German submarine U - 953 U - 953 was a Type VIIC U - boat of the German " Kriegsmarine " during World War II . The submarine was laid down on 10 February 1942 in the Blohm & Voss yard at Hamburg , launched on 28 October 1942 , and commissioned on 17 December 1942 under the command of " Oberleutnant " Karl - Heinz Marbach . After training with the 5th U - boat Flotilla at Kiel , " U - 953 " was transferred to the 3rd U - boat Flotilla based at La Pallice ( in southwestern France ) , for front - line service on 1 June 1943 . She sailed on ten war patrols , but sank only one ship of . Transferred to the 33rd U - boat Flotilla on 15 October 1944 , she surrendered at Trondheim in Norway in May 1945 . Service history . 1st patrol . " U - 953 " first sailed from Kiel on 13 May 1943 , and out into the mid - Atlantic . She had no successes , and on 9 July was attacked by an aircraft , which killed one crewman and wounded two others . The U - boat arrived at La Pallice on 22 July after 71 days on patrol . 2nd and 3rd patrols . " U - 953 " s second Atlantic patrol from 2 October to 17 November 1943 was uneventful , but her next , which began on 26 December 1943 and took her to the waters off North Africa , was . On 11 January 1944 the U - boat fired a T - 5 homing torpedo at a corvette , missed , and was then hunted for the next 13 hours by escort ships equipped with depth charge s and hedgehogs . About 4 February the U - boat approached Convoy ON 222 , but was attacked by an unknown Allied aircraft . 4th - 6th patrols . After being fitted with a " Schnorchel " underwater - breathing apparatus , the U - boat ' s next three patrols from March to June 1944 were short , from 3 to 13 days and uneventful . 7th patrol . " U - 953 " made her first and only kill on a patrol that began on 24 June 1944 . She sailed from Brest into the English Channel and at 08 : 00 on 5 July fired a spread of two torpedoes , and then another at 08 . 05 , sinking the 1 , 927 ton British merchant ship " Glendinning " , part of convoy ETC - 27 . Two crewmen and two gunners were lost . 8th - 10th patrols . Under her new commander , Oblt . Herbert A . Werner , who had been due to stay in " Festung " ( Fortress ) Brest and fight on the ground , " U - 953 " sailed from the French port with a composite crew from " U - 415 " and " U - 953 " on 23 August 1944 . This mixing was due to a number of the latter boat ' s crew being on leave in Germany and being unable to return after the invasion of Normandy and the subsequent Allied advance . It had taken two attempts at leaving , due to the chaotic situation in the port and the British anti - submarine forces waiting outside . The submarine arrived at La Pallice on the 28th with no torpedoes and about twice the normal complement , but left again on 7 September following incomplete repairs . Failure of one engine and the non - operation of the " Schnorchel " were just two of the mechanical problems she encountered as the boat sailed around the British Isles to Bergen in Norway , arriving there on 11 October . She sailed to Germany for overhaul at the end of the month ; first to Kiel , then Lübeck ; returning to Bergen on the surface ( due to more defects ) , in February 1945 . She left Bergen for her final patrol around the southwest English coast on 17 February , but had to return when it was discovered that the torpedo tube outer doors would not open fully . She arrived in Bergen on 7 April , before heading to Trondheim for repars , arriving on 14 April 1945 . Fate . Three weeks after the German surrender , on 29 May 1945 , the boat was transferred to England and used by the Royal Navy for trials . " U - 953 " was finally broken up in 1950 .