The design starts with the largest available super-battleship hull and sits roughly three hundred tons overweight. Moving from 16.5-inch to 17-inch guns looks attractive, but the available 17-inch mount is only a Mark I turret. Its poor range and slow firing cycle compare badly with the more mature smaller weapon. The design keeps the 16.5-inch guns because turret generation, rate of fire, and useful range matter more here than nominal caliber. That choice also releases weight for other systems while retaining the more effective battery.
Chapter · 46:17-54:04
Why mature 16.5-inch turrets beat newer 17-inch guns
A new super-battleship design rejects a nominally larger gun because its immature Mark I turret sacrifices the range and firing cycle delivered by the established 16.5-inch weapon.