German submarine U-657

History
Nazi Germany
Name	U-657
Ordered	9 October 1939
Builder	Howaldtswerke, Hamburg
Yard number	806
Laid down	5 October 1940
Launched	12 August 1941
Commissioned	8 October 1941
Fate	Sunk on 17 May 1943 in the North Atlantic in position 58°54′N 42°33′W / 58.900°N 42.550°W / 58.900; -42.550, by depth charges from HMS Swale.
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced 871 t (857 long tons) submerged
Length	67.10 m (220 ft 2 in) o/a 50.50 m (165 ft 8 in) pressure hull
Beam	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull
Draught	4.74 m (15 ft 7 in)
Installed power	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels) 750 PS (550 kW; 740 shp) (electric)
Propulsion	2 shafts 2 × diesel engines 2 × electric motors
Speed	17.7 knots (32.8 km/h; 20.4 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement	4 officers, 40–56 enlisted
Armament	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) 14 × torpedoes 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 1 x 2 cm (0.79 in) C/30 AA gun
Service record[1]
Part of:	8th U-boat Flotilla 8 October 1941 – 28 February 1942 3rd U-boat Flotilla 1 March – 30 June 1942 11th U-boat Flotilla 1 July 1942 – 17 May 1943
Identification codes:	M 38 963
Commanders:	Oblt.z.S. Hans-Jürgen Radke[2] 8 October – 14 December 1941 K.Kapt. Heinrich Göllnitz[3] 20 December 1941 – 17 May 1943
Operations:	7 patrols: 1st patrol: 26 March – 11 April 1942 2nd patrol: 17 June – 9 July 1942 3rd patrol: a. 23 July – 16 August 1942 b. 17 – 20 August 1942 c. 22 – 27 August 1942 d. 4 November 1942 e. 12 – 13 November 1942 f. 14 – 15 November 1942 g. 18 – 21 November 1942 4th patrol: a. 22 November – 25 December 1942 b. 20 – 21 January 1943 5th patrol: 23 January – 14 February 1943 6th patrol: a. 15 February – 15 March 1943 b. 16 – 19 March 1943 c. 24 – 28 April 1943 7th patrol: 4 – 17 May 1943
Victories:	1 merchant ship sunk (5,196 GRT)

German submarine U-657 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 5 October 1940 by Howaldtswerke, Hamburg as yard number 806, launched on 12 August 1941 and commissioned on 8 October 1941 under Oberleutnant zur See Hans-Jürgen Radke.

Radke was killed in a fire while the boat was undergoing trials on 14 December 1941.^[2]

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-657 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[4] She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).^[4]

The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph).^[4] When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-657 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.^[4]

The boat's career began with training at 8th U-boat Flotilla on 8 October 1941, followed by active service on 1 March 1942 as part of the 3rd Flotilla in La Pallice, France. Four months later, she transferred to 11th Flotilla, in Bergen, Norway, for the remainder of her service.^[1]

In seven patrols she sank one merchant ship, for a total of 5,196 gross register tons (GRT).

U-657 took part in six wolfpacks, namely:

• Naseweis (31 March – 10 April 1942)
• Eisteufel (21 June – 8 July 1942)
• Nebelkönig (27 July – 14 August 1942)
• Nordwind (24 January – 4 February 1943)
• Iller (12 – 15 May 1943)
• Donau 1 (15 – 17 May 1943)

U-657 was sunk on 17 May 1943 in the North Atlantic, E of Cape Farewell, Greenland, in position 58°54′N 42°33′W / 58.900°N 42.550°W / 58.900; -42.550, by depth charges from Royal Navy frigate HMS Swale. All hands were lost.

Date	Ship Name	Nationality	Tonnage (GRT)	Fate[5]
17 May 1943	Aymeric	United Kingdom	5,196	Sunk

• Helgason, Guðmundur. "The Type VIIC boat U-657". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.