The preliminary draft design of the battleship developed in Japan in the mid-1930s had a displacement of 49,000–69,500 tons, a speed of 24–31 knots, and a main gun caliber of 410–460 mm in various versions. The final version was Yamato, the largest battleship in the world. Admiral Yamamoto took command of the Japanese forces from her bridge during the Battle of Midway. On April 7, 1945, Yamato was sunk off Kyūshū island by attacking U.S. Navy aircraft during Operation Ten-Go.