German submarine U-521 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II.
She was built by the Deutsche Werft yard at Finkenwerder, Hamburg with yard number 336. Commissioned in June 1942, she was commanded by Kapitänleutnant Klaus Bargsten.
The U-boat was assigned to the 4th U-boat Flotilla for training and the 2nd flotilla for operations.
U-521 was sunk on 2 June 1943 by the submarine chaser . The only survivor was Bargsten himself. This was the second boat under Bargsten's command, and the first that suffered heavy losses. The wreck of the submarine has never been found.
Design
German Type IXC submarines were slightly larger than the original Type IXBs. U-521 had a displacement of when at the surface and while submerged. The U-boat 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 MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 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-521 was fitted with six torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one SK C/32 naval gun, 180 rounds, and a SK C/30 as well as a C/30 anti-aircraft gun. The boat had a complement of forty-eight.
Service history
First patrol
U-521 sailed from Hamburg on her first patrol on 6 October 1942. She followed the usual course, sailing up the coast of Norway and then west, through the "Rosengarten" into the Atlantic. When she was north of Scotland, U-521 was attacked by an aircraft. According to Bargsten, he was standing on the bridge when the aircraft suddenly appeared out of the clouds, flying very low. The aircraft was carrying a trailing antenna, which almost struck the boat. Bargsten thought at first that it was a new weapon. The bomb-bay doors were open, but the aircraft did not drop any bombs. U-521 submerged, and, after it had gained considerable depth, several bombs were heard to explode.
The first war cruise lasted over nine weeks and accounted for five merchant vessels and a corvette. Two ships were sunk from an eastbound convoy and two more from one that was westbound. The fifth ship was a freighter which had been crippled by an attack from another U-boat and had dropped out of her convoy. She was guarded by a corvette. U-521 approached this target at night on the surface. The first torpedo was fired at a range of about . Due to the presence of the corvette, Bargsten was somewhat cautious, and after firing, immediately turned the boat in order to be able to fire again from his stern tube while escaping. The first torpedo passed astern of the merchantmen and hit the corvette which sank rapidly. The freighter was then easily disposed-of at close range.
U-521s first patrol ended on 8 December 1942. She put in at Lorient in occupied France, where she had been assigned to the 2nd U-boat Flotilla, commanded by Korvettenkapitän Viktor Schütze of the 1925 naval term. Schütze was greatly admired by Bargsten, he spoke of a four-hour interview that he (Bargsten) had had with the flotilla commander. Bargsten was given credit for having sunk 29,000 tons of shipping and one corvette.
U-521 remained in Lorient for about three weeks, taking on supplies and preparing for her next sortie.
Second patrol
U-521 sailed from Lorient on her second patrol on 7 January 1943. Her operational area was in the vicinity of the Azores. She attacked several convoys on this patrol in the company of other U-boats. One of these attacks took place about 25 February 1943 in company with commanded by Oberleutnant Hans Johannsen (U-569 was sunk on 22 May 1943).
During the course of an attack on a Gibraltar-bound convoy, U-521 sank three ships. After firing at the last of the three, Bargsten noticed another U-boat on a collision course with his boat. U-521 came to a full stop, the other submarine crossed her bow about away. These maneuvers attracted the attention of American destroyers escorting the convoy, and U-521 was severely depth charged. Although about 70 depth charges were dropped, Bargsten was rather scornful of this attack. He stated that he easily eluded his enemies without making use of the S.B.T. and he criticized the destroyers for a lack of tenacity. The U-boat sustained some damage, including a slightly bent propeller shaft.