Key point: They were still very vulnerable to torpedoes.
When one thinks of carrier warfare in World War II, the Japanese and U.S. navies usually come to mind. While the two powers were the major proponents of carrier-based aviation as the primary instrument of sea power, the British Royal Navy operated a substantial fleet of aircraft carriers. And while they are often overlooked in discussions of the naval war in the Pacific, the Royal Navy’s carriers were very much a part of that conflict as well as the European Theater.
Request For Carriers With Armored Decks
During the mid-1930s, the British Admiralty asked for a new series of aircraft carriers that would feature armored flight decks configured as integral to the ship’s basic structure instead of being part of their superstructure, as was the practice with U.S. and most other aircraft carrier designs. Whether or not this concept increased the overall survivability of the British carriers is open to debate, but it did reduce the likelihood of aerial bombs penetrating into the depths of the ships.
The design plans for the new carriers were approved in June 1936. The landing decks were to be covered with 3-inch armor plates, while the hangar walls were to be built with armor plating 4 inches thick. The ships’ magazines and their vital machinery were to be protected by a 4-inch armor belt below the waterline. Final design changes included the armored side belt being lengthened forward by 28 feet and aft by 24 feet, the hangar being widened to 62 feet, and the main armament consisting of eight dual 4.5-inch QF MkIII HA guns. This would provide the carriers with a total of 16 4.5-inch guns for antiaircraft and ship defense.
An Illustrious Class Of Carriers