SM UB-23

SM UB-45, a U-boat similar to UB-23
History
German Empire
NameUB-23
Ordered30 April 1915
BuilderBlohm & Voss, Hamburg
Yard number253
Launched9 October 1915
Commissioned13 March 1916
FateInterned at Corunna, Spain, 29 July 1917
General characteristics
Class & typeType UB II submarine
Displacement
  • 263 t (259 long tons) surfaced
  • 292 t (287 long tons) submerged
Length
Beam
  • 4.36 m (14 ft 4 in) o/a
  • 3.85 m (13 ft) pressure hull
Draught3.70 m (12 ft 2 in)
Propulsion
Speed
  • 9.15 knots (16.95 km/h; 10.53 mph) surfaced
  • 5.81 knots (10.76 km/h; 6.69 mph) submerged
Range
  • 6,450 nmi (11,950 km; 7,420 mi) at 5 knots (9.3 km/h; 5.8 mph) surfaced
  • 45 nmi (83 km; 52 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth50 m (160 ft)
Complement2 officers, 21 men
Armament
Notes45-second diving time
Service record
Part of:
  • Flandern Flotilla
  • 19 May 1916 – 29 July 1917
Commanders:
  • Oblt.z.S. Ernst Voigt
  • 13 March – 9 November 1916
  • Oblt.z.S. Heinz Ziemer
  • 10 November 1916 – 5 February 1917
  • Oblt.z.S. Herbert Lefholz
  • 6 – 18 February 1917
  • Oblt.z.S. Matthias Graf von Schmettow
  • 19 February – 19 March 1917
  • Oblt.z.S. Hans Ewald Niemer
  • 20 March – 29 July 1917
Operations: 21 patrols
Victories:
  • 51 merchant ships sunk
    (33,880 GRT)
  • 1 merchant ship damaged
    (419 GRT)

SM UB-23 was a German Type UB II submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 30 April 1915 and launched on 9 October 1915. She was commissioned into the Imperial German Navy on 13 March 1916 as SM UB-23. The submarine sank 51 ships in 21 patrols for a total of 33,880 gross register tons (GRT). On 26 July 1917, UB-23 was badly damaged by a depth charge attack by HMS PC-60 off the Lizard; she put in at Corunna, Spain, on 29 July 1917 and was interned. On 22 January 1919 she was surrendered to France in accordance with the requirements of the Armistice with Germany, and she was broken up in Cherbourg in July 1921.