German submarine U-742 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. Her keel was laid down on 12 May 1942 by Schichau-Werke of Danzig. She was commissioned on 1 May 1943 with Kapitänleutnant Heinz Schwassmann in command.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-742 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-742 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.