History
Nazi Germany
Name	U-434
Ordered	23 September 1939
Builder	Schichau-Werke, Danzig
Yard number	1475
Laid down	20 January 1940
Launched	15 March 1941
Commissioned	21 June 1941
Fate	Sunk on 18 December 1941
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced 871 t (857 long tons) submerged
Length	67.10 m (220 ft 2 in) o/a 50.50 m (165 ft 8 in) pressure hull
Beam	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull
Height	9.60 m (31 ft 6 in)
Draught	4.74 m (15 ft 7 in)
Installed power	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels) 750 PS (550 kW; 740 shp) (electric)
Propulsion	2 shafts 2 × diesel engines 2 × electric motors
Speed	17.7 knots (32.8 km/h; 20.4 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement	4 officers, 40–56 enlisted
Armament	5 × 53.3 cm (21 in) torpedo tubes (4 bow, 1 stern) 14 × torpedoes or 26 TMA mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 1 x 2 cm (0.79 in) C/30 AA gun
Service record
Part of:	7th U-boat Flotilla 21 June – 18 December 1941
Identification codes:	M 43 633
Commanders:	Kptlt. Wolfgang Heyda 21 June – 18 December 1941
Operations:	1 patrol: 2 November – 18 December 1941
Victories:	None

German submarine U-434 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

The U-boat was laid down on 20 January 1940 at the Schichau-Werke yard, Danzig, launched on 15 March 1941, and commissioned on 21 June 1941, Kapitänleutnant Wolfgang Heyda commanding.^[1]

U-434 sailed from Kristiansand, Norway on 2 November 1941, on her only war patrol. On 18 December, U-434 was sunk in the North Atlantic north of Madeira, Portugal, in position 36°15′N 15°48′W / 36.250°N 15.800°W / 36.250; -15.800. The U-boat was forced to the surface by depth charges from the British escort destroyer HMS Blankney and the destroyer HMS Stanley. There were two dead and 42 survivors.

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-434 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[2] 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 AEG GU 460/8-276 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).^[2]

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).^[2] 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-434 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 a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.^[2]

U-434 took part in two wolfpacks, namely:

• Steuben (14 November – 1 December 1941)
• Seeräuber (15 – 18 December 1941)

• Helgason, Guðmundur. "The Type VIIC boat U-434". German U-boats of WWII - uboat.net. Retrieved 26 December 2014.
• Movietone News Clip of the sinking of U-434 - Title: U-Boats destroyed in convoy