Type XXI submarines were a class of German diesel–electric Elektroboot submarines designed during the Second World War. One hundred and eighteen were completed, with four being combat-ready. During the war only two were put into active service and went on patrols, but these were not used in combat.
U-2540 in wartime configuration and exhibited at the Maritime Museum in Bremerhaven. It is the only floating example of a Type XXI U-boat.
Construction consisted of nine prefabricated sections
U.S. Navy diagram of a Type XXI U-boat. Note the teardrop-shaped fairing for the large hydrophone array beneath the bow and the wasp-waist pressure hull. The large sonar array and its housing did slow the boat down, but its placement and size allowed for a very sensitive system to be installed, and gave it near-360 degree coverage around the submarine.
Three Type XXI U-boats and one Type VII U-boat moored at Bergen, Norway (May 1945). The Type XXI in the middle is U-2511
A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. British Royal Navy personnel often refer to it as the snort. A concept devised by Dutch engineers, it was widely used on German U-boats during the last year of World War II and known to them as a schnorchel.
USS U-3008 (former German submarine U-3008) conning tower, with the snorkel raised
Head of the snorkel mast from German type XXI submarine U-3503, scuttled outside Gothenburg on May 8, 1945 but raised by the Swedish Navy and carefully studied for the purpose of improving future Swedish submarine designs
