German submarine U-661

German submarine U-661 was a [German German Type VIIC submarine|Type VIIC submarine|Type VIIC] U-boat built for Nazi Germany's Kriegsmarine for service during World War II.
She was laid down on 12 March 1941 by Howaldtswerke, Hamburg as yard number 810, launched on 11 December 1941 and commissioned on 12 February 1942 under Oberleutnant zur See Erich von Lilienfeld.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-661 had a displacement of when at the surface and while submerged. She 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 Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two Siemens-Schuckert GU 343/38-8 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-661 was fitted with five torpedo tubes, fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and a C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

The boat's career began with training at 5th U-boat Flotilla on 12 February 1942, followed by active service on 1 October 1942 as part of the 3rd Flotilla for the remainder of her very short career. In one patrol she sank one merchant ship, for a total of.

U-661 took part in three wolfpacks, namely:

U-661 was sunk on 15 October 1942 in the North Atlantic in position, she was rammed and thereafter sunk by gun fire and a heavy depth charge from Royal Navy destroyer. All hands were lost.