German submarine U-31 (1936)

U-33, a typical Type VIIA boat
History
Nazi Germany
NameU-31
Ordered1 April 1935
BuilderAG Weser, Bremen
Cost4,189,000 Reichsmark
Yard number912
Laid down1 March 1936
Launched25 September 1936
Commissioned28 December 1936
Recommissioned30 July 1940
Decommissioned24 March 1940
Fate
  • Sunk, 11 March 1940, raised
  • sunk again 2 November 1940
General characteristics
Class and typeType VIIA submarine
Displacement
  • 626 t (616 long tons) surfaced
  • 745 t (733 long tons) submerged
Length
  • 64.51 m (211 ft 8 in) o/a
  • 45.50 m (149 ft 3 in) pressure hull
Beam
  • 5.85 m (19 ft 2 in) o/a
  • 4.70 m (15 ft 5 in) pressure hull
Height9.50 m (31 ft 2 in)
Draught4.37 m (14 ft 4 in)
Installed power
  • 2,100–2,310 PS (1,540–1,700 kW; 2,070–2,280 bhp) (diesels)
  • 750 PS (550 kW; 740 shp) (electric)
Propulsion
Speed
  • 17 knots (31 km/h; 20 mph) surfaced
  • 8 knots (15 km/h; 9.2 mph) submerged
Range
  • 6,200 nmi (11,500 km; 7,100 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 73–94 nmi (135–174 km; 84–108 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth
  • 220 m (720 ft)
  • Crush depth: 230–250 m (750–820 ft)
Complement4 officers, 40–56 enlisted
Sensors and
processing systems
Gruppenhorchgerät
Armament
Service record[1][2]
Part of:
Identification codes: M 28 961
Commanders:
  • Kptlt. Rolf Dau
  • 28 December 1936 – 8 November 1938
  • Kptlt. Johannes Habekost
  • 8 November 1938 – 11 March 1940
  • Kptlt. Wilfried Prellberg
  • 30 July 1940 – 2 November 1940
Operations:
  • 7 patrols:
  • 1st patrol:
  • 27 August – 2 September 1939
  • 2nd patrol:
  • 9 September – 2 October 1939
  • 3rd patrol:
  • 21 – 31 October 1939
  • 4th patrol:
  • 19 November – 11 December 1939
  • 5th patrol:
  • 15 January – 4 February 1940
  • 6th patrol:
  • 16 September – 8 October 1940
  • 7th patrol:
  • 19 October – 2 November 1940
Victories:
  • 11 merchant ships sunk
    (27,751 GRT)
  • 2 auxiliary warships sunk
    (160 GRT)
  • 1 warship damaged
    (33,950 tons)

German submarine U-31 was a Type VIIA U-boat of Nazi Germany's Kriegsmarine during World War II. She was laid down on 1 March 1936 as yard number 912, launched on 25 September and commissioned on 28 December 1936.[1]

  1. ^ a b Helgason, Guðmundur. "The Type VIIA boat U-31". German U-boats of WWII - uboat.net. Retrieved 19 December 2009.
  2. ^ Helgason, Guðmundur. "War Patrols by German U-boat U-31". German U-boats of WWII - uboat.net. Retrieved 19 December 2009.