German submarine U-103 was a Type IXB U-boat of Nazi Germany's Kriegsmarine that operated during World War II. She was one of the most successful boats in the entire war, sinking of Allied shipping in 11 patrols, in a career lasting more than four years. U-103 was laid down on 6 September 1939 at DeSchiMAG AG Weser in Bremen as yard number 966. She was launched on 12 April 1940 and commissioned on 5 July under the command of Korvettenkapitän Victor Schütze. After her warm-up, (designed to give her an opportunity to train and repair minor faults), she was deployed into the North Atlantic in September 1940 and saw overwhelming success, sinking 46 ships and damaging three other vessels. Design German Type IXB submarines were slightly larger than the original German Type IX submarines, later designated IXA. U-103 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-103 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 The boat entered the Atlantic via the gap between the Faroe and Shetland Islands. Her first victory was sinking Nina Borthen in mid-ocean on 6 October. After being hit by a torpedo, the ship developed a list, which the crew corrected. Two more torpedoes hit the ship, which also caused a list. Another torpedo hit broke the vessel in two and she sank with all hands. On 9 October, U-103 sank Zanes Gounaris and damaged Graigwen and Delphin. Delphin sank the next day. She sank Nora