German submarine U-139 (1940)

German submarine U-139 was a Type IID U-boat of Nazi Germany's Kriegsmarine during World War II. Her keel was laid down on 20 November 1939 by Deutsche Werke in Kiel as yard number 268. She was launched on 28 June 1940 and commissioned on 24 July 1940 with Kapitänleutnant Robert Bartels in command. U-139 began her service life with the 1st U-boat Flotilla. She was then assigned to the 21st flotilla and subsequently to the 22nd flotilla where she conducted two patrols, but did not sink or damage any ships. She spent the rest of the war as a training vessel. She was scuttled on 5 May 1945. German Type IID submarines were enlarged versions of the original Type IIs. U-139 had a displacement of when at the surface and while submerged. Officially, the standard tonnage was , however. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to . The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-139 was fitted with three torpedo tubes at the bow, five torpedoes or up to twelve Type A torpedo mines, and a anti-aircraft gun. The boat had a complement of 25. She made short voyages from Oxhöft (a suburb of Gdynia in modern-day Poland), to Windau (Ventspils in Latvia) and Stormelö between 16 July and 18 August 1941. The boat's first official patrol commenced with her departure from Windau on 29 July 1941. She arrived in Stormelö without incident on 18 August. Her second patrol was also abortive, departing Stormelö on 28 August 1941 and arriving in Gotenhafen (Gdynia) on 31 August. U-139 was scuttled in the Raederschleuse (lock) in Wilhelmshaven on 5 May 1945.