German submarine U - 873 German submarine " U - 873 " was a German long range Type IXD2 U - boat of World War II . Following the surrender of Germany , the United States Navy studied " U - 873 " to improve United States submarine designs . " U - 873 " is remembered for the controversial treatment of its crew as prisoners of war and the death of commanding officer Friedrich Steinhoff in a Boston jail cell . Six months after Steinhoff ' s death , his brother was one of the Operation Paperclip rocket scientists from Peenemünde arriving in the United States to work at White Sands Missile Range . History . " U - 873 " was commissioned on 1 March 1944 under the command of Kapitänleutnant Friedrich Steinhoff and assigned to the 4th U - boat Flotilla for training in the Baltic Sea from the base in Stettin . The crew of the new submarine was assembled around a nucleus of Engineering Officer Helmut Jürgens , Quartermaster Albert Finister , and ten other survivors from , which had been sunk off the coast of Brazil on 11 August 1943 . On 29 July 1944 a small aerial bomb struck the control room of " U - 873 " during a bombing raid on Bremen which injured four of the crew . Crewmen Fritz Grusa died of those injuries and " U - 873 " did not complete repairs until November . A Deschimag Type I schnorchel was fitted in December . Upon completion of training on 31 January 1945 " U - 873 " was assigned to the 33rd U - boat Flotilla at Flensburg for war patrols to the Atlantic Ocean . " U - 873 " departed from Kiel on 17 February 1945 and arrived in Horten on 22 February . " U - 873 " sailed from Horten on 21 March 1945 and reached Kristiansand the following day . " U - 873 " sailed from Kristiansand on 30 March 1945 and was proceeding to an assigned operations area in the Caribbean Sea when Germany surrendered on 8 May . At 04 : 30 GMT on 11 May , " U - 873 " surrendered to of Escort Division 45 ( CortDiv 45 ) while it was escorting convoy UGS 90 at . " Vance " placed a prize crew aboard " U - 873 " and escorted the U - boat to Portsmouth Naval Shipyard on 16 May . " U - 873 " was placed in drydock for a design study of the Type IXD2 class of U - boats by Portsmouth Naval Shipyard engineers ; and was later transferred to the Philadelphia Naval Shipyard . Following completion of trials , the U - boat was scrapped in 1948 . Portsmouth . German Type IX submarine had arrived at Portsmouth the day before " U - 873 " arrived , and arrived the following day . German Type X submarine arrived on 19 May . Possessions of the crews of these U - boats had been scattered by the prize crews in the process of searching for intelligence information and evidence of sabotage . Upon arrival at Portsmouth the U - boat crews were sent to Portsmouth Naval Prison for interrogation by the Office of Naval Intelligence ( ONI ) . Subsequent investigation concluded personal possessions of the U - boat crewmen were looted contrary to provisions of the Geneva Convention . Following interrogation at Portsmouth Naval Prison , the handcuffed crew of U - 873 was pelted with insults and garbage while marching through the streets of Boston to the Suffolk County Charles Street Jail to await transfer to a prisoner - of - war camp in Mississippi . Commanding Officer . Friedrich Steinhoff was born in Küllstedt on 14 July 1909 and was a merchant marine officer prior to joining Kriegsmarine crew 34 . After serving with the 4th minesweeping flotilla from December 1939 to May 1940 , he was a watch officer aboard from July through October 1941 . He then commanded during rocket launching experiments of 1942 in cooperation with his brother Ernst Steinhoff , who was Director for Flight Mechanics , Ballistics , Guidance Control , and Instrumentation at the Peenemünde Army Research Center . Command of " U - 873 " was preceded by a year of staff duty with the 7th U - boat Flotilla . " U - 873 " crewman Georg Seitz reported Steinhoff ' s face was bleeding and swollen when he returned to his cell after being questioned by a civilian ONI interrogator who ordered a husky United States Marine Corps guard to slap the officer . On 19 May 1945 Steinhoff bled to death in his Boston jail cell from wrist wounds possibly inflicted with the broken lens of his sunglasses . He was buried in grave 934 at Fort Devens .