German submarine U-428

German submarine U-428 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

She carried out no patrols. She did not sink or damage any ships.

She was scuttled in northern Germany on 5 May 1945. The wreck was broken up in 1946.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-428 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-428 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 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 13 August 1942 at the Danziger Werft (yard) at Danzig (now Gdansk), as yard number 129, launched on 11 March 1943 and commissioned on 26 June under the command of Capitano di Corvetta Athos Fraternale.

She served with the 8th U-boat Flotilla from 26 June 1943 and the 23rd flotilla from 1 October. She was reassigned to the 31st flotilla on 1 March 1945.

The U-boat was named S-1 after being acquired by the Italian Navy in exchange for some transport ships. She returned to Germany after the Italian surrender where she was renamed U-428.

Fate
The submarine was scuttled in the Kiel canal near Audorf on 5 May 1945. The wreck was broken up in 1946.