Staff Writer (Updated: 3/12/2015):
With international treaties limited new warship construction to a reasonable 35,000 tons, the Imperial Japanese Navy set about to construct the massive 65,000+ ton Yamato and her sister ship, the IJN Musashi, under a cloak of secrecy so as to avoid disclosure. Such was the development of the type that the Japanese public was shielded from its construction and the Yamato was only revealed to a few Japanese high ranking officials. Great care was also taken to ensure the secrecy of the shipyard itself, which was partially covered to avoid detection.
Design of the Yamato was a special one - not only was she to be the most heavily armored battleship ever made, her main gun mountings exceeding 18" would be the largest caliber types to ever be fitted the type. These elements required a large foundation to operate from and an equally large superstructure to support the floating arsenal. Though to some this may seem a extreme, there was a method to the direction for the Imperial Navy knew that any US battleship constructed to take the Yamato on directly would originate from the east coast of the United States. To make it to the Pacific in due time, the new American vessel would have to pass through the Panama Canal to access the Pacific Ocean. If the Americans attempted to build a matching battleship to the Yamato, the sheer size of the new battleship would deem the Panama Canal route impassable to the extreme.
Outwardly, the Yamato followed traditional design elements found in warships prior to the Second World War. The 18.1" main guns were housed in three heavily-armored turrets with two located forward of the bridge and a third aft with three guns to a turret. Amazingly, the Yamato was fitted with 12 x 6.1" and 12 x 5" guns to supplement the main guns for a very potent firepower capability. Anti-aircraft defense was given priority as well and was left to the 24 x 25mm cannon systems and 4 x 13.2mm machine guns. Inwardly, she made heavy use of arc welding to ensure a strong seal and featured a plethora of damage control sections under the waterline. From bow to stern she measured over 800 feet and was over 120 feet at the beam. Because of the secrecy involved in development, the Yamato had to forgo any formal launching ceremonies when she set out for trials on August 8th, 1940.