SM UC-78

SM UC-78 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 8 December 1916. She was commissioned into the German Imperial Navy on 10 January 1917 as SM UC-78. In twelve patrols UC-78 was credited with sinking 1 warship, either by torpedo or by mines laid. UC-78 was rammed and sunk by the British steamer Queen Alexandra west of Cherbourg on 9 May 1918.

Design
A Type UC II submarine, UC-78 had a displacement of 410 t when at the surface and 493 t while submerged. She had a length overall of 50.45 m, a beam of 5.22 m, and a draught of 3.65 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 30 seconds and was capable of operating at a depth of 50 m.

The submarine had a maximum surface speed of 11.8 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 10230 nmi at 7 kn. UC-78 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.