German submarine U - 371 German submarine " U - 371 " was a Type VIIC U - boat of the Nazi German " Kriegsmarine " during World War II . The submarine was laid down in November 1939 in Kiel , launched in January 1941 , and commissioned in March under the command of " Oberleutnant zur See " Heinrich Driver . After training , " U - 371 " was ready for front - line service with the 1st U - boat Flotilla from 1 July 1941 . Operating mostly in the Mediterranean Sea , in 19 patrols between June 1941 and May 1944 the U - boat sank 13 ships totalling 67 , 573 tons , including the American destroyer , and damaged six more totalling 30 , 572 tons . " U - 371 " was sunk at 04 : 09 local time on 4 May 1944 in the Mediterranean north of Constantine , in position by a force of American , French and British destroyers . Three men were killed , there were 49 survivors . Construction and Design . " U - 371 " was ordered by the " Kriegsmarine " on 23 September 1939 . She was laid down about two months later at the Howaldtswerke yard in Kiel , on 17 November . Just over a year and two months later , " U - 371 " was launched on 27 January 1941 . She was formally commissioned later that year on 15 March . " U - 371 " carried 5 × torpedo tube s ( four located in the bow , one in the stern ) and had one C35 88mm / L45 deck gun with 220 rounds . She could also carry 14 G7e torpedo es or 26 TMA mines and had a crew of 44 - 52 men . Service history . 1st patrol . " U - 371 " left Kiel on 5 June 1941 , under the command of " Kapitänleutnant " Heinrich Driver , and sailed out into the north Atlantic . She sank two merchant ships ; the British 6 , 373 ton " Silverpalm " on 12 June and the Norwegian 4 , 765 ton " Vigrid " on 24 June , before arriving at Brest in France on 1 July . 2nd patrol . The U - boat sailed from Brest on 23 July 1941 to patrol between the coast of Portugal and the Azores . Early on 30 July she sank two more merchant ships south - east of the Azores , both from Convoy OS - 1 ; the British 6 , 935 ton " Shahristan " , and the Dutch 7 , 049 ton " Sitoebondo " . She returned to Brest on 19 August . 3rd patrol . " U - 371 " departed from Brest on 16 September 1941 , sailing south , and then through the Strait of Gibraltar into the Mediterranean Sea . After patrolling the coast of Egypt , the U - boat arrived at Salamis in Greece on 24 October , having had no successes , officially transferring to the " 23rd U - boat Flotilla " on 1 November . 4th and 5th patrols . " U - 371 " carried out two more patrols along the coast of Egypt and in the Eastern Mediterranean from December 1941 to January 1942 and again in March 1942 , but sank no ships . 6th patrol . Now part of the " 29th U - boat Flotilla " , " U - 371 " left Salamis again on 21 April 1942 under the temporary command of " Kapitänleutnant " Heinz - Joachim Neumann , and headed south to the coast of Egypt . However on 7 May the U - boat was depth charged by two submarine chasers and was so badly damaged that she had to return to base . She arrived back at Salamis on 9 May . 7th patrol . Command of " U - 371 " was now assumed by " Kapitänleutnant " Waldemar Mehl , who took the U - boat from Salamis to Pola , Venezia Giulia , in early July , not sailing on a combat patrol until 5 September when he took the U - boat along the length of the Adriatic Sea , and through the eastern Mediterranean to the coast of British Palestine and French Syria , arriving back at Salamis on 18 September , and returning to Pola in mid - October . 8th and 9th patrols . The U - boat left Pola and sailed to Messina in Sicily on 1 – 4 December 1942 , leaving on 7 December to attack the Allied shipping off the coast of French Algeria after " Operation Torch " , the invasion of North Africa . There , on 7 January 1943 , she attacked Convoy MKS - 5 , sinking the British naval trawler , and later the same day damaged the 7 , 159 ton British troopship " Ville de Strasbourg " . The U - boat then sailed to La Spezia in north - western Italy , arriving on 10 January 1943 . 10th patrol . The Algerian coast now became " U - 371 " s hunting ground , and she left La Spezia on 14 February 1943 to return there to sink the unescorted 2 , 089 ton British merchant ship " Fintra " on 23 February , and to damage the 7 , 176 ton American liberty ship " Daniel Carroll " from Convoy TE - 16 , before returning to La Spezia on 3 March . 11th patrol . " U - 371 " departed La Spezia again on 7 April 1943 , once more heading to the Algerian coast , where she sank the 1 , 162 ton Dutch merchant ship " Merope " on 27 April , before heading to her new home port of Toulon in southern France on 11 May 1943 . 12th patrol . After leaving Toulon on 3 July 1943 , on the 10th , " U - 371 " attacked Convoy ET - 22A , damaging two American ships ; the 6 , 561 ton tanker " Gulfprince " and the 7 , 176 ton liberty ship " Matthew Maury " , returning to Toulon on the 12th . 13th and 14th patrol . " U - 371 " s next patrol lasted from 22 July until 11 August 1943 , during which she sank the 6 , 004 ton British merchant ship " Contractor " , part of Convoy GTX - 5 . " U - 371 " patrolled again from 21 August to 3 September 1943 , but made no successful attacks . 15th patrol . Leaving Toulon on 7 October 1943 , " U - 371 " once more haunted the Algerian coast , sinking the British minesweeper on 11 October , the American destroyer on the 13th , and on the 15th torpedoed the American liberty ship " James Russell Lowell " , damaging her so badly that she was declared a total loss . The U - boat returned to base on 28 October . 16th and 17th patrols . The U - boat ' s next patrol was short , lasting from 15 to 23 November 1943 , and was unsuccessful . Her 17th patrol began on 22 January 1944 , and took her to the western coast of Italy after the launching of " Operation Shingle " , the Allied landings at Anzio . She made no successful attacks and returned to Toulon on 13 February . 18th patrol . " U - 371 " departed Toulon on 4 March 1944 and returned to the Algerian coast . On the 17th she attacked Convoy SNF - 17 , sinking the 17 , 024 ton Dutch troopship " Dempo " , and badly damaging the 6 , 165 ton American C2 cargo ship " Maiden Creek " , which later broke in two after being beached . The U - boat returned to Toulon on 25 March . Three days later , " U - 371 " s commander , Waldemar Mehl , received the Knight ' s Cross of the Iron Cross , before leaving the U - boat to serve on the staff of FdU " Mittelmeer " ( " U - boat Command Mediterranean " ) . On 5 April command of " U - 371 " passed to " Oberleutnant zur See " Horst - Arno Fenski , former commander of . 19th patrol . Under Fenski ' s command , " U - 371 " left Toulon for the final time at about 19 : 00 at on 23 April 1944 , and headed back to the coast of Algeria , patrolling from 10 to 15 miles offshore . On 28 April " U - 371 " received a report of a large convoy and set course to intercept it . On the night of 2 May the U - boat planned to surface in order to top up her batteries by running on her diesel engines , as she expected to contact the convoy within a few hours . Unfortunately on doing so , she found herself almost in the middle of the convoy , and immediately crash - dived to about . After an hour the U - boat surfaced again and headed toward the convoy , but was soon detected by the American destroyer escort . As the US ship closed to " U - 371 " fired a T - 5 acoustic torpedo from her stern tube , and immediately dived . The " Menges " was hit ; the aft third of the vessel was destroyed , killing 31 men and wounding 25 . However she remained afloat and was towed to Bougie in Algeria and later repaired and returned to service . " U - 371 " was now unlucky enough to be the first victim of an Allied submarine hunting tactic called " Swamp " . This called for the area of a known or suspected U - boat to be packed with escort ships and patrol aircraft . They would then systematically and continually search the area , forcing the U - boat to remain submerged until its batteries ran out or it tried to escape on the surface . Either option was almost hopeless . " U - 371 " found herself being relentlessly hunted by the American destroyer escort s and , the Free French and " L ' Alcyon " , and the British . When " U - 371 " first attempted to surface after crippling the " Menges " , depth charges forced her back down , while putting out all the lights , damaging the hydroplanes , and rupturing the trim tanks . The U - boat levelled off at about , leaking badly . The depth charge attacks continued at about 30 - minute intervals , with increasing accuracy , and the U - boat sustained further damage . At around 06 : 00 on 3 May , " U - 371 " attempted to evade ASDIC ( sonar ) detection by lying on the sea floor . This would also conserve battery power , which was becoming dangerously low . She lay on the sea - bed at around for the rest of the day , hoping that the attackers would give up the hunt . Late that night though , the surface vessels could still be heard , but with the air quality in the boat rapidly deteriorating , the emergency lighting system out , and having taken on about 15 tons of water , the U - boat ' s commander decided that their only hope was to surface and attempt to escape in the darkness . Blowing her ballast tanks only attracted the attention of the attackers , which began dropping depth charges again , and the U - boat was still stuck . The crew had to run from one end of the U - boat to the other while the engines ran at full power in order to break the grip of the mud before the U - boat finally began to surface . All torpedo tubes were loaded and readied for firing , and all guns were manned when " U - 371 " , with her batteries practically exhausted , surfaced and ran for safety . After fifteen minutes the enemy was seen coming up astern , immediately opening fire and scoring several hits . The U - boat returned fire , but the situation was clearly hopeless and most of her crew jumped overboard . As a last show of defiance the U - boat fired a T - 5 acoustic torpedo from her stern tube , and managed to hit the " Sénégalais " , causing some damage . By this time , around 04 : 00 on 4 May 1944 , only the commander Horst - Arno Fenski , the Engineering Officer and a control room petty officer remained aboard . The latter two remained below to flood the tanks , which caused " U - 371 " to sink so rapidly that they were unable to escape and the both drowned .