German submarine U-309

History
Nazi Germany
Name	U-309
Ordered	5 June 1941
Builder	Flender Werke, Lübeck
Yard number	309
Laid down	24 January 1942
Launched	5 December 1942
Commissioned	27 January 1943
Fate	Sunk on 16 February 1945
General characteristics
Class and 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
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	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 (four bow, one stern) 14 × torpedoes or 26 TMA mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 2 × twin 2 cm (0.79 in) C/30 anti-aircraft guns
Service record[1][2]
Part of:	8th U-boat Flotilla 27 January – 31 July 1943 11th U-boat Flotilla 1 August – 31 October 1943 9th U-boat Flotilla 1 November 1943 – 1 October 1944 33rd U-boat Flotilla 1 October 1944 – 16 February 1945
Identification codes:	M 49 703
Commanders:	Oblt.z.S. Hans-Gert Mahrholz 27 January 1943 – August 1944 Oblt.z.S.. Herbert Loeder August 1944 – 16 February 1945
Operations:	9 patrols: 1st patrol: a. 13 – 18 September 1943 b. 25 September – 7 November 1943 2nd patrol: a. 19 December 1943 – 14 February 1944 b. 8 – 10 April 1944 3rd patrol: 20 – 25 June 1944 4th patrol: 28 June – 6 July 1944 5th patrol: a. 12 July – 3 August 1944 b. 7 – 12 August 1944 6th patrol: 29 August – 13 October 1944 7th patrol: 15 – 21 October 1944 8th patrol: 30 January – 2 February 1945 9th patrol: 8 – 16 February 1945
Victories:	1 merchant ship total loss (7,219 GRT)

German submarine U-309 was a Type VIIC U-boat of the German Navy (Kriegsmarine) during World War II. The submarine was laid down on 24 January 1942 at the Flender Werke yard at Lübeck, launched on 5 December 1942, and commissioned on 27 January 1943 under the command of Oberleutnant zur See Hans-Gert Mahrholz. She sailed on nine combat patrols, but damaged only one ship, before being sunk off Scotland on 16 February 1945.^[1]