Essex-Class Aircraft Carriers

As aviation and naval technology advanced in the early-to-mid twentieth century, aircraft became faster and carried heavier weapons. The US Navy responded to these developments by designing the Essex, a new class of aircraft carriers that could accommodate more and bigger planes. From 1942 through 1945, large numbers of the Essex-class, the most successful fleet aircraft carrier in history joined the United States Navy. The rapid pace of production belied the long period of research and innovation that culminated in their quick delivery to the Fleet.[1] After the invasion of Tarawa in 1943, Essex-class carriers served as the backbone of the Navy’s combat strength in World War II, playing a critical role in the Fleet’s operational successes, particularly in the Pacific theater. The ascendance of the Essex-class marked the dawn of a new era in US naval power owing to the strength of carrier task forces.[2]

To understand the success of the Essex-class, it is necessary to trace the development of the first aircraft carriers. During World War I, navies across the globe deployed the then-new technology of airplanes at sea. Beginning with floatplanes and seaplanes that could take-off and land from the ocean, the European and Japanese navies used aircraft to conduct reconnaissance missions. Navies initially based these aircraft on auxiliary ships, which would store the aircraft in hangars, lift them outboard with a crane for takeoff, and then hoist them back for recovery. For lack of a better term, the specialized vessels became known as “aircraft carriers.” [3]

A dramatic increase in aircraft performance over the course of World War I made these earlier aircraft carriers obsolete. At the start of the war, sea and land plane speed, agility, and firepower had been nearly equivalent. By the end of the war, land planes vastly outperformed their sea-based counterparts and navies began searching for ways to use the higher-performance planes at sea. This desire resulted in what we now call aircraft carriers, a flat-decked ship that could launch and recover wheeled aircraft similar to those found on land. The British launched the first of these ships in 1918, and the United States and Japan soon followed their example.[4]

In the early 1920s, however, just as naval powers began testing their carrier innovations, public sentiment shifted in favor of disarmament. In response to this sentiment, Great Britain, the United States, Japan, France, and Italy (with the limited participation of Belgium, China, Portugal, and the Netherlands) convened the Washington Naval Arms Limitation Conference from November 1921 to February 1922. The Washington Naval Treaty (also known as the Five-Power Treaty), signed at the conclusion of the conference, established a 5:5:3 tonnage ratio (UK: US: Japan) for battleships and aircraft carriers and allotted Italy and France a 1^3/4 ratio each. The treaty included a ten-year ban on the construction of new capital ships, restricted individual battleships to fewer than 35,000 tons, and compelled Navies to scrap older ships, reducing the overall size of each navy. For the United States, the treaty limited total tonnage for aircraft carrier construction to 135,000, with individual aircraft carriers limited to 33,000 tons or less (depending on whether conversions or new construction).[5] Based on these limitations, the US Navy scrapped or changed the function of capital ships already under construction and planned to convert two incomplete battlecruisers into aircraft carriers.
Indeed, the first three U.S. aircraft carriers were ad hoc conversions of ships already built or currently under construction. In 1919, the US Navy ordered the collier Juniper to be converted to a 14,000-ton provisional aircraft carrier and in 1922, the service commissioned its first “flattop” as Langley (CV-1).[6] The next two aircraft carriers, Lexington (CV-2) and Saratoga (CV-3), were much bigger (36,000-tons), being battlecruiser conversions, but still adopted several design features from Langley, including its athwart ship arresting wires that the aircraft would engage with their tail hook, essentially having a controlled crash for a landing, which would become standard for future carriers.[7]

Following the Treaty, American aircraft carriers developed in fits and starts with trial and error informing every step of the development of sequential designs. Each new carrier reflected lessons learned from the last, retaining the design aspects that worked and discarding those that did not. In 1931, when the US Navy built the 15,000-ton Ranger (CV-4), the first ship the service designed from inception as an aircraft carrier, they based many of the preliminary features on war games conducted at the US Naval War College. At this point, the Navy decided, based on war games and the tonnage limits set by the Treaty, to build more, smaller carriers rather than fewer, larger ones. While the resulting Ranger design reflected the at-sea experiences of the three earlier carriers,[8] operationally Ranger proved to be too small, too slow, and lacked adequate protection.[9]

Given those limitations, Navy engineers at the Bureau of Construction and Repair took carrier design in a different direction with Yorktown (CV-5) and Enterprise (CV-6), providing a different mix of speed, protection, and aircraft carrying capacity in a hull of about 20,000 tons.[10] The final treaty-limited aircraft carrier was Wasp (CV-7), which ended up about 5,000 tons smaller than Yorktown. While the reduced size resulted in limited armor and modest speed, it did incorporate lessons learned from the two Yorktown-class carriers still building, such as the use of a deck-edge aircraft elevator, which freed up movement space on the flight deck because there was no forward elevator.[11] The Essex-class ultimately incorporated an improved version this feature and other aspects of the earlier carriers’ designs and avoided many of their shortcomings. These lessons, and their resulting improvements, contributed to the easier use of the Essex design for mass wartime production.

The Essex-design was only possible due to the expiration of the 1922 Washington Naval Treaty, when Japan and Italy spurned a proposed revision in 1937. Given that other powers had already built to treaty limits (and the U.S. had not) and were now moving beyond, the U.S. Navy ordered Hornet (CV-8), an additional Yorktown-class carrier that was authorized by Congress in 1938, and accelerated a new design for the 30,000-ton Essex-class. Intended to maximize striking power, a choice mirroring the navy’s doctrine envisioning offensive fleet operations against Japan, the larger design enabled the needed long range and good endurance. This still required designers to balance aircraft capacity, crew habitability, and seaworthiness against adequate armament, survivability, and speed.[12] In order to accomplish these goals, the Navy prioritized longer, wider flight decks, better protection including a triple hull and greater compartment subdivision, more anti-aircraft guns, a significant increase in aviation gas storage, increased speed, and a rearrangement of the engineering plant to lessen the effect of single hit.[13]

After Pearl Harbor, the US Navy urgently needed the Essex-class carriers for combat in the Pacific theater, and thus cut short or omitted altogether some steps of the pre-commissioning process. For example, they skipped the builder’s trials, in which shipbuilders put their own crews on board carriers to evaluate performance underway and then make corrections accordingly.[14] Because of their immediate need for carriers, the Navy made many of the earliest corrections to Essex-class carriers in response to actual combat experience. As Admiral Donald Duncan, the first commanding officer of Essex (CV-9) later recalled: “we had a good many lessons, even at that time, when we’d been in the war less than a year in the actions in the Pacific which showed us things that needed correction.”[15]
Wartime exigencies would continue to affect the development of Essex-class carriers. For example, the need for more close-range antiaircraft firepower became increasingly important, which in turn led to a redesign of the Essex-class bow to improve seakeeping and fit new 40mm gun mounts. In addition to these alterations, as the war progressed, aircraft grew in number and size, creating a need for greater and better carrying capacity. In 1943, when the first Essex-class warships entered combat, they carried 91 aircraft, comprised of 36 fighters, 36 dive-bombers, and 19 torpedo bombers. By the end of the war, the typical air group consisted of 102 aircraft, comprised of 36 fighters, 36 fighter-bombers, 15 dive-bombers, and 15 torpedo bombers. The newer aircraft were also larger, carried more and heavier weapons, consumed greater quantities of fuel, and took up more hangar and deck space. To accommodate these changes, air groups refined and improved launch, retrieval, and deck movement controls to maintain efficiency.[16]

Essex-class carriers participated in some of the most pivotal battles of World War II and several important military engagements in the decades that followed. Surviving bombs, kamikazes, and violent weather, not a single Essex carrier sank during the Second World War.[17] Following the war, as tensions with the Soviet Union escalated, Essex carriers, including some completed after World War II, took part in several Cold War engagements.[18] Most significantly, eleven Essex-class carriers participated in the Korean War, primarily attacking ground targets and conducting antisubmarine patrols. Later modified as anti-submarine warfare (ASW) assets, Essex-class carriers continued to play a major role in US naval operations until the advent of the supercarriers in the 1960s and 70s.[19]
As technology advanced, however, the carriers began to slide slowly into obsolescence and fared poorly in the digital age despite ongoing modernization efforts.[20] By the time of the Vietnam War, this once-innovative carrier class faced a mounting series of challenges resulting from its outmoded design. Perhaps most notably, the size and angle of the Essex-class decks prevented them from dependably supporting rapidly advancing jet aircraft innovations.[21]

Despite its waning importance to the Fleet, Essex-class carriers functioned as a bridge to the Midway-class and, ultimately, to nuclear-powered carriers. In fact, naval engineers originally designed the Midway-class, the first carrier to embark nuclear weapons, as an armored variant of the Essex.[22] Midway’s massive size and larger flight deck, when compared to the Essex, allowed the ship to carry more planes and accommodate the landings of jet aircraft. Even as the Essex ceded importance to later carriers, it continued to see combat action. Thirteen Essex-class carriers served in Vietnam, providing critical support for helicopters and carrying out antisubmarine patrols.[23] In addition to combat service, between 1960 and 1973, Essex-class carriers supported the United States in the space race, operating as the primary recovery ships during Projects Gemini and Apollo.[24]

As the most numerous class of American fleet carriers, the Essex represents one of the most important classes of warships in the history of the United States Navy. Serving in three wars during a career that began with operating propeller planes before adapting to the advent of jet aircraft and ending in the space age, the success of the Essex-class can be attributed to its innovation and adaptability. Although the Essex proved to be too small and obsolete to continue serving the Fleet in the later Cold War, naval engineers incorporated many of its innovative and effective design features into subsequent generations of carriers. The long-term success of the Essex-class contributed to the ascendance of the aircraft carrier as the capital ship of the U.S. Navy.[25]