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Essex class fleet aircraft carriers
Displacement: 34,881 tons full load
Dimensions: 820 x 93 x 28.5 feet/250 x 28.3 x 8.7 meters
Extreme Dimensions: 872 x 147.5 x 28.5 feet/265.8 x 45 x 8.7 meters ("Long Hull" types: 888 x 147.5 x 28.5 feet/270.6 x 45 x 8.7 meters)
Propulsion: Steam turbines, 8 565 psi boilers, 4 shafts, 150,000 shp, 33 kts
Crew: 2,631
Armor: 1.5 inch hangar deck, 2.5-4 inch belt
Armament: 4 dual, 4 single 5/38 DP, 18 quad 40 mm AA, 61 single 20 mm AA ; single 20 mm AA replaced late WWII/postwar by 35 dual 20 mm AA
Aircraft: 100
Concept/Program: Conceived as a Yorktown modified to include better underwater protection. As war drew near and treaties became less of an issue, the design was allowed to grow into a large, powerful, and versatile ship. The first units were initially scheduled for completion in 1944, but production was rushed due to war. These ships formed the mainstay of US WWII fast carrier forces, and the US postwar carrier fleet. All ships served in the Pacific from completion to the end of hostilities.
Class: During 1943 an AA improvement program was undertaken, resulting in the "long hull" group. These ships had a slightly shorter flight deck, a slightly longer bow and other changes to allow a larger AA battery. Ships involved in this upgrade were those which were at an early stage of construction, so they could be altered without delaying completion. During WWII and in postwar upgrade programs the "long hull" and "short hull" ships were considered to be interchangeable. There is some evidence that the "long hull" ships were officially known as the Ticonderoga class, but these ships are far more commonly known simply as the "long hull" Essex class, and this list continues that convention.
The post-war reconstruction programs resulted in these ships being broken up into several different classes. The final class separations were as follows.
Intrepid Class (SCB 27C/125/125A): CVS 11, 14, 16, 31, 34, 38
Essex Class (SCB 27A/125): CVS 9, 10, 12, 15, 18, 20, 33
Antietam (prototype SCB 125): CVS 36
Lake Champlain (SCB 27A): CVS 39
Boxer Class (LPH): CVS 21 (LPH 4), CVS 37 (LPH 5), CVS 45 (LPH 8)
(all LPH conversions were previously of the spartan CVS configuration.)
Spartan CVS Conversion (no SCB): CVS 32, CVS 40, CVS 47
Unmodified: CV 13, CV 17
Design: The Essex design was in general superb. The ships were able to absorb massive increases in AA guns, ammunition allowances, aircraft munitions and equipment, etc. Postwar they could accommodate rebuilds that allowed them to operate modern jet aircraft throughout the Cold War. The only real weakness in the design was the wooden, unarmored flight deck, which made the ships very vulnerable to aircraft attack. This was considered an acceptable tradeoff, compared to the RN's armored flight decks and much smaller air wings. One flaw in the design was the ventilation system, which allowed smoke to rapidly spread throughout the ship. This problem was fixed during postwar reconstructions.
Variations: See "long hull" description above. Some units were completed with athwartships catapults in the forward hangar bay, but these were soon removed in favor of additional AA guns. Postwar reconstructions lead to major variations within the class and within each rebuild configurations.
Modifications: Numbers of .50 cal, 20 mm, 1.1 inch and 40 mm weapons varied throughout the war; therefore only the ultimate numbers of guns are listed. Some ships were completed with .50 cal and 1.1 inch guns, but these were replaced with 20 mm and 40 mm guns early in the war. Postwar the 20 mm guns were removed; in ships remaining active into the 1950's dual 3/50 AA mounts replaced quad 40 mm guns. As time went on the gun batteries were gradually reduced until ships carried little, if any, gun armament.
Modernization: Following WWII most ships underwent extensive upgrades under several programs.
SCB 27A: First major upgrade program applied to Essex class. This was a general, all-around upgrade, including a completely rebuilt and reconfigured island, new arresting gear and hydraulic catapults, new aircraft fueling arrangements, and all deck-level 5 inch guns removed. The gun armament was reduced to 8 single 5/38 DP and 12 to 14 dual 3/50 AA; the gun battery was gradually reduced over time. The rebuild did not include an angled flight deck. Displacement was 40,600 tons.
SCB 27C: This program replaced the SCB 27A, and went one slightly further. Most details were the same as SCB 27A, but the ships carried steam catapults rather than hydraulic, and had only 4 5/38 guns. The change to steam catapults was a major operational improvement, and allowed the ships to operate much larger and heavier aircraft. Displacement was 43,600 tons.
"Ultimate" Reconstruction: This was a never-realized program to upgrade Essex class ships to a final, completely modern configuration. The SCB 27A/27C programs were seen as a temporary measure pending development of an "ultimate" configuration for the class. Ships of this configuration would have operated with the "supercarrier" United States in large nuclear-strike groups. The design would have been completely flush-decked, with no island at all. With the death of United States and the development of the angled deck, the "ultimate" plan was reconfigured but probably stayed alive. It is unclear when it was realized that the "ultimate" modernization of Essex class ships should be dropped in favor of SCB 125 and new construction. Two ships were excluded from other modernization programs to make them available for the "ultimate" conversion -- Bunker Hill and Franklin. These ships had been heavily damaged near the end of the war, fully repaired, and laid up in excellent condition. Ultimately they went to the breakers unmodified.
SCB 125: This program was applied to ships already modernized under the SCB 27A/27C programs. The principal change under SCB 125 was the addition of an angled flight deck to replace the old axial deck arrangement. Other features of the ship, includung the hydraulic/steam catapult separation between SCB 27A and SCB 27C, were not changed. In some cases this modernization was performed at the same time as an SCB 27A/27C conversion, leading to confusion between the two programs. The prototype conversion for this program was applied to an otherwise unmodified ship, yielding an odd ship with all her WWII features intact, but with an angled deck.
SCB 125A: This was a slightly more advanced version of the SCB 125A program, the main difference being use of an aluminum flight deck to replace the old wooden deck. This modernization also included replacement of the SCB 27A's hydraulic catapults with the steam catapults of SCB 27C.
CVS Conversion: This conversion was applied to SCB 27A and SCB 27C ships as they left the front-line fleet and assumed ASW duties. Conversion, which was not always done at the same time as redesignation to CVS, included outfitting the ships with an ASW command center, additional communications, support facilities for ASW aircraft and helicopters, etc. The early CVS conversions, from unmodified axial-deck (non-SCB) ships, were far less extensive and are best classed as a refit rather than a full conversion.
LPH Conversion: This conversion was applied to unmodified, axial deck ships that had previously served as CVSs. Most guns and radars were removed, 4 of 8 boilers were deactivated, and troop berthing spaces and equipment storage spaces were added. Speed was 25 knots; most ships carried 2 dual and 2 single 5/38 DP.
FRAM II: This was a general update and life extension overhaul applied to some late CVSs and LPHs. The CVSs received a hull-mounted sonar, and all ships had their service lives extended by 5 years.
Classification: Initially classed CV; all reclassed CVA in 1952. Various ships reclassied CVS or LPH as they were modified; some changed to CVS while in reserve. Unmodified ships laid up in reserve eventually became aircraft transports (AVT). Some ships remaining as CVAs in 1975 were reclassed CV, but no change of role resulted.
Operational: These ships saw extensive service over a span of nearly 50 years and in at least a half-dozen roles.
Progression of Roles: Following WWII 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, mostly reduction of light AA, etc. Starting in the 1950's the older ships were put back into service after going through massive upgrade/reconstruction programs, starting with the SCB 27A program. The SCB 27A ships took the front-line attack roles, reducing the unrebuilt ships to duties as ASW carriers, in turn replacing CVEs and CVLs that had served in the ASW role. The SCB 27C program followed the 27A program, and these ships took over the front-line attack roles as they came into service. With the introduction of the 27C rebuilds the 27A ships moved to ASW roles, and the unrebuilt ships moved from ASW to service as amphibious assault ships (LPH), or to retirement. Eventually the war-built carriers serving as LPHs were replaced by purpose-built ships, and the SCB 27C carriers were reduced to ASW roles or served as light attack carriers as more "supercarriers" came into service. Finally the end of the Vietnam war spelled the end for ships operating as light CVAs, and age caught up with the other ships.
Other Notes: During the 1980's reactivation of one or more mothballed Essex class ships was considered, but the idea did not proceed. The ships were considered to be too old and in poor condition, and there were few aircraft suitable for operation from their small decks.
AND MIDWAY
Midway class large fleet aircraft carriers
Displacement: 59,901 tons full load
Dimensions: 900 x 113 x 32.75 feet/274.3 x 34.4 x 10 meters
Extreme Dimensions: 968 x 136 x 32.75 feet/295 x 41.5 x 10 meters
Propulsion: Steam turbines, 12 565 psi boilers, 4 shafts, 212,000 shp, 33 kts
Crew: 3,583 (as planned in 1943, was over 4000 by completion)
Armor: 3.5 inch flight deck, 7.6 inch belt
Armament: 18 single 5/54, 21 dual 40 mm AA, 28 single 20 mm AA (as planned)
Aircraft: 137 initially
Concept/Program: These ships were a new, much larger design intended to correct certain problems in the Essex class design. They had armored flight decks, requiring a much larger hull and lower freeboard, to reduce topweight. They also carried a very heavy AA battery of 5/54 weapons. The armor requirement was originally meant to counter 8" cruiser gunfire, but by the time the ships were laid down the focus had shifted to defending against aircraft attack. The ships entered service soon after WWII. In their early years they were the only ships capable of operating nuclear strike aircraft.
Design: An all-new design. These ships were very wet, very crowded and quite complex; these problems were never solved. The design made them difficult and expensive to modernize or upgrade. In later years these ships were limited by low freeboard, severe crowding of crew and equipment, low hangar clearances, poor seakeeping and extreme age; they were unable to operate the latest and largest aircraft. Overall they must be considered to be a less than satisfactory design, but they had long service lives because of the urgent need for large carriers.
Variations: Configurations varied as completed; only Midway was completed to the original design. Roosevelt and especially Coral Sea carried fewer guns at completion. There were major differences following the 1950's reconstructions.
Modifications: All ships had their gun batteries gradually reduced over time. All ships were upgraded in 1947-48 with strengthened flight decks, 10 dual 3/50 AA fitted in place of 40 mm guns, facilities for nuclear weapons, and other improvements. Continual updating of electronics outfit.
Modernization: Underwent major reconstructions during the 1950's, but no two ships were reconstructed to the same standard. These rebuilds were the equivalent of the SCB 27C/125 reconstructions in the Essex class.
SCB 110: (Midway & Roosevelt) First reconstruction applied to this class, generally equivalent to the SCB 27C/125 combination. Additions included an angled deck, new catapults and arresting gear and a new electronics outfit; the gun battery was reduced and general improvements were carried out. Displacement was approximately 63,500 tons.
SCB 110A: (Coral Sea) A more extensive version of the SCB 110 applied to the other ships of the class. Aviation features and electronics were further improved, and gun battery was further reduced.
SCB 101: (Midway) A second reconstruction meant to be applied to all ships, to upgrade them beyond the SCB 110/110A configuration. This reconstruction included a longer flight deck, new catapults, and general all-around improvements. Due to the cost of this work, only one ship was upgraded under this program.
After SCB 110A Coral Sea was the most capable of the ships, but Midway surpassed her with the SCB 101 reconstruction. In addition to the SCB reconstructions, each ship received at least one major overhaul/upgrade, the details of which varied.
Classification: Initially classified as CV, but changed to CVB prior to completion, and CVA postwar. Returned to CV classification in 1975 when modified to operate ASW aircraft.
Operational: Saw extensive service as tactical and strategic platforms. Operational lives continually extended due to force level build-ups and lack of replacements.
Departure from Service/Disposal: Roosevelt was in poor condition when she was discarded in 1977. Others remained in service long pasts their intended retirement dates. Coral Sea replaced and retired in 1990; Midway retired without replacement in 1992, due to force reductions.
Edited by Universal, 25 April 2005 - 04:39 PM.
