CV-9 ESSEX Class
Warship requirements were referred to as “characteristics” within the U.S. Navy. Initially, characteristics were developed by the Navy General Board based on evidence derived during hearings where both technical bureaus and seagoing officers provided data. However, by 1945 the characteristics function was absorbed by a Ship Characteristics Board within the office of the Chief of Naval Operations.
In 1943 anti-aircraft improvements resulted in the Ticonderoga class, the so-called "long hull Essex" design. With a slightly shorter flight deck, a somewhat longer bow and other changes to accomodate an expanded anti-aircraft battery, hulls in early stages of construction were built to this modified design that incorporated lessons learned from early combat, without delaying completion. During the war and subsequently the classes were otherwise considered to be interchangeable. Following World War II most of the older ships which had seen extensive war service, were decommissioned to reserve. Ships completed near the end of the war and postwar remained in service with minimal modifications.
Starting in the 1950's the older ships were put back into service after going through massive upgrade/reconstruction programs. As a result of the Korean War and the continuing "Cold War," the Navy found enough money to update some of its mothballed Essex-class aircraft carriers. The Essex hulls offered the navy three advantages; first they were well built, second they were plentiful and third, they were a cost effective alternative to building new carriers from the keel up.
The jet engine, introduced to U.S. aircraft with the Army Air Force P-80 Shooting Star in 1945, led to a significant increase in aircraft weight and a decrease in low speed handling characteristics. The Navy's jet propelled F2 Banshee introduced in 1949 had a takeoff weight of 16,200 pounds, a marked contrast to the standard Navy fighter of World War II, the F6F Hellcat, which weighed 12,441 pounds. In carrier aviation the lessons of Korea, the availability of more money, and the implications of the future led to an extensive conversion program for existing aircraft carriers. Here the most significant new step was the incorporation of the angled deck, a British development, which permitted simultaneous launching and landing and at the same time removed the hazards of the barrier crash. With success of an experimental installation on Antietam, other Essex-class ships were put into the works to emerge in due time with the new deck configuration, modernized elevators, new steam catapults, and other improvements, and in 1954 similar modernization of the three Midway-class carriers was begun.
Most ships underwent extensive upgrades under several programs, which led to major variations within the class and among rebuilt configurations.
- Essex Class (SCB 27A/125): CV 9, 10, 12, 15, 18, 20, 33, 39 -- On 04 June 1947 the CNO approved Project 27A by which Essex-class carriers were modernized to be able to handle aircraft to 40,000 pounds and included the installation of two H-8 catapults, strengthening the flight deck and clearing it of guns, increasing elevator capacity and adding special provisions for jet aircraft such as blast deflectors. USS Oriskany (CV 34), the first of nine carriers modernized under this project, began conversion at the New York Naval Shipyard on 01 October 1947. Oriskany became the prototype, while Essex was the second carrier to be modernized to the SCB-27A design. The USS Essex (CV 9) was placed out of commission in reserve on 09 January 1947. The first of the World War II carriers to do so, she then underwent modernization which gave her a new flight deck, and a streamlined island superstructure. USS Essex (CV 9) was recommissioned 16 January 1951, and on 23 August 1951 she went into combat in Korea, the first carrier to launch F2H Banshee twinjet fighters on combat missions. The SCB-27 modernization was very extensive, requiring two years for each carrier. To handle much heavier, faster aircraft, flight deck structure was massively reinforced. Stronger elevators, much more powerful catapults, and new arresting gear were installed. A distinctive new feature was a new island. Ready rooms were moved to below the hangar deck, with a large escalator on the starboard side amidships to move airmen up to the flight deck. Internally, aviation gasoline storage was increased by nearly half and its pumping capacity enhanced. Also improved were electrical generating power, fire protection, and weapons stowage and handling facilities. All this added considerable weight: displacement increased by some twenty percent.
- Essex Class (SCB 27A/125): CV 9, 10, 12, 15, 18, 20, 33, 39 -- The SCB 125 modification, applied to ships already modernized under the SCB 27A/27C programs, replaced the axial deck arrangement with the angled flight deck first tested on CV 36 Antietam. Oriskany was out of commission from January 1957 until March 1959, during which time she was modernized with an angled flight deck, steam catapults, an enclosed "hurricane" bow and many other improvements that permitted safer operation of high-performance aircraft. In 1961, she became the first aircraft carrier to be fitted with the revolutionary Naval Tactical Data System (NTDS). Of the ships modernized under SCB 27A, only Lake Champlain (CVS 39) was not modified under the SCB 125 program. The CVS anti-submarine warfare support aircraft carrier conversion was applied as these ships assumed ASW duties, and included an ASW command center, additional communications, support facilities for ASW aircraft and helicopters.
- Intrepid Class (SCB 27C/125/125A): CV 11, 14, 16, 31, 34, 38 -- On 01 February 1952 the CNO approved Project 27C, a modification of Project 27A. These changes included more powerful arresting gear, higher performance steam catapults [rather than hydraulic], and a replacement of the number three centerline elevator with a deck-edge type of greater capacity. Three Essex-class carriers and three Ticonderoga Class ship incorporating these modifications were completed under Project 27C. The SCB 125 modification, applied to ships already modernized under the SCB 27A/27C programs, replaced the axial deck arrangement with the angled flight deck first tested on CV 36 Antietam. The CVS conversion was applied as these ships assumed ASW duties, and included an ASW command center, additional communications, support facilities for ASW aircraft and helicopters.
The conversions altered the outward appearances but left the World War II interior spaces largely intact. The ships went from a carrier with a straight deck, open bow and a low rat's nest of radar antenna, to an angled deck carrier with an enclosed hurricane bow and a single pole antenna mast. The angled deck was a significant change, adding additional flight deck space and catapults.
The modifications involved strengthening of the flight deck in the landing area, removing all 5-inch twin turrets from the flight deck and relocating new, open, single 5-inch mounts. Larger more powerful elevators were installed as well as fittings (such as electrical outlets) to permit operation of jet aircraft. Stronger bomb and ammunition lifts (to accommodate "special" or nuclear weapons) were installed. Three standby rooms for aircrews were transferred to below deck and an escalator from the standby room to the flight deck was added. The island was shortened and the bridge and stack combined and side armor was removed at the waterline. A deck landing mirror and higher capacity aircraft cranes were added, and storage capacity for aviation fuel was increased. Blast deflectors behind the catapults were installed and hangar space was divided by two fire and splinter proof steel doors.
The SCB-27C specific changes included an increased beam of 103' at waterline (to increase stability), replacement of the Type H-4-1 hydraulic catapults with two Type C-11 steam catapults to handle heavier aircraft, and strengthening of the entire flight deck. As well, elevator number 3 (centerline lift) was replaced with a larger, folding, deck-edge lift, and hull bulges were added. SCB-125 conversions were incorporated during the same dry-dock period as the SCB-27C changes. These modifications added an angled flight deck, an enclosed "hurricane" bow, and improved dual arrester wire system (MK 7), which halved the number of arrester wires from sixteen to eight. The forward elevator length was increased to 70' 3", air-conditioning was added to certain areas such as the crew ready rooms, and crash barriers were strengthened. There were also improvements made to the primary flight control center and flight deck illumination as well as installation of improved soundproofing to island accommodations adjacent to the flight deck.
- Antietam (prototype SCB 125): CV 36 -- In September-December 1952, after joining the Atlantic Fleet, Antietam was modified to receive the US Navy's first angled flight deck. The prototype conversion was applied to an otherwise unmodified ship with all her World Ware II features intact. On 12 January 1953 test operations begin on USS Antietam (CVA 36), which emerged in December 1952 from the New York Naval Shipyard as America's first angled-deck aircraft carrier. During the next few years, she served as the test platform for this feature, which was to revolutionize carrier flight operations. After being rated as an attack aircraft carrier (CVA-36) from October 1952 to August 1953, she was thereafter classified as an antisubmarine support aircraft carrier, with the hull number CVS-36. In that role, Antietam made Sixth Fleet cruises in the Mediterranean Sea in 1955 and in 1956-57. She was then assigned to carrier flight training duty, generally operating in waters near Pensacola, Florida. Relieved as training carrier in October 1962, she was decommissioned for the last time in May 1963. Following a decade in the Reserve Fleet, USS Antietam was sold for scrapping in February 1974.
- CVS Conversion (no SCB): CV 32, 40, 47 -- This refit for ASW duties, applied to unmodified axial-deck (non-SCB) ships, included outfitting the ships with ASW command and communications as well as support facilities for ASW aircraft and helicopters. With their flight decks essentially unchanged from its World War II design, these vessels were increasingly unable to handle the new high-performance, heavier jet aircraft of the post-Korean War era, and they were reclassified an anti-submarine warfare (ASW) support carrier.
- Boxer Class (LPH): CV 21 (LPH 4), CV 37 (LPH 5), CV 45 (LPH 8) - The three LPH units had previously undergone CVS configuration, and were otherwise unmodified axial deck ships. Most guns and radars were removed, half the boilers were deactivated, and troop berthing spaces and equipment storage spaces were added. Most ships carried 2 dual and 2 single 5/38 DP.
- Unmodified: CV 13, 17 -- Two ships [Bunker Hill and Franklin] had been heavily damaged in combat near the end of World War II. While off Okinawa on 11 May 1945, Bunker Hill was hit by two enemy "Kamikaze" suicide planes, losing nearly 400 crewmen killed in the resulting explosions and fires. Despite severe damage, the carrier was able to return under her own power to the US for repairs. On the morning of 19 March 1945, while her flight and hangar decks were crowded with fully armed and fueled planes preparing to take off to attack the enemy, a Japanese plane approached undetected and hit the Franklin with two bombs. The resulting inferno badly damaged the ship and resulted in the deaths of 724 of her crew. Heroic work by the survivors, assisted by nearby ships, brought the fires and flooding under control. After a brief period under tow, Franklin's engineers again had her steaming on her own. Fully repaired, they were laid up in excellent condition and excluded from other modernization programs to be available for the "ultimate" conversion to operate with the supercarrier United States. Following the cancellation of the United States, they were eventually broken up unmodified. Stricken from the Naval Vessel Register in November 1966, Bunker Hill was used as a stationary electronics test platform at San Diego during the 1960s and early 1970s. She was sold for scrapping in May 1973. Franklin remained in the Reserve Fleet until she was stricken from the Naval Vessel Register in October 1964. She was sold for scrapping in July 1966.
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