Ark Royal trades propulsion weight for protection and air power

Ark Royal used three shafts rather than the Admiralty's familiar four-shaft arrangement for a large, fast warship. The machinery saved enough weight to help provide 3.5 inches of deck armour over the boiler rooms and magazines, a 4.5-inch belt, and a substantial anti-aircraft battery. Her unusually tall hull was designed for seventy-two aircraft, although supply problems usually held the complement to roughly fifty or sixty. The difference between designed and operational capacity shows how much a carrier depended on the wider naval aviation system. Ark Royal preceded the Illustrious class's armoured hangar, yet her vital spaces already received substantial protection. The account attributes her eventual loss to a submarine torpedo compounded by poor battle management.