German submarine U-1055 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 30 March 1943 by Friedrich Krupp Germaniawerft, Kiel as yard number 689, launched on 9 March 1944 and commissioned on 8 April 1944 under Oberleutnant zur See Rudolf Meyer.
She was fitted with a Schnorchel underwater breathing apparatus in November 1944.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-1055 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two AEG GU 460/8âÂÂ27 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-1055 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, (220 rounds), one Flak M42 and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
The boat's career began with training at 5th U-boat Flotilla on 8 April 1944, followed by active service on 1 December 1944 as part of the 11th Flotilla for the remainder of her service.
In two patrols she sank four merchant ships, for a total of .
On 6 April 1945 U-1055 was attacked by MTB-715 and MTB-719; apparently undamaged U-1055 went missing on 23 April 1945 in the North Atlantic with no explanation after sending a message while en route to the English Channel. All hands were lost. Other accounts (Flypast April 2021) state that U-1055 was sunk west of Brest shortly after 18:00 on 30 April by an anti-submarine PBY-5 Catalina commanded by Lt. F. G. Lake of 19 Group, but this attack actually resulted in the sinking of .