German submarine U-548

History
Nazi Germany
Name:	U-548
Ordered:	5 June 1941
Builder:	Deutsche Werft, Hamburg
Yard number:	369
Laid down:	4 September 1942
Launched:	14 April 1943
Commissioned:	30 June 1943
Fate:	Sunk, April 1945 by depth charges from American warships southeast of Halifax, Nova Scotia
General characteristics
Class & type:	Type IXC/40 submarine
Displacement:	1,144 t (1,126 long tons) surfaced 1,257 t (1,237 long tons) submerged
Length:	76.76 m (251 ft 10 in) o/a 58.75 m (192 ft 9 in) pressure hull
Beam:	6.86 m (22 ft 6 in) o/a 4.44 m (14 ft 7 in) pressure hull
Height:	9.60 m (31 ft 6 in)
Draught:	4.67 m (15 ft 4 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
Speed:	18.3 knots (33.9 km/h; 21.1 mph) surfaced 7.3 knots (13.5 km/h; 8.4 mph) submerged
Range:	13,850 nmi (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph) surfaced 63 nmi (117 km; 72 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 30 June 1943 – 31 March 1944 2nd U-boat Flotilla 1 April – 30 September 1944 33rd U-boat Flotilla 1 October 1944 – 19 April 1945
Identification codes:	M 52 470
Commanders:	Kptlt. Eberhard Zimmermann 30 June 1943 – 8 February 1945 Kptlt. Günther Pfeffer August – November 1944 Oblt.z.S. Erich Krempl 9 February – 19 April 1945
Operations:	1st patrol: 21 March – 24 June 1944 2nd patrol: 11 August – 25 September 1944 3rd patrol: 7–12 October 1944 4th patrol: 5 March – 19 April 1945
Victories:	One warship sunk, 1,445 tons

German submarine U-548 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II.

She was laid down at the Deutsche Werft (yard) in Hamburg as yard number 369 on 4 September 1942, launched on 14 April 1943 and commissioned on 30 June with Kapitänleutnant Eberhard Zimmermann in command.

U-548 began her service career with training as part of the 4th U-boat Flotilla from 30 June 1943. She was re-assigned to the 2nd flotilla for operations on 1 April 1944, then the 33rd flotilla on 1 October.

She carried out four patrols and sank one ship.

She was sunk in April 1945 by depth charges from American warships southeast of Halifax, Nova Scotia.

Design

German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-548 had a displacement of 1,144 tonnes (1,126 long tons) when at the surface and 1,257 tonnes (1,237 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 6.86 m (22 ft 6 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.67 m (15 ft 4 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 shaft horsepower (1,010 PS; 750 kW) 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 13,850 nautical miles (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph). U-548 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.

Service history

1st patrol

U-548's first patrol began with her departure from Kiel on 21 March 1944. She passed through the gap separating Iceland and the Faroe Islands before heading out into the Atlantic Ocean. The boat was involved in a rather bizarre incident on the night of 3 May when a B-24 Liberator illuminated HMS Hargood east of Conception Bay, Newfoundland, thinking she was a U-boat. U-548 fired at the aircraft which in turn wrongly assumed they had been engaged by the ship. The real quarry aborted her attack and escaped.

The boat was the target of an unsuccessful hunt by Allied escorts after the sinking of HMCS Valleyfield on 7 May 50 nautical miles (93 km; 58 mi) south of Cape Race, (Newfoundland).

She entered Lorient, on the French Atlantic coast, on 24 June 1944.

2nd and 3rd patrols

On her second foray, U-548 lost a man overboard, (Mechanikergefreiter (A) Walter Heise), during a crash-dive on 30 August 1944. Reversing the course of her first patrol, she arrived at Bergen in Norway, on 25 September.

Having moved to Hölen (southeast of Stavanger) in Norway, the boat began her third sortie on 7 October 1944. She docked at Flensburg on the 12th.

4th patrol and loss

By now, U-548 was based at Horten Naval Base (south of Oslo) also in Norway, from where she began her fourth and last patrol on 5 March 1945. She crossed the Atlantic once more and was sunk southeast of Halifax, Nova Scotia on 19 April by depth charges from the American destroyer escorts Reuben James and Buckley.

Fifty-eight men died with the U-boat; there were no survivors.

Summary of raiding history

Date	Name	Nationality	Tonnage	Fate
7 May 1944	HMCS Valleyfield	Royal Canadian Navy	1,445	Sunk