German submarine U-623

History
Nazi Germany
Name:	U-623
Ordered:	15 August 1940
Builder:	Blohm & Voss, Hamburg
Yard number:	599
Laid down:	15 July 1941
Launched:	31 March 1942
Commissioned:	21 May 1942
Fate:	Sunk 21 February 1943 in the North Atlantic in position , by depth charges from a RAF Liberator.
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:	8th U-boat Flotilla 21 May – 30 November 1942 - Training 6th U-boat Flotilla 1 December 1942 – 21 February 1943
Commanders:	Oblt.z.S. Hermann Schrüder 21 May 1942 – 21 February 1943
Operations:	1st patrol: 5 November – 26 December 1942 2nd patrol: 2–21 February 1943
Victories:	None

German submarine U-623 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 15 July 1941 by Blohm & Voss, Hamburg as yard number 599, launched on 31 March 1942 and commissioned on 21 May 1942 under Oberleutnant zur See Hermann Schrüder.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-623 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-623 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 8th U-boat Flotilla on 21 May 1942, followed by active service on 1 December 1942 as part of the 6th Flotilla for the remainder of her service.

In two patrols she sank no ships.

Wolfpacks

U-623 took part in five wolfpacks, namely

• Drachen (22 November – 3 December 1942)
• Panzer (3–9 December 1942)
• Ungestüm (11–13 December 1942)
• Raufbold (13–18 December 1942)
• Ritter (11–21 February 1943)

Fate

U-623 was caught while hurrying on the surface to join the attack against Convoy ON 166 and sunk on 21 February 1943 in the North Atlantic, at the position , by depth charges from a RAF Liberator of 120 Squadron. All hands were lost.

See also

• Convoy ON 166