What changed most in large naval-gun design and construction after the Second World War?
Short answerContinuous funding and production ended, causing Britain to lose the industrial capability that could have built very large guns.
NotesWartime machinery and expertise could plausibly have produced 16.5-inch or even 18-inch weapons for a Vanguard-like design if time and money were available. The postwar break in funded development erased more than a blueprint. It dispersed the production knowledge and capacity needed to build such systems.