Keeping a 16.5-inch gun program alive

How early would Britain need to begin developing a 16.5-inch gun for the King George V class?

The cheapest route is to continue the post-Nelson heavy-gun program without interruption; restarting from scratch would need to begin around 1933.

Rather than launch a new project, the Royal Navy could keep experimentation active after Nelson and Rodney and preserve the people, tools, and knowledge already assembled. If that continuity were lost, a fresh start would need to begin around 1933. The exchange illustrates why apparently small peacetime research budgets can protect major wartime options.