German submarine U-712

Summary

German submarine U-712 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. Commissioned on 5 November 1942, she served with the 8th U-boat Flotilla until 31 October 1943 as a training boat, and as a front boat in the 3rd U-boat Flotilla under Oberleutnant zur See Walter Pietschmann until 14 December, before being replaced by Oberleutnant zur See Walter-Ernst Koch.

History
Nazi Germany
NameU-712
Ordered7 December 1940[1]
BuilderHC Stülcken & Sohn, Hamburg
Yard number778
Laid down4 September 1941[1]
Launched10 August 1942[1]
Commissioned5 November 1942[1]
Fate
  • Surrendered to Allied forces on 9 May 1945[1]
  • Scrapped in 1950
General characteristics
Class and typeType VIIC submarine
Displacement
Length
Beam
  • 6.20 m (20 ft 4 in) o/a
  • 4.70 m (15 ft 5 in) pressure hull
Height9.60 m (31 ft 6 in)
Draught4.74 m (15 ft 7 in)
Installed power
  • 2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels)
  • 750 PS (550 kW; 740 shp) (electric)
Propulsion
Speed
  • 17.7 knots (32.8 km/h; 20.4 mph) surfaced
  • 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range
  • 8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth
  • 230 m (750 ft)
  • Crush depth: 250–295 m (820–968 ft)
Complement4 officers, 40–56 enlisted
Armament
Service record
Part of:
Identification codes: M 50 836
Commanders:
  • Oblt.z.S. Walter Pietschmann
  • 5 November 1942 – 14 December 1943
  • Oblt.z.S. Walter-Ernst Koch
  • 15 December 1943 – 2 July 1944
  • Oblt.z.S. Freiherr Eberhard von Ketelhodt
  • 3 July 1944 – 9 May 1945
Operations: None[1]
Victories: None[1]

Design edit

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-712 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.[2] 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 AEG GU 460/8–27 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).[2]

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).[2] 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-712 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.[2]

Service history edit

Built as yard number 778 at the HC Stülcken & Sohn shipyard in Hamburg, U-712 was launched on 10 August 1942. After the completion of system checks and crew training, U-712 was transferred to the 3rd Flotilla on 1 November 1943. On 1 January 1944, she was reassigned to the 21st U-boat Flotilla as a training boat. On 3 July 1944, Oberleutnant zur See Koch handed over to Freiherr Eberhard von Ketelhodt, leaving to command U-975.[3] U-712's purpose was succeeded by a similar function with the 31st from 1 March 1945.[citation needed]

In the rest of her career under Walter-Ernst Koch and Freiherr Eberhard von Ketelhodt, she served as a training vessel, never having made a single patrol.[citation needed]

Fate edit

After Germany's surrender in May 1945, U-712 was surrendered at Kristiansand on 9 May 1945 in Norway. She was later taken to Loch Ryan in Scotland, where the British used her bulk for testing before breaking her up at Hayle in 1950.

References edit

  1. ^ a b c d e f g Helgason, Guðmundur. "The Type VIIC boat U-712". German U-boats of WWII - uboat.net. Retrieved 1 March 2010.
  2. ^ a b c d Gröner 1991, pp. 43–46.
  3. ^ Helgason, Guðmundur. "Walter-Ernst Koch". German U-boats of WWII - uboat.net. Retrieved 27 March 2010.

Bibliography edit

  • 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). Der U-Boot-Krieg, 1939-1945: Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945] (in German). Vol. IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
  • Gröner, Eric; Jung, Dieter; Maass, Martin (1991). German Warships 1815-1945: U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.

External links edit

  • Helgason, Guðmundur. "The Type VIIC boat U-712". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.