Ironclad construction also prefigured the later debate in battleship design between tapering and ' all @-@ or @-@ nothing ' armour design . Warrior was only semi @-@ armoured , and could have been disabled by hits on the bow and stern . As the thickness of armor grew to protect ships from the increasingly heavy guns , the area of the ship which could be fully protected diminished . Inflexible 's armor protection was largely limited to the central citadel amidships , protecting boilers and engines , turrets and magazines , and little else . An ingenious arrangement of cork @-@ filled compartments and watertight bulkheads was intended to keep her stable and afloat in the event of heavy damage to her un @-@ armored sections .