German submarine U-637

German submarine U-637 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 17 October 1941 by Blohm & Voss, Hamburg as yard number 613, launched on 7 July 1942 and commissioned on 27 August 1942 under Kapitänleutnant Max Bernd Dieterich.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-637 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-637 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and one twin 2 cm C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
The boat's career began with training at 5th U-boat Flotilla on 27 August 1942, followed by active service on 1 June 1944 as part of the 1st Flotilla.

In three patrols she sank one warship, for a total of 39 tons.

Fate
U-637 surrendered on 9 May 1945 at Stavanger and later sunk as part of Operation Deadlight on 21 December 1945 at position 55.58333°N, -7.76667°W.