German submarine U-548

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 reassigned 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 on 19 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 1144 t when at the surface and 1257 t while submerged. The U-boat had a total length of 76.76 m, a pressure hull length of 58.75 m, a beam of 6.86 m, a height of 9.60 m, and a draught of 4.67 m. The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4400 PS for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1000 shp for use while submerged. She had two shafts and two 1.92 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 18.3 kn and a maximum submerged speed of 7.3 kn. When submerged, the boat could operate for 63 nmi at 4 kn; when surfaced, she could travel 13850 nmi at 10 kn. U-548 was fitted with six 53.3 cm torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm SK C/32 naval gun, 180 rounds, and a 3.7 cm SK C/30 as well as a 2 cm C/30 anti-aircraft gun. The boat had a complement of forty-eight.

First 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 (K582) 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 (K329) on 7 May 50 nmi south of Cape Race, (Newfoundland).

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

Second and third 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.

Fourth 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 USS Reuben James (DE-153) and USS Buckley (DE-51).

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