German submarine U-65 was a Type IXB U-boat of Nazi Germany's Kriegsmarine during World War II. Over the course of six war patrols between 9 April 1940 and 28 April 1941, she sank twelve ships and damaged three others for a total loss of . Construction and design Construction U-65 was ordered by the Kriegsmarine on 16 July 1937. Her keel was laid down on 6 December 1938 by AG Weser, Bremen as yard number 953. She was launched on 6 November 1939 and commissioned on 15 February 1940 under the command of Kapitänleutnant Hans-Gerrit von Stockhausen. Design German Type IXB submarines were slightly larger than the original German Type IX submarines, later designated IXA. U-65 had a displacement of when at the surface and while submerged. 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 MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 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-65 was fitted with six torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one SK C/32 naval gun, 180 rounds, and a SK C/30 as well as a C/30 anti-aircraft gun. The boat had a complement of forty-eight. Service history First patrol U-65s first war patrol began on 9 April 1940 when she left her home port of Wilhelmshaven. For 36 days she patrolled the North Sea and the waters off the coast of Norway, participating in the invasion of that country. During this time, she sank no enemy vessels. On 13 April, the U-boat attacked a group of British destroyers north of Bergen, Norway; but her torpedoes failed to detonate, the destroyers counter-attacked, causing some minor damage to the submarine. U-65 was able to escape the attack, she returned safely to Wilhelmshaven on 14 May. Second patrol U-65s second war patrol began on 8 June 1940. Over 30 days