German submarine U-631

German submarine U-631 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 5 September 1941 by Blohm & Voss, Hamburg as yard number 607, launched on 27 May 1942 and commissioned on 16 July 1942 under Oberleutnant zur See Jürgen Krüger.

History
Nazi Germany
NameU-631
Ordered15 August 1940
BuilderBlohm & Voss, Hamburg
Yard number607
Laid down5 September 1941
Launched27 May 1942
Commissioned16 July 1942
FateSunk on 17 October 1943 in the North Atlantic in position 58°13′N 32°29′W / 58.217°N 32.483°W / 58.217; -32.483, by depth charges from HMS Sunflower.
General characteristics
Class and typeType VIIC submarine
Displacement
Length
Beam
  • 6.20 m (20 ft 4 in) o/a
  • 4.70 m (15 ft 5 in) pressure hull
Draught4.74 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
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)
Complement4 officers, 40–56 enlisted
Armament
Service record[1]
Part of:
Identification codes: M 22 458
Commanders:
  • Oblt.z.S. Jürgen Krüger
  • 16 July 1942 – 17 October 1943
Operations:
  • 3 patrols:
  • 1st patrol:
  • 19 December 1942 – 4 February 1943
  • 2nd patrol:
  • 6 March – 11 May 1943
  • 3rd patrol:
  • 18 September – 17 October 1943
Victories: 2 merchant ships sunk
(9,136 GRT)

Design

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German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-631 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.[2] 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 BBC GG UB 720/8 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).[2]

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).[2] 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-631 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 one twin 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.[2]

Service history

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The boat's career began with training at 5th U-boat Flotilla on 16 July 1942, followed by active service on 1 January 1943 as part of the 9th Flotilla for the remainder of her service. In three patrols she sank two merchant ships, for a total of 9,136 gross register tons (GRT).[3]

Fate

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U-631 was sunk on 17 October 1943 in the North Atlantic SE of Cape Farewell, Greenland, in position 58°13′N 32°29′W / 58.217°N 32.483°W / 58.217; -32.483, by depth charges from British corvette HMS Sunflower. All crew members died.[3]

Wolfpacks

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U-631 took part in seven wolfpacks, namely:

  • Falke (28 December 1942 – 19 January 1943)
  • Landsknecht (19 – 28 January 1943)
  • Stürmer (11 – 20 March 1943)
  • Seewolf 2 (21 – 30 March 1943)
  • Meise (11 – 27 April 1943)
  • Rossbach (27 September – 9 October 1943)
  • Schlieffen (14 – 17 October 1943)

Summary of raiding history

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Date Ship Name Nationality Tonnage
(GRT)
Fate[4]
29 December 1942 Ingerfem   Norway 3,978 Sunk
17 March 1943 Terkoelei   Netherlands 5,158 Sunk

References

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  1. ^ Helgason, Guðmundur. "The Type VIIC boat U-631". German U-boats of WWII - uboat.net. Retrieved 23 August 2014.
  2. ^ a b c d Gröner 1991, pp. 43–46.
  3. ^ a b Busch & Röll 1999.
  4. ^ Helgason, Guðmundur. "Ships hit by U-631". German U-boats of WWII - uboat.net. Retrieved 23 August 2014.

Bibliography

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