The design discussion balances range, armour, speed, and displacement instead of simply maximizing gun calibre. A 16.5-inch gun can handle most intended jobs while remaining light enough to fit a formidable battery. Moving to 18-inch weapons offers limited benefit when the smaller calibre covers roughly ninety percent of the campaign requirements. The resulting standard is a heavily armoured fast battleship with nine such guns and a 30-knot target, which also provides a benchmark for deciding which older ships are worth refitting.
Chapter · 2:51:10-2:58:10
Choosing 16.5-inch guns for fast capital ships
The refit programme settles on 16.5-inch guns, heavy armour, and 30-knot speed as a practical standard for the next generation of ships.