SM UB-23

SM UB-23 was a German Type UB II submarine or U-boat in the German Imperial Navy (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. 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.

Design
A Type UB II submarine, UB-23 had a displacement of 263 t when at the surface and 292 t while submerged. She had a total length of 36.13 m, a beam of 4.36 m, and a draught of 3.70 m. The submarine was powered by two Körting six-cylinder, four-stroke diesel engines each producing a total 280 PS, a Siemens-Schuckert electric motor producing 206 kW, and one propeller shaft. She was capable of operating at depths of up to 50 m.

The submarine had a maximum surface speed of 9.15 kn and a maximum submerged speed of 5.81 kn. When submerged, she could operate for 45 nmi at 4 kn; when surfaced, she could travel 6650 nmi at 5 kn. UB-23 was fitted with two 50 cm torpedo tubes, four torpedoes, and one 5 cm SK L/40 deck gun. She had a complement of twenty-one crew members and two officers and a 45-second dive time.