German submarine U-413 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II.
She was laid down on 25 April 1941 at the Danziger Werft (as yard number 114), launched on 15 January 1942 and commissioned on 3 June, with Oberleutnant zur See Gustav Poel in command. Poel commanded her (receiving promotion to Kapitänleutnant), until 19 April 1944, when he was relieved by Oberleutnant zur See Dietrich Sachse who commanded her until her loss. She conducted seven patrols in World War II, sinking six ships totalling and 1,100 tons.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-413 had a displacement of 769t when at the surface and 871t while submerged. She had a total length of 67.1m (220.1feet), a pressure hull length of 50.5m (165.7feet), a beam of 6.2m (20.3feet), a height of 9.6m (31.5feet), and a draught of 4.74m (15.55feet). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of NaNPS for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of 750PS for use while submerged. She had two shafts and two 1.23abbr=onNaNabbr=on 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-413 was fitted with five 53.30NaN0 torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.82NaN2 SK C/35 naval gun, 220 rounds, and one 2sp=usNaNsp=us C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
The U-boat departed Kiel on 22 October 1942, on her first patrol.On 14 November 1942, she sank the 20,107 GRT troop transport ship MV Warwick Castle (one of the largest sunk in World War II).
At 08:44, the ship, under the command of Henry Richard Leepman-Shaw in Convoy MKF-1X was hit by one of two torpedoes fired, about NW of Cape Espichel, Portugal. The U-boat hit her again at 08:57, causing the ship to sink about one hour later. The master, 61 crew members and 34 service personnel died. 201 crew members, 29 gunners and five naval and 131 service personnel were rescued by,,, and the British . The latter ship had been in Convoy KMF-1 for Operation Torch (the invasion of North Africa).
On 19 November 1942, U-413 was attacked by a British Lockheed Hudson aircraft with five bombs and was damaged so severely that she had to return to a new base - Brest in occupied France.
Her second patrol was marked by sinking the American ship West Portal in mid-Atlantic on 5 February 1943; there were no survivors. She also attacked and sank the Greek Mount Mycale on 22 January 1943, northeast of Newfoundland.
Her third patrol saw her leave Brest on 29 March 1943, once more for the Atlantic. There, she sank the British vessel Wanstead south of Greenland, whose survivors were picked up by the corvette and the ASW (anti-submarine warfare) .
Her fourth sortie was a frustrating one; it was split into three parts, but she failed to sink any ships.
On 20 February 1944, she sank the British 1,100 tons destroyer about 15 miles off Trevose Head, north Cornwall. This was Poel's last patrol. He moved to the Naval Academy Mürwik in Flensburg.
Her last victory was when she sank Saint Enogat on 19 August 1944 in the English Channel.
U-413 did not suffer any casualties until 20 August 1944, when she was sunk, by one of the 115 strategically placed Naval Mines in the Cornish corridor 15 miles off the coast from Padstow. 45 of her crew were killed; there was one survivor.
The wreck of U-413 was located and identified by marine archaeologist Innes McCartney in 2000 close to the official sinking position.
U-413 took part in 15 wolfpacks, namely:
Neal Stephenson's novel Cryptonomicon features a fictitious U-413, a milchkuh (supply boat).
| Date | Ship Name | Nationality | Tonnage[1] | Fate[2] | |
|---|---|---|---|---|---|
| 14 November 1942 | Warwick Castle |  United Kingdom | 20,107 | Sunk | |
| 22 January 1943 | Mount Mycale |  Greece | 3,556 | Sunk | |
| 5 February 1943 | West Portal |  United States | 5,376 | Sunk | |
| 21 April 1943 | Wanstead | United Kingdom | 5,486 | Sunk | |
| 21 April 1944 | 1,100 | Sunk | |||
| 19 August 1944 | Saint Enogat | United Kingdom | 2,360 | Sunk |