, named after the former Japanese province, was one of four planned s built for the Imperial Japanese Navy (IJN), beginning in the late 1930s. The Yamato-class ships were the heaviest and most powerfully armed battleships ever constructed, displacing almost fully loaded and armed with nine main guns. Their secondary armament consisted of four triple-gun turrets formerly used by the s. They were equipped with six or seven floatplanes to conduct reconnaissance.
Commissioned in mid-1942, Musashi was modified to serve as the flagship of the Combined Fleet, and spent the rest of the year working up. The ship was transferred to Truk, Japan's main wartime naval base in the South Pacific theatre, in early 1943 and sortied several times that year with the fleet in unsuccessful searches for American forces. She was used to transfer forces and equipment between Japan and various occupied islands several times in 1944. Torpedoed in early 1944 by an American submarine, Musashi was forced to return to Japan for repairs, during which the navy greatly augmented her anti-aircraft armament. She was present during the Battle of the Philippine Sea in June, but did not come in contact with American surface forces. During the Battle of Leyte Gulf, Musashi was sunk by an estimated 19 torpedo and 17 bomb hits from American carrier-based aircraft on 24 October 1944. Over half of her crew was rescued. Her wreck was located in March 2015 by a team of researchers employed by Microsoft co-founder Paul Allen.
Design and description
Since the IJN anticipated it would be unable to produce as many ships as the United States, the Yamato-class ships with their great size and heavy armament were designed to be individually superior to American battleships. Musashi had a length of between perpendiculars and overall. She had a waterline beam of and a draught of at deep load. She displaced at standard load and at deep load. Her crew consisted of 2,500 officers and ratings in 1942, and about 2,800 in 1944.
The battleship had four sets of Kampon geared steam turbines, each of which drove one propeller shaft. The turbines were designed to produce a total of , using steam provided by 12 Kampon water-tube boilers, giving the ship a maximum speed of . She had a stowage capacity of of fuel oil, giving a range of at a speed of .
Armament
Musashis main battery consisted of nine 45-calibre 460-milliimetre Type 94 guns mounted in three triple gun turrets, numbered from front to rear. The guns had a rate of fire of 1.5 to 2 rounds per minute. The ship's secondary battery consisted of twelve 60-calibre 155-millimetre 3rd Year Type guns mounted in four triple turrets, one each fore and aft of the superstructure and one on each side amidships. These had become available once the Mogami-class cruisers were rearmed with guns. Heavy anti-aircraft defence was provided by a dozen 40-calibre 127-millimetre (5 in) Type 89 dual-purpose guns in six twin turrets, three on each side of the superstructure. Musashi also carried thirty-six 25-millimetre (1 in) Type 96 light anti-aircraft (AA) guns in 12 triple-gun mounts, all mounted on the superstructure. The ship was also provided with two twin mounts for the licence-built Type 93 anti-aircraft machine guns, one on each side of the bridge.
While the ship was under repair in April 1944, the two 155 mm wing turrets were removed and replaced with three triple 25 mm gun mounts each. A total of sixteen triple 25 mm mounts and twenty-five single mounts were added at that time, giving the ship a light AA armament of 115 guns.
Armour
The ship's waterline armour belt was identical to 's at thick and angled outwards 20 degrees at the top. Below it was a strake of armour that ranged in thickness from over the magazines and machinery spaces, respectively; it tapered to a thickness of at its bottom edge. The deck armour ranged in thickness from . The turrets were protected with an armour plate thick on the face, on the sides, and 270 millimetres on the roof. The barbettes of the turrets were protected by armour thick, and the turrets of the 155 mm guns were protected by armour plates. The sides of the conning tower were thick and its roof was 200 millimetres thick. Underneath the magazines were armour plates to protect the ship from mine damage. Musashi contained 1,147 watertight compartments (1,065 underneath the armour deck, 82 above) to preserve buoyancy in the event of battle damage.
Aircraft
Musashi was fitted with two catapults on her quarterdeck and could stow up to seven floatplanes in her below-decks hangar. The ship operated Mitsubishi F1M biplanes and Aichi E13A1 monoplanes and used a , stern-mounted crane for recovery.