Kaiten Type 1 (Version 2)
Type 1 Japanese kaiten in the collection of the Naval History and Heritage Command; photographed while on loan to the U.S. Naval Undersea Museum. Kaiten were manned torpedoes designed and used by Japan during World War II to attack enemy ships. Kaiten inventors adapted Japan’s powerful oxygen-propelled torpedo, the Type 93 Long Lance, by adding a middle compartment that held a human pilot, periscope, and controls. Each kaiten carried 3,418 pounds of explosives, more than five times the size of American torpedo warheads. Kaiten proved largely unsuccessful as difficult controls and mechanical problems often caused failures before or during attacks; only two American ships were sunk by kaiten. In exchange, the Japanese suffered heavy losses: 80 kaiten weapons, 95 kaiten pilots, and eight transport submarines and their crews.