German World War II submarine
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 &amp; Voss, Hamburg as yard number 616, launched on 23 July 1942 and commissioned on 17 September 1942 under "Oberleutnant zur See" Karl-Heinz Nagel.
Design.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. "U-640" had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two Brown, Boveri &amp; Cie GG UB 720/8 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . "U-640" was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and one twin C/30 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 , 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 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 , by depth charges from a US Catalina of VP-84. All hands were lost.
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