German submarine U-990

History
Nazi Germany
Name:	U-990
Ordered:	25 May 1941
Builder:	Blohm & Voss, Hamburg
Yard number:	190
Laid down:	17 October 1942
Launched:	16 June 1943
Commissioned:	28 July 1943
Fate:	Sunk on 25 May 1944 in the Norwegian Sea by depth charges from a RAF Liberator bomber
General characteristics
Class & type:	Type VIIC submarine
Displacement:	769 tonnes (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
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 × 53.3 cm (21 in) torpedo tubes (4 bow, 1 stern) 14 × torpedoes or 26 TMA mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) Various AA guns
Service record
Part of:	5th U-boat Flotilla (Training) 28 July – 31 December 1943 11th U-boat Flotilla 1 January – 25 May 1944
Commanders:	Kptlt. Hubert Nordheimer 28 July 1943 – 25 May 1944
Operations:	4 patrols
Victories:	1 warship sunk (1,920 tons)

German submarine U-990 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 17 October 1942 by Blohm & Voss, Hamburg as yard number 190, launched on 16 June 1943 and commissioned on 28 July 1943 under Kapitänleutnant Hubert Nordheimer.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-990 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-990 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 an anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history

The boat's career began with training at 5th Flotilla on 28 July 1943, followed by active service on 1 January 1944 as part of the 11th Flotilla.

Wolfpacks

U-990 took part in four wolfpacks, namely

• Werwolf (28 January – 27 February 1944)
• Orkan (5 – 10 March 1944)
• Hammer (10 – 26 March 1944)
• Blitz (2 – 4 April 1944)

Fate

U-990 was sunk on 25 May 1944 in the Norwegian Sea at after being depth charged by a RAF Liberator bomber of 59 Squadron.

Sqn Ldr B. Sisson sighted U-990 on the surface at 06:23 and attacked under cover of a rain squall, dropping six depth charges. Following the battack, the submarine could be seen sinking amid a large oil slick.

There were 20 crew killed, and 33 survivors.

Summary of raiding history

Date	Name	Nationality	Tonnage	Fate
25 February 1944	HMS Mahratta	Royal Navy	1,920	Sunk