U 570.jpg
Type VIIC submarine U-570 which looked almost identical to U-991.
History
Nazi Germany
Name: U-991
Ordered: 25 May 1941
Builder: Blohm & Voss, Hamburg
Yard number: 667
Laid down: 30 October 1942
Launched: 24 June 1943
Commissioned: 29 July 1943
Fate: Scuttled on 11 December 1945
General characteristics
Class and type: Type VIIC submarine
Displacement: 864.7 t (851 long tons) submerged
Length:
Beam:
  • 6.18 m (20 ft 3 in) o/a
  • 4.68 m (15 ft 4 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:
Speed:
  • 17.6 knots (32.6 km/h; 20.3 mph) surfaced
  • 7.5 knots (13.9 km/h; 8.6 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:
  • 220 m (720 ft)
  • Crush depth: 250–295 m (820–968 ft)
Complement: 44–57 crew
Armament:
Service record
Part of:
Commanders:
Operations: 1 patrol
Victories: None

German submarine U-991 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.[1]

Construction

The U-991 was laid down on 30 October 1942 at the Blohm & Voss yard in Hamburg, Germany. She was launched on 24 June 1943 and commissioned on 29 July 1943 under the command of Kapitänleutnant Diethelm Balke. Her U-boat emblem was a diving eagle.[2]

A cross-section of a Type VIIC U-boat.

When she was completed, the submarine was 67.10 metres (220 ft 2 in) long, with a beam of 6.18 metres (20 ft 3 in), a height of 9.60 metres (31 ft 6 in) and a draft of 4.74 metres (15 ft 7 in). She was assessed at 864.7 t (851 long tons) submerged. 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 and two BBC 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 submarine was capable of operating at depths of up to 230 metres (750 ft), had a maximum surface speed of 17.6 knots (32.6 km/h; 20.3 mph) and a maximum submerged speed of 7.5 knots (13.9 km/h; 8.6 mph).When submerged, the U-boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) and when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph).[1]

The submarine 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) deck gun (220 rounds) and an 3.7 cm (1.5 in) Flak M42 anti-aircraft gun. The boat had a complement of 44 to 57 men.[1]

Service history

U-991 was used as a Training ship in the 5th U-boat Flotilla from 29 July 1943 to 31 August 1944 before serving in the 11th U-boat Flotilla for active service on 1 September 1944.[2]

Training and tests

During U-991's service as a training ship, she completed a number of trainings and tests for the Kriegsmarine.[3]

Date Place Activity
30 July 1943 to 19 August 1943 Keel Trials at UAK
20 August 1943 Sonderborg Auscultation at UAK
22 August 1943 to 26 August 1943 Swinemünde Flakausbildung at Flakschule
27 August 1943 to 29 August 1943 Danzig Trials at UAK
30 August 1943 to 4 September 1943 Hela Front training at AGRU-Front
5 September 1943 to 5 February 1944 Flensburg School boat
9 February 1944 to 11 May 1944 Hela Front training at AGRU-Front
12 May 1944 to 23 May 1944 Pillau Torpedo shooting at the 26th U-boat Flotilla
24 May 1944 to 4 June 1944 Gotenhafen Tactical Training at the 27th U-boat Flotilla
5 June 1944 to 8 June 1944 Baltic Sea March over Königsberg to Stettin. Equipment for the company Wallenstein
10 June 1944 to 14 August 1944 Königsberg Remaining work in F. Schichau yard
15 August 1944 to 16 August 1944 Danzig Trials at UAK
21 August 1944 to 26 August 1944 Swinemünde Flakausbildung at Flakschule
29 August 1944 to 12 September 1944 Königsberg Installation of a Schnorchel underwater-breathing apparatus
13 September 1944 to 20 September 1944 Hela Snorkel training at AGRU-Front
21 September 1944 to 22 September 1944 Rönne Auscultation at AUK
23 September 1944 to 29 September 1944 Keel Remaining work and equipment to the 1st company

[3]

Active Service

During her active service, U-991 made 1 patrol and left Kristiansand on 15 October 1944. Her patrol lasted 73 days and U-991 patrolled the North Atlantic from Norway, around the United Kingdom and Ireland and also to France before returning to Bergen. She arrived in Bergen on 26 December 1944, which marked the end of her first and only patrol during World War II.[2]

Date Port of Departure Port of Arrival Duration
5 October 1944 to 7 October 1944 Kiel Horten 3 days
11 October 1944 to 12 October 1944 Horten Kristiansand 2 days
15 October 1944 to 26 December 1944 Kristiansand Bergen 73 days (Patrol)
27 December 1944 to 29 December 1944 Bergen Marviken 3 days
2 January 1945 to 4 January 1945 Marviken Flensburg 3 days
20 April 1945 to 27 April 1945 Kiel Horten 8 days
29 April 1945 to 4 May 1945 Horten Bergen 6 days

[3]

In total, the U-991 spend 98 days at sea during her active service until 9 May 1945.[3]

Capture And End

U-991 surrendered on 9 May 1945 at Bergen, Norway to the Allied Forces. The submarine was transferred from Bergen to Scapa Flow on 2 June 1945 and from Scapa Flow to Loch Ryan on 5 June 1945. She stayed in Loch Ryan for her immersion in Operation Deadlight (post-war Allied operation) until 11 December 1945, when she was towed to sea by the British Navy tug HMS Freedom (W.139).[3]

The U-2377 taken to sea to be scuttled during Operation Deadlight, the same fate was waiting for U-991.

U-991 was sunk at 12.15am on 11 December 1945 in the North Atlantic, North-West off the coast of Ireland by a torpedo from the British submarine HMS Tantivy. Her wreck still lies at 56°10′N 10°05′W / 56.167°N 10.083°W / 56.167; -10.083.[2]

References

  1. ^ a b c "U-991 (+1945)". wrecksite.eu. 29 November 2009. Retrieved 7 April 2016.
  2. ^ a b c d Helgason, Guðmundur (1995). "U-991". German U-boats of WWII - uboat.net. Retrieved 7 April 2016.
  3. ^ a b c d e Hofmann, Markus (23 December 2013). "U-991". Deutsche U-Boote 1935-1945 - u-boot-archiv.de (in German). Retrieved 7 April 2016.

Bibliography

  • 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.
  • 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.