Armoured Flight Deck - Midway and Forrestal Classes

Midway and Forrestal Classes

While flight deck level armour was eventually adopted by the Americans for the Midway design, the strength deck remained on the hangar level. Midway had originally been planned to have a very heavy gun armament (8 in weapons). The removal of these weapons freed up enough tonnage to add 3 inches (76 mm) of armour at the flight deck level. While this made a great deal of sense from an air group perspective, the Midway ships sat very low in the water for carriers (due to their much greater displacement), certainly much lower than the smaller Essex-class carriers, and had a great deal of difficulty operating in heavy seas. Flight deck armoured ships almost universally (except for the Midway class as completed) possessed a hurricane bow, where the bows were sealed up to the flight deck; wartime experience demonstrated that ships with the hurricane bow configuration (also including the American Lexington class) shipped less water than ships with an open bow. Late-life refits to Midway to bulge her hull and improve freeboard instead gave her a dangerously sharp roll, and made flight operations difficult even in moderate seas. This was therefore not repeated on Coral Sea (Roosevelt had been decommissioned years earlier). After the war, most of the Essex class ships were modified with a hurricane bow and in the case of Oriskany the wooden flight deck surface was replaced with aluminium for improved resistance against the blast of jet engines, making them appear to have armoured flight decks, but in fact their armour remained at hangar level.

The supercarriers of the postwar era, starting with the Forrestal class — nearly 200 feet (61 m) longer and 40 feet (12 m) wider in the beam than their World War II counterparts – would eventually be forced to move the strength deck up to the flight deck level as a result of their great size; a shallow hull of those dimensions became too impractical to continue. The issue of protection had no influence on the change; the Forrestal class had an armoured flight deck of at least 1.5" thickness. Some of the follow on classes to the Forrestals also had armoured flight decks although deck armour is of little to no use against modern anti-ship missiles, it may help limit the damage from flight deck explosions. The experience of World War Two caused the USN to change their design policy in favour of armoured flight decks:

The main armor carried on Enterprise is the heavy armored flight deck. This was to prove a significant factor in the catastrophic fire and explosions that occurred on Enterprise's flight deck in 1969. The US Navy learned its lesson the hard way during World War II when all its carriers had only armored hangar decks. All attack carriers built since the Midway class have had armored flight decks. —