Name U-640 Yard number 616 Commissioned 17 September 1942 Launched 23 July 1942 Draft 4.74 m Builder Blohm + Voss | Ordered 20 January 1941 Laid down 30 October 1941 Construction started 30 October 1941 Length 67 m Beam 6.2 m | |
Part of 5th U-boat Flotilla, 6th U-boat Flotilla | ||
German submarine U-640 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 30 October 1941 by Blohm & Voss, Hamburg as yard number 616, launched on 23 July 1942 and commissioned on 17 September 1942 under Oberleutnant zur See Karl-Heinz Nagel.
Contents
Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-640 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 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).
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-640 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 an 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 17 September 1942, followed by active service on 1 May 1943 as part of the 6th Flotilla.
In 1 patrol she sank no ships.
Wolfpacks
U-640 took part in one wolfpack, namely
Fate
There are discrepancies between the fate of U-640 and U-657, which was sunk in the same vicinity around the same time. Paul Kemp’s book attributes the sinking of British freighter Aymeric to U-640, and then subsequently sunk by HMS Swale on the 17 May 1943, whereas UBoat.net attributes this success and fate to U-657.
Uboat.net states that U-640 was sunk on 14 May 1943 in the Atlantic Ocean in position 60°32′N 31°05′W, by depth charges from a US Catalina of VP-84. All hands were lost.