SM UC-47  SM "UC-47" was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy () during World War I. The U-boat was ordered on 20 November 1915, laid down on 1 February 1916, and was launched on 30 August 1916. She was commissioned into the German Imperial Navy on 13 October 1916 as SM "UC-47". In 13 patrols "UC-47" was credited with sinking 56 ships, either by torpedo or by mines laid. "UC-47" was rammed and depth charged by British patrol boat "P-57", under the command of H.C. Birnie, off Flamborough Head on 18 November 1917. "UC-47" went down with all hands. A German Type UC II submarine, "UC-47" had a displacement of when at the surface and while submerged. She had a length overall of , a beam of , and a draught of . The submarine was powered by two six-cylinder four-stroke diesel engines each producing (a total of ), two electric motors producing , and two propeller shafts. She had a dive time of 48 seconds and was capable of operating at a depth of . The submarine had a maximum surface speed of and a submerged speed of . When submerged, she could operate for at ; when surfaced, she could travel at . "UC-47" was fitted with six mine tubes, eighteen UC 200 mines, three torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one Uk L/30 deck gun. Her complement was twenty-six crew members.