# German submarine U-128 (1941)

German submarine U-128 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II. She was sunk 17 May 1943, by American action.

## Design

German Type IXC submarines were slightly larger than the original Type IXBs. U-128 had a displacement of 1,120 tonnes (1,100 long tons) when at the surface and 1,232 tonnes (1,213 long tons) while submerged. The U-boat had a total length of 76.76 m (251 ft 10 in), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.76 m (22 ft 2 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.70 m (15 ft 5 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 metric horsepower (740 kW; 990 shp) for use while submerged. She had two shafts and two 1.92 m (6 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,450 nautical miles (24,910 km; 15,480 mi) at 10 knots (19 km/h; 12 mph). U-128 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) SK C/30 as well as a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of forty-eight.

## Service history

Ordered on 7 August 1939 from DeSchiMAG AG Weser in Bremen, U-128 was laid down on 10 July 1940, launched on 20 February 1941 and commissioned by Kapitänleutnant Ulrich Heyse on 12 May 1941.
The boat was a training vessel in the second flotilla until 30 November 1941 based in Wilhelmshaven. She was then based in Lorient.
During her six completed war patrols, U-128 sank 12 ships, for a total of 83,639 tons. On 1 March 1943 command was transferred to Kptlt. Hermann Steinert, who commanded her until her loss a few months later.

## Fate

On 17 May 1943, while operating in the South Atlantic near Pernambuco, two Mariner flying boats, PBM 74-P5 and PBM-74-P6 of the US Navy Patrol Squadron VP-74, made U-128 surface with depth charges. Two US Navy destroyers (USS Jouett and Moffett) also hit her with 5-inch gunfire. The crew opened the submarine's seacocks as they abandoned ship, scuttling the submarine. The final toll was seven dead but there were 47 survivors.

## Summary of raiding history

| Date | Ship Name | Nationality | Tonnage (GRT) | Fate | Position | Deaths |
| 19 February 1942 | Pan Massachusetts | United States | 8,202 | Sunk | 28°27′N 80°08′W﻿ / ﻿28.450°N 80.133°W﻿ / 28.450; -80.133 | 20 |
| 22 February 1942 | Cities Service Empire | United States | 8,103 | Sunk | 28°25′N 80°02′W﻿ / ﻿28.417°N 80.033°W﻿ / 28.417; -80.033 | 14 |
| 5 March 1942 | O.A. Knudsen | Norway | 11,007 | Sunk | 26°17′N 75°50′W﻿ / ﻿26.283°N 75.833°W﻿ / 26.283; -75.833 | 2 |
| 13 May 1942 | Denpark | United Kingdom | 3,491 | Sunk | 22°28′N 28°10′W﻿ / ﻿22.467°N 28.167°W﻿ / 22.467; -28.167 | 21 |
| 8 June 1942 | South Africa | Norway | 9,234 | Sunk | 12°47′N 49°44′W﻿ / ﻿12.783°N 49.733°W﻿ / 12.783; -49.733 | 6 |
| 21 June 1942 | West Ira | United States | 5,681 | Sunk | 12°28′N 57°05′W﻿ / ﻿12.467°N 57.083°W﻿ / 12.467; -57.083 | 1 |
| 23 June 1942 | Andrea Brøvig | Norway | 10,173 | Sunk | 12°10′N 59°10′W﻿ / ﻿12.167°N 59.167°W﻿ / 12.167; -59.167 | 0 |
| 27 June 1942 | Polybius | United States | 7,041 | Sunk | 10°55′N 57°40′W﻿ / ﻿10.917°N 57.667°W﻿ / 10.917; -57.667 | 10 |
| 8 November 1942 | Maloja | Norway | 6,400 | Sunk | 11°58′N 27°08′W﻿ / ﻿11.967°N 27.133°W﻿ / 11.967; -27.133 | 2 |
| 10 November 1942 | Cerinthus | United Kingdom | 3,878 | Sunk | 12°27′N 27°45′W﻿ / ﻿12.450°N 27.750°W﻿ / 12.450; -27.750 | 20 |
| 10 November 1942 | Start Point | United Kingdom | 5,293 | Sunk | 13°12′N 27°27′W﻿ / ﻿13.200°N 27.450°W﻿ / 13.200; -27.450 | 2 |
| 5 December 1942 | Teesbank | United Kingdom | 5,136 | Sunk | 03°33′N 29°35′W﻿ / ﻿3.550°N 29.583°W﻿ / 3.550; -29.583 | 1 |