How large a nine-turret 18-inch battleship becomes

How large would a battleship with nine twin 18-inch turrets have to be?

Roughly 250,000 to 300,000 tons, with stability, magazine volume, wing-turret protection, and ammunition handling dominating the design.

Nine twin 18-inch turrets would put an enormous weight of armament high in the ship, particularly with the forward guns in three superfiring tiers. The rough displacement estimate is 250,000 to 300,000 tons. At 200 rounds per gun, the magazines would need to hold 3,600 shells. Clarifying that P, Q, R, and S are wing turrets introduces a further beam problem: torpedo protection would need to extend beyond their barbettes. Angling the barbettes inward is floated as an awkward alternative, and the resulting stability calculations remain unresolved.