German submarine U-634

German submarine U-634 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 23 September 1941 by Blohm & Voss, Hamburg as yard number 610, launched on 10 June 1942 and commissioned on 6 August 1942 under Oberleutnant zur See Hans-Günther Brosin.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-634 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-634 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 6 August 1942, followed by active service on 1 February 1943 as part of the 9th Flotilla for the remainder of her service. In three patrols she sank one merchant ship, for a total of.

Fate
U-634 was sunk on 30 August 1943 in the North Atlantic in position 40.21667°N, -19.4°W, by depth charges from HMS Stork (L81) and HMS Stonecrop (K142). All crew members died.

Wolfpacks
U-634 took part in five wolfpacks, namely:
 * Westmark (6 – 11 March 1943)
 * Amsel (22 April – 3 May 1943)
 * Amsel 2 (3 – 6 May 1943)
 * Elbe (7 – 10 May 1943)
 * Elbe 1 (10 – 14 May 1943)