Background
The design of the ''Yamato''-class battleships was shaped by expansionist movements within the Japanese government, Japanese industrial power, and the need for a fleet powerful enough to intimidate likely adversaries. Most importantly, the latter, in the form of the Kantai Kessen (“Decisive Battle Doctrine”), a naval strategy adopted by the Imperial Japanese Navy prior to the Second World War, in which the Japanese navy would win a war by fighting and winning a single, decisive naval action. After the end of the First World War, many navies—including those of the United States, the United Kingdom, and Imperial Japan—continued and expanded construction programs that had begun during the conflict. The enormous costs associated with these programs pressured their government leaders to begin a disarmament conference. On 8 July 1921, the United States' Secretary of State Charles Evans Hughes invited delegations from the other major maritime powers—France, Italy, Japan, and the United Kingdom—to come to Washington, D.C. and discuss a possible end to the naval arms race. The subsequent Washington Naval Conference resulted in the Washington Naval Treaty. Along with many other provisions, it limited all future battleships to a standard displacement of and a maximum gun caliber of . It also agreed that the five countries would not construct more capital ships for ten years and would not replace any ship that survived the treaty until it was at least twenty years old. In the 1930s, the Japanese government began a shift towards ultranationalist militancy. This movement called for the expansion of theDesign
Preliminary studies for a new class of battleships began after Japan's departure from the League of Nations and its renunciation of the Washington and London naval treaties; from 1934 to 1936, 24 initial designs were put forth. These early plans varied greatly in armament, propulsion, endurance, and armor. Main batteries fluctuated between and guns, while the secondary armaments were composed of differing numbers of , , and guns. Propulsion in most of the designs was a hybrid diesel- turbine combination, though one relied solely on diesel and another planned for only turbines. The maximum range of the various designs was between in design A-140-J2 to a high of in designs A-140A and A-140-B2, at a speed of . Armor varied between providing protection from the fire of 406 mm guns to enough protection against 460 mm guns. After these had been reviewed, two of the original twenty-four were finalized as possibilities, A-140-F3 and A-140-F4. Differing primarily in their range ( versus at ), they were used in the formation of the final preliminary study, which was finished on 20 July 1936. Tweaks to that design resulted in the definitive design of March 1937,Garzke and Dulin, pp. 49–50 which was put forth by Rear-Admiral Fukuda Keiji; a range of 7,200 nmi was finally decided upon, and the hybrid diesel-turbine propulsion was abandoned in favor of turbines. The diesel engines were removed from the design because of problems with the engines aboard the submarine tender '' Taigei''. Their engines, which were similar to the ones that were going to be mounted in the new battleships, required a "major repair and maintenance effort"Garzke and Dulin, p. 49 to keep them running due to a "fundamental design defect". In addition, if the engines failed entirely, the armored citadel deck roof that protected the proposed diesel engine rooms and attendant machinery spaces, would severely hamper any attempt to remove and replace them. The final design called for a standard displacement of and a full-load displacement of ,Garzke and Dulin, p. 53 making the ships of the class the largest battleships yet designed, and the largest battleships ever constructed. The design called for a main armament of nine 460 mm naval guns, mounted in three three-gun turrets—each of which weighed more than a 1930s-era destroyer. The designs were quickly approved by the Japanese Naval high command,Johnston and McAuley, p. 122 over the objections of naval aviators, who argued for the construction ofShips
Although five ''Yamato''-class vessels had been planned in 1937, only three—two battleships and a converted aircraft carrier—were completed. All three vessels were built in extreme secrecy, to prevent American intelligence officials from learning of their existence and specifications; indeed, the United States' Office of Naval Intelligence only became aware of ''Yamato'' and ''Musashi'' by name in late 1942. At this early time, their assumptions on the class's specifications were quite far off; while they were correct on their length, the class was given as having a beam of —in actuality, it was about and a displacement of 40,000–57,000 tons (actually, 69,000 tons). In addition, the main armament of ''Yamato'' class was given as nine guns as late as July 1945, four months after ''Yamato'' was sunk.Johnston and McAuley, p. 128 Both '' Jane's Fighting Ships'' and the Western media also misreported the specifications of the ships. In September 1944, ''Jane's Fighting Ships'' listed the displacement of both ''Yamato'' and ''Musashi'' as 45,000 tons. Similarly, both the '' New York Times'' and the Associated Press reported that the two ships displaced 45,000 tons with a speed of 30 knots, and even after the sinking of ''Yamato'' in April 1945, '' The Times'' of London continued to give 45,000 tons as the ship's displacement. Nevertheless, the existence of the ships—and their supposed violation of naval treaties—heavily influenced American naval engineers in the design of the 60,500-ton s, though they were not designed specifically to counter the ''Yamato'' class.''Yamato''
was ordered in March 1937, laid down 4 November 1937, launched 8 August 1940, and commissioned 16 December 1941. She underwent training exercises until 27 May 1942, when the vessel was deemed "operable" by Admiral Isoroku Yamamoto. Joining the 1st Battleship Division, ''Yamato'' served as the flagship of the Japanese Combined Fleet during the Battle of Midway in June 1942, yet did not engage enemy forces during the battle. The next two years were spent intermittently between Truk and Kure naval bases, with her sister ship ''Musashi'' replacing ''Yamato'' as the flagship of the Combined Fleet. During this time period, ''Yamato'', as part of the 1st Battleship Division, deployed on multiple occasions to counteract American carrier-raids on Japanese island bases. On 25 December 1943, she suffered major torpedo damage at the hands of and was forced to return to Kure for repairs and structural upgrades. In 1944—following extensive anti-aircraft and secondary battery upgrades—''Yamato'' joined the Second Fleet in the Battle of the Philippine Sea, serving as an escort to a Japanese Carrier Division. In October 1944, as part of Vice-Admiral Takeo Kurita's Center Force for the''Musashi''
was ordered in March 1937, laid down 29 March 1938, launched 1 November 1940, and commissioned 5 August 1942. From September to December 1942, she was involved in surface and air-combat training exercises at''Shinano''
''Shinano'', originally Warship Number 110, was laid down as the third member of the ''Yamato'' class, albeit with a slightly modified design. Most of the original armor values were slightly reduced, including the belt, deck, and turrets. The savings in weight this entailed meant that improvements could be made in other areas, including added protection for fire-control and lookout positions. In addition, the secondary armament on the first two ''Yamato''s was to have been replaced by the /65 caliber Type 98 gun. Although smaller, this gun was superior to the 127 mm, possessing a significantly greaterWarships Number 111 and 797
Warship Number 111, never named, was planned as the fourth member of the ''Yamato'' class and the second ship to incorporate the improvements of ''Shinano''. The ship's keel was laid after ''Yamato''s launch in August 1940 and construction continued until December 1941, when the Japanese began to question their ambitious capital ship building program—with the coming of war, the resources essential in constructing the ship would become much harder to obtain. As a result, the hull of the fourth vessel, only about 30% complete, was taken apart and scrapped in 1942; materials from this were used in the conversions of and to hybrid battleship/aircraft carriers.Johnston and McAuley, p. 124Although the hull was scrapped, the double bottom was not; later construction of four large submarines took place on top of it. See: Garzke and Dulin, p. 84. Available sources do not report when the double bottom was scrapped. The fifth vessel, Warship Number 797, was planned as an improved ''Shinano'' but was never laid down. In addition to the modifications made to that ship, 797 would have removed the two wing turrets in favor of additional 100 mm guns; authors William Garzke and Robert Dulin estimate that this would have allowed for 24 of these weapons. ''Yamato'' was eventually modified in 1944 to something akin to this.Specifications
Armaments
Primary armament
The ''Yamato-''class battleships had primary armaments consisting of three 3-gun turrets mounting /45 caliber Type 94 naval guns – the largest guns ever fitted to a warship,Johnston and McAuley, p. 123 although they were officially designated as the 40 cm/45 caliber (15.9 in) Type 94 – each of which weighed 2,774 tonnes for the complete mount.Jackson, p. 75 Each gun was long and weighed , and could fire armor-piercing shells and high explosive shells out to at a rate of 1½ to 2 shells per minute. The main guns were also capable of firing '' 3 Shiki tsûjôdan'' ("Common Type 3") anti-aircraft shells.These shells may have been nicknamed "The Beehive" while in service. See: A time fuze was used to set how far away the shells would explode (although they were commonly set to go off away). Upon detonation, each of these shells would release 900 incendiary-filled tubes in a 20° cone facing towards incoming aircraft; a bursting charge was then used to explode the shell itself to create more steel splinters, finally, the tubes would ignite. The tubes would burn for five seconds at about and would start a flame that was around long. Even though they comprised 40% of the total main ammunition load by 1944, ''3 Shiki tsûjôdan'' were rarely used in combat against enemy aircraft due to the severe damage the firing of these shells inflicted on the barrels of the main guns; indeed, one of the shells may have exploded early and disabled one of ''Musashi''s guns during the Battle of the Sibuyan Sea. The shells were intended to put up a barrage of flame that any aircraft attempting to attack would have to navigate through. However, U.S. pilots considered these shells to be more of a pyrotechnics display than a competent anti-aircraft weapon.Secondary armament
In the original design, the ''Yamato'' class' secondary armament comprised twelve 15.5 cm/60 Type 3 guns mounted in four 3-gun turrets (one forward, two amidships, one aft), and twelve 12.7 cm/40 Type 89 guns in six double turrets (three on each side amidships). These had become available once the ''Mogami''-class cruisers were rearmed with guns. With a AP shell, the guns had a maximum range of at an elevation of 45 degrees. Their rate of fire was five rounds per minute. The two midships turrets were removed in 1944 in favor of additional heavy and light anti-aircraft guns. Initially, heavy anti-aircraft defence was provided by a dozen 40-caliber 127-mm Type 89 dual-purpose guns in six double turrets, three on each side of the superstructure. In 1944, the two amidship 15.5 cm turrets were removed to make room for three additional 127-mm mounts on each side of ''Yamato'', bringing the total number of these guns to twenty-four . When firing at surface targets, the guns had a range of ; they had a maximum ceiling of at their maximum elevation of 90 degrees. Their maximum rate of fire was 14 rounds a minute; their sustained rate of fire was around eight rounds per minute.Anti-aircraft armament
The ''Yamato'' class originally carried twenty-four 25 mm Type 96 anti-aircraft guns, primarily mounted amidships. In 1944, both ''Yamato'' and ''Musashi'' underwent significant anti-aircraft upgrades in preparation for operations in Leyte Gulf using the space freed up by the removal of both midships secondary battery turrets,Johnston and McAuley, p. 180 and ended up with a complement of twenty-four guns, and one hundred and sixty-two antiaircraft guns, The 25 mm anti-aircraft guns could tilt at 90-degree angles to aim at planes directly overhead, but their mountings' lack of protection made their gunnery crews extremely vulnerable to direct enemy fire. These guns had an effective range of , and an effective ceiling of at an elevation of +85 degrees. The maximum effective rate of fire was only between 110 and 120 rounds per minute because of the frequent need to change the fifteen-round magazines. This was the standard Japanese light AA gun during World War II; it suffered from severe design shortcomings that rendered it a largely ineffective weapon. According to historian Mark Stille, the twin and triple mounts "lacked sufficient speed in train or elevation; the gun sights were unable to handle fast targets; the gun exhibited excessive vibration; the magazine was too small, and ... the gun produced excessive muzzle blast".Stille, p. 11 The class was also provided with two twin mounts for the licence-built 13.2 mm Type 93 anti-aircraft machine guns, one on each side of the bridge. The maximum range of these guns was , but the effective range against aircraft was only . The cyclic rate was adjustable between 425 and 475 rounds per minute; the need to change 30-round magazines reduced the effective rate to 250 rounds per minute. The armament on ''Shinano'' was quite different from that of her sister vessels due to her conversion. As the carrier was designed for a support role, significant anti-aircraft weaponry was installed on the vessel: sixteen guns, one hundred and twenty-five anti-aircraft guns, and three hundred and thirty-six anti-aircraft rocket launchers in twelve twenty-eight barrel turrets.Preston, p. 84 None of these guns were ever used against an enemy vessel or aircraft.Armor
Designed to engage multiple enemy battleships simultaneously,Schom, p. 270 the ''Yamato''s were fitted with heavy armor plating described by naval historian Mark Stille as providing "an unparalleled degree of protection in surface combat". The main belt of armor along the side of the vessel was up to thick, with transverse bulkheads of the armoured citadel up to thick. A lower belt armor thick extending below the main belt was included in the ships as a response to gunnery experiments upon and the new Japanese Type 91 shell which could travel great lengths underwater.Garzke and Dulin, p. 94 Furthermore, the top hull shape was very advanced, the peculiar sideways curving effectively maximizing armor protection and structural rigidity while optimizing weight. The armor on the main turrets surpassed even that of the main belt, with turret face plating thick. Armor plates in both the main belt and main turrets were made of Vickers Hardened steel, which was a face-hardened steel armor.Garzke and Dulin, p. 65 Main armored deck— thick—was composed of a nickel-chromium-molybdenum alloy. Ballistics tests at the proving ground at Kamegakubi demonstrated the deck alloy to be superior to the homogeneous Vickers plates by 10–15%. Additional plating was designed by manipulating the chromium and nickel composition of the alloy. Higher contents of nickel allowed the plate to be rolled and bent without developing fracture properties. For torpedo protection, a multiple bulkhead side protection system was used which consisted of several void spaces as well as the lower belt armor; the system has a depth of and was designed to withstand a TNT charge. No torpedo defense system compartments were liquid loaded, despite the known benefits. This may have been the result of overestimating the effectiveness of the lower belt armor against torpedoes, an effort to decrease draft, and provision of additional counter-flooding spaces.U.S. Naval Technical Mission to JapanPropulsion
The ''Yamato'' class was fitted with 12 Kampon boilers, which powered quadruple"Super ''Yamato''"-class battleships
Two battleships of an entirely new and larger design were planned as a part of the 1942 fleet replenishment program. Designated as Design A-150 and initially named Warship Number 178 and Warship Number 179, plans for the ships began soon after the design of the ''Yamato'' class was finished, probably in 1938–39. Everything was "essentially completed" sometime in 1941, but with war on the horizon, work on the battleships was halted to fill a need for additional warships, such as aircraft carriers and cruisers, to replace war losses of those vital ships. The Japanese loss in the Battle of Midway, where four carriers were sunk (out of ten, to date, in the entire navy), made it certain that work on the ships would never begin. In the third volume of their ''Battleships'' series, ''Axis and Neutral Battleships in World War II'', the authors William H. Garzke and Robert O. Dulin asserted that these ships would have been the "most powerful battleships in history" because of their massive main battery and extensive anti-aircraft weaponry.Gardiner and Chesneau, p. 178Garzake and Dulin, pp. 85–86 Similar to the fate of papers relating to the ''Yamato'' class, most papers and all plans relating to the class were destroyed to prevent capture at the end of the war. It is known that the final design of the ships would have had an even greater firepower and size than the ''Yamato'' class—a main battery of six guns in three turrets and secondary dual purpose armament consisting of twenty-four dual mounted guns (similar to the s). The displacement was to be bigger than the ''Yamato''s, and a side armor belt of was planned.Destruction of records
On the eve of the Allies'Cultural significance
From the time of their construction until the present day, ''Yamato'' and ''Musashi'' have carried a notable presence in Japanese culture, ''Yamato'' in particular. Upon completion, the battleships represented the epitome of Imperial Japanese naval engineering. In addition, the two ships, due to their size, speed, and power, visibly embodied Japan's determination and readiness to defend its interests against the western powers, especially the United States. Shigeru Fukudome, chief of the Operations Section of the Imperial Japanese Navy General Staff, described the two ships as "symbols of naval power that provided to officers and men alike a profound sense of confidence in their navy." ''Yamato'', and especially the story of her sinking, has appeared often in Japanese popular culture, such as the anime '' Space Battleship Yamato'' and the 2005 film ''Yamato''. The appearances in popular culture usually portray the ship's last mission as a brave, selfless, but futile, symbolic effort by the participating Japanese sailors to defend their homeland. One of the reasons that the warship may have such significance in Japanese culture is that the word "Yamato" was often used as a poetic name for Japan. Thus, the end of the battleship ''Yamato'' could serve as a metaphor for the end of theSee also
* H-class battleship proposals (World War II German ''Notes
Footnotes
References
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