SM U-31 (Austria-Hungary)

History
Austria-Hungary
NameSM U-31
Ordered12 October 1915[1]
BuilderGanz Danubius, Fiume
Laid down4 July 1916[2]
Launched20 March 1917[3]
Commissioned24 April 1917[4]
FateScrapped 1920
Service record
Commanders:
  • Franz Nejebsy
  • 24 April 1917 – 2 January 1918[4]
  • Hermann Rigele
  • 11 March – 31 October 1918
Victories:
  • 2 merchant ships sunk
    (4,088 GRT)[4]
  • 1 warship damaged
    (5,250 tons)
General characteristics
TypeU-27-class submarine
Displacement
  • 264 t (260 long tons) surfaced
  • 301 t (296 long tons) submerged[3]
Length121 ft 1 in (36.91 m)[3]
Beam14 ft 4 in (4.37 m)[3]
Draft12 ft 2 in (3.71 m)[3]
Propulsion
Speed
  • 9 knots (17 km/h) surfaced
  • 7.5 knots (14 km/h) submerged[3]
Complement23–24[3]
Armament

SM U-31 or U-XXXI was a U-27 class U-boat or submarine for the Austro-Hungarian Navy. U-31, built by the Hungarian firm of Ganz Danubius at Fiume, was launched in March 1917 and commissioned in April.

U-31 had a single hull and was just over 121 feet (37 m) in length. She displaced nearly 265 metric tons (261 long tons) when surfaced and over 300 metric tons (295 long tons) when submerged. Her two diesel engines moved her at up to 9 knots (17 km/h; 10 mph) on the surface, while her twin electric motors propelled her at up to 7.5 knots (13.9 km/h; 8.6 mph) while underwater. She was armed with two bow torpedo tubes and could carry a load of up to four torpedoes. She was also equipped with a 75 mm (3.0 in) deck gun and a machine gun.

In October 1917, U-31 sank while in port at Porto Bergudi and was out of service through April 1918 while she was raised and repaired. During her service career, U-31 sank two ships and damaged one warship, sending a combined tonnage of 4,088 to the bottom. U-31 was at Cattaro at war's end and was awarded to France as war reparation in 1920, towed to Bizerta and scrapped there.[5]

  1. ^ Miller, p. 20.
  2. ^ "Tengeralattjárók" (PDF) (in Hungarian). Imperial and Royal Navy Association. pp. 25–26. Archived from the original (PDF) on 11 October 2021. Retrieved 22 January 2009.
  3. ^ a b c d e f g h i Cite error: The named reference Con-344 was invoked but never defined (see the help page).
  4. ^ a b c Helgason, Guðmundur. "WWI U-boats: KUK U31". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 22 January 2009.
  5. ^ Gibson and Prendergast, pp. 388–89.