German submarine U-734 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 20 October 1941 by Schichau-Werke, Danzig as yard number 1525, launched on 19 September 1942 and commissioned on 5 December 1942 under Oberleutnant zur See Hans-Jörg Blauert.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-734 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two AEG GU 460/8âÂÂ27 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-734 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
The boat's career began with training at 8th U-boat Flotilla on 5 December 1942, followed by active service on 1 August 1943 as part of the 3rd Flotilla for the remainder of her service.
In two patrols she sank no ships.
U-734 took part in three wolfpacks, namely:
U-734 was sunk on 9 February 1944 in the North Atlantic, southwest of Ireland, at position , by depth charges from the Royal Navy sloops and . All hands were lost.