Speed-build choices and the final 27,000-ton reconstruction

Features such as the unequal aircraft lifts may reflect a decision to reuse Illustrious and Indomitable components for faster construction. That inheritance did not prevent the class from having substantially more room and weight margin for postwar conversion than Victorious. The existing 27,000-ton study was the quickest available large-carrier option in 1938-1939. Implacable retained a three-inch armored flight deck, but her two-inch hangar sides were thinner than Illustrious's four-and-a-half-inch sides, and her two-inch bulkheads were thinner than Illustrious's two-and-a-half-inch bulkheads. Those thinner plates still protected a much larger double-hangar area in a longer hull. The extent of the structure supports the heavier figures discussed in Norman Friedman's notes and makes a 23,000-ton interpretation unconvincing.