German submarine U-624

German submarine U-624 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 15 July 1941 by Blohm & Voss in Hamburg as yard number 600, launched on 31 March 1942 and commissioned on 28 May 1942 under Kapitänleutnant Ulrich Graf von Soden-Fraunhofen.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-624 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 Brown, Boveri & Cie 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-624 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 a 2 cm C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
The boat's service began on 28 May 1942 with training as part of the 8th U-boat Flotilla. She was transferred to the 7th Flotilla, operating out of St.Nazaire, on 1 October 1942 for active service in the North Atlantic.

In just two patrols she sank five merchant ships and three warships for a total of and 873 tons, plus one merchant ship damaged.

Fate
U-624 was sunk on 7 February 1943 in the North Atlantic in position 55.7°N, -26.28333°W. She was caught unawares on the surface whilst transmitting to base a lengthy report of the previous night's action around Convoy SC 118. A RAF B-17 Flying Fortress aircraft of (Sqdn. 220/J), operating out of Londonderry Port, depth charged her 55 nmi astern of the convoy. All 45 hands were lost.

Wolfpacks
U-624 took part in five wolfpacks, namely:
 * Puma (23 – 29 October 1942)
 * Natter (30 October – 8 November 1942)
 * Kreuzotter (8 – 24 November 1942)
 * Habicht (10 – 19 January 1943)
 * Haudegen (19 January – 7 February 1943)