The TNC allocated '' U-1057 '' to the Soviet Union . On 4 December 1945 , she arrived in Libau , Latvia , as British '' N '' - class '' N22 '' . On 13 February 1946 , the Soviet Navy allocated her to the Baltic Fleet . She was renamed '' S-81 '' on 9 June 1949 then sent to the reserve fleet on 30 December 1955 . '' S-81 '' went to the Northern Fleet as a test hulk and was later sunk in the Barents Sea on 24 September 1957 , during an atomic bomb test off of Novaja Zemlja . She was struck from the Soviet Navy on 16 October 1957 and broken up for scrap
atomic bomb test
1957 Soviet nuclear tests
German submarine U-1057