German World War II submarine
German submarine "U-311" was a Type VIIC U-boat of Nazi Germany's "Kriegsmarine" during World War II. The submarine was laid down on 21 March 1942 at the Flender Werke yard at Lübeck as yard number 311, launched on 20 January 1943 and commissioned on 23 March under the command of "Kapitänleutnant" Joachim Zander.
During her short career, the U-boat sailed on two combat patrols, sinking a single ship, before she was sunk on 22 April 1944.
Design.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. "U-311" 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 Garbe, Lahmeyer &amp; Co. RP 137/c 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-311" 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 two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
Service history.
First patrol.
After training with the 8th U-boat Flotilla at Kiel, "U-311" was transferred to the 1st U-boat Flotilla based at Brest in France, for front-line service on 
25 November 1943. On that day she departed Kiel and sailed out into the middle of the Atlantic, via the North Sea and the gap between Iceland and the Faroe Islands. She operated as part of 8 wolfpacks before arriving at Brest on 26 January 1944.
Second patrol and loss.
"U-311" sailed from Brest on 7 March 1944. On the 19th, she sank the "Seakay" west of Fastnet. On 22 April, she was sunk by depth charges dropped by the Canadian frigates and .
Previously recorded fate.
The boat was previously thought to have been sunk southwest of Ireland on 24 April 1944 by a Canadian Sunderland flying boat of 423 Squadron, RCAF.
Wolfpacks.
"U-311" took part in eight wolfpacks, namely:
References.
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