German submarine U-612

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 GS 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 1 May 1945.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-612 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-612 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and a 2 cm C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
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 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 reassigned to another boat, GS U-230.

U-612 completed repairs the following year and was re-commissioned 31 May 1943. 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.

On 1 May 1945 she was caught at Warnemünde by the advancing Red Army and was scuttled to avoid seizure.