# SCB-27 > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/SCB-27 > Markdown URL: https://mediated.wiki/source/SCB-27.md > Source: https://en.wikipedia.org/wiki/SCB-27 > Source revision: 1302180591 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|US Navy aircraft carrier upgrade program}} thumb|USS ''Hornet'' showing her SCB-27A configuration.{{Use dmy dates|date=April 2017}} '''SCB-27''' (also known as "Two Seven-Alpha" or "Two Seven-Charlie") was the [United States Navy](/source/United_States_Navy) designation for a series of upgrades to the {{sclass|Essex|aircraft carrier}}s (both the short-hull and long-hull ''Ticonderoga'' versions), conducted between 1947 and 1955. These upgrades were intended to allow the [World War II](/source/World_War_II)-era carriers to operate [jet aircraft](/source/jet_aircraft). {{USS|Oriskany|CV-34|6}}, [laid up](/source/Reserve_fleet) incomplete at the conclusion of World War II, served as the prototype and was re-ordered to the SCB-27 standard. All but one of the SCB-27 modernized ''Essex'' carriers, the {{USS|Lake Champlain|CV-39|6}}, were further modified under the [SCB-125](/source/SCB-125) modernization program.{{Citation needed|date=June 2022}} ==Modifications== Officially, [Ship Characteristics Board](/source/Ship_Characteristics_Board) Program 27 proper referred to the completion of {{USS|Oriskany|CV-34|2}}, left unfinished at war's end, to a heavily revised design; reconstructions of earlier ships were programs SCB-27A and 27C. The SCB-27 modernization was very extensive, requiring some two years for each carrier. To handle the much heavier, faster aircraft of the early jet-era, the [flight deck](/source/flight_deck) structure was significantly reinforced, able to support aircraft weighing up to {{convert|52000|lb|kg|0}}, namely the [North American AJ Savage](/source/North_American_AJ_Savage). Stronger and larger elevators, much more powerful [catapults](/source/aircraft_catapult), and new Mk 5 [arresting gear](/source/arresting_gear) were installed. The original four twin [5-inch/38 gun](/source/5%22%2F38_caliber_gun) mounts were removed, clearing the flight deck of guns. The new five-inch gun battery consisted of eight weapons, two on each quarter beside the flight deck. Twin [3-inch/50 gun](/source/3%22%2F50_caliber_gun) mounts replaced the [40 mm guns](/source/Bofors_40_mm_Automatic_Gun_L%2F60), offering much greater effectiveness through the use of [proximity fuze](/source/proximity_fuze)d ammunition. The reconstruction eliminated the difference between "short-hull" and "long-hull" ships; all now had similar clipper bows. New [Mark 56](/source/Mark_56_Gun_Fire_Control_System) [fire-control system](/source/fire-control_system)s were also added to the ships. The island was completely redesigned, made taller, but shorter in overall length with the removal of its gun mounts. In addition, the boiler uptakes were rebuilt and angled aft to accommodate a single [radar](/source/radar) and communications mast atop the island. To better protect aircrews, [ready room](/source/ready_room)s were moved from the gallery deck to below the armored [hangar deck](/source/hangar_deck), with a large [escalator](/source/escalator) on the [starboard](/source/starboard) side [amidships](/source/amidships) to move flight crews up to the flight deck. Internally, [aviation fuel](/source/aviation_gasoline) capacity was increased to {{convert|300000|USgal|L|0}} (a 50% increase) and its pumping capacity enhanced to {{convert|50|USgal|L|1}} per minute.{{cite book | last = Friedman | first = Norman | title = U.S. Aircraft Carriers: An Illustrated Design History | year = 1983 | publisher = Naval Institute | location = Annapolis | isbn = 0-87021-739-9 }} Fire fighting capabilities were enhanced through the addition of two emergency fire and splinter [bulkheads](/source/Bulkhead_(partition)) to the hangar deck, a fog/[foam](/source/Fire_fighting_foam) firefighting system, improved [water curtains](/source/safety_curtain) and a [cupronickel](/source/cupronickel) fire main. Also improved were electrical generating power, and weapons stowage and handling facilities. All this added considerable weight: [displacement](/source/displacement_(fluid)) increased by some twenty percent. The armor belt was removed and blisters were fitted to the hull sides to compensate, widening waterline [beam](/source/beam_(nautical)) by {{convert|8|to|10|ft|m}}. The ships also sat lower in the water, and maximum speed was slightly reduced, to {{convert|31|kn|lk=in}}. ===Modification sub-types=== thumb|USS ''Intrepid'' showing her SCB-27C configuration. The two sub-types of SCB-27 modifications were primarily a result of changes in catapult technology in the early-1950s. '''SCB-27A''' vessels used a pair of H 8 slotted-tube [hydraulic catapults](/source/Aircraft_catapult), while the later '''SCB-27C''' vessels were fitted with a pair of [C 11 steam catapults](/source/steam_catapults), a British innovation (in fact the first four installed, on ''Hancock'' and ''Ticonderoga'', were British-built). To accommodate the catapult machinery, the SCB-27C vessels were slightly heavier (43,060 vice 40,600 tons) and after bulging wider abeam (103 vice 101 feet) than their SCB-27A sisters. Additionally, the SBC-27C carriers were equipped with [jet blast deflector](/source/jet_blast_deflector)s, deck cooling, fuel blending facilities, emergency recovery barrier and storage and handling for [nuclear weapon](/source/nuclear_weapon)s, which was not included in all of the SCB-27A carriers. Under SCB-27C the No. 3 (after) elevator was moved to the starboard deck edge; this elevator was located further aft on the first three SCB-27C ships than it was on the ships which received it concomitantly with an angled flight deck under the [SCB-125](/source/SCB-125) program. The greater capacity of steam catapults meant that the 27C ships were able to serve as attack carriers through the Vietnam era while their hydraulic-equipped 27A sisters were relegated to antisubmarine duties. == Program history == Source:{{cite web |date=8 October 2001 |title=U.S. Navy Ship Types – SCB-27 modernization of ''Essex''/''Ticonderoga'' class aircraft carriers |url=http://www.history.navy.mil/photos/usnshtp/cv/scb27cl.htm |publisher=U.S. Navy Historical Center |accessdate=4 December 2006 |archive-date=20 June 2012 |archive-url=https://web.archive.org/web/20120620104133/http://www.history.navy.mil/photos/usnshtp/cv/scb27cl.htm |url-status=dead }} {| ! Ship !! Program !! Shipyard !! Work Began || Recommissioned !! Decommissioned |- | {{USS|Oriskany|CV-34}} | SCB-27 || [New York](/source/New_York_Naval_Shipyard) || Aug 1947 || Sep 1950 || September 1976 |- | {{USS|Essex|CV-9}} | SCB-27A || [Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Feb 1949 || Jan 1951 || June 1969 |- | {{USS|Wasp|CV-18}} | SCB-27A || [New York](/source/New_York_Naval_Shipyard) || May 1949 || Sep 1951|| July 1972 |- | {{USS|Kearsarge|CV-33}} | SCB-27A ||[Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Feb 1950 || Feb 1952|| February 1970 |- | {{USS|Lake Champlain|CV-39}} | SCB-27A || [Newport News](/source/Newport_News_Shipbuilding) || Aug 1950 ||Sep 1952|| May 1966 |- | {{USS|Bennington|CV-20}} | SCB-27A || [New York](/source/New_York_Naval_Shipyard) || Dec 1950 || Nov 1952|| January 1970 |- | {{USS|Yorktown|CV-10}} | SCB-27A || [Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Mar 1951 || Feb 1953|| June 1970 |- | {{USS|Randolph|CV-15}} | SCB-27A || [Newport News](/source/Newport_News_Shipbuilding) || June 1951 || Jul 1953|| February 1969 |- | {{USS|Hornet|CV-12}} | SCB-27A || [New York](/source/New_York_Naval_Shipyard) || July 1951 || Sep 1953 || June 1970 |- | {{USS|Hancock|CV-19}} | SCB-27C || [Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Dec 1951 || Feb 1954|| January 1976 |- | {{USS|Intrepid|CV-11}} | SCB-27C || [Newport News](/source/Newport_News_Shipbuilding) || Apr 1952 || Jun 1954 || Mar 1974 |- | {{USS|Ticonderoga|CV-14}} | SCB-27C || [New York](/source/New_York_Naval_Shipyard) || Apr 1952 || Sep 1954|| September 1973 |- | {{USS|Shangri-La|CV-38}} | SCB-27C/125 || [Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Oct 1952 || Jan 1955||July 1971 |- | {{USS|Lexington|CV-16}} | SCB-27C/125 || [Puget Sound](/source/Puget_Sound_Naval_Shipyard) || Sep 1953 || Aug 1955|| November 1991 |- | {{USS|Bon Homme Richard|CV-31}} | SCB-27C/125 || [Hunters Point](/source/San_Francisco_Naval_Shipyard) || May 1953 || Sep 1955 || 2 July 1971 |- |} ==References== {{reflist}} ''Portions of this entry were drawn from the [http://www.history.navy.mil/photos/usnshtp/cv/scb27cl.htm Naval Historical Center SCB-27 information and photos] {{Webarchive|url=https://web.archive.org/web/20120620104133/http://www.history.navy.mil/photos/usnshtp/cv/scb27cl.htm |date=20 June 2012 }}'' {{Essex class aircraft carrier}} Category:Cold War aircraft carriers of the United States Category:Korean War aircraft carriers of the United States Category:Essex-class aircraft carriers --- Adapted from the Wikipedia article [SCB-27](https://en.wikipedia.org/wiki/SCB-27) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/SCB-27?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.