German submarine U-720

History
Nazi Germany
Name	U-720
Ordered	25 August 1941
Builder	H. C. Stülcken Sohn, Hamburg
Yard number	786
Laid down	17 August 1942
Launched	5 June 1943
Commissioned	17 September 1943
Fate	Surrendered on 5 May 1945; sunk as part of Operation Deadlight on 21 December 1945
General characteristics
Class and type	Type VIIC submarine
Displacement	769 t (757 long tons) surfaced; 871 t (857 long tons) submerged;
Length	67.10 m (220 ft 2 in) (o/a); 50.50 m (165 ft 8 in) (pressure hull);
Beam	6.20 m (20 ft 4 in) (o/a); 4.70 m (15 ft 5 in) (pressure hull);
Height	9.60 m (31 ft 6 in)
Draught	4.74 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	2 shafts; 2 × diesel engines; 2 × electric motors;
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);
Complement	4 officers, 40–56 enlisted
Armament	5 × torpedo tubes (four bow, one stern); 14 × 53.3 cm (21 in) torpedoes or 26 TMA mines; 1 × 8.8 cm (3.46 in) deck gun (220 rounds); 2 × twin 2 cm (0.79 in) C/30 anti-aircraft guns;
Service record
Part of:	21st U-boat Flotilla; 17 September 1943 – 28 February 1945; 31st U-boat Flotilla; 1 March – 5 May 1945;
Identification codes:	M 54 671
Commanders:	Lt.z.S. / Oblt.z.S. Wolf-Harald Schüer; 17 September 1943 – 31 March 1944; Oblt.z.S. Walter Boldt; 1 April – 22 November 1944; Oblt.z.S. Erhard Wendelberger; 23 November 1944 – 5 May 1945;
Operations:	None
Victories:	None

German submarine U-720 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 17 August 1942 at the H. C. Stülcken Sohn yard at Hamburg, launched on 5 June 1943, and commissioned on 17 September 1943 under the command of Leutnant zur See Wolf-Harald Schüer.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-720 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[1] 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 Garbe, Lahmeyer & Co. RP 137/c 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).^[1]

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).^[1] 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-720 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.^[1]

Service history

U-720 was surrendered on 5 May 1945,^[2] sank on 21 December 1945 as part of Operation Deadlight by artillery fire from ORP Piorun, HMS Onslaught, HMS Zetland, and HMS Fowey in position 56°4′N 9°35′W / 56.067°N 9.583°W / 56.067; -9.583.^[3]

References

^ ^a ^b ^c ^d Gröner 1991, pp. 43–46.
^ Helgason, Guðmundur. "The Type VIIC boat U-720". German U-boats of WWII - uboat.net. Retrieved 1 March 2010.
^ Busch & Röll 1999b, p. 386.

Bibliography

Busch, Rainer; Röll, Hans-Joachim (1999a). 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 (1999b). 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.