|Ordered:||15 August 1940|
|Builder:||Blohm & Voss, Hamburg|
|Laid down:||22 September 1941|
|Launched:||10 June 1942|
|Commissioned:||30 July 1942|
|Fate:||Sunk 10 March 1943 in the North Atlantic in position Coordinates: , after being rammed by British freighter SS Scorton.|
|Class and type:||Type VIIC submarine|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||4 officers, 40–56 enlisted|
|Operations:||20 February – 10 March 1943|
|Victories:||1 merchant ship sunk (3,921 GRT)|
German submarine U-633 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 22 September 1941 by Blohm & Voss, Hamburg as yard number 609, launched on 10 June 1942 and commissioned on 30 July 1942 under Oberleutnant zur See Bernhard Müller.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-633 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-633 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and one twin 2 cm (0.79 in) 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 30 July 1942, followed by active service on 1 March 1943 as part of the 9th Flotilla for the remainder of her short service. In one patrol she sank one merchant ship, for a total of 3,921 gross register tons (GRT).
U-633 took part in two wolfpacks, namely
- Neuland (4–6 March 1943)
- Ostmark (6–10 March 1943)
Summary of raiding history
|8 March 1943||Guido||United Kingdom||3,921||Sunk|
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