The reconstruction rules prohibited changes to the caliber, number, or general mounting type of retained ships' main armament. An improved 15-inch gun would retain the caliber and could use an existing turret with modified machinery. Contemporary legal and industrial arguments reportedly explored this reading separately from the F2 and F3 design debate, although it strained the treaty's spirit. Increasing turret elevation offered another possible improvement. Installing the heavier barrels would require balancing and mechanical changes, making peacetime refits a suitable opportunity. Slow, space-intensive conversion work could keep specialist industrial infrastructure open without requiring a wartime-sized workforce.
Notable Point · 10:54-15:11
An improved 15-inch gun might fit the treaty's reconstruction wording
A 15-inch/50 gun could arguably preserve caliber and mounting type while upgrading the Royal Navy's common battleship weapon.