|Ordered:||15 August 1940|
|Builder:||Blohm & Voss, Hamburg|
|Laid down:||21 April 1941|
|Launched:||9 January 1942|
|Commissioned:||5 March 1942|
|Fate:||Rammed and sunk by U-444 on 6 August 1942, scuttled on 2 May 1945|
|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-612 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was ordered on 15 August 1940 and laid down at Blohm & Voss, Hamburg, on 21 April 1941. She was launched on 9 January 1942 and commissioned 5 March 1942 Oberleutnant zur See Paul Siegmann was her first commanding officer. He was joined in May 1942 by Herbert Werner, author of the book Iron Coffins, as First Officer.
While still on trials in the Baltic U-612 was sunk in collision with U-444 on 6 August 1942. She was later salvaged and served as a training boat until the end of the war, when she was scuttled on 2 May 1945.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-612 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-612 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.
After commissioning, U-612 was engaged in working up and sea trials in the eastern Baltic, assigned to 5th U-boat Flotilla and based at Königsberg. On 6 August 1942 she was at sea off Danzig when she was accidentally rammed by U-444. Werner describes the event in his book; he states neither boat was aware of the other and that the captain of U-444 was unaware he had struck U-612. He describes in detail the struggle to get out of the rapidly sinking U-boat, and the crew's rescue by two other U-boats, one of which he states was the hapless U-444 Two men died in the incident.
Siegman and his crew undertook to salvage U-612 and put her back into action; the hull was raised in during August but found to be too water-damaged for them to continue. The U-boat was handed over to the dockyard at Danzig and Seigmann and his crew were re-assigned to another boat, U-230.
U-612 completed repairs the following year and was re-commissioned 31 May 1942. However she was deemed unsuitable as a "Front-boat" and was confined to training in the Baltic. On commissioning, under Oblt. T Petersen she joined 24 Flotilla, a training unit. In February 1944 she joined 31 Flotilla, another training unit, under the command of Oblt.z.S. HP Dick.
- Neistle p27
- Neistle p75
- Helgason, Guðmundur. "The Type VIIC Uboat U-612". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.
- Werner p73
- Gröner 1991, pp. 43-46.
- Blair p619
- Kemp p86
- Werner p77
- Werner p75-7
- Neistle and Kemp both give one casualty only
- Helgason, Guðmundur. "P Seigmann". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.
- Clay Blair, Hitler’s U-Boat War Vol I (1996). ISBN 0-304-35260-8
- Erich Gröner German Warships 1815-1945 Vol II (1990). Conway Maritime Press ISBN 0-85177-593-4
- Paul Kemp : U-Boats Destroyed ( 1997) . ISBN 1-85409-515-3
- Axel Neistle : German U-Boat Losses during World War II (1998). ISBN 1-85367-352-8
- Herbert Werner Iron Coffins (1969) Cassel & Co. ISBN 0-304-35330-2
- 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-612". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.