Ignoring the Washington and London Naval Treaties the Yamato class was designed to be superior to any battleship in the world. Japanese Naval strategy called for superior weapons, not quantity of weapons. However, they were to be relegated obsolete by the upcoming supremacy of the aircraft carrier.
Design work started in 1934 and was finalized in March 1937. An order for two battleships was placed under the 1937 3rd Reinforcement Program. The next two were ordered under the 1939 4th Reinforcement Program.
Electrical welding was used throughout the ship to help streamline and reduce weight.
To keep the construction secret the IJN Musashi had a 408 ton camouflage net to cover it.
There were two catapults to launch the aircraft.
The 18.1" guns fired a 3,220 lb / 1,460 kg shell 45,000 yards / 45,275 yards / 41,400 m. A gun could fire a round about every 90 seconds.
The turret alone weighed 2,530 tons / 2,730 tons.
The deck armor was intended to withstand an 1,100 lb bomb or 18" rounds fired from 16 miles / 22,000 - 33,000 yards.
A bulbous bow was installed that greatly helped decrease resistance.
An auxiliary rudder was added in front of the main rudder to help in steering.