Essex class aircraft carrier

The United States Navy's Essex class aircraft carriers constituted the industrial age's largest class of heavy warships. Although thirty-two were originally ordered, all but ten were cancelled before construction or completed as longer Ticonderoga class carriers.

Overview

The preceding Yorktown class carriers formed the basis from which the Essex class was developed. Intended to carry a larger air group, and unencumbered by the naval limitations treaties then recently-obsolete, USS Essex (CV-9) 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 facilitated more efficient aviation operations, enhancing the ships' offensive and defensive air power. Machinery arrangement and armor protection was greatly improved from previous designs. These features, with the provision of more anti-aircraft guns, gave the ships much-enhanced survivability. In fact, none of the Essex class carriers were lost and two of them, Franklin (CV-13) and Bunker Hill (CV-17), came home under their own power even after being grievously damaged.

US carriers had deck armor, though less than that carried by their British counterparts. The difference was that American ships carried their armor on the hangar floor, designed such that the flight deck and all above it were superstructure. This allowed for larger hangar bays, while their Royal counterparts carried their armor at the flight deck level. The British solution allowed more effective defense from bombs and particularly kamikaze attacks. Later USN carriers would adopt the British approach making the strength deck to be the flight deck rather than the hangar deck, leaving only the island as superstructure.

Their construction greatly accelerated, the Essexes and the first few Ticonderogas formed the backbone of the Navy's mobile air striking power during the climactic years of the Pacific War. With their larger contemporaries of the Midway class, these carriers sustained the Navy's air power through the rest of the 1940s, during the Korean War era and beyond. Even after the arrival of the Forrestal-type "super carriers", the Essex class and its sisters remained vital elements of naval strength. By the mid-1950s, fourteen of them of them had been modernized along the lines of Oriskany (CV-34), with all but one of those being further updated under the SCB-125 program to facilitate operation of high-performance fighters and heavy attack aircraft.

Korean War and subsequent Cold War needs ensured that twenty-two of the twenty-four ships had extensive post-World War II service, all initially with attack air groups. As bigger carriers entered the fleet, seven of the Essex class and eleven Ticonderogas were reassigned to the anti-submarine warfare mission. Unmodernized ships began to leave active service in the late 1950s, but three had about a decade of additional duty as helicopter assault transports for the Marine Corps. The updated units remained active until age and the increasing fleet of supercarriers drove them from the high seas from the late 1960s into the middle 1970s. However, one of the very first of the type, Lexington (CV-16), ran on until 1991 as the Navy's training carrier. She then became a museum, a new role that also employs three of her siblings, Yorktown (CV-10), Intrepid (CV-11), and Hornet (CV-12).

Development

After the abrogation by Japan from disarmament treaties, the U.S. took a realistic look at its naval strength. With the Naval Expansion Act of Congress passed on May 17, 1938, an increase of 40,000 tons in aircraft carriers was authorized. This permitted the building of USS Hornet (CV-8) and USS Essex (CV-9) which was to become the lead ship of its class.

CV-9 was to be the prototype of the 27,000-ton (standard displacement) aircraft carrier, considerably larger than the Enterprise (CV-6) yet smaller than the Saratoga (CV-3) (a battlecruiser converted to a carrier). These were to become known as the Essex class carrier, although this classification was latter dropped in the 1950s. On September 9, 1940, eight more of these carriers were ordered and were to become the Hornet (CV-12), Franklin (CV-13), Ticonderoga (CV -14), Randolph (CV-15), Lexington (CV-16), Bunker Hill (CV-17), Wasp (CV-18) and Hancock (CV-19). The last two of the 13 originally programmed CV-9 class aircraft carriers, Bennington (CV-20) and Boxer (CV-21), were ordered on December 15, 1941.

It should be noted that the Lexington, Wasp, Hornet and the Yorktown names were not their originally intended ones, but were used in line with the Navy's intent to carry on the traditions of the fighting predecessors who were lost during combat in 1942. It should also be noted that of the original 13 ordered "Essex class" ships, several of them, the Ticonderoga (CV-14), Randolph (CV-15), Hancock (CV-19), and Boxer (CV-21) were modified during design and construction and became those of the directly-related Ticonderoga or "long hull" class carriers.

1941 design plans for the Essex class.

In drawing up the preliminary design for USS Essex (CV-9), particular attention was directed at the size of both her flight and hangar decks. Aircraft design had come a long way from the comparatively light planes used in carriers during the 1930s. Flight decks now required more takeoff space for the heavier fighters and bombers being developed. Most of the first-line carriers of the pre-war years were equipped with flush deck catapults, but owing to the speed and size of these ships very little catapulting was doneâ€"except for experimental purposes.

With the advent of war, airplane weights began to go up as armor and armament got heavier; crew size aboard the planes also increased. By the war's end in 1945, catapult launchings would become more common under these circumstances with some carrier commanding officers reporting that as much as 40 per cent of launchings were effected by the ships' catapults.

The hangar area design came in for many design conferences between the naval bureaus. Not only were the supporting structures to the flight deck to carry the increased weight of the landing and parked aircraft, but they were to have sufficient strength to support the storing of spare fuselages and parts (50 per cent of each plane type aboard) under the flight deck and still provide adequate working space for the men using the area below.

A startling innovation in the Essex (CV-9) was a port side deck edge elevator in addition to two inboard elevators. Earlier, experiments with a ramp arrangement between the hangar and flight decks, up which aircraft were hauled by crane proved too slow. The Naval Bureau of Ships and the Chief Engineer of A.B.C. Elevator Co., designed the engine for the side elevator. Essentially, it was a standard elevator, 60 by 34 ft (18 by 10 m) in platform surface, which traveled vertically on the port side of the ship. The design was a huge success which greatly improved flight deck operations over carriers prior to the Essex.

Since there was no large hole in the flight deck when the elevator is in the ‘down' position, a critical factor if the elevator were to ever become inoperable during combat operations, the development of the side elevator was a significant improvement in flight operations. Its new position made it easier to continue normal operations on deck, irrespective of the position of the elevator. The elevator also increased the effective deck space when it was in the ‘up' position by providing additional parking room outside the normal contours of the flight deck, and increased the effective area on the hangar deck by the absence of elevator pits. In addition its machinery was less complex than the two inboard elevators, requiring about 20 percent fewer man-hours of maintenance.

Ongoing improvements to the class were made, particularly with regards to the ventilation system, lighting systems and the trash burner design and implementation.

Nineteen more Essex class ships were ordered or scheduled, starting with ten of them on August 7, 1942. Though only two of the ships, the Bon Homme Richard (CV-31) and the Oriskany (CV-34) where laid down as Essex "short hull" keels. The remainder became the Ticonderoga or "long hull" class ships.

The USS Lexington (CV-16); originally to be laid down as the "Cabot" but was renamed "Lexington" during construction after the Lexington (CV-2) was lost in the Battle of the Coral Sea in May 1942, was commissioned on February 17, 1943, followed by USS Yorktown (CV-10); originally to be named the "Bon Homme Richard", but changed after the Yorktown (CV-5), was lost at the Battle of Midway on June 7, 1942, on April 15, the Bunker Hill (CV-17) on May 25, the Intrepid (CV-11) on August 16, the Wasp (CV-18); name changed from "Oriskany" after the Wasp (CV-7) was sunk in September 1942 in the South Pacific while escorting a troop convoy to Guadalcanal, on November 24, and the Hornet (CV 12); name changed from "Kearsarge" when the Hornet (CV-8) was lost in October 1942 in the Battle of Santa Cruz Islands, on November 29 that year. In 1944, Franklin (CV-13) was commissioned on January 31 and the Bennington (CV-20) on August 6.

In recap, after WW II erupted and until its successful conclusion by Allied forces, the U.S. Navy ordered 32 aircraft carriers of the Essex and the related Ticonderoga class, of which the keels of 26 were laid down, 24 actually being commissioned.

These carriers had better protecting armor than their predecessors, better facilities for handling ammunition, safer and greater fueling capacity, and more effective damage control equipment.

The tactical employment of U.S. carriers changed as the war progressed. In early operations, through 1942, the doctrine was to operate singly or in pairs, joining together for the offense and separating when on the defenseâ€"the theory being that a separation of carriers under attack not only provided a protective screen for each, but also dispersed the targets and divided the enemy's attack. Combat experience in those early operations did not bear out the theory and new proposals for tactical deployment were the subject of much discussion.

As the new Essex, Ticonderoga and Independence class carriers became available, tactics changed. Experience taught the wisdom of combined strength. Under attack, the combined anti-aircraft fire of the task group carriers and their screen provided a more effective umbrella of protection against marauding enemy aircraft than was possible when the carriers separated.

When two or more of these task groups supported each other, they constituted a fast carrier task force. Lessons learned from operating the carriers as a single group of six, as two groups of three, and three groups of two, provided the basis for many tactics which later characterized carrier task force operations. With the evolution of the fast carrier task force and its successful employment in future operations.

Armaments

Ordnancemen working on bombs amid F6F-3 "Hellcat" fighters parked on the carrier's hangar deck, circa October-December 1943. Other crewmen are watching a movie in the background.

"Sunday Punch"
The pride of the carrier known as the "Sunday Punch" was the offensive power of 36 fighters; 36 dive bombers and 18 torpedo planes. The F6F Hellcat would prove to be superior to the Japanese Zero. It was twice as powerful as the Zero and could therefore climb higher and fly faster. Due to the increase in power, the Hellcat could carry an enormous amount of firepower. The Hellcat boasted six .50 caliber (12.7 mm) machine guns with a rate of fire of over 1000 rounds per minute. The SB2C-1 Helldiver, was a dive-bomber with a capacity of 2650 pounds (1,200 kg) of ordnance or one torpedo. Designed solely as a torpedo plane, Avenger (TBF-1) was produced by Grumman Aircraft. Some Essex-class carriers, such as the USS Bunker Hill (CV-17), also included squadrons of F4U Corsairs in Fighter-Bomber squadrons (VBF's), the precursor to modern Fighter-Attack (VFA) squadrons.

Guns, Radar, & Radios
The defensive plan for the carriers was to use radio and radar in a combined effort to concentrate anti-aircraft fire. The ship boasted seventeen quad-barrel, 40 mm, anti-aircraft guns and 65 single, 20 mm, close-in defense guns. The main defensive weapons were the five-inch guns. With a range of ten miles and a rate of fire of fifteen rounds per minute these guns launched the deadly VT shells. The VT shells, known as proximity fuzed-shells, would detonate when they came within 70 feet (21 m) of an enemy aircraft. The Essex Class made use of advanced technological and communications equipment. The Mark 4 sweeping radar was installed but could not track incoming low-level intruders and was quickly replaced with the improved Mark 12 radar. The Position Plan Indicator (PPI) radar was used to keep track of ships and enabled a multi-carrier force to maintain a high-speed formation at night or in foul weather. The new navigational tool known as the Dead Reckoning Tracer was also implemented for navigation and tracking of surface ships. The Identification Friend-or-Foe (IFF) was used to identify hostile ships and aircraft, especially at night or in adverse weather. The four-channel very high frequency (VHF) radio permitted channel variation in an effort to prevent enemy interception of transmissions. A four-channel radio also allowed for simultaneous radio contact with other ships and planes in the taskforce.

The Essex class ships

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