A cross-section of a Type VIIC U-boat.
|Ordered||5 June 1941|
|Builder||Danziger Werft, Danzig|
|Laid down||13 August 1942|
|Launched||11 March 1943|
|Commissioned||26 June 1943|
|Fate||Scuttled in northern Germany on 5 May 1945. Wreck broken up in 1946|
|Class and type||Type VIIC submarine|
|Height||9.60 m (31 ft 6 in)|
|Draught||4.74 m (15 ft 7 in)|
|Complement||4 officers, 40–56 enlisted|
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.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-428 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 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 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-428 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
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.
The submarine was scuttled in the Kiel canal near Audorf on 5 May 1945. The wreck was broken up in 1946.