Essex class aircraft carrier
From Wikipedia, the free encyclopedia
| Essex class Aircraft carrier | |
|---|---|
| The USS Ticonderoga with an angled-deck | |
| Class Overview | |
| Type: | Aircraft carrier |
| Name: | Essex |
| General characteristics | |
The United States Navy's Essex-class aircraft carriers constituted the Twentieth Century's largest class of heavy warships, with 24 ships built. Although thirty-two were originally ordered, six were cancelled before construction, and two were cancelled after construction had begun. They, along with the far less-numerous Midway-class carriers, were the backbone of the Navy's combat strength in the years after World War II, until the supercarriers began to come into the fleet in numbers during the 1960s and 70s.
Contents |
[edit] Overview
The preceding Yorktown-class carriers formed the basis from which the Essex class was developed. Designed to carry a larger air group, and unencumbered by pre-war naval treaty limits, the 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 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, 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 the same amount of deck armor as that carried by their British counterparts. While debates raged, and continue to this day, regarding the effect of placement (flight deck level on British ships vs. hangar deck level on American ships), British designers' comments tended to disparage the use of deck armor, and serious historians, such as D.K. Brown in Vanguard to Trident, generally see the American arrangement to have been superior, until the larger size of the first supercarriers necessitated a deeper hull, and thus moving the strength deck to the flight deck.
[edit] 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 carriers, 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.
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 done—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% 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% 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 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 Navy's 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% 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. Only two of the ships, the Bon Homme Richard (CV-31) and the Oriskany (CV-34) were laid down as Essex "short hull" keels. The remainder became the Ticonderoga or "long hull" class ships.
CV-16 was originally 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; she was commissioned on February 17, 1943. CV-10, originally to be named the "Bon Homme Richard", was renamed after the Yorktown (CV-5) was lost at the Battle of Midway on June 7, 1942. CV-18's name was changed from "Oriskany" after the Wasp (CV-7) was sunk in September 1942 in the South Pacific while escorting a troop convoy to Guadalcanal, and the CV-12's name was changed from "Kearsarge" after the Hornet (CV-8) was lost in October 1942 in the Battle of Santa Cruz Islands.
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 defense—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- and Independence-class carriers became available, tactics changed. Experience taught the wisdom of combined strength. Under attack, the combined anti-aircraft fire of a task group's 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.
[edit] Armaments
[edit] "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 Bunker Hill (CV-17), also included squadrons of F4U Corsairs in Fighter-Bomber squadrons (VBFs), the precursor to modern Fighter-Attack (VFA) squadrons.
[edit] Guns, radar, and 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.
[edit] The "long-hull" Essexes
Throughout the very large program to build Essex-class aircraft carriers, modifications were constantly made. The number of 40 mm and 20 mm anti-aircraft machine guns was greatly increased, new and improved radars were added, the original hangar deck catapult installation was deleted, the ventilation system was massively revised, details of protection were altered and hundreds of other large and small changes were executed. In fact, to the skilled observer, no two ships of the class looked exactly the same.
Beginning in March 1943, one visually very significant change was authorized for ships then in the early stages of construction. This involved reshaping the bow into a rather elegant "clipper" form to provide deck space for two 40 mm quadruple gun mountings, thus greatly improving forward air defenses. Thirteen ships were completed to this "long-hull", or Ticonderoga, class. Four of these were finished in 1944, in time to join their short-hull Essex-class sisters in Pacific combat operations. The rest went into commission between early 1945 and late 1946.
[edit] Post-war rebuilds
Their construction greatly accelerated, the Essex class 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.
Five of the long-hulls were laid up in 1946–47, along with all of the short-hulls. Eight stayed on active duty to form, with the three much larger Midways, the backbone of the post-war Navy's combat strength. Though the Truman administration's defense economies sent three of the active Essexes into "mothballs" in 1949, these soon came back into commission after the Korean War began. Ultimately, all thirteen had active Cold War service.
Five of them were thoroughly rebuilt in the early 1950s under the SCB-27 program, and four of these were further modernized a few years later to the SCB-125 design. Another got a combined SCB-27 and SCB-125 redo, while yet another was given a modest reworking to test the revolutionary "angled deck" landing area.
Even after the arrival of the Forrestal-type "super carriers", the Essex class 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, 18 of the Essex class were reassigned to the anti-submarine warfare (ASW) 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).
Of the six unmodernized long-hull Essexes, three decommissioned in the late 1950s and early 1960s and were promptly reclassified as aircraft transports (AVT), reflecting their very limited ability to safely operate modern aircraft. The other three, converted to Landing Platform Helicopter (LPH) amphibious assault ships, were active until about 1970. The two least modernized units went into reserve in the mid-1960s, and the rest passed out of the active fleet between 1969 and 1976. All were scrapped, most in the 1970s, although Shangri-La survived until the late 1980s.
[edit] General characteristics
[edit] USS Essex (Dec 1942)
- Displacement: 27,200 tons (standard)/36,380 tons (full load)
- Length: 872'
- Beam: 93'
- Draft: 23'
- Armament: 12 × 5 in (127 mm) / 38 caliber DP; 32 × 40 mm quads; 46 × 20 mm
- Speed: 33 knots (61 km/h)
- Power: 150,000 horsepower
- Drive: 4 screws; geared turbines
- Aircraft: 91
[edit] The Essex class ships
| Keel laid | Launched | Commissioned | Decommissioned | |
| USS Essex (CV-9) | Apr 1941 | Jul 1942 | Dec 1942 | |
| USS Yorktown (CV-10) | Dec 1941 | Jan 1943 | Apr 1943 | |
| USS Intrepid (CV-11) | Dec 1941 | Apr 1943 | Aug 1943 | |
| USS Hornet (CV-12) | Aug 1942 | Aug 1943 | Nov 1943 | |
| USS Franklin (CV-13) | Dec 1942 | Oct 1943 | Jan 1944 | |
| USS Ticonderoga (CV-14) | Feb 1943 | Feb 1944 | May 1944 | Sep 1973 |
| USS Randolph (CV-15) | May 1943 | Jun 1944 | Oct 1944 | Feb 1969 |
| USS Lexington (CV-16) | Jul 1941 | Sep 1942 | Feb 1943 | |
| USS Bunker Hill (CV-17) | Sep 1941 | Dec 1942 | May 1943 | |
| USS Wasp (CV-18) | Mar 1942 | Aug 1943 | Nov 1943 | |
| USS Hancock (CV-19) | Jan 1943 | Oct 1944 | Apr 1944 | Jan 1976 |
| USS Bennington (CV-20) | Dec 1942 | Feb 1944 | Aug 1944 | |
| USS Boxer (CV-21) | Sep 1943 | Dec 1944 | Apr 1945 | Dec 1969 |
| USS Bon Homme Richard (CV-31) | Feb 1943 | Apr 1944 | Nov 1944 | |
| USS Leyte (CV-32) | Feb 1944 | Aug 1945 | Apr 1946 | May 1959 |
| USS Kearsarge (CV-33) | Mar 1944 | May 1945 | Mar 1946 | Feb 1970 |
| USS Oriskany (CV-34) | May 1944 | Oct 1945 | Sep 1950 | |
| USS Antietam (CV-36) | Mar 1943 | Aug 1944 | Jan 1945 | May 1963 |
| USS Princeton (CV-37) | Sep 1943 | Jul 1945 | Nov 1945 | Jan 1970 |
| USS Shangri-La (CV-38) | Jan 1943 | Feb 1944 | Sep 1944 | Jul 1971 |
| USS Lake Champlain (CV-39) | Mar 1943 | Nov 1945 | Jun 1945 | May 1966 |
| USS Tarawa (CV-40) | Mar 1943 | May 1945 | Nov 1945 | Jun 1967 |
| USS Valley Forge (CV-45) | Sep 1944 | Nov 1945 | Nov 1946 | Jan 1970 |
| USS Philippine Sea (CV-47) | Aug 1944 | Sep 1945 | May 1946 | Dec 1958 |
The Oriskany (CV-34) was ordered and laid down as an Essex-class vessel, was completed in 1950 to the much modified SCB-27A design.
Reprisal (CV-35), laid down in July 1944 at the New York Navy Yard and launched in 1945, was scrapped incomplete after tests; and Iwo Jima (CV-46) was laid down at Newport News Shipbuilding yards in January 1945 but cancelled in August 1945 and broken up on the shipways.
Six fiscal-year 1945 ships, none of which received names, were assigned to Bethlehem Steel Company (CV-50), New York Navy Yard (CVs 51 & 52), Philadelphia Navy Yard (CV-53) and Norfolk Navy Yard (CVs 54 and 55). Their construction was cancelled in March 1945.
[edit] Notes and references
- Faltum, Andrew (1996), The Essex Aircraft Carriers. The Nautical and Aviation Publishing Company of America ISBN 1-877853-26-7
- Donald, David, and Daniel J. March (2001), Carrier Aviation Air Power Directory. AIRtime Publishing ISBN 1-880588-43-9
- This article includes text from the public domain Dictionary of American Naval Fighting Ships.
[edit] See also
- Aircraft carrier classes:
- Ticonderoga class cruiser
- List of aircraft carriers of the United States Navy
| Essex-class aircraft carrier |
|
Short-hull carriers Long-hull (Ticonderoga-class) carriers |
| List of aircraft carriers of the United States Navy |
ja:エセックス級航空母艦 pl:Lotniskowce typu Essex sl:Razred letalonosilk essex
