SM UC-70

SM UC-70 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 and was launched on 7 August 1916. She was commissioned into the German Imperial Navy on 20 November 1916 as SM UC-70. In ten patrols UC-70 was credited with sinking 33 ships, either by torpedo or by mines laid. On 28 August 1918, UC-70 was spotted lying submerged on the sea bottom and attacked by a Blackburn Kangaroo patrol aircraft of No. 246 Squadron RAF and then was then sunk by depth charges from the British destroyer HMS Ouse (1905). The wreck is a Protected Wreck managed by Historic England.

Design
A Type UC II submarine, UC-70 had a displacement of 427 t when at the surface and 508 t while submerged. She had a length overall of 50.35 m, a beam of 5.22 m, and a draught of 3.64 m. The submarine was powered by two six-cylinder four-stroke diesel engines each producing 300 PS (a total of 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 12 kn and a submerged speed of 7.4 kn. When submerged, she could operate for 52 nmi at 4 kn; when surfaced, she could travel 10420 nmi at 7 kn. UC-70 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.

Loss
UC-70 was depth charged and sunk off Whitby, Yorkshire on 28 August 1918 with the loss of all 31 crew. The wreck was given protected status by Historic England in 2017.