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The ''Essex'' class was a class of aircraft carriers of the United States Navy that constituted the 20th century's most numerous class of capital ships. The class consisted of 24 vessels, which came in both "short-hull" and "long-hull" versions. Thirty-two ships were originally ordered; however as World War II wound down, six were canceled before construction, and two were canceled after construction had begun. No ''Essex''-class ships were lost to enemy action, despite several vessels sustaining very heavy damage. The ''Essex''-class carriers were the backbone of the U.S. Navy's combat strength during World War II from mid-1943 on, and, along with the addition of the three carriers just after the war, continued to be the heart of U.S. naval strength until the supercarriers began to come into the fleet in numbers during the 1960s and 1970s. ==Overview== The preceding s and the designers' list of trade-offs and limitations forced by arms control treaty obligations shaped the formative basis from which the ''Essex'' class was developed — a design formulation sparked into being when the Japanese and Italians repudiated the limitations proposed in the 1936 revision of the Washington Naval Treaty of 1922 (as updated in October 1930 in the London Naval Treaty) — in effect providing a free pass for all five signatories to resume the interrupted naval arms race of the 1920s in early 1937. At the time of the repudiations, both Italy and Japan had colonial ambitions, intending 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 in beam, and more than a third heavier. A longer, wider flight deck and a deck-edge elevator (which had proven successful in the one-of-a-kind ) facilitated more efficient aviation operations, enhancing the ship's offensive and defensive air power. Machinery arrangement and armor protection was 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. Some ships in the class would serve until well after the end of the Vietnam War, when the class was retired and replaced by newer classes. Debates raged, and continue to this day, regarding the effect of strength deck location. 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. Subsequently, 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.〔Faltum 1996, p. 12.〕 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;〔Friedman, table 7-1. "Evolution of Schemes for the Essex Design, 1939-40". 9G had a 2.5 inch STS armored deck, a length on the waterline of 830 ft and a beam of 96.3 ft compared to 820 ft by 91 ft for Design 9F.〕 9G became the ancestor of the 45,000-ton . 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Essex-class aircraft carrier」の詳細全文を読む スポンサード リンク
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