was one of two semi-dreadnought battleship built for the Imperial Japanese Navy (IJN) during the first decade of the 20th century. She was the second battleship built domestically in Japan and the first to use steam turbines for propulsion. The ship was named for Aki Province, now a part of Hiroshima Prefecture. The ship saw no combat during World War I. Aki was disarmed in 1922 and sunk as a target in 1924 in accordance with the terms of the Washington Naval Treaty of 1922. Background The Satsuma class was ordered in late 1904 under the 1904 War Naval Supplementary Program during the Russo-Japanese War. Unlike the previous pre-dreadnought battleships, they were the first battleships ordered from Japanese shipyards. They were originally designed with a dozen guns, but had to be redesigned because of a shortage of guns in Japan and to reduce costs. Design and description The ship had an overall length of , a beam of , and a normal draft of . She displaced at normal load. The crew consisted of 931 officers and enlisted men. Aki was fitted with a pair of Curtiss steam turbine sets, each driving one shaft using steam from 15 Miyabara water-tube boilers. The turbines were rated at a total of for a design speed of . The ship reached a top speed of during her sea trials from . She carried enough coal and oil to give her a range of at a speed of . Unlike her half-sister, she had three funnels. The ship's main battery consisted of four 45-caliber 12-inch (305 mm) 41st Year Type guns in two twin-gun turrets, one each fore and aft of the superstructure. Her intermediate armament consisted of six twin-gun turrets equipped with 45-caliber Type 41 10-inch (254 mm) guns, three turrets on each side of the superstructure. Her heavy intermediate armament of guns larger than is why the ship is considered to be a semi-dreadnought. Akis secondary armament consisted of eight 45-caliber 6-inch (152 mm) 41st Year Type guns, mounted in casemates in the sides of the hull. The ship was also equipped with eight quick-firing (QF) 40-caliber 12-pounder () 12-cwt guns and four 28-caliber 12-pounder QF guns. In addition, the battleship was fitted with five submerged torpedo tubes, two on each broadside and one in the stern. The waterline main belt of the Satsuma-class vessels consisted of Krupp cemented armor that had