The tonnage cost of four triple 15-inch/50 turrets

How large would a 28-knot Royal Navy battleship with four triple 15-inch/50 turrets need to be in an F3 design lineage?

Roughly 40,000 to 45,000 tons standard, with about 42,000 tons offered as a useful central estimate.

The hypothetical F3-derived battleship combines twelve 15-inch/50 guns with a 28-knot requirement. Its estimated displacement is 40,000 to 45,000 tons standard, with about 42,000 tons as a central figure. The range allows for different design choices and is a rough estimate.