The very simply designed boat had a long, cylindrical central part. The bow and stern were conical. The boat could not dive, only undercut the surface of the water. It was designed so simply that it didn't even get a periscope. The two crew members only had a small round tower structure with viewing slits. The primary armament consisted of a 45 cm torpedo with a 600 kg explosive charge, which was embedded in the bow area of the boat. By the end of the war, 14 boats from the naval shipyard in Kure had been completed. However, they were no longer used in the war.
literature
Harald Fock: Naval small weapons. Manned torpedoes, small submarines, small speedboats, explosives yesterday - today - tomorrow. Nikol, Hamburg 1996, ISBN 3-930656-34-5 , p. 51.