German submarine U - 109 ( 1940 ) The German submarine " U - 109 " was a Type IXB U - boat of the Nazi German " Kriegsmarine " that operated during World War II . She conducted nine war - patrols , sinking 12 ships and damaging one . All but one of these successes were during the six patrols she carried out under the command of the U - boat ace , Heinrich Bleichrodt . On 4 May 1943 , she was sunk with all hands by a B - 24 Liberator , operated by 86 Squadron RAF . Construction and design . Construction . " U - 109 " was ordered by the " Kriegsmarine " on 24 May 1938 ( as part of Plan Z and in violation of the Treaty of Versailles ) . Her keel was laid down on 9 March 1940 by AG Weser , Bremen as " Werk 972 " . " U - 109 " was launched on 14 September 1940 and commissioned on 5 December under the command of Hans - Georg Fischer . Design . Like all Type IXB submarines , " U - 109 " had a total output of on the surface and while submerged . As a result , she could reach a maximum speed of while surfaced and submerged . She had a range of at while on the surface and at while submerged . She was equipped with six torpedo tubes ( four in the bow , two in the stern ) and carried a total of 22 torpedoes . The submarine could also be equipped with 44 TMA mines . " U - 109 " s main deck gun was a " Utof " 10 . 5 cm SK C / 32 naval gun with 110 rounds . The last piece of armament that " U - 109 " was equipped with the standard 2 cm FlaK 30 anti - aircraft gun . " U - 109 " s complement was 52 men but could carry up to 56 crew members at any given time . After being commissioned and deployed , " U - 109 " was stationed in the German port city of Kiel . Service history . " U - 109 " conducted a total of nine war patrols in her career and sank 12 enemy vessels for a total of 79 , 969 GRT ( Gross Register Tons ) . She also damaged one other of 6 , 548 GRT . First patrol . Following training exercises with the 2nd U - boat Flotilla from 5 December 1940 to 30 April 1941 , " U - 109 " was transferred to frontline service , still as a member of the " 2 . Unterseebootsflottille " on 1 May . " U - 109 " left Kiel on 6 May . For 24 days , she roamed the North Sea and eventually the North Atlantic in search of Allied convoys heading to Britain . It was here that she claimed her first enemy vessel , the British steam merchantman " Harpagus " , which was torpedoed and sunk on 24 May , a loss of 5 , 173 tons . Following this victory , " U - 109 " entered the German occupied port of Lorient in France . This city was to remain her home base for the remainder of her career . Second and third patrols . " U - 109 " s second and third patrols took place without any victories . Her second voyage began on 28 June 1941 when she left her home port of Lorient . For 51 days , she travelled south past Cape Verde in search of any Allied convoys off the coast of Africa . Having not found any , " U - 109 " returned to Lorient on 17 August . Her third patrol was much like her second . Having left Lorient on 5 October 1941 , she proceeded to travel north into the North Atlantic . The U - boat travelled as far west as Nova Scotia and as far north as Labrador before heading back , arriving in Lorient on 18 November after spending 45 days at sea and without sinking any vessels . Fourth patrol . " U - 109 " s fourth patrol was much more successful than her last two . The U - boat left Lorient on 27 December 1941 and for 59 days she travelled to the eastern seaboard of the United States in search of Allied shipping as part of Operation " Paukenschlag " ( Drumbeat ) . On 23 January 1942 , she sank her first enemy vessel when she torpedoed the British merchant vessel , " Thirlby " . On 1 February , " U - 109 " sank another British vessel , the " Tacoma Star " . These victories were followed by the sinking of the Canadian " Montrolite " on 5 February and the Panamanian " Halcyon " on 6 February . Following these victories , " U - 109 " returned to Lorient on 23 February 1942 , she was reported by the BBC to be sunk and the crew taken prisoner . Fifth patrol . Her fifth patrol was also eventful . Having left Lorient on 25 March 1942 , the U - boat headed to the southern coast of the United States . On 20 April , she sank the British merchant vessel " Harpagon " . This was followed by the damaging of the British ship " La Paz " off the coast of Florida on 1 May . Two days later , on 3 May , " U - 109 " torpedoed and sank the Dutch vessel " Laertes " . She returned to Lorient on 3 June 1942 , after 72 days at sea . Sixth patrol . Much like her second patrol , " U - 109 " s sixth foray took place off the coast of Africa . For 81 days , she traveled as far south as the Gold Coast and sank five enemy vessels : the Norwegian " Arthur W . Sewall " on 7 August ; and a further four British vessels , the " Vimeira " on 11 August , the " Ocean Might " on 3 September , the " Tuscan Star " on 6 September and the " Peterton " on 17 September . " U - 109 " then returned to Lorient on 6 October 1942 . Seventh and eighth patrols . " U - 109 " s remaining patrols were without any victories . The U - boat left Lorient on 28 November 1942 and traveled south off the northern coast of South America . 57 days later , on 23 January 1943 , she returned to Lorient without any victories . Her eighth patrol was much the same . The submarine left port on 3 March and travelled as far south as the Azores , circled the island chain and returned to Lorient on 1 April after 30 days at sea and without sighting any enemy vessels . Loss . " U - 109 " s ninth and last war patrol took place from 28 April 1943 , when she left Lorient , on 4 May . She was sunk by four depth charges from a British Liberator aircraft south of Ireland . The aircraft was flying to a rendezvous with an Allied convoy when it detected the boat with its H2S radar , north - east of the Azores . The U - boat was seen to surface before slowly sinking , apparently with enough time for the crew to abandon her , although none were seen to emerge from her hatches . It is assumed that all 52 of her crew went down with her .