Preliminary design of a battleship with 457 mm guns in twin-gun turrets, based on the South Dakota-class ships. When intelligence came to light that Japan was working on ships with guns larger than 406 mm, two battleship projects with 457 mm guns were created in the U.S., one of which was fast and had six such guns housed in three turrets. The project was never implemented, but its further development led to the emergence of the Iowa class.