The "Devastation"-class ships had a complete wrought iron waterline armour belt that was 12 inches thick amidships and tapered to outside the armoured citadel towards the ends of the ship. The armour plates were tapered to a thickness of at their bottom edges respectively and they extended from the upper deck to below the waterline. The armoured citadel protected the bases of the gun turrets, the funnel uptakes and the crew's quarters. The sides of the citadel were 12 inches thick around the bases of the turrets and 10 inches thick elsewhere. The turrets were protected by two plates, separated by a layer of teak with the turret face having the thicker armour. The magazine were protected by a 6-inch forward bulkhead and a one aft. The conning tower ranged in thickness from 9 to 6 inches in thickness. The ships had a complete upper deck that was reinforced by another thick inside the citadel.