SM UB-55  SM "UB-55" was a German Type UB III submarine or U-boat in the German Imperial Navy () during World War I. She was commissioned into the Flanders Flotilla of the German Imperial Navy on 1 July 1917 as SM "UB-55". She operated as part of the Flanders Flotilla based in Zeebrugge. "UB-55" was sunk at 05:05 on 22 April 1918 at after striking a mine, 30 crew members lost their lives in the event. She was built by AG Weser, Bremen and following just under a year of construction, launched at Bremen on 9 May 1917. "UB-55" was commissioned later that same year under the command of "Kptlt." Ralph Wenninger. Like all Type UB III submarines, "UB-55" carried 10 torpedoes and was armed with a deck gun. "UB-55" would carry a crew of up to 3 officer and 31 men and had a cruising range of . "UB-55" had a displacement of while surfaced and when submerged. Her engines enabled her to travel at when surfaced and when submerged.