German submarine U-51 (1938)

U-52, a typical Type VIIB boat
History
Nazi Germany
Name:	U-51
Ordered:	21 November 1936
Builder:	Germaniawerft AG, Kiel
Cost:	4,439,000 Reichsmark
Yard number:	586
Laid down:	26 February 1936
Launched:	11 June 1938
Commissioned:	6 August 1938
Fate:	Sunk in the Bay of Biscay in August 1940 by a British submarine
General characteristics
Class and type:	Type VIIB U-boat
Displacement:	753 t (741 long tons) surfaced 857 t (843 long tons) submerged
Length:	66.50 m (218 ft 2 in) o/a 48.80 m (160 ft 1 in) pressure hull
Beam:	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull
Draught:	4.74 m (15 ft 7 in)
Installed power:	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels) 750 PS (550 kW; 740 shp) (electric)
Propulsion:	2 shafts 2 × diesel engines 2 × electric motors
Range:	8,700 nmi (16,112 km; 10,012 mi) at 10 knots (19 km/h; 12 mph)surfaced 90 nmi (170 km; 100 mi) at 4 knots (7.4 km/h; 4.6 mph)
Test depth:	230 m (750 ft) Calculated crush depth: 250–295 m (820–968 ft)
Complement:	4 officers, 40–56 enlisted
Sensors and processing systems:	Gruppenhorchgerät
Armament:	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) 14 × torpedoes or 26 TMA mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 1 × 2 cm (0.79 in) anti-aircraft gun
Service record
Part of:	7th U-boat Flotilla 6 August 1938–31 August 1939 7th U-boat Flotilla 1 September – 31 December 1939 7th U-boat Flotilla 1 January – 20 August 1940
Commanders:	Kptlt. Ernst-Günther Heinicke 6 August 1938 – August 1939 Kptlt. Dietrich Knorr 15 January – 20 August 1940
Operations:	Four 1st patrol: 17 January – 8 February 1940 2nd patrol: 11 March – 22 April 1940 3rd patrol: 6 June – 5 July 1940 4th patrol: 9–20 August 1940
Victories:	Five ships sunk, total 26,296 GRT; one auxiliary warship (Q-ship) sunk, 4,724 GRT

German submarine U-51 was a Type VIIB U-boat of Nazi Germany's Kriegsmarine that operated during World War II. She was ordered in November 1936 and laid down in February 1937 in Kiel. She was launched in August 1939 and commissioned in November.

During her service in the Kriegsmarine, U-51 conducted four war patrols and sank five enemy vessels for a loss of 26,296 gross register tons (GRT) and one auxiliary warship of 4,724 GRT. She was a member of one wolfpack.

She was sunk in August 1940 in the Bay of Biscay by a torpedo from a British submarine.

German Type VIIB submarines were preceded by the shorter Type VIIA submarines. U-51 had a displacement of 753 tonnes (741 long tons) when at the surface and 857 tonnes (843 long tons) while submerged. She had a total length of 66.50 m (218 ft 2 in), a pressure hull length of 48.80 m (160 ft 1 in), a beam of 6.20 m (20 ft 4 in), a height of 9.50 m (31 ft 2 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two MAN M 6 V 40/46 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).