German submarine U-577

German submarine U-577 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 1 August 1940 by Blohm & Voss, Hamburg as yard number 553, launched on 15 May 1941 and commissioned on 3 July 1941 under Kapitänleutnant Herbert Schauenburg.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-577 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-577 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
The boat's career began with training at 7th U-boat Flotilla on 3 July 1941, followed by active service on 1 October 1941 as part of the 1st Flotilla. On 1 January 1942, she transferred to operations in the Mediterranean with 29th Flotilla, and was sunk just two weeks later.

In 3 patrols she sank no ships.

Wolfpacks
U-577 took part in three wolfpacks, namely
 * Stosstrupp (30 October – 1 November 1941)
 * Raubritter (1–8 November 1941)
 * Störtebecker (17–22 November 1941)

Fate
U-577 was sunk on 15 January 1942 in the Mediterranean NW of Mersa Matruh, in position 32.66667°N, 25.8°W, by depth charges from RN Swordfish from 815 Squadron. All hands were lost.