Japanese battleship Aki 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 battleship s , 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 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 was completed with four 45 - caliber 12 - inch 41st Year Type guns in two gun turrets , one each fore and aft of the superstructure . They fired armor - piercing ( AP ) shells to a maximum range of . The intermediate armament consisted of six twin - gun turrets equipped with 45 - caliber Type 41 10 - inch 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 . " Aki " s secondary armament consisted of eight 45 - caliber 6 - inch 41st Year Type guns , mounted in casemate s 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 tube s , 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 a maximum thickness of amidships . It tapered to a thickness of at the ends of the ship . A strake of armor protected the casemates . The barbettes for the main guns were thick . The armor of " Aki " s main gun turrets had a maximum thickness of . The deck armor was thick and the conning tower was protected by six inches of armor . Construction and career . " Aki " , named for Aki Province , was laid down at Kure Naval Arsenal on 15 March 1906 . She was launched on 15 April 1907 , but construction was suspended for about five months after the decision was made on 26 November to install steam turbines on " Aki " and the armored cruiser . " Aki " s turbines were already behind schedule and the suspension allowed the less valuable ship to be completed first , and changes made to its turbines after testing were also incorporated into " Aki " s turbines . " Aki " was finally completed on 11 March 1911 and her first captain was Tatsuo Matsumura . When World War I began in August 1914 , " Aki " was refitting at Kure Naval Arsenal . She was assigned to the 1st Battleship Squadron upon the completion of her refit and remained with it until she was transferred to the 2nd Battleship Squadron in 1918 . The ship was disarmed at Yokosuka in 1922 to comply with the provisions of the Washington Naval Treaty , stricken from the Navy List during 1923 and converted into a target ship . " Aki " was sunk by the battlecruiser and the battleship on 2 September 1924 in Tokyo Bay . Two of her 10 - inch gun turrets were installed as coastal artillery batteries on Jōgashima island to protect Tokyo Bay .