The Type UCII class minelaying submarine UC-55 was ordered on 12th January 1916 from the Kaiserliche Werft yard in Danzig. Her keel was laid on 25th February (Yard No 37) and she was launched on 2nd August that year. She measured 50.52 metres x 5.22 metres x 3.61 metres and displaced 415 tons on surface and 498 tons submerged. Her twin propeller shaft were powered by 2 x 6 cylinder 4 stroke diesel engines for surface travel delivering 580 – 600 metric shaft horsepower and 2 x electric motors for underwater travel delivering 610 metric shaft horsepower. She was fitted with six 100 centimetres mine tubes, eighteen UC 200 mines, three 50 centimetres torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8cm Uk L/30 deck gun. Her standard complement was twenty-six crew members. After her trials she was commissioned into the German Imperial Navy on 15th November 1916. she was to complete 6 active patrols and was credited with sinking 9 Allied ships either by torpedo or by the mines she laid although her one victim in Scottish waters, HMS Albacore, was probably the victim of another U-boat UC-44.
UC-55 in dry dock
On 25th September 1917 UC-55 headed out of her home port at Heligoland destined for her latest mission to lay her deadly mines in the Lerwick shipping channel off Shetland. A few days later, on reaching her target area on 29th September, she began laying her mines but, almost immediately something went wrong and she lost her trim, which plunged her deep down beyond her normal maximum operating depth of 50 metres. The resultant hull pressure caused multiple leaks and, with water pouring in and reaching her batteries causing chlorine gas to develop, her commander Oberleutnant sur Zee Horst Ruhle von Lilienstern was left with no choice but to blow her tanks and surface to avoid the poisonous fumes building up inside the submarine. As she breached the surface, and with a further issue with her steering, she was exposed and helpless.
HMS Sylvia
HMS Tirade
The floundering U-boat was quickly spotted by two British destroyers, HMS Tirade and HMS Sylvia and the armed trawler Moravia. The two destroyers sped toward the submarine and started firing at her when the reached to within three miles. The exact sequence of what happened next is somewhat confused due to the various differing reports from the destroyer crews and the German survivors. The Germans claimed she went down due to the firing of the explosive charges the crew had placed inside the U-boat but British versions indicated that she was hit by 12 pounder shell from HMS Sylvia killing her commander then by multiple shells from both destroyers before she was finished off by two or three depth charges fired as she began to sink. Of her crew of 27 10 men were lost and 17 recovered and taken prisoner.
The wreck of UC-55 lies in position 60° 03.186’N, 00° 58.067’W lying in 103 metres with a least depth clearance of 97 metres. The 50 metre long wreck is oriented 015.195 degrees. The wreck was dived by a team of divers in July 2023 and confirmed as the wreck of a UC class submarine, undoubtedly UC-55.
