|Ordered:||13 June 1942|
|Builder:||Blohm & Voss, Hamburg|
|Laid down:||6 May 1943|
|Launched:||13 April 1944|
|Commissioned:||25 May 1944|
|Fate:||Sunk, 14 March 1945|
|Class and type:||Type VIIC/41 submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||4 officers, 40–56 enlisted|
|Service record |
|Operations:||1st patrol: 20 February – 14 March 1945|
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1021 had a displacement of 759 tonnes (747 long tons) when at the surface and 860 tonnes (850 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-1021 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), one 3.7 cm (1.5 in) Flak M42 and two 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
U-1021 was one of only ten Type VIIC's to be fitted with a Balkongerät (literally 'Balcony apparatus or equipment'). The Balkongerät was used on U-boats (U-682, U-788, U-799, U-997, U-1105, U-1172, U-1306, U-1307 and U-1308). The Balkongerät was standard on the Type XXI and the Type XXIII. Nonetheless, it was also fitted to several Type IXs and one Type X. The Balkongerät was an improved version of Gruppenhorchgerät (GHG) (group listening device). The GHG had 24 hydrophones, the Balkongerät had 48 hydrophones and improved electronics, which enabled more accurate readings to be taken.
Patrol and loss
However, the wreck of U-1021 was identified by nautical archaeologist Innes McCartney and historian Axel Niestle in December 2006, 7 nautical miles (13 km) off Newquay, Cornwall, at position Coordinates: , close to two other U-boats, U-325 and U-400. Further research by Innes McCartney led to the conclusion that all three submarines were sunk in the Bristol Channel by a deep-trap minefield. Minefield "HW A3", which was fatal to U-1021, was laid by HMS Apollo on 3 December 1944.
- Helgason, Guðmundur. "The Type VIIC/41 boat U-1021". German U-boats of WWII - uboat.net. Retrieved 6 January 2010.
- Helgason, Guðmundur. "War Patrols by German U-boat U-1021". German U-boats of WWII - uboat.net. Retrieved 6 January 2010.
- Gröner 1991, pp. 43-46.
- Base on war-time photographs.
- "Hydrophones". U-boats Aces - uboataces.com. Retrieved 20 May 2016.
- Helgason, Guðmundur. "Patrol of U-boat U-1021 from 20 Feb 1945 to 14 Mar 1945". German U-boats of WWII - uboat.net. Retrieved 6 January 2010.
- "War Mystery Solved". www.cix.co.uk. Retrieved 6 January 2010.
- Helgason, Guðmundur. "The loss of U 325, U 400 and U 1021: Re-assessment of German U-boat losses in World War II". German U-boats of WWII - uboat.net. Retrieved 31 May 2010.
- 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.
- "Geheimes Minenfeld: Drei deutsche U-Boote vor britischer Küste gefunden". Spiegel Online (in German). www.spiegel.de. 22 December 2006. Retrieved 4 January 2010.
- Hofmann, Markus. "U 1021". Deutsche U-Boote 1935-1945 - u-boot-archiv.de (in German). Retrieved 30 January 2015.
- Helgason, Guðmundur. "The loss of U-325, U-400 and U-1021". German U-boats of WWII - uboat.net. Retrieved 4 January 2010.
- Helgason, Guðmundur. "The Type VII/C41 boat U-1021". German U-boats of WWII - uboat.net. Retrieved 6 December 2014.