German submarine U-91 (1941)

For other ships of the same name, see German submarine U-91.

Career (Nazi Germany)
Name:	U-91
Ordered:	25 January 1939
Builder:	Flender Werke, Lübeck
Yard number:	295
Laid down:	12 November 1940
Launched:	30 November 1941
Commissioned:	28 January 1942
Fate:	Sunk 26 February 1944 in the Northern Atlantic by British warships
General characteristics
Type:	Type VIIC submarine
Displacement:	769 tonnes (757 long tons) ↑ 871 t (857 long tons) ↓
Length:	67.1 m (220 ft 2 in) o/a 50.5 m (165 ft 8 in) pressure hull
Beam:	6.2 m (20 ft 4 in) o/a 4.7 m (15 ft 5 in) pressure hull
Draft:	4.74 m (15 ft 7 in)
Propulsion:	2 × supercharged Germaniawerft 6-cylinder 4-stroke F46 diesel engines, totalling 2,800–3,200 bhp (2,100–2,400 kW). Max rpm: 470-490 2 × Brown, Boveri & Cie. electric motors, totalling 750 shp (560 kW) and max rpm: 296
Speed:	17.7 knots (20.4 mph; 32.8 km/h) surfaced 7.6 knots (8.7 mph; 14.1 km/h) submerged
Range:	8,500 nmi (15,700 km) at 10 kn (19 km/h) ↑ 80 km (43 nmi) at 4 kn (7.4 km/h) ↓
Test depth:	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement:	44–52 officers and ratings
Armament:	• 5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) • 14 × G7e torpedoes or 26 TMA mines • 1 × 8.8 cm (3.46 in) deck gun (220 rounds) • Various AA guns

Service record
Part of:	Kriegsmarine: 5th U-boat Flotilla 9th U-boat Flotilla
Commanders:	Kptlt. Heinz Walkerling (28 January–31 August 1942) Kptlt. Heinz Hungerhausen (1 September 1942–26 February 1944)
Operations:	Six 1st patrol: 15 August–6 October 1942 2nd patrol: 1 November– 26 December 1942 3rd patrol: 11 February–29 March 1943 4th patrol: 29 April–7 June 1943 5th patrol: 21 September–22 November 1943 6th patrol: 25 January–26 February 1944
Victories:	Four ships sunk for a total of 26,194 gross register tons (GRT); one warship sunk of 1,375 tons

German submarine U-91 was a Type VIIC U-boat of the Nazi German Kriegsmarine during World War II.

She was laid down at the Flender Werke in Lübeck as 'werk' 295, launched on 30 November 1941 and commissioned on 28 January 1942 with Kapitänleutnant Heinz Walkerling as commanding officer. Command was transferred to Kapitänleutnant Heinz Hungershausen on 20 April 1943.

She was a fairly successful boat, sinking over 26,000 tons of Allied shipping in a career lasting just 14 months and six patrols. She was a member of fifteen wolfpacks. After training with the 5th U-boat Flotilla, U-91 was assigned to the 9th flotilla on 1 September 1942 for operations.

Operational career

1st patrol

U-91 departed Kiel for her first patrol on 15 August 1942. Having negotiated the Iceland/Faroes 'gap', she was attacked by a US PBY Catalina on 1 September. (This incident was originally thought to have been against U-756).

The escort vessels of convoy ON 127 fired on the boat on 12 September; minor damage was sustained.

U-91 sank the Canadian destroyer HMCS Ottowa on 14 September. The boat fired two torpedoes at 02:05 and confirmed a hit. At 02:15, the submarine came across the damaged Ottawa once again, but mistook her for a different vessel and fired a third torpedo, which destroyed the ship, killing 114 of the 181 men aboard.

She also sank the New York southeast of Cape Farewell (Greenland) on 26 September.

She docked in Brest, on the French Atlantic coast, on 6 October.

2nd patrol

The boat's second foray started from Brest on 1 November 1942 and finishing there on 26 December. It was relatively uneventful.

3rd patrol

U-91 was subject to a "rain of aircraft bombs and depth charges from surface ships" which obliged her to break off an attack to carry out repairs on 21 February 1943.

The boat was soon back in action; on 17 March, U-91 attacked Convoy HX-229. Two American vessels - Harry Luckenbach and Irénée Du Pont - were destroyed along with the British merchant ship Nariva. The Luckenbach was hit by two torpedoes after five were fired between 03:37 and 03:41. The Luckenbach sank in a mere three minutes, with seventy-one of the eighty men evacuating in lifeboats, although there were no reports of them being rescued. Nariva and the Irénée Du Pont had been damaged by U-600 earlier that day. U-91 fired three torpedoes at 05:56: Two finishing off the Du Pont, a third crippled the Nariva.

The inbound submarine was attacked by a Leigh Light equipped Vickers Wellington of No. 172 Squadron RAF on the western edge of the Bay of Biscay on 27 March. Although not damaged, the boat dived with three men still top-side. Two were recovered, but the third could not be found.

U-91 returned to France, but to Lorient, on 29 March.

4th patrol

Sortie number four began from Lorient on 29 April 1943; it was also relatively quiet but terminated in Brest on 7 June.

5th patrol

U-91 was attacked by a B-24 Liberator of No. 10 Squadron RCAF on 26 October 1943. The undamaged U-boat had been searching for U-584 to supply her with fuel. The Liberator's assault was thought to have sunk U-420. A few days later, (on the 31st), having found U-584, she commenced the re-fuelling operation, but the two boats were spotted by aircraft from the escort carrier Card. In the ensuing mayhem, U-91 escaped without damage after diving; U-584 was not so lucky, she was sunk.

6th patrol and loss

U-91 departed Brest for the last time on 25 January 1944; on 26 February she was sunk in the middle of the North Atlantic by depth charges from the British frigates HMS Affleck, Gore and Gould.

36 men died with the U-boat; there were 16 survivors. Kapitänleutnant Heinz Hungershausen was not one of them.

Patrols

#	Departure	Date	Arrival	Date	Length
1	Kiel	15 Aug 1942	Brest	6 Oct 1942	53 days
2	Brest	1 Nov 1942	Brest	26 Dec 1942	56 days
3	Brest	11 Feb 1943	Lorient	29 Mar 1943	47 days
4	Lorient	29 Apr 1943	Brest	7 Jun 1943	40 days
5	Brest	21 Sep 1943	Brest	22 Nov 1943	63 days
6	Brest	25 Jan 1944	Sunk	26 Feb 1944	33 days

Summary of raiding history

Date	Ship	Nationality	Tonnage	Fate
14 September 1942	HMCS Ottawa	Canada	1,375	Sunk
26 September 1942	New York	Great Britain	4,989	Sunk
17 March 1942	Harry Luckenbach	USA	6,366	Sunk
17 March 1942	Irénée Du Pont	USA	6,125	Sunk
17 March 1942	Nariva	Great Britain	8,714	Sunk

References

Notes

Bibliography

• U-91 at uboat.net
• U-91 at ubootwaffe.net

External links

• U-91 at u-boot-archiv.de (German)

See also

• List of German U-boats