German submarine U-715

German submarine U-715 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 28 March 1942 at the H. C. Stülcken Sohn yard at Hamburg, launched on 14 December 1942, and commissioned on 17 March 1943 under the command of Oberleutnant zur See Helmut Röttger.

History
Nazi Germany
Name	U-715
Ordered	10 April 1941
Builder	H. C. Stülcken Sohn, Hamburg
Yard number	781
Laid down	28 March 1942
Launched	14 December 1942
Commissioned	17 March 1943
Fate	Sunk by Canadian aircraft off Faeroe on 13 June 1944
General characteristics
Class & type	Type VIIC submarine
Displacement	769 t (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 × torpedo tubes (four bow, one stern) 14 × 53.3 cm (21 in) 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
Part of:	5th U-boat Flotilla 17 March 1943 – 31 May 1944 9th U-boat Flotilla 1 – 13 June 1944
Identification codes:	M 51 222
Commanders:	Oblt.z.S. / Kptlt. Helmut Röttger 17 March 1943 – 13 June 1944
Operations:	1 patrol: 8 – 13 June 1944
Victories:	None

Attached to 5th U-boat Flotilla based at Kiel, U-715 completed her training period on 31 May 1944 and was assigned to front-line service.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-715 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[1] 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 Garbe, Lahmeyer & Co. RP 137/c 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).^[1]

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).^[1] 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-715 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 two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.^[1]

Service history

On the first and final patrol, U-715 was spotted north-east of Faeroe on 13 June 1944 by Canso T of No. 162 Squadron RCAF and attacked with depth charges while snorkeling at periscope depth. Heavily damaged, the U-boat surfaced and returned fire, managing to down the Canadian aircraft before sinking in position 62°55′N 2°59′W. This was the first occasion when a submerged U-boat was detected and attacked. Of the crew of 52, only 16 survived.^[2]