German submarine U-511

German submarine U-511 was a Type IXC U-boat of the Nazi German Kriegsmarine during World War II. The submarine was laid down on 21 February 1941 at the Deutsche Werft yard in Hamburg as 'werk' 307, launched on 22 September 1941 and commissioned on 8 December 1941 under the command of Kapitänleutnant Friedrich Steinhoff. After training with the 4th U-boat Flotilla, from May 1942, U-511 was used for testing the possibility of launching Wurfkörper 42 30 cm artillery rockets from U-boats. In cooperation with the commanding officer's brother Ernst Steinhoff of the Peenemünde Army Research Center, a rack of six rockets were mounted on deck, and were successfully launched while on the surface and while submerged up to a depth of 12 m. However, the rockets were not particularly accurate and the racks on the deck had a negative effect on the U-boat's underwater handling and performance, so the project was abandoned.

The U-boat was attached to the 10th U-boat Flotilla for front-line service on 1 September 1943. In that role she carried out four war patrols, two commanded by Kptlt. Steinhoff, and two by Kptlt. Fritz Schneewind, sinking five ships totalling and damaging one of.

The U-boat was transferred to Japan on 16 September 1943 and served in the Imperial Japanese Navy as submarine RO-500 until August 1945 when she surrendered to the Allies.

1st patrol
On 16 July 1942	U-511 sailed from Kiel and across the Atlantic to the Caribbean Sea.

At 06:29 on 27 August, U-511 fired a spread of four torpedoes at Convoy TAW-15, en route from Trinidad to Key West, about 120 mi south-south-east of Guantánamo Bay in Cuba, sinking two ships and damaging another. The 13,031 ton British tanker San Fabian, loaded with 18,000 tons of fuel oil, was hit and sunk. The master, 31 crewmen and one gunner were picked up by the destroyer USS Lea (DD-118) and the patrol craft USS PC-38, 23 crew members and three gunners were lost. The 8,968 ton Dutch tanker Rotterdam, carrying 11,364 tons of gasoline was struck and immediately began to settle by the stern. The 37 survivors of her crew of 47 abandoned the ship in lifeboats and were picked up by USS SC-522. The 8,773 ton American tanker Esso Aruba, loaded with 104170 oilbbl of diesel fuel and serving as the flagship of the convoy commodore, was hit by a single torpedo on the port side which badly damaged the ship, but left the engines and steering gear still operating. This allowed the ship, in danger of breaking in two, to proceed under her own power to Guantánamo Bay, arriving the next day. The ship was beached and her cargo unloaded. After temporary repairs the ship proceeded to Galveston, Texas, and was returned to service in February 1943.

The U-boat arrived at her new home port of Lorient in occupied France, on 29 September after a voyage lasting 76 days.

2nd patrol
U-511 sailed from Lorient on 24 October 1942, and patrolled the waters off the coast of north-west Africa before returning to base after 36 days, on 28 November, having had no successes.

3rd patrol
U-511, now under the command of Oberleutnant zur See Fritz Schneewind, left Lorient once more on 31 December 1942 to patrol the waters between Spain, the Canary Islands and the Azores. At 21:42 on 9 January 1943 she had her only success, sinking the 5,004 ton British merchant ship William Wilberforce, loaded with 5,054 tons of West African produce, including palm kernels, palm oil and rubber en route from Lagos to Liverpool. The unescorted ship was torpedoed west of the Canary Islands, with the loss of three crewmen. The master, 41 crewmen, six gunners and 12 passengers were later picked up by the Spanish merchant ship Monte Arnabal.

U-511 returned to Lorient on 8 March after 68 days at sea.

4th patrol
U-511's final patrol took her all the way to Japan, as part of the ongoing programme of technological exchange. She had aboard additional personnel, including the German ambassador to Tokyo, the Japanese Naval Attaché in Berlin and German scientists and engineers. Leaving Lorient on 10 May 1943 under the command of the now Kapitänleutnant Fritz Schneewind, she sailed through the Atlantic and around the Cape of Good Hope into the Indian Ocean where she made two kills.

The first attack was made at 09:42 on 27 June, when she hit the unescorted 7,194 ton American Liberty ship Sebastian Cermeno with two torpedoes, disabling the engines and killing an officer and two men. The survivors abandoned ship in five lifeboats. Ten minutes after being hit, the ship sank. The U-boat surfaced and questioned the survivors before leaving. The lifeboats lost contact with each other, but all were eventually rescued by Allied ships, apart from one boat which made its own way to Madagascar. Her second success came on 9 July when she torpedoed the 7,176 ton American Liberty ship Samuel Heintzelman, loaded with 5,644 tons of ammunition and general cargo. The U-boat dived after firing and did not directly observe the results, but heard underwater explosions. On surfacing they saw no trace of the ship, only floating debris. There were no survivors from the 75 men on board. The ship was reported missing, and was at first believed to have been sunk by a Japanese surface raider. On 30 September, wreckage from the ship was discovered off the Maldives.

The U-boat arrived at Kure on 7 August after a voyage lasting 90 days. and was handed over to Japan on 16 September.

Fate
The submarine was scuttled in the Gulf of Maizuru by the United States Navy on 30 April 1946.