The XXIII and the larger XXI are small offshore defense submarines developed by Germany at the same time. Research and development began in late 1942, but the more advanced XXII, designed with the same hull, was never completed. The hull of the XXIII submarine is produced in segmented mode at different factories around the country and then transported to the shipyard for later assembly and processing. The main reason for this arrangement is to make the submarines small enough to be transported by rail. The boat has a displacement of only 258 tons and is powered by a 572-horsepower MWM 6-cylinder diesel engine and a 572-horsepower AEG electric motor. It is also equipped with a slower motor with a smaller force of only 35 horsepower, which simultaneously pushes a single drive shaft. The boat cruises at a flat? speed of 9.7 nautical miles per hour and dives at 12.5 nautical miles per hour, or 4,800 kilometers per hour if it cruises at 8 sections on the surface. The weapon is a 2 torpedo launch tube that can fire 2 torpedoes. The XXIII submarines are produced in Germany, France, Italy and Russia, with 61 completed before the war. But only six were actually used to carry out missions, including the U 2336, which sank a merchant ship in European waters on May 7, 1945, before the end of World War II