SM UC-69

SM UC-69 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: 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 22 December 1916 as SM UC-69.^{[Note 1]} In nine patrols UC-69 was credited with sinking 54 ships, either by torpedo or by mines laid. UC-69 was sunk after being accidentally rammed by U-96 near Barfleur on 6 December 1917. The wreck was accidentally discovered in November 2017 by the Dutch naval mine sweeper Zr.Ms. Makkum which was mapping the sea-bed off the French Normandy coast.^[1]

A Type UC II submarine, UC-69 had a displacement of 427 tonnes (420 long tons) when at the surface and 508 tonnes (500 long tons) while submerged. She had a length overall of 50.35 m (165 ft 2 in), a beam of 5.22 m (17 ft 2 in), and a draught of 3.64 m (11 ft 11 in). The submarine was powered by two six-cylinder four-stroke diesel engines each producing 300 metric horsepower (220 kW; 300 shp) (a total of 600 metric horsepower (440 kW; 590 shp)), two electric motors producing 620 metric horsepower (460 kW; 610 shp), and two propeller shafts. She had a dive time of 48 seconds and was capable of operating at a depth of 50 metres (160 ft).^[3]

The submarine had a maximum surface speed of 12 knots (22 km/h; 14 mph) and a submerged speed of 7.4 knots (13.7 km/h; 8.5 mph). When submerged, she could operate for 52 nautical miles (96 km; 60 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 10,420 nautical miles (19,300 km; 11,990 mi) at 7 knots (13 km/h; 8.1 mph). UC-69 was fitted with six 100 centimetres (39 in) mine tubes, eighteen UC 200 mines, three 50 centimetres (20 in) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm (3.5 in) Uk L/30 deck gun. Her complement was twenty-six crew members.^[3]