España's thin protection and deterrent value

Eight 12-inch guns and a 19.5-knot speed sat behind an eight-inch belt and only about an inch and a half of deck protection. The ten-inch conning tower protected command personnel more heavily than much of the fighting ship around them. España could overmatch lesser vessels and force an enemy to commit a battleship rather than a cruiser. That requirement gave the class value as a fleet-in-being or deterrent even when it was not strong enough to fight a larger contemporary dreadnought on equal terms. The design is therefore best understood as a compact battleship that imposed costs and constrained an opponent, not as a miniature peer of the major navies' capital ships.