The Essex class was a class of aircraft carriers of the United States Navy. The 20th century's most numerous class of capital ship, the class consisted of 24 vessels, which came in "short-hull" and "long-hull" versions. Thirty-two ships were ordered, but as World War II wound down, six were canceled before construction, and two were canceled after construction had begun. Fourteen saw combat during World War II. None were lost to enemy action, though several sustained crippling damage. Essex-class carriers were the backbone of the U.S. Navy from mid-1943 and, with the three carriers added just after the war, continued to be the heart of U.S. naval strength until supercarriers joined the fleet in the 1950s, 1960s and 1970s. Several of the carriers were rebuilt to handle heavier and faster aircraft of the early jet age, and some served until well after the Vietnam War.
Overview
The preceding s and the designers' list of trade-offs and limitations forced by arms control treaty obligations shaped the development of the Essex class – a design sparked by the Japanese and Italian repudiation of the limitations proposed in the 1936 revision of the Washington Naval Treaty of 1922 (as updated in October 1930 in the London Naval Treaty). Effectively, this rejection allowed all five signatories to resume the interrupted naval arms race of the 1890s-1910s in early 1937.
At the time of the repudiations, both Italy and Japan had colonial ambitions, intent on or already conducting military conquests. With the demise of the treaty limitations and the growing tensions in Europe, naval planners were free to apply both the lessons they had learned operating carriers for fifteen years and those of operating the Yorktown-class carriers to the newer design.
Designed to carry a larger air group, and unencumbered by the latest in a succession of pre-war naval treaty limits, was over sixty feet longer, nearly ten feet wider, and more than a third heavier than Yorktown-class carriers. A longer, wider flight deck and a deck-edge elevator (which had proven successful in the one-off ) facilitated more efficient aviation operations, enhancing the ship's offensive and defensive air power.
Machinery arrangement and armor protection were greatly improved from previous designs. These features, plus the provision of more anti-aircraft guns, gave the ships much enhanced survivability. In fact, during the war, none of the Essex-class carriers were lost and two, and , came home under their own power and were successfully repaired even after receiving extremely heavy damage.
Debates raged regarding armoring the hangar deck. British designers' comments tended to disparage the use of hangar deck armor, but some historians, such as D.K. Brown in Nelson to Vanguard, see the American arrangement to have been superior. In the late 1930s, locating the strength deck at hangar deck level in the proposed Essex-class ships reduced the weight located high in the ship, resulting in smaller supporting structures and more aircraft capacity for the desired displacement. The which followed armored both the hangar and flight deck (the latter more heavily).
The larger size of the first supercarriers necessitated a deeper hull and shifted the center of gravity and center of stability lower, enabling moving the strength deck to the flight deck, thus freeing US Naval design architects to move the armor higher and remain within compliance of US Navy stability specifications without imperiling seaworthiness. One of the design studies prepared for the Essex project, "Design 9G", included an armored flight deck but reduced aircraft capacity, and displaced 27,200 tons, or about 1,200 tons more than "Design 9F", which formed the basis of the actual Essex design; 9G became the ancestor of the 45,000-ton Midway class.
Development
After the abrogation of disarmament treaties by Japan in 1936, the U.S. took a realistic look at its naval strength. With the Naval Expansion Act of Congress passed on 17 May 1938, an increase of 40,000 tons in aircraft carriers was authorized. This permitted the building of , which was the third -class carrier, and , which was the lead ship of a new class.