|Ordered:||20 January 1941|
|Builder:||Danziger Werft AG, Danzig|
|Laid down:||3 December 1941|
|Launched:||18 August 1942|
|Commissioned:||16 December 1942|
|Status:||Missing in the North Atlantic since October 1943|
|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|
German submarine U-420 was a Type VIIC U-boat built for the Kriegsmarine for service during World War II. She was laid down in the Danziger Werft as yard number 121, launched on 18 August 1942 and commissioned on 16 December the same year under Oberleutnant zur See Peter Högqvist. She then joined the 8th U-boat Flotilla for training before transferring to the 11th flotilla for operations.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-420 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 Siemens-Schuckert GU 343/38–8 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-420 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 two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
U-420's first patrol involved her leaving Kiel on 12 June 1943 and arriving at Lorient in occupied France on 16 July 1943, having hugged the Norwegian coast and sailed around the north of Scotland. She then crossed the Atlantic, but was attacked on 3 July by a Canadian B-24 Liberator. The boat was hit by a Fido homing torpedo which killed two men and wounded a third. The boat sustained enough damage to force the patrol to be cut short.
2nd patrol and loss
- Gröner 1991, pp. 43-46.
- Helgason, Guðmundur. "Patrol of German U-boat U-420 from 12 Jun 1943 to 16 Jul 1943". German U-boats of WWII - uboat.net. Retrieved 27 December 2014.
- Helgason, Guðmundur. "Patrol of German U-boat U-420 from 9 October 1943 to 20 October 1943". German U-boats of WWII - uboat.net. Retrieved 27 December 2014.
- 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.
- Helgason, Guðmundur. "The Type VIIC boat U-420". German U-boats of WWII - uboat.net. Retrieved 26 December 2014.