History
Nazi Germany
Name	U-642
Ordered	20 January 1941
Builder	Blohm & Voss, Hamburg
Yard number	618
Laid down	19 November 1941
Launched	6 August 1942
Commissioned	1 October 1942
Fate	Sunk on 5 July 1944 in the Mediterranean at the Military port of Toulon in position 43°07′N 05°55′E / 43.117°N 5.917°E / 43.117; 5.917, in a US air raid.
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced 871 t (857 long tons) submerged
Length	67.10 m (220 ft 2 in) o/a 50.50 m (165 ft 8 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
Speed	17.7 knots (32.8 km/h; 20.4 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement	4 officers, 40–56 enlisted
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 × twin 2 cm (0.79 in) C/30 anti-aircraft gun
Service record[1]
Part of:	5th U-boat Flotilla 1 October 1942 – 28 February 1943 6th U-boat Flotilla 1 March – 30 November 1943 29th U-boat Flotilla 1 December 1943 – 5 July 1944
Identification codes:	M 50 471
Commanders:	Kptlt. Herbert Brünning 1 October 1942 – 5 July 1944
Operations:	4 patrols: 1st patrol: 20 February – 8 April 1943 2nd patrol: 4 May – 17 July 1943 3rd patrol: a. 11 – 12 September 1943 b. 18 October – 13 November 1943 4th patrol: 22 December 1943 – 23 January 1944
Victories:	1 merchant ship sunk (2,125 GRT)

German submarine U-642 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 19 November 1941 by Blohm & Voss, Hamburg as yard number 618, launched on 6 August 1942 and commissioned on 1 October 1942 under Kapitänleutnant Herbert Brünning.

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-642 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[2] 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 Brown, Boveri & Cie 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).^[2]

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).^[2] 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-642 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.^[2]

The boat's career began with training at 5th U-boat Flotilla on 1 October 1942, followed by active service on 1 March 1943 as part of the 6th Flotilla. She transferred for operations in the Mediterranean on 1 December 1943 to serve with 29th Flotilla for the remainder of her service.

In 4 patrols she sank 1 merchant ship, for a total of 2,125 gross register tons (GRT).

U-642 took part in nine wolfpacks, namely:

• Neuland (4 – 6 March 1943)
• Ostmark (6 – 11 March 1943)
• Stürmer (11 – 20 March 1943)
• Seewolf (21 – 30 March 1943)
• Oder (17 – 19 May 1943)
• Mosel (19 – 24 May 1943)
• Trutz (1 – 16 June 1943)
• Trutz 1 (16 – 29 June 1943)
• Geier 3 (30 June – 15 July 1943)

U-642 was sunk on 5 July 1944 in the Mediterranean at Military port of Toulon in position 43°07′N 05°55′E / 43.117°N 5.917°E / 43.117; 5.917, by a US air raid.

Date	Ship Name	Nationality	Tonnage (GRT)	Fate[3]
8 March 1943	Leadgate	United Kingdom	2,125	Sunk

• Mediterranean U-boat Campaign (World War II)

• Helgason, Guðmundur. "The Type VIIC boat U-642". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.