

use of the teletypewriter for communications. The speed, accuracy,, and 

dependability of this type of communication by all)" method 0£ transmission 

has been a very important .factor in the efficiency of communication systems. 

l. Telegra,ph M tchb9ard FQuinm,ent. Telegraph Central Office Set 

TC-.3 with ita lllfljor component Switchboard BD-lOO·was generally and widely used 

in the field. The switchboard operates on a neutral basis with 10 line capacity. Three switchboards may be operated together to give a total capacity 

of 30 lines. 

2. Telegram Statign FR)lt.mnent. Items of equipment in this c'a.tegory 

which are now standard follow. • 

a. Telegraph Set TG-5, a small, manually operated, telegraph set 

for tranpisaion of international Morse code. With the advent of the teletypewriter, the use of' th.is set has greatly declined. 

s 
REF ID:A68389 

b. Telet}':ewriter Sets EE-97-A and EE-98-A. Principal componant 

Teletypewriter TG-7-( ~ This is the Teletype Corp. #15 Printer vrith standard 

keyboard adapted for Army use. lt is very generally used in all echelons :from 

Division upward and in fixed plant. 

c. 'l'elet;y;pewri ter Set EE=l02. Principal component 'I'eletype111'1 ter '.l'G-37-( ). '.Ibie equipment is similar to the TG-7-( ) except that a 

meteorolo~ical keyboard is employed. 

d. Renertorator Telet e ter Set TC-1 • Principal component 

P.epertora tor Tranami t. ter TG-26- ) • 'i'hia component consists of two uni ta, the 

printer reperforator for preparing lihe tape either by local keyboard operation 

or from received line signal.a• and a trans.mitter-di&tributor tar transmitting 

the prepared message over the line. Ueed quite extensively in the fixed plant 

at teletyPewr1ter centers and to a 11.mited extent at Jr-my .Headquarters and 

higher echelons, although not authorized equipment, 

e. Reneater Set TC-18. 14ajor component Repeater TG-30. Polarential type d-c terminal telegraph repeater for extending teletypewriter operating range on field and open-wire lines ami also to interconnect u. S. and 

British telegraph equipments. 

t. f'.epeater Set '.l'C-12. MaJor component Repeater TG-31. Polal"-

antial type d-c intermediate telegraph repeater for long field and open-wire 

lines. May be operated on a:t:.teuded or unattended buia. 

IV. CUP.RENT 'l'REilD OF DEVE.'LOP?4ENT. Developments now in progi•esa were inf tiated 

when the emphasis waa placed on the Pacific War anc1 re.fleet the lessons learned 

in that war. In general, emphasis ia placed on lighten.tng of equipment. because 

of the necessity for man-packing much of the equipment used in this theater • 

.la might be expected, there baa been no call. tor new or radical departures 

trom present communication systems since the introduction of such methods in 

an al.ready satisf'actory system in the middle of 8 war would be difficult, 1£ 

not impossible. Description of the developments now being prosecuted follows. 

A. filgh §peed Coil.s. ~'he desire to eliminat.e the clumsy, cumbersome, 

reels and reel unite required in laying out field lines resulted in t~1e initiation of the develop~ent or high speed coils. A high speed coil consists of 

a precision layer-wound coil of field wire inclosed in a light~e1ght container 

and wound in sue.~ a manner that the coil may be unwound from the center without rotation or use of other auxiliary equipment. By this method wire may be 

laid at high speed from a plane or at low speed from a packboard or a soldier's 

back with equal facility. Thia method of packing wire has been auccessfully 

applied to Wire W-130 of all types which in this form. is packaged in Wire 

Dispenser ia-301/G. Prior to V-J Day, there was ll'llited production of this 

dispenser tor field use. It is believed that the method can be generally 

appl~ed to field wires and cables and it is now being investigated for 

application to fie1d Wire• WD-1( )/TT arad WD-14( )/TT, TJhich will be packaged in Wire Dispenser "\.U:-306/G. 

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REF ID:A68389-

B. Wires !J?-1{ >M fad 'UID-14( )/TT. Development of these wires was 

initiated to provide a replacement for Wires w-110-a and W-130-( ) in the Infantry Division. ThSJ" employ a new, more efficient, light¥.-eight insul.s.tion 

with a. thin, ext.ruded plastic or braided cover. 'l'a1king range is equal to or 

slightl7 better than field Wire W-110-B with l/3 the weight and 2/3 of the 

strength. In range, strength, and durability, it far exceeds wires of the 

W-130 type with relatinly small increase in weight. These rtres have been 

standardized and some production of Wire WD-1( )/TT was obte.ined -:n-ior to 

V-J Day. 

c. Switchboard SB-22b'l'. Js mentioned above, the present standard 

field Switchboard& BD-71 and PD-'72 were designed about switchboard units of 

World War I vintage. '!'hey were extremely heavy for man-pack enC. as a result 

development of Switchboard S~2/PT, an eight line, patch cord type board 

was authorized. Present indications are that the board will be about 1/2 

the weight of the present switchboards on equivalent f1mctiom1 baais. 

ta.teat advances in component design and moistureproofing technique• are 

being incorporated. 

D. Teletyp!.,1!J'itet TT-4/TG. Aa mentioned above, present teletypewriters in use in the Ar'JIJ:y networks are star.dB.rd commercie.l machines adopted 

for military use. Their bulk and weight prevents man-pack and restricts 

use to the higher echelone. Development of Teletypewriter TT-4/'l'G was 

authorized to produce a machine which was especially designed for Army use. 

By complete mechanical reeesign1 simplification, adoption of new techniques 

and elimination 0£ certain extraneous f'eatures not needed in Army circuits, 

a considerable reduction in weight has been found possible. Development is 

well underway and f'rom present indications, the completed machine will weigh 

only about 25% ot the weight of' the present standard Teletypewriter TG-7-( ). 

V. ?i.'Dl REQUIRFil.E~TS APP AREHT AT CLOSE Ol!' WAR. The potentialities of weapone 

under development at end or World War II are such that the future of military 

tactics cannot be foretold with any degree or assurance. It is obvious that 

the processea of war will be immensely speeded up, and that the scope or 

actual combat will not be localized. Military developments in the rr. s • .Army 

during World War II were all in the direction of higher specialigation fr, all 

fields toward the end of enormously increasing the amount and the mo'l'-ility of 

destructive fire power per combat unit of both land and air forces. There was 

a correspondingly great increa•e in the requirements for communication for 

planning ~ effecting the coordination and control of' the highl.y specialized 

elements involved in supplying and delivering this fire Power. Every present 

indication clearly points to a future course 0£ greatl7 inereaeed technical 

special1zat:lon, greatly increased destructive capacities and highly complex 

technica1 defe naive and off'enaive eyatems. The concomi tnnt need tor greatly 

increased capabilities tor communication arid data transmission are inevitable. 

Accordingly, the wend ot military communications must be toward a .flex:ible, 

high grade communications system which at£orda the greatest nmber of ohannel.s 

for the transmission of intelligence in the shortest time over any distance 

and between any given points. l''urther, the equipment involved must be 

lighter, smaller, more durable, and so designed that it is possible to rapidly 

interchange and multiple units for the oost efficient operation as the situation 

chanaee. 

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REF ID:A68389 

A. 'l'he Com111unice.t1ons Svstem. A cliscussion of the require;:ients for 

t.he futUl"e comaunications system e.nd the various classes of ~-:ire col'Dr.lunication 

equipments as they now appear follows. VJith the growth and size of the /.rrny 

and greater interdependence or one unit on another, the vast !iJ!lount of mattrial 

required, and the increased move~ent it has become :u.ore and more im~erative 

that hll com.'lunicatio~ be interrated into a complete system. '!be following 

are suggested requirements for such a systems 

. 

l. Complete integration of wire and radio COUllllunications in a single 

net'!J10rk. 

2. Four-wire or equivalent four-wire operation of all trunk (long 

distance) circuits either wire or radio. 

3. four-wire switchi~ or trunk. circuits at all switching centers 

so that high grade 6 db loss circuits may be established over long distance 

where required and so that a.11 circuits may be interconnected at will on a 

voice-frequency basis. 

4. Design of 9iJu1pment to be such that a standard termfosl. impedEu1ce 

will be used, such as 600 ohms, the noise generated in the equipment Y1i11 be 

less th&.n 15 dbrn• the distortion 0£ the system less th&.n one percent, the 

frequency response substantially fle.t over the operating range, radio receivers 

capable of delivering an output of' plus 10 dbm snd radio tranamitters capable 

of accepting signals from minus JJ to 0 dbm with full modulation. 

5. A tone source and transmission measuring equipment to be provided 

with all radio and wire trunk terminal equipment and at other points in the 

system where tran811liesion levels are ,important. 

6. Eliminate direct cUITent whenever possible and particularly on 

all circuits tba t require switching. 

7. Local loops, bo1ih wire and radio, be operated on a two-wire basis. 

In connection with the operation of local radio loope, the folloring requirements are suggesteda 

a. Operation to be full duplex on a continuous or intermittent 

basis. Intermittent full duplex 1ervice is defined as th.at type of operation 

in which the transmitter is under control of the switchboard operator. 

b. A single remote control unit be developed to ecco~plish this 

type of service with no change in the usual tel&J>hone operating procedures 

and without substantial change in the a wi tchbou'd. 

8. Wherever practicable equip111ent should be designed to serve both 

. in the fixed and tactical plant, thus simplifying maintenance, supply, trailling and operating problems. 

B. Wire and Ca,ble. The equipment which providea the transmission med!.um 

between •witchboarda of a wire cOllJIDunication system conatitut.ee the major weight 
. 

'· 

REF ID:A68384t 

and volume ot such a system and consumes, in its installation e.nd maintenance, 

a high percentage of the man-hours necessary for the overall operation of such 

a system. It is imperative, therefore, that this equipment be: radically improved. The following ob3ectivee should be kept 1n minds 

1. Reduce the size and weight ot these facilities by employing more 

efficient conductor, insulating and protective materials and by emploYfl\ent of 

new desit'Tl methods. 

2. Reduce the volume of these facilities required by improving 

message carrying ability in conjunction with new item.a of transmission equipment. This resolves itself fundamentally into increasing the usable frequency 

pass band.. It is desirable that the facility be capable of passing video or 

other television Sif118.18 as well as con"V·entio.nal communication frequencies. 

3. Improve the durability of these facilities insofar as vossible 

without substantial sacrifice of electrica.t properties. 

c. Line Equipment, The conetruction and placement of wire linen is a 

development field where new 111ethods would be of great benefit in the overall 

wire communication system. With improved methods, the amount of' wire ar.d 

cable req,uired would be reduced and the reliability of the syatem increased. 

Some of the apparent requirements for developments in this category follow. 

1. Devise methods for placement and construction of wire lines well 

off travelled roads. The method devised shall not endanger cona~ruction personne1 by requiring them to work at sides of roads where mine £ields are often 

present. Also, it shall not open new trails or roads through the use of a 

large vehicle in the construction work. 

2. Improve security or wire lines from the effects of eng1neer 1 s 

construction equipment, bombings, shell rire and vehicles. 

3. Increase the apeed of placement and construction of lines consistent with security and reliability. 

1+.. li'.educe t.b.e size and weight of the equipment reqUired, particularly reels, reel units, plows. etc. 

5. Eliminate open-wire lines .as a transmission medimn, thus reducing 

the amount and bulk of line construction equipment. 

6. Provide :f'e.ult location equipment which fives speedy precise 

locations of troub1e on the line, both when located in the field or &t a 

central office. 

D. Transmission :Equipment. This type of equipment was first extensively 

used in military communications during the war just ended. It is apparent that 

its use will be greatly extended in the .t'uture because it reduces the amount of 

outside pl&nt equipment required6 improves the performance of the communication 

system end facilitates int-egration of wire and radio syatems. Some requirements 

for equipment in this category now apparent i'ollow. 

9 
REF ID:A68389 

i. Feduction in size and weight 0£ equipment to permit man-pack 

through employment of new materials and techniques. 'lhia 111.ll make possible 

the extenuion ot the use of this equipment to lower echelons. 

2. F.mploym.ent of the unit principle to increase the flexibility ot 

the equipment for use in both radio and "Ni.re a.pplica.tions. 

3. Increase the message carryi!lE, ability of wire fecili~ies by 

the devel.opment of cerrier telephone equipment capable of pl~cill6 lilly number up to ~ro voice channels on a single four-wire :facility. 

4. Improve the quality of the voice channel by widening the frequency 

band, thus !J&rmitting the operation of a greater number of l.inka in tandem as 

well as providing hifh quality circuits !'or specis.l epplicationa. 

5. Provide voice-frequency carrier telegraph equipment usable on 

any carrier telephone channel and capable of at least 100 "NOrds per ll'inute 

speed on oach telegraph channel. 

6. Provide equipment for placing video or other television signal.a 

on the cOU1111unication system. 

7. Investigate the possibility of utilizing simplified carrier 

equipment on local or comm&nd post telephone aysteme. 

E. Telephone Foui:gnent. Requirements apparent at the c1ose of the war 

for this type of equipment follow. 

J.. A reduction in the number of types of switchboards by developing 

one universal magneto-common battery multiple awitchhla:rd capable of extension 

to a capacity of at least 1000 lines with as many positions as required by 

traffic considerations. 

2. An all magneto multiple board of approximately 40 line capacity 

is required at Di vision. ~:his board should be capable or being mul tipled for 

approximately 120 line capacity. 

. 3. 1'he development of the lightqeight field Switchboard SB-22/PT 

should be continued to meet the requirements for a light fielc switchboard .. 

4. Components employed in the switchboards should be standardized 

in design ao as to simplify main~enance a&l supply procedures. 

5. In every case, minimum size and weight should be achieved in 

'both the overall equipment and the components employed. 

F. Telegraph Z:Juipm.ent. One of the importfnt advances in military communications in this war was the greatly increased use of the teletypewriter. 

Aa a consequence, the use of manual telegraphy in t.he id.re system practically 

disappeared. With the development and employment of voice-frequency carrier 

10 

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. 

' 

REF ID:A68389 e 

telegraph equipment, the use of d-c telegraph transmission was confined in 

greeter part to short loops. From these trends, the following requirements 

for equipment in this categol")" were apparent at the close of the wars 

1.. Development of teletypewriter for military use with greatly reduced aize and weight and improvement in ruggedness. Development of' such a 

teletypewriter will extend the use of thia equipment to the lower echelons • 

.2. Development ot equipment for extending voice-frequency telegraph 

operation throughout the telegraph system including the local loops. Development or such equipment provides advantages in simplified switching methods 

and transmission techniques. 

3. Develop1Uent of an ul tra-llghtweight teietypewri ter possibly of 

the tape type for use in the extreme forward areas with optional manual or 

electrical power drive. 

VI. REQyI.RED RESEARCH AND DEVELOPMENT .. 

A. Proposed COJ!l!!lunication Szatem. In order to more fully 111.ustrate 

the neceseit7 for and uae of the various types or equipment which are suggested for development, a system for their employment is illustrated in 

Figure l attached, and described below. '!'he center of the system is the 

System Control Board which is essentially a tour-wire and four-wire - twowire patching board. AU trunk circuits, wire and"ra.dio, would terminate 

in this board on a voice-frequency four-wire basis. At the board they may 

be extended to the loca1 telephone or telegraph switchboard on a two-wire 

basis by means or a four-wire terminating set or be patched t..tu-ough to 

another trunk on· a four-wire basis. The various voice-frequency trun.lca 

eminating from the control board pass to carrier equipment for trensmisaion 

over wire lines or radio. 'I'he wire facility would be spiral-four cable 

where only a few channels are required and twin coaxi&l cable for a greater 

number of channels. Where coaxial cable is used it is also possible- to 

transmit television or other video signals over the sa~e facility ~1th proper equipment. The optional use of video filter equipment for thia purpose i• 

provided. It is anticipated tbe.t there will be a great need for rapid tranamisaion of this type of information in air warning systems of the future. 

By proper operation of 'thia syetem, it is possible to obtain a good 6 db 

loss circuit .from the Pentagon to a .foxhole command poat in a f'ar off theater 

if neces88.l"T• In other words, it seems to provide the necessary flexibility 

and qualit:r which the best military communications of the future will require. 

The individual components, development of which is required are discussed in 

the following parE..graph1. 

B. §Dtem ConWJ>l BovJi. As indicated above this will be eesential.ly 

a voice-trequeney patchinr board providing four-wire or .f'olll"-wire - two-wire 

•witching with aUJd.119.?'7 equipment consistina; of four-wire terminating sets, 

voice-frequency ringing equipment and necessary test equi~me4t. Two t-ypea 

of boards are enviaione4 as tollowas 

11 
REF ID:A68389 

1. The system control board for the lr.rger 1nstellat1ons, probably 

echelons above Division incl.uding the fixed plant, would be a flexible patch- ing bof&rd providing the necessary switching facilities and a'!JJd.liary equipment. 

The latter would consist or four-wire terminating sets with a hybrid coil end 

other necessary equipment, voice-frequency ringing equipment for insertion in 

those tvo-wire lines requiring it r.nd a panel of test equipment, including an 

oscillator G.nd transmission measuring equipment. It ia essential. that the 

method 01~ establishing coonections be completely flexible and rapid srid that 

the wire chief in charge be familiar with circuit condition and require..rnent.a 

at all times. This requi:red fiexi bil.1 ty must be ta.ken into consideration in 

the design •. 

2. · For the lower echelona, a smaller Yersion of this board is required conaiatina eaaent.ially of a jack panel and pa't.ching facilities with 

the neces&e.17 tour-wire terllli.nat.ing aeta, voic&-frequency ringing equipment, 

tranemiaeion. meu1ring set and fault location equipmeut preferably in separate 

packages to facilitate transportation. 

c. Ifllll!!!i§sion Ituimem. 

1. Caaier Telephone !qμipment. Essentially 1 t is required that 

carrier telephone equipment be developed which ia capable of obtaining 8117 

number of channelB from 4 to 40 or more for tranam.1ss1on over a single fourwire facili 'GY or suitable radio circuit. Two methods of achieving this 

objective, both of which should be investigated follow. 

a. Ste - - te ~Aodul.ation ui ent . e o • In t.h.ia 

method, (Figure 2 , there would be a basic folll"-channel unit with group 

modulation equipment for integrating three of these units to derive 11 or 

12 channels and further group modulation equipment to integr~te three or 

four o:f the latter to derive from 33 to A6 channels as design liini tationa 

may dictate. The group modulation technique may be carried out further to 

derive a greater nmber or channels provided the transmission medim is 

capable of accommodating them. At present, a mini.Jnum of 40 chennels ia 

the goal. With this method, the three different uni ts of equipane">.t are expected to be about the 1ame size. A description of the equipment development 

required f ollowa. 

(1) !'gJ.g-Chapnel Ca1"Tier Telenh2ne EguJ.nment. Th;is would 

sern as the b&sic unit in the system. It would serve 

to modulate the voice-frequency signals to cover a band 

from 200 to l60CX>cps with 20V to 3500 cps band width 

per channel. ':'!iniature deaign techniques would be 

employed aa far ae passible and package weight would be 

kept to IJJ pounds or leas. Military characteristics for 

Telephone Terminal AN/TCC-3 recent!) submitted appear 

1atiaf&ctor, for this item. . 

(2) Group llodulator - il. or 12 Channel, This equipment 

would serve to atel'-up the signals from three bEsic 

four-channel units to occupy succet1sive bands in the 

frequency spectrum making it possible to apply 11 or 

12 
( r 

REF ID:A68389-

12 channela to a eirt~le four-wire cn:--radio facility. 

Uinimm weight and pze would, of course, be the goal 

in design including.consideration of crystal filters. 

(3) Group Moqylator - M £.bannels·. 'Ihis equipment would 

step-up the signals from three of the modul.E:.tor equipments previously described to occupy successive chnnnela 

in the frequency spectrum for appl.1.ca ti on to e. f'ourwire or radio facili t;y. Yinimum weight and size woul.d • 

of course, be the goal in design.· 

b. Four-Chfge1 Group l\fodul~:tW.n Eauiment Method. In this 

method• (Figure 3) t the basic mdt would bs the four-channel unit described 

in sμbparagraph C-la(l) above. For stepping-up the signals from 'the basic 

unit L to the proper place in the frequency spectrum a single type of modulat-or 

woul.a be developed wt th w.riable carrier oscills tor and necess&l'Y plug-in 

1'11 ter uni ts. This system has the ad"f'8.ntage of permitting dropping or four--

channel groups along the line w1 th a nd.nimm of equipment. llowever, the 

system requires close control to prevent interference and will require conaiderable administration. 

c. v14eo filter lguipment. There is every indication that the 

transmission 0£ television and other video signals to widely scattered places 

will be an essential requirement of the Army- tactical plan. !or this reason, 

it is believed that equipment should be developed which will permit transmission 

of these signals and communication signals over suitable communication transmission mediums~ The equipment would consist essentially of 1111e terminating 

equipment, modulating equipment., filters and broadband amplifiers, if necessary .. .At first glance it appears tbe.t the most feasible method would place the video 

transmission in the lower region of the frequency spectrum and the commmdcatiol'..8 

signals above it. 

d. Repeater l&Juipment.. From present consider9.t1ons, there are 

three types of this equipment required. All will be of the broadband, tour-wire 

type. One will be required tor each of the four-channel, 12-channel, and 44-

channel s;rsteme. Mea111 for dropping c.'iannels b,y bridging a carrier terminal 

unit at repeater points should be provided. Military characteristics tor the 

tour-channel repeater have been recently submitted. To decrease attendance required on the 40-cha.nnel system, it is expected that power for operating repeaters 

will be transmitted on the line •o that a power source will ol'Jly be required at 

every third repeater. 

•· Joice-E£!!9'1'!m Carrier TJllHraPh Eauimnent. Six-channel voicefrequency carrier telegraph equipment capable or being applied to any channel 

of the four-channel basic oarrier telephone equipment described sbove1 or to 

other voice-frequency facilities i• required. Design should be suitable tor 

100 worda per minute telegraph transmission. Military characteristics recently 

submitted for Telegraph Terminal AN/TCC-4 are satisfactory ror this development. 

In addition. it is believed that there is a requirer1ent £or equipment similar 

to present Telegraph Terminal Tfl-l( )/TCC-1 (speech plus duplex). ~1th the 

anticipated development of voice-frequency telegraph operation, there is a 
c \. 

REF ID:A68389 

posaibility th.at very aimple equipment could be 1118de to achieTe this method of 

operation using the components of one ohanne1 ot Telegraph Terminal AN/TCC-4 

when developed. With the wide £requency band in the carrier telephone channel, 

consideration should be given ~ operating this equipment at the upper end of 

the voice bind. 

2. VoS;ce;-f'.t•.9.~l).C;Y:,Y-~~A!.e.r.. Egu,ipment. l"or this type or equipment, 

inveatieation of methods c,f obt.-Jimng bidirectional tranemis•ion or inte:.11-

gence withoti:t. uae of the bllan~~ principle is required. "Voice relay switching 

and pulse Pitching of mnr-lit1E=:i·s ere possible path• to follow. 

3. .J.Qj.c,e:tJ"~91.?!_nez I:i.!agjpg F.guipment. J. requirement eld..eta for 

the dHelop:>ient of vo1c~-rr'4u~.,~y ringing equipment for general use. One 

universal l~nlt capable o'f eonvi!trt1.ng low trequenC'J' ringing signals to a 

uuitable vaic&-.frequeney e1gnal :or UBe in the two-wire portion of any telephone channel is required. This unit will be used with the S1atem Controi 

Board carrier telephone 64uipm1Jr.t when used separately, or aey other voice 

circuit. Some 1nTest1gat1o!.1 elld coordination is required to determine the 

moat desirable .frequency for ringing signals in the voice band. 

4. T£e.namia1ion Meyuring Fsuioment. This tiPe of equipment. is 

ver7 neceSB81'J' for proper operation of the syatem. The Signe! Corps has 

neglected operational test equipment in the paat considering that testing 

was prifnarily an equipment repair problem.. This is tar .from true •!nee 

proper eetting for operatio.oal controls is dependent on transmisaion lot• 

of the circuit which is best determined by measurement on a. tranam.iaaion 

measuring set. Fortunately present carrier telephone sets incorporate such 

equipment. A single tone source and transmission measuring set is needed 

in the teat panel of the proposed System Control Boa.rd. A compact, portable 

version is raquired for general use. For circuit maintenance, the develoP1nent ot a continuously variable Toice-frequency oscillator and recording 

transmie&ion measuring aet ii0uld be a desirable addition. 

S. Research. The following general. research is desirable if 

advances are to be made in tbie type of ~u:lpmenta 

a. Expended use ot electron tubes as basic circuit elements. 

b. New filter iaetboda. 

c. Investigation of new methods of modulation to determine if 

they are better adapted to message security. 

D. !!Y'-! and Cable, Baaed on the requirements of the system outlined 

above, three typea of facilitiea appear to be required. Coaxial cable for 

':ide band multi-channel and video transmiasio.n systems, spiral-four cal:le 

for f'our and 12 channel carrier telephone trana1nission, and field wire for 

voice-frequency transmission over local extensions. The diecuasion of the 

equipment required for development f'ollowa. 

14 
REF ID:A68389 e 

1. Co•r?al C&.ble. To tranamit the wide band of frequencies contemplated in the system, a twin coaxial cable or two single coaxial cables will be 

required. It is anticipated that it will be of the solid dielectric type construction with suitable conductor, inaulation, shield and covering. Attenuations 

or about one and one-half db per 1000 feet at one megacycle with a cable of 

approximately .3 inch is now possible. Thia would give a repeater spacing ot 

between five and eix miles and with power tranamitted through the cable to 

adjacent repeaters, attended repeater spacing would be approximately 15 to 

20 miles. Constant impedance connectors are a necessity for joining two 

lengths of such cable. Considerable development is required on this item. 

It is anticipated that cables of this t;ype with their superior message handling 

ability and inherent stab~lity will replace open wire construction in the 

Arrq- of the future. It rill be 111.d table tor both the tactical &rid fixed 

plant and capable of aerial, surface or subterranean placement. Military 

charaoteriat1oa recently aubaitted for coaxial cable appear to be satisfactory. 

2. SPira1-.(oμr C!ble. Where transmission is confined to frequencies 

in the lower part of the spectrum, field cables of the spiral-to"Ur type are 

more efficient per unit of weight than coaxial types. From present considerations, it appears that two types o:f this t'ac1lity' may be requi.red. 

a. The first type, an ultra lightweight cable would be intended 

primarily for use within the division and would have a frequency pass band 

euitable for tran1mitting four-cbe.nnela of the carrier telephone system. In 

this connection, it would replace field wire tor use on the trunk circuits 

in the diviaion. It would probably be advantageous t-o employ loading coil• 

with this facility considering the relatively low cut-off frequency requiredo 

Thia would be provided in the connector associated with the cable. 

b. The second type, a lightweight spiral-four cable, would be 

employed for tranamisaion or 12 channel carrier telephone systems between 

Corpe and Division. Inasmuch as the cut-off frequency is considerably higher 

than in the previous caae, it le doubtful that efficient loading can be provided. Ho-wever, connectors for joining two lengths of cable together will be 

required. 

3. .field Wfre. At the preaent stage ot the art, it appears that 

a. wire of the WD-1( 7TT or WD-14( )/TT type when fully developed haa all the 

neceasary characteristiaa ior use !n local loop• and extended forward area 

operations on. a voice-frequency baai1. Continuation of the development of 

these two typea of Wire, it. is believed, will fulfill the requirements for 

Army field wire. 

4. Besearch. In 'ri.ew ot the large vo1um.e of this material consumed 

during war time, it is essential that a continuing study on insulating, con--

ducting and protective materials be made in order that advantage can be taken 

of auch improvements in the art u are made and in order that the Army may 

be familiar vith all eimilar materials which may be 'ropoaed as possible 

aubaU tutee. 

15 
REF ID:A68389 

E. TeJ;epJlQpe fsuiR)nent. 

l. lJniyer•al h1Ucbbs'G· Military characteriat.ica have recently been approved tor a unive:ra..i, common battery, local batte17 1witchboard, part 

ot AN/TTC-4. 'l'hia board will ban a capability of approxima.tely 1000 lines 

and will be capable of exteneion to ae man;r positions a1 the trattic requires. 

It is anticipated that it will be built with bookca•e type construction with 

a minimum of 15 cord circulta at eaah operator•• position. Jr.a.ch ot the line 

circuit& will be capable of being employed as either a common b&tt.ery or local 

battery circuit with simple wiring change. As a univer•~ awitchboard, it 

will be capable of accommodating all radio circu:l ta lfhi.ch are required to be 

employed in the integrated communications ayatem. .At preeent, plans are 

being mde for accommodating so-called full duplex radio circuits operated 

on a continuous o-r intermittent baaia as diacuseed previoual.7. Decision is 

required aa to whether other torma of radio circuit operation will be permitted in the integrated ay8t9lll ao that the design will include the proper 

prorleiona. The jack ~:ppearancea at each position will be a:tmUar. The type 

ot construction and circuit• employed will proTide a very nextble switchboard 

which ia capable of expansion tro11 60 to 1000 lines with a minimm of equipment 

alld installation e:t'i"ort. 

2. Mage\g Switch]?gatd• Inasmuch as common la ttery operation ie 

neyer uaed at division headquarter&, Army Ground Forces has nropoeed the 

development of a magneto awitchboard. with a capacity of 40 linea per poaition 

and capable or expansion to a three position multiple board with 120 l1ne 

capacity. While it would be desirable to employ the universal nitchboard 

described above, nen at Division headquei.rters, it is felt that the line 

relays and other extra equipment used in that switchboard lJDllecesss:rily 

complicated the division headquarters problem. Discussion of lJrOVisiona 

-ror accOT11modating radio circuit in the paragraph just above, apply to 

this Pitcbboard also. Nomenclature Telephone Central Office Set AN/'l'TC-5 

has been assigned to this item and military characteristics eubnitted by 

the Army Ground Forces~ 

3. field SwJ.tohb;zf£d.. Switchboard SB-22/P'l' now under development 

ia an eight-line patch cord type of board which is capable of stacking in 

euch a manner that four ot these board• may be operated together without 

undue e.t'fort giving a total capacity of 32 lines. It 1a believed that completion ot this development will solve the lightweight field switchboard 

problem at the present time. 

4. Jli!l l!leRhone Sz•ta• There has been considerable discueaion 

ot the posaib111tiee or applT!ng the dial telephone r.>rinciple to Arrq communication sy•tem.a. The use of dial bitching equipment at Corpe and higher 

echelons can materially reduce .the operator load with a corresponding reduction in operating personnel required on these switchboards. It is generall7 

conceded that dial •ri.tching equlpnent aa at present designed, 1• not suitable 

far taetioal ue, due pr1nc1pall)t to ita weight and structurt:.1. design. However, it ia the opimon of these Laboratories that a care£ul 11tud1 could 

reault in the design of dial switching equipment of such weight and unit 

conatruction a• to 'te adapt.able to tactical uae. 

16 
l' 

REF ID:A6838'9 

a. In order to simplify dial equipment for field use, it is 

proposed that all local calls in a Corps, Army or Army- Group Central be completed by station dialing. An 11 overiding blltiy feature" will be evailabl.e to 

the sw1tchboa.rd operator so that priority I 1ervice will remain evailable to 

authorized personnel. Calls to outside entchboards will be completed by 

manual operation,· using Telephone Central Office Set .AN/'l'TC-4. A dial on 

the keyselt of this board ldll provide a trunk die1ing feature. 

b. In order to determine tho e:x:tetit to which a dial. system 

my be efficiently emplo;yed in the Arm;y communication s;yatam,. a dial system 

especially designed ror mobile field use over tactical communication circuits 

should be provided for field trials. Nomenclature Telephone Centra1 Office 

Set AN/'!'TC-6 has been aeaigned tor a trial switchboard and suggested military 

characterist!ca prepared. 

• 5. Remate Control Egm,pment,. 'l"'nere is a requirement tor universal 

remote control equipment for operation of single channel radio tranceivers 

from a two-wire line where the radio circuit ia oprn-ated on a f'ull duplex 

or equivalent tour-wire basis and the operation of the radio transmitter 

ia ttader the control of the switchboard operator. Two proposals for equipment to achieve this method ot operation have been given preliminary test 

and appear feasible. Both proposal.a permit normal switchboard operation 

and require little or no additional apparatus at the switchboard. 

6. TeieJlh9ne §tati~Set. Military characteristics have been 

approved for !elephone TA-AS which is a 'Ulliversal telephone set for 

attachment to either local or coDIDlon batte17 lines to replace Telephone 

EE-8-( ). While extreme light weight appears to be the important consideration in development of this telephdne1 a number of conflicting addit.ional 

requirements have been added to complicate the design. It is felt that 

some of these requirements a.re of use in onl.y a VfJry small percentage of 

the cases and might be eliminated without detracting from the usefulness 

ot the telephone set. Inasmuch as the handset is the most important feature 

0£ the telephone, the report ot the appropriate committee considering the 

item will be or value in anticipating the u1timate design. 

7. Tetegra;eh F..guitpent. The development of equipment fo1· the improved telegraph IY'&teia of the future 1'ollowa two general trends, improvement or 

the te1etypewriter tor Arf'll¥ use and extension ot transmission on a voice-

:trequency basis throughout the sy1tem, including the local loops. A description of the required equipment development to achieve this objective followa. 

1. Pye T:me Telet:mewriter. Development of a page type teletypewriter specially designed for Arrq use is now being conducted.. Nomenclature 

Teletypewriter T'l'~TG, part o:t Teletype11.Titer Set .AN/PGC-1, has been assigned • 

.As mentioned pr_e'lioualy', it is expected that the weight of' tbi11 unit will be 

only 25% of the present atandard Metypewri ter TG-7-( ) • Improvement in 

mecbanical reliability and weatherproofing te~nj.ques will also be features 

17 
REF ID:A68389 

of thia machine. The equipment will be able to operate directly on field 

lines without the use ot a line relay or separete line unit. Inasmuch a1 

development of this machine we.a in1tieted on an expedited basis before the 

end ot the Pacific war, all the desirable features and characteriatica "111 

not be incorporated in the first models and further improvement should be 

permitted on a long term be.sis. 

2. f'aRe T-r.ae 'leletypewri ter. A tape teletypewriter 111 inherently 

lighter in weight than the page type lll8Chine with the same general construction 

since the bulk;y carriage, paper holder and paper teed mechani8Jll are not nece&S&rJ"• 

Development of an ultra-lightweight machine of tbia type tor use iPI extreme 

forward areas to auppleinent or replace the telephone end Jl.Torse code te1egra!Jh7 

is required. As visualized, this unit would be arranged for operation eit."1er 

by manually applied power or by a low current drllin electric ~otor at the option 

of the user. It would also be capable of operation on a point-to-point basis 

and would 1nteropera te w1 th page type tel.etypewri ters now in use and under 

development. 

3. .Y,n1versa1 Voice-.Freguency Telegraph Tranmnission yg,tje. In 

order to extend the advent.ages of voice-frequency tranSJ.BiSSion of te1egraph 

signals throughout the sy-stem, it is pro:)oaed to develop a unit which is 

capable or operating on a ha1f duplex baeis on tele~hone lines having 

losses varying from 0 to JO db rl thout adjustment. Development o·f such 

equipment will eliminate the necessity for separate telegraph awl tchboarda, 

repeaters, and other mtching and transmission apparatus. Two general 

applications are visualized as follows1 

a. Cgmbinati9n Telephone-T~letyoewri ter Station Set. The 

station set connected to the telephone switchboard would be capable of 

operation either as a telephone or telet;ypewriter at the option of the user. 

Placement end reception ot calls would be by use o:t the telephone. The 

teletypewriter could be placed on the line when desired by operation of a 

simple switch and would trana..lJlit and receive thro1J€h the voiee-.f'requency unit 

described above. Automatic restoration to the telephone position when the 

station set is in the atari..d.-by condition would be a feature. This equipment 

ia expected to haTe considerable application for use by start officers where 

security end accuracy of communication trom station to station is 1mportent. 

b. Teletypewriter StatJ.on Unit• lf'nere the voice-f'requeney 

unit is part of a teletypewriter station set connected to s teletypewriter 

central office s~me ~eana of siglllllling the operator must be ~ded. 

Since it ie expected that the teletypewriter switchboard wil.l be operated 

similar to an all magneto telephone awitchboard, it is expected that 20 

cycle ringing generators 1'1111 be uaed at the eta tion set for signalling 

purposes. Coneiderable experiment will be required to determine the best 

method of communicating with the operator and placing cells. 

i• 
\ 

REF ID:A68389e 

4. T1letypewriter Switchboa1."d., With the wide 1presd use of voieefreq11ency telen-aph transmission, it is expected that separate development 

of telegraph switchboards will not ~ required since telephone switchboards 

will be adequete for the purpose. The magneto switchboard of Telephone Central Office Set AN/TT0-5 should provide all necessary racilities. The 

operator's teletypewriter set would be similar to the stetion teietypewriter 

aet discussed in suhparagreph 3 ~ust above, and would be connected in place 

ot the operator's telephone set. Signalling over loce.l loops would be by 

means of a 20 cycle ringing generator but the method of aignalling over 

trunks will require some experimentation to determine.. It is e:xpectea t}lat 

devel.opment or equipment of this type will greatly improve eht ease, flexibility, and accuracy ot telet1P8 operation and considerably reduce the number 

of equipments required in wire communications. 

5. Inyestigatiop and Rfsearch. ~or continuing improvemertt of the 

telegraph eyBtem, it is considered necessary thst the following 1nvestigst1ons 

be pursued on a long term basisa 

a. Investigation of the telautograph principle to determine 

its application, if &?11'1 in the Army communications system. Present telautogrnph apparatus is operated on a d-c basis and is heavy, cumbersome, and 

not too accurate. There is some expectation that extension of this principle 

to operation on a voice-frequency baeis would provide lighter weight, more 

reliable equipment for transm.iasion of written messages. 

b. Determination or optimun keyboard arranger1ent for the teletypewriter. There has bean considerable contention that the present arrangement of the letters on the teletypewriter keyboard are not the most ideal ror 

fast operation. It is suggested.that the Army participate with industry a:nd 

other Government departments in determining a suitable keyboard ar.range"lent. 

c. Investigation of lu'br~.cants and inks employed in teletypewriters with the aim of providing improved service over extended climatic 

conditions. 

d. Investigation for :lmprov9ent of teletypewriter paper and 

paper handling devices. 

e. Determination of an optimum transmission speed. While the 

normal tiranamiseion speed at present ia 60 words per minute, it~is entirely 

feasible to materially' increase this :rate. There has been considerable 

operation on commercial tacilities at 75 words per minute and 100 words per minute, although the latter is at111 mostly in an experimental stage. .Although 

1ncrea1ed speed is probabl:y desirable, it would appear impractical to increaae 

it be;rond a certain limit. Factors pertaining to this limit area 

(1) Increased signalling 1peed reduces the TB.nge and 

margin of line and station equipment. 

(2) Increased aignal.11~ frequency requires broader bend 

widths and coneequently reduces the number of channel• 

a'V&ilable in a~ given band width. 19 
. 

' 

REF ID:A68389 

(3) At speeds above the norm.el operator typing rate, a profJOrtionate 1ncre6se in personnel and equipment is required 

to ptepare traffic for automatic transmission in order to 

effect most efficient circuit utilization. 

(4) Reliability and maintenance requirements tor mechanica1 

equipment -~e affe~ted adversely at increased speeds. 

a. LiM F.auipment. In thi~ category, radically new equipment and techniques are required. With. the gx:eat improveraent in cable meaae.ge hP.ndling 

ability through the use or' new transmission equipment, it is upected that 

there will be 11 ttle or rt.Jl pl.ace .in the Army communication system for openwire line construction as we kno,. it today. Lea• than 1/2 the weight o£ 

equipment and considerably less effort will be required to install cable o~ 

equivalent message handlin& ability. Discussion or line construction equip-

:nent is divided into two phases, _!!quipm.ent required for the tactical area and 

that required for the zone ot communications or other stable areas. 

1. Tactical Line Construction &uiment. It ia ex;;>ected that the 

epeed and security demanded in the construction of wire lines in tactical ~reas 

will be such that no possible construction technique should be allowed to 

remain unexplored. Equipment development and inve&titations required follow. 

a. .W,gh Speed Coils. Development or this method of packaging 

wire and cable should be extended to cover all types used in the tactical 

plant. Improvement of the methods and machinery used should be maC:e so that 

wire and cable 111a;y be payed out at speeds up to .20~ miles per hour. 

b. Poles. .Development should be conducted to produce small 

lightweight poles to conserve shipping space and reduce total Neieht of l.ine 

con&truction equipment. i.1etal poles are indicated. The following general 

types are suggested• 

(1) Round •ectional poles similar to pipe section11. 

(2) Tapered seci.ional poles. 

(3) Tripid supported structures which are suitable for placetnent from a helicopter or other airplane without the 

necessity for digging pole holes, 

c. Pole Erection. 'Iruck K-44 pole hole digging equipment ie 

unsatisfactory in all reapecta. A completely new and much more rugged vehicular 

pole hole di£ging equipment, designed aroUDd a standard Ordnance or Corps of 

Engineer's chassis is required. Portable hole digging equipment ia required. 

1''urther investigation of e.xplosive methods of producing suitable pole holes ia 

suggested. \\'ith the use of smaller diameter poles, it is quite posaibl.e that 

simpler methods such as the use of a hand auger or l!lal.let and apike may be 

aUfficient in most instances. 

20 
.(' REF ID:A6838 • 

• 

, d. ME E\ptat.J.op et W1re.Jane1.. Ir the weight of the 1'1.re and 

cable can be made su:ff'icientl,- light Tihile retaining its longitudinal strength, 

considerably longer spans can be tolerated. Thia would be .pnrticulerly advantageous for traversing difficult and inaccessible areas where pole' can not be 

readily erected. Investigation of employment of small kite balloons from which 

the cable or wire is suspended as a means for obtaining increased sir flotation 

i• suggested. 

e. V.!!U,q.:J.es apd PJiaus. Inasmuch aa the erection of communication lines is a civil engineering conatruction oroblem simil&r to those encountered by the Corps of Engineers, it is considered that special purpose vehicles 

are justified for this work. Some of the vehicles and planes which &hau.ld be 

considered tollow. 

(1.) A line conatruction truck equipped with an extensible 

side platform and derrick so that poles ma7 be erected 

&nd equipment moved off the side of the ro~.a -,ii thout the 

neceaaity for the personnel coming 1n contact witb the 

ground and encountering mine fields.should be developed. 

(2) The helicopter haa considerable potentiality for line 

conatruction use. It can be UBed as auxiliary to the 

line construction and supply truck for placing a line 

well off the road, removing it from danger or damage 

tv friendly vehicles. It is 'Visualized that poles cen 

be set and cables placed b,y the use of this machine. 

It a helicopter of' autficient capacity is available, 

it is possible that it could be used to carry the 

equipment and carry on the construction work without 

the necesait7 for frequent trips to the SU(>ply truck. 

(.3) It is believed that in mafl3" cases sub-aurf'a.ce co11-

struot1on may be feasible and desirabl.e even aa far 

.forward as division command posts. Thia is particularly 

t.t'ue when th• situation is such that following higher 

echelon• will in turn take over and supplement the 

existing communication axle. ~·or this purpose, it ia 

required that a small plow capable of' plowing-in two 

light'l'eight apirBl-four cables be developed tor use in 

conJmction "1th the 6 feasel" or similar tracked vehicle. 

t. Laying of wire on the surface or the ground from planes has 

already been succe•s~ aocompl!•hed. .trurther experimentation a.long thia 

line should be carried out. Some consideration might be given to the use of ~be rocket principle for accompli•hing this mission. 

2. Csu11tructiop tor StQ!>le ,Areas. It is believed the.t line construction in this region •111 be mo1tly' subterranean, since thie appears to 

be the i1lO&t eec'lll'e ot tb.e various construction methods. In general, coaxial 

cable will be emplo7ed and a suitable vehicle for placintt this cable is required. Since thi• type of construction is a ma~or civil engineering problem, 

21 
I 

-\ 

REF ID:A68389 

it 1a again considered that special purpose vehicles similar to those ueed 

by the Corpa of Engineers will be required. 'l'he p1ow and prime mover shou1d 

be one unit equipped with treads for traversing all typee or terrain. The 

vehicle llhould be capable of bm"Ting two cables eimultaneoualy to depthe of 

at leaat 30 inches when 0.111ernti:...g at speeds up to 15 miles par hour. In 

places it Yt1.ll be required that aerial construction be resorted to. Extension 

ot the e.erlal conatruct.1.o.1:1 t.ecbm-ques diacusaed just above to cover this field 

should mnt requiremen._~.· -( 

3. FaW.;t tQ~j:.~n :rg,l.~1nant. \'iith the greatl.y increased uae of 

cablee, eap:;cially coa.-.rJ.e.1 cabl rs, and the hig!ie1"' i'reque.n.cies er.1ployed in 

tre.nsm1sa1on, 1 \. is pa.S"'t1$~ult!.rl~· important that improl'ed taul. t loea tion 

equipment be provided fot.·. use a• ... a teat boP.rd in the central office end by" 

the lineman in tbe field.. t>eve.; ppment of the following types o:f equipment 

ia required& i ~-· 

'.), r-r 

a. Pu1se ftrJ'l.ectipu &lmament 1 F.quipment employing t.liis 

method transmi ta high t.requency pulses which ere reflected back along the 

line when impedance irregul.B.ritiea are encountered. Readings are obtained 

on a cathode ra7 tube. Thi11 is essentially a .Rada? technique applied to 

wire lines. It is capable of detecting faults and potential faults l't!l.ich 

are not fouud by any other method. While some development of this tjpe of 

equipment ns made during '1orld War II. further development ia required 

since the need will be mo.re acuiie in future communication systems. It is 

visualized that this equ1~ent will be the main component of a wire chief'• 

test board used at •very System Control Center. Development ot a similar 

type equipment of conaidere.bly emaller size for uae by the linemen in 

localizing trouble is also required. 

b. 'J9,ne Tea~ Seti. The Uf.\e of sub-audio tone teat sets and 

electrostatic and magnetic pick-up devices for location of faults on cables 

is now used to some extent in tbe commercial ple.nt. It 1t'ill be necessary 

to adapt and improve this equipment for Army field use. 

~::~:rr J~i. Col.~ Sir,nal Carps 

~~· 

1st 

if~ tt., Signal Corps 

Member 

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