SM UC-56

SM UC-56 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (Kaiserliche Marine) during World War I. The U-boat was ordered on 12 January 1916, laid down on 4 March 1916, and was launched on 26 August 1916. She was commissioned into the German Imperial Navy on 18 December 1916 as SM UC-56. In six patrols UC-56 was credited with sinking one ship by torpedo: the British hospital ship HMHS Glenart Castle. UC-56 suffered from mechanical breakdowns that prevented her from submerging. She put in at Santander, Spain, on 24 May 1918 and was interned there for the duration of the war.

Design
A Type UC II submarine, UC-56 had a displacement of 415 t when at the surface and 498 t while submerged. She had a length overall of 50.52 m, a beam of 5.22 m, and a draught of 3.61 m. The submarine was powered by two six-cylinder four-stroke diesel engines each producing 290 - 300 PS (a total of 580 - 600 PS), two electric motors producing 620 PS, and two propeller shafts. She had a dive time of 48 seconds and was capable of operating at a depth of 50 m.

The submarine had a maximum surface speed of 11.6 kn and a submerged speed of 7.3 kn. When submerged, she could operate for 52 nmi at 4 kn; when surfaced, she could travel 8660 to 9450 nmi at 7 kn. UC-56 was fitted with six 100 cm mine tubes, eighteen UC 200 mines, three 50 cm torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm Uk L/30 deck gun. Her complement was twenty-six crew members.

Fate
The U-boat was attacked with depth charges dropped by the USS Christabel (SP-162) on 21 May 1918. It was not capable of submerging again due to battle damage. On 24 May 1918, the U-boat arrived at Santander, Spain after a dangerous three-day voyage in a severely damaged condition. The crew of UC-56 were interned, the Germans reported to the Spanish authorities that their submarine had been seriously damaged by Christabel, and that they had had no choice but to take refuge in a neutral port.