German submarine U - 51 ( 1938 ) German submarine " U - 51 " was a Type VIIB U - boat of the Nazi German " Kriegsmarine " that operated during World War II . She was ordered in November 1936 and laid down in February 1937 in Kiel . She was launched in August 1939 and commissioned in November . During her service in the " Kriegsmarine " , " U - 51 " conducted four war patrols and sank five enemy vessels for a loss of and one auxiliary warship of 4 , 724 GRT . She was a member of one wolf pack . She was sunk in August 1940 in the Bay of Biscay by a torpedo from a British submarine . Construction . " U - 51 " was ordered by the " Kriegsmarine " on 21 November 1936 ( as part of Plan Z and in violation of the Treaty of Versailles ) . She was laid down on 15 September 1938 by " F . Krupp Germaniawerft AG " , in Kiel as " Werk " 586 . " U - 51 " was launched on 11 June 1938 and commissioned on 6 August of that same year under the command of " Kapitänleutnant " ( " Kptlt . " ) Ernst - Günther Heinicke . On the surface the boat was powered by two supercharged MAN , 6 cylinder , 4 - stroke M6V 40 / 46 diesels giving a total of 2 , 800 to 3 , 200 bhp ( 2 , 400 kW ) at 470 to 490 rpm . When submerged , she was powered by two BBC GG 460 / 8 - 276 electric motors giving a total of 750 shp ( 560 kW ) at 295 rpm . " U - 51 " had five torpedo tubes ( four in the bow , one in the stern ) . She carried a total of 14 x torpedoes or 26 TMA mines and had a 8 . 8 cm SK C / 35 deck gun with 110 rounds . She was also equipped with the standard 2 cm FlaK 30 anti - aircraft gun . " U - 51 " had a crew of up to forty - eight men . After being commissioned and deployed , " U - 51 " was stationed in the German port of Kiel . This city was to be her home for the rest of her brief career . Operational history . " U - 51 " had a very short operational life . During her service with the " Kriegsmarine " , she took part in four combat patrols . She joined the 7th U - boat Flotilla on 6 August 1938 . She was to remain a part of this flotilla until her loss . 1st patrol . The first of " U - 51 " s four patrols began on 17 January 1940 when she left Kiel and crossed the North Sea . She negotiated the ' gap ' between the Orkney and Shetland Islands and claimed her first success west of Rockall when she sank the " Gothia " on 22 January . Moving south down the west coast of Ireland , she encountered the " Eika " west of the Scilly Isles on the 29th and sent her to the bottom . After sailing between the Scottish islands once more , but in the opposite direction , the boat docked at Wilhelmshaven on 8 February after 23 days at sea . 2nd patrol . The main incident of note on the submarine ' s second sortie was when the French submarine " Orphée " launched two torpedoes at her in the North Sea on 21 April 1940 . They missed . The rest of the patrol was carried out parallel to the Norwegian coast . 3rd patrol . For her third foray , the boat entered the Atlantic after passing between the Faroe and Shetland Islands . Having left Kiel on 6 June 1940 , she sank the " Saranc " on the 26th about west southwest of Lands End . " U - 51 " went on to sink the Q - ship on the 29th . This ship , used as a decoy , was formidably armed with nine 4 - inch guns and four torpedo tubes . Her ballast was given extra buoyancy which meant three ' eels ' ( U - boat slang for torpedoes ) , were needed to dispose of the vessel , which still took over an hour to sink . 4th patrol and loss . The boat departed Kiel on 9 August 1940 . She sank the " Sylviafield " about west northwest of Rockall . There were 36 survivors , of which 20 were picked up by the Belgian trawler " Rubens " and landed at Fleetwood on the English west coast . The remainder were recovered by another trawler which was under British Admiralty control and named . Her human cargo was discharged at Tobermory , Isle of Mull . " U - 51 " was sunk by a torpedo from the British submarine in the Bay of Biscay on 28 August 1940 . Forty - three men died ; there were no survivors . Summary of raiding career . During her service , " U - 51 " sank five commercial ships for a loss of and one auxiliary warship of 4 , 724 GRT .