German submarine U-172

U-505, a typical Type IXC boat
History
Nazi Germany
Name:	U-172
Ordered:	23 December 1939
Builder:	DeSchiMAG AG Weser, Bremen
Yard number:	1012
Laid down:	11 December 1940
Launched:	31 July 1941
Commissioned:	5 November 1941
Fate:	Sunk, 13 December 1943, by US aircraft and warships
General characteristics
Class and type:	Type IXC submarine
Displacement:	1,120 t (1,100 long tons) surfaced 1,232 t (1,213 long tons) submerged
Length:	76.76 m (251 ft 10 in) o/a 58.75 m (192 ft 9 in) pressure hull
Beam:	6.76 m (22 ft 2 in) o/a 4.40 m (14 ft 5 in) pressure hull
Height:	9.60 m (31 ft 6 in)
Draught:	4.70 m (15 ft 5 in)
Installed power:	4,400 PS (3,200 kW; 4,300 bhp) (diesels) 1,000 PS (740 kW; 990 shp) (electric)
Propulsion:	2 shafts 2 × diesel engines 2 × electric motors
Range:	13,450 nmi (24,910 km; 15,480 mi) at 10 knots (19 km/h; 12 mph) surfaced 64 nmi (119 km; 74 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth:	230 m (750 ft)
Complement:	4 officers, 44 enlisted
Armament:	6 × torpedo tubes (4 bow, 2 stern) 22 × 53.3 cm (21 in) torpedoes 1 × 10.5 cm (4.1 in) deck gun (180 rounds) 1 × 3.7 cm (1.5 in) AA gun 1 × twin 2 cm FlaK 30 AA guns
Service record
Part of:	4th U-boat Flotilla November 1941 – April 1942 10th U-boat Flotilla May 1942 – December 1943 Attached to Wolfpack Eisbär (August 1942)
Commanders:	Kptlt. Carl Emmermann Oblt.z.S. Hermann Hoffmann 1 November 1943 – 13 December 1943
Operations:	Six patrols 1st patrol: 22 April – 3 May 1943 2nd patrol: 11 May – 27 July 1942 3rd patrol: 19 August – 27 December 1942 4th patrol: 21 February – 17 April 1943 5th patrol: 29 May – 7 September 1943 6th patrol: 22 November – 13 December 1943
Victories:	26 commercial vessels (152,080 GRT)

German submarine U-172 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II. She was first assigned to the 4th U-boat Flotilla for training and on 1 May 1942 was reassigned to the 10th flotilla, an operational long-range organization.

German Type IXC submarines were slightly larger than the original Type IXBs. U-172 had a displacement of 1,120 tonnes (1,100 long tons) when at the surface and 1,232 tonnes (1,213 long tons) while submerged. The U-boat had a total length of 76.76 m (251 ft 10 in), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.76 m (22 ft 2 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.70 m (15 ft 5 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 metric horsepower (740 kW; 990 shp) for use while submerged. She had two shafts and two 1.92 m (6 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 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,450 nautical miles (24,910 km; 15,480 mi) at 10 knots (19 km/h; 12 mph). U-172 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) as well as a 2 cm (0.79 in) anti-aircraft gun. The boat had a complement of forty-eight.