Colombike is wrong. The only 3 turret version was for 18.1" triples
There where 3 studies. 1 planned to build, and the plan to build it came from 39-40'
4x 20.1" would have been its armament. Look it up in te archives.
When im home i tell you the story once again alvama
Why 4 turrets? Japan wanted a answer to the H class battleships. Wich where answered by the montana and lion class.
Japan wanted to finish their super battleships as first. So it enlarged the yamato class. But when they wanted to build it, Japan needed more carriers and submarines.
To be able to catch large amount of torpedoes, she was to be fitted with a new structural type. * got picture on my desktop*
More later, got a solicitation