Guaranteeing a one-hit battleship disablement takes extreme weapons

What torpedo warhead or shell could disable a 1920s-1940s battleship with one waterline hit?

A guaranteed single-hit disablement would require something like a 24-inch torpedo against weak underwater protection or an 18-inch heavy shell, and even then more than one hit is preferable.

Battleships vary too much in underwater protection and internal subdivision for a modest weapon to promise a one-shot result. The deliberately extreme examples underline why operational planners would still want multiple damaging hits.