German submarine U-477

German submarine U-477 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

She carried out one patrol. She sank no ships.

She was sunk by a Canadian aircraft, west of Trondheim on 3 June 1944.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-477 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 Siemens-Schuckert GU 343/38–8 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-477 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), one 3.7 cm Flak M42 and two twin 2 cm C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

Service history
The submarine was laid down on 17 October 1942 at the Deutsche Werke in Kiel as yard number 308, launched on 3 July 1943 and commissioned on 18 August under the command of Oberleutnant zur See Karl-Joachim Jenssen.

She served with the 5th U-boat Flotilla from 18 August 1943 for training and the 3rd flotilla from 1 June 1944 for operations.

Patrol and loss
U-477's only patrol was preceded by a short trip from Kiel in Germany to Kristiansand in Norway. The patrol itself began with the boat's departure from Kristiansand on 15 May 1944.

On 3 June she was attacked and sunk by depth charges dropped from a Canadian Canso flying boat of No. 162 Squadron RCAF west of Trondheim.

Fifty-one men went down with U-477; there were no survivors.