German submarine U-234 was a Type XB U-boat of Nazi Germany's Kriegsmarine during World War II, she was commanded by Kapitänleutnant Johann-Heinrich Fehler. Her first and only mission into enemy or contested territory consisted of the attempted delivery of uranium oxide and German advanced weapons technology to the Empire of Japan. After receiving Admiral Dönitz' order to surface and surrender and of Germany's unconditional surrender, the submarine's crew surrendered to the United States on 14 May 1945. Construction Originally built as a minelaying submarine, she was laid down at the Germaniawerft in Kiel on 1 October 1941; U-234 was damaged during construction, but launched on 23 December 1943. Following the loss of in July 1944, it was decided not to use U-234 as a minelayer; she was completed instead as a long-range cargo submarine with missions to Japan in mind. Sensors Radar U-234 was one of the few U-boats that was fitted with a FuMO-61 Hohentwiel U-Radar Transmitter. This equipment was installed on the starboard side of the conning tower. Radar detection U-234 was also fitted with the FuMB-26 Tunis antenna. The FuMB 26 Tunis combined the FuMB Ant. 24 Fliege and FuMB Ant. 25 Cuba II antennas. It could be mounted in either the Direction Finder Antenna Loop and separately on the bridge. Wartime service U-234 returned to the Germaniawerft yard at Kiel on 5 September 1944, to be refitted as a transport. Apart from minor work, she had a snorkel added and 12 of her 30 mineshafts were fitted with special cargo containers the same diameter as the shafts and held in place by the mine release mechanisms. In addition, her keel was loaded with cargo, thought to be optical-grade glass and mercury, and her four upper-deck torpedo storage compartments (two on each side) were also occupied by cargo containers. Cargo The cargo to be carried was determined by a special commission, the Marine Sonderdienst Ausland, established towards the end of 1944, at which time the submarine's officers were informed that they were to make a special voyage to Japan. When loading was completed, the submarine's officers estimated that they were carrying 240 tons of cargo plus sufficient diesel fuel and provisions for a six- to nine-month voyage. The cargo included technical drawings, examples of the newest electric torpedoes, one crated Me 262 jet aircraft, a Henschel Hs 293 glide bomb and what was later listed on the