|Ordered:||30 October 1939|
|Builder:||Deutsche Werke AG, Kiel|
|Yard number:||Werk 282|
|Laid down:||18 May 1940|
|Launched:||5 March 1941|
|Commissioned:||3 May 1941|
|Fate:||Sunk 21 December 1941 in the Atlantic Ocean at position Coordinates: , by depth charges from a British Swordfish aircraft (Sqdn. 812/A). 44 dead and 1 survivor northwest of Tangier|
|Class and type:||Type VIIC submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||4 officers, 40–56 enlisted|
Commissioned on 3 May 1941, with Korvettenkapitän Eberhard Hoffmann in command, she was assigned from then until 1 July to the 3rd U-boat Flotilla for training, and from 1 July 1941 to 21 December, she remained with the 3rd flotilla for operations.
She carried out four patrols before being lost in action.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-451 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-451 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
The boat set-off from Kiel and moved into Norwegian waters between 23 June and 24 July 1941.
1st and 2nd patrols
She departed Kirkenes in the far north on 30 July 1941, patrolled the Barents Sea and sank one warship of 550 tons, the Soviet corvette Zhemchug (No 27), on 10 August. She returned to Kirkenes on 12 August.
Her second patrol, between 19 August and 12 September 1941, lasted 25 days. She then returned to Kiel.
3rd and 4th patrols
Starting from Kiel on 25 November 1941, she sailed to Lorient in occupied France, arriving on 12 December.
She was sunk off Tangier, Morocco, on the night of 21 December 1941 by a Fairey Swordfish Mk. I, V4431, flying with 812 Naval Air Squadron from RNAS North Front, Gibraltar. U-451 was first detected by Air-to-Surface Vessel radar (ASV) at a range of 3-1/2 miles and about 18 miles NW of Cape Spartel. "The Swordfish closed the contact and sighted the U-Boat on the surface steering to the eastward. Three depth charges were dropped ahead of the U-Boat and across her bows. The centre depth charge of the stick, set at 25 feet, exploded immediately under the U-Boat, which was not seen again. The details of the U-Boat's disappearance could not be observed as U 451 was enveloped in the spray of the depth-charge explosions. Two large oil patches were seen, each 300 yards in diameter." The sole surviving crew member, Oberleutnant zur See (Lieutenant) Walter Köhler, stated that he was on the bridge with three ratings at the time of the attack, and that the noise of the diesel engines obscured the sound of the attacking aircraft until the moment of weapons release. He was unable to get inside the vessel before the hatch was closed. "He stated that the U-boat then sank bows down. The prisoner flung himself into the water and swam for an hour and a half before he was picked up by Myosotis."
- Helgason, Guðmundur. "The Type VIIC boat U-451". German U-boats of WWII - uboat.net. Retrieved 27 January 2012.
- Laws, Allan, "Fairey Swordfish: The Fleet Air Arm's enigmatic warrior", International Air Power Review, Volume 27, AIRTime Publishing Inc., Westport, Connecticut, 2010, ISSN 1473-9917, page 133.
- Kemp 1999, pp. 76-7.
- Gröner 1985, p. 72.
- Gröner 1991, pp. 43-46.
- Helgason, Guðmundur. "Zhemchug (No 27)". German U-boats of WWII - uboat.net. Retrieved 26 December 2014.
- "U-boat Archive - U-451 - Interrogation Report".
- Busch, Rainer; Röll, Hans-Joachim (1999). German U-boat commanders of World War II : a biographical dictionary. Translated by Brooks, Geoffrey. London, Annapolis, Md: Greenhill Books, Naval Institute Press. ISBN 1-55750-186-6.
- Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945]. Der U-Boot-Krieg (in German). IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
- Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
- Kemp, Paul (1999). U-Boats Destroyed - German Submarine Losses in the World Wars. London: Arms & Armour. ISBN 1-85409-515-3.
- Helgason, Guðmundur. "The Type VIIC boat U-451". German U-boats of WWII - uboat.net. Retrieved 26 December 2014.