Editing Nimitz-class aircraft carrier (section)

==Description==
The ''Nimitz''-class aircraft carriers have a length of {{convert|1092|ft|m|abbr=on}} overall and {{convert|1040|ft|m|0|abbr=on}} at the waterline, with a [[Beam (nautical)|beam]] of {{convert|252|ft|m|abbr=on}} overall and {{convert|134|ft|m|abbr=on}} at the waterline; the individual ships have slight variations in their dimensions.<ref name="Navy.mil CVN"/><ref name="NVR Nimitz"/> They were initially designed with a full-load displacement of {{convert|87000|LT|MT ST}} and a draft of {{convert|37|ft|m|abbr=on}}, but the ships would be delivered several thousand tons heavier, particularly for later members of the class.<ref name="Navy.mil CVN"/> As the vessels were overhauled and installed more equipment, loaded displacement would climb to exceed {{convert|100000|LT|MT ST}}. For example, {{USS|Abraham Lincoln|CVN-72|6}} currently displaces {{convert|104112|LT|MT ST}} at full load.<ref>{{cite web|url= https://dspace.mit.edu/bitstream/handle/1721.1/91342/49898754-MIT.pdf;sequence=2|title=An Alternate Method for the Determination of Aircraft Carrier Limiting Displacement for Strength |publisher=dspace.mit.edu|date=June 2001|access-date=27 May 2022}}</ref> The ships' nominal complement comprises: 3,000–3,200; 1,500 (air wing); and 500 (other).<ref name="Navy.mil CVN" />

===Design===
The ''Nimitz''-class aircraft carriers were ordered to supplement the aircraft carriers of the {{sclass|Midway|aircraft carrier|5}}, {{sclass|Forrestal|aircraft carrier|5}}, {{sclass|Kitty Hawk|aircraft carrier|5}} and {{sclass|Enterprise|aircraft carrier|4}}es, maintaining the strength and capability of the U.S. Navy after the older carriers were decommissioned.<ref name="CVN 21"/> The ships were designed to be improvements on previous [[List of aircraft carriers of the United States Navy|U.S. aircraft carriers]], particularly the ''[[USS Enterprise (CVN-65)|Enterprise]]'' and {{sclass|Forrestal|aircraft carrier|0}} supercarriers, although the arrangement of the vessels is relatively similar to that of the ''Kitty Hawk'' class.<ref name="Polmar 113">Polmar 2004, p. 113</ref> Among other design improvements, the two reactors on ''Nimitz''-class carriers take up less space than the eight reactors used on ''Enterprise''. Along with a more generally improved design, ''Nimitz''-class carriers can carry 90% more aviation fuel and 50% more ordnance when compared to the ''Forrestal'' class.<ref>Labayle Couhat 1980, p. 630</ref>

The U.S. Navy has stated that the carriers could withstand three times the damage sustained by the {{sclass|Essex|aircraft carrier|4}} inflicted by Japanese air attacks during [[World War II]].<ref name="SE">{{cite book |title=The Encyclopedia of Ships |last=Gibbons |first=Tony |year=2001 |publisher=Amber Books |location=London, United Kingdom |isbn=978-1-905704-43-9 |page=444}}</ref> The hangars on the ships are divided into three fire bays by thick steel doors that are designed to restrict the spread of fire. This addition has been present on U.S. aircraft carriers since World War II, after the fires caused by [[kamikaze]] attacks.<ref name="Fire Protection">{{cite book|title=Aircraft Carrier Flight and Hangar Deck Fire Protection: History and Current Status |last1=Darwin |first1=Robert |last2=Bowman |first2=Howard |last3=Hunstad |first3=Mary |last4=Leach |first4=William |last5=Williams |first5=Frederick |year=2005 |url=http://handle.dtic.mil/100.2/ADA432176 |archive-url=https://web.archive.org/web/20101202092111/http://handle.dtic.mil/100.2/ADA432176 |url-status=dead |archive-date=2 December 2010 |page=10 |publisher=Defense Technical Information Center |access-date=1 July 2011}}</ref>

The first ships were designed around the time of the [[Vietnam War]], and certain aspects of the design were influenced by operations there. To a certain extent, the carrier operations in Vietnam demonstrated the need for increased capabilities of aircraft carriers over their survivability; they were used to send sorties into the war and were, therefore, less subject to attack. As a result of this experience, ''Nimitz''-class carriers were designed with larger stores of aviation fuel and larger [[Magazine (artillery)#Naval magazines|magazines]] compared to previous carriers, although this was partly a result of increased space available by the new design of the ships' propulsion systems.<ref name="Friedman p316">Friedman 1983, p. 316</ref>

A major purpose of the carriers was initially to support the U.S. military during the [[Cold War]]. They were designed with capabilities for that role, including using nuclear power instead of oil for greater endurance and the ability to adjust their weapons systems on the basis of new intelligence and technological developments.<ref>Jim Wilson "21st Century Carrier Force" ''[[Popular Mechanics]]'' October 1998, pp. 58–66</ref> They were initially categorized only as attack carriers, but ships have been constructed with [[Anti-submarine warfare|anti-submarine capabilities]] since {{USS|Carl Vinson|CVN-70|6}}.<ref name="ASW">{{cite web |url=http://www.nationaldefensemagazine.org/ARCHIVE/2003/JULY/Pages/7th_Fleet3817.aspx |title=7th Fleet Experiment Probes Navy's Near-Term Concerns |author=Sandra I. Erwin |date=July 2003 |publisher=[[National Defense Industrial Association]] |access-date=31 December 2009 |url-status=dead |archive-url=https://web.archive.org/web/20101202024729/http://www.nationaldefensemagazine.org/ARCHIVE/2003/JULY/Pages/7th_Fleet3817.aspx |archive-date=2 December 2010 |df=dmy-all}}</ref><ref>{{cite web |url=http://www.navyleague.org/sea_power/sep_03_12.php |title=Navy Should Bolster Crisis Planning for Theater ASW |author=Patricia Kime |date=September 2003 |publisher=[[Navy League of the United States]] |access-date=31 December 2009 |url-status=dead |archive-url=https://web.archive.org/web/20100305125731/http://www.navyleague.org/sea_power/sep_03_12.php |archive-date=5 March 2010 |df=dmy-all}}</ref> As a result, the ships and their aircraft can participate in a wide range of operations, including sea and air blockades; [[Naval mine|mine]] laying; and missile strikes on land, air, and sea.<ref name="Cold war ship"/>

Because of a design flaw, ships of this class have inherent [[List (watercraft)|lists]] to starboard when under combat loads that exceed the capability of their list control systems. The problem appears to be especially prevalent on some of the more modern vessels. This problem has been previously rectified by using damage control voids for ballast, but a solution using solid ballast that does not affect the ship's survivability has been proposed.<ref name="list">[[Dianna Wolfson|Wolfson, Dianna]]. "[https://dspace.mit.edu/handle/1721.1/33439 A Solution to the Inherent List on Nimitz Class Aircraft Carriers] {{Webarchive|url=https://web.archive.org/web/20180821145845/http://dspace.mit.edu/handle/1721.1/33439|date=21 August 2018}}" MIT thesis 2004</ref><ref name="Navy.mil CVN"/>
<gallery class="center" widths="250px" heights="180px">
File:Artist's impression of Nimitz-class aircraft carrier in 1968.jpg|An artist's impression of USS ''Nimitz'' in 1968
File:US Navy 031130-N-3653A-002 USS George Washington (CVN 73) Carrier Strike Group formation sails in the Atlantic Ocean.jpg|''George Washington'' [[Carrier Strike Group]] formation sails in the Atlantic Ocean
</gallery>

===Construction===
All ten ''Nimitz''-class carriers were constructed between 1968 and 2006 at Newport News Shipbuilding in Newport News, Virginia. The first three units of the class were erected in Dry Dock 11, the other seven ships were constructed in the largest [[dry dock]] in the western hemisphere, Dry Dock 12, now {{convert|2172|ft|m}} long after a recent expansion.{{citation_needed|date=August 2019}}

Beginning with {{USS|Theodore Roosevelt|CVN-71|6}}, the aircraft carriers were manufactured with modular construction. This means that whole sections could be welded together with plumbing and electrical equipment already fitted, improving efficiency. The modules were lifted into the dry dock using [[gantry cranes]] and welded. In the case of the bow sections, these can weigh over {{convert|1500000|lb|tonne}}.<ref>{{cite web |url=http://www.sb.northropgrumman.com/products/geraldrfordclass/construction/index.html |title=CVN 78 Construction & Facilities |publisher=Northrop Grumman Shipbuilding |access-date=30 May 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100107050658/http://www.sb.northropgrumman.com/products/geraldrfordclass/construction/index.html |archive-date=7 January 2010 |df=dmy-all}}</ref><ref>{{cite web|url=http://www.sb.northropgrumman.com/bush/docs/Facts_about_CVN_77.pdf |archive-url=https://www.webcitation.org/5qB8plOHX?url=http://www.sb.northropgrumman.com/bush/docs/Facts_about_CVN_77.pdf |archive-date=2 June 2010 |title=George H.W. Bush (CVN 77) Christening |date=7 October 2006 |publisher=[[Northrop Grumman Shipbuilding]] |access-date=30 May 2010 |url-status=dead}}</ref> This method was originally developed by [[Ingalls Shipbuilding]] and increases the rate of work because much of the fitting out does not have to be carried out within the confines of the already-finished hull.<ref>{{cite web|url=http://www.northropgrumman.com/heritage/index.html |title=Our Heritage: Litton Industries |publisher=Northrop Grumman Shipbuilding |access-date=30 May 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100316174653/http://www.northropgrumman.com/heritage/index.html |archive-date=16 March 2010}}</ref>

The total cost of construction for each ship was around $4.5&nbsp;billion.<ref group="Note">All monetary values are adjusted for inflation to 2000s figures</ref><ref name="CVN 21">{{cite web|url=http://www.history.navy.mil/library/online/navycvn21.htm |title=Navy CVN-21 Aircraft Carrier Program: Background and Issues for Congress |author=Ronald O'Rourke |year=2005 |publisher=US Department of the Navy |access-date=18 December 2009 |url-status=dead |archive-url=https://web.archive.org/web/20061201055019/http://www.history.navy.mil/library/online/navycvn21.htm |archive-date=1 December 2006}}</ref>

===Propulsion===
[[File:USS George Washington (CVN-73) propeller.jpg|thumb|upright|alt=Shipyard employees reattaching the bronze propeller of USS ''George Washington'' while in dry dock|One of the four propellers of ''George Washington'']]

All ships of the class are powered by two [[A4W reactor|A4W nuclear reactors]], housed in separate compartments. The reactors produce heat through [[nuclear fission]], which heats water to produce steam. This is then passed through four turbines, which are shared by the two reactors. A [[Transmission (mechanics)|gearbox]] transmits power to four propeller shafts, producing a maximum speed of over {{convert|30|kn|km/h}} and maximum power of {{convert|260000|bhp|MW|lk=in|0}}.<ref name="SE" /> <!-- this part is commented out because it appears to be rumor, I cannot find any article citing such in Google. —Though actual top speeds are generally withheld for security purposes, in June 1999, the USN publicly released these trial speeds: ''Nimitz'': {{convert|31.5|knots}} ''Theodore Roosevelt'': {{convert|31.3knots}} ''Harry S. Truman'': {{convert|30.9|knots}} --> The turbines power the four [[bronze]] propellers, each with a diameter of {{convert|25|ft|m}} and a weight of {{convert|66000|lb|MT}}. Behind these are the two rudders, which are {{convert|29|ft|m}} high and {{convert|22|ft|m}} long, and each weighs {{convert|110000|lb|MT|abbr=off}}.<ref name="USN Info">{{cite web|url=http://www.public.navy.mil/usff/nctamspac/Pages/AboutUs.aspx |title=Information About Us |date=14 October 2009 |publisher=U.S. Navy |access-date=24 May 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101203050328/http://www.public.navy.mil/usff/nctamspac/Pages/AboutUs.aspx |archive-date=3 December 2010}}</ref>

The ''Nimitz''-class ships constructed since {{USS|Ronald Reagan|CVN-76|6}} also have [[bulbous bow]]s to improve speed and [[fuel efficiency]] by reducing [[wave-making resistance]].<ref>{{cite book |title=A Methodology for Estimating the Effect of Aircraft Carrier Operational Cycles on the Maintenance Industrial Base: Technical Report |last1=Yardley |first1=Roland |last2=Schank |first2=John |last3=Kallimani |first3=James |year=2007 |publisher=[[RAND Corporation]] |isbn=978-0-8330-4182-1 |page=30}}</ref> As a result of nuclear power, the ships are capable of operating continuously for over 20 years without refueling and are predicted to have a service life of over 50 years.<ref name="USN Info"/>

===Armament and protection===
[[File:USS Theodore Roosevelt (CVN-71) Sea Sparrow.jpg|thumb|upright=0.8|alt=Firing of a missile from ''Theodore Roosevelt'' while at sea, seen from the flight deck. There is a Phalanx cannon on the left, with a white, domed upper section and a black cannon on the lower part.|The firing of a [[RIM-7 Sea Sparrow|Sea Sparrow missile]] from ''Theodore Roosevelt''. A [[Phalanx CIWS]] is in the left of the image.]]
[[File:US Navy 050615-N-8148A-063 The Nimitz-class aircraft carrier USS Ronald Reagan (CVN 76) activates her countermeasures wash down system as part of a series of test and evaluations to certify the vessel in the event of a chemical.jpg|thumb|upright=0.8|The counter-measure wash-down system of ''Ronald Reagan'' being tested. This is part of the ship's [[CBRN|defense]] against chemical, biological or radiological threats, and also against fires]]

In addition to the aircraft carried on board, the ships carry defensive equipment for use against missiles and hostile aircraft. These consist of either two or three [[RIM-7 Sea Sparrow]] or [[RIM-162 ESSM|RIM-162 Evolved SeaSparrow Missile]] Mk 29 missile launchers designed for defense against aircraft and [[anti-ship missile]]s, as well as either three or four 20&nbsp;mm [[Phalanx CIWS]].<ref>Wertheim 2005, pp. 919–920</ref>

USS ''Ronald Reagan'' has none of these, having been built with the Mk 49 Guided Missile Launching Systems for [[RIM-116 Rolling Airframe Missile]]s, two of which have also been installed on {{USS|Nimitz|CVN-68|6}} and {{USS|George Washington|CVN-73|6}}. These will be installed on the other ships as they return for [[Refueling Complex Overhaul]] (RCOH).<ref name="SE" /><ref name="Navy.mil CVN"/> Since USS ''Theodore Roosevelt'', the carriers have been constructed with {{convert|2.5|in|mm|abbr=on}} [[Kevlar]] armor over vital spaces, and earlier ships have been retrofitted with it: ''Nimitz'' in 1983–1984, ''Dwight D. Eisenhower'' from 1985 to 1987 and ''Carl Vinson'' in 1989.<ref name="Fontenoy"/><ref>Wertheim 2007, p. 884</ref>

The ships' other countermeasures are four Sippican [[SRBOC]] (super rapid bloom off-board [[chaff]]) six-barrel Mk 36 decoy launchers, which deploy infrared [[Flare (countermeasure)|flares]] and [[Chaff (countermeasure)|chaff]] to disrupt the sensors of incoming missiles; an SSTDS torpedo defense system; and an [[AN/SLQ-25 Nixie]] torpedo countermeasures system. The carriers also use [[AN/SLQ-32 Electronic Warfare Suite|AN/SLQ-32(V)]] [[Radar jamming and deception|jamming]] systems to detect and disrupt hostile [[radar]] signals in addition to the [[electronic warfare]] capabilities of some of the aircraft on board.<ref>Wertheim 2007, p. 885</ref><ref>Polmar 2004, p. 108</ref>

The presence of [[Tactical nuclear weapon|nuclear weapon]]s on board U.S. aircraft carriers since the end of the Cold War has neither been confirmed nor denied by the U.S. government. As a result, the presence of a U.S. aircraft carrier in a foreign port has occasionally provoked protest from local people, for example, when ''Nimitz'' visited [[Chennai]], India, in 2007. At that time, the Strike Group commander [[Rear admiral (United States)|Rear Admiral]] John Terence Blake stated, "The U.S. policy [...] is that we do not routinely deploy nuclear weapons on board ''Nimitz''."<ref>{{cite news |url=http://www.indianexpress.com/news/nimitz-docks-off-chennai-to-build-new-relat/203639/ |title=Nimitz docks off Chennai to 'build new relations with India' |date= 3 July 2007 |newspaper=[[The Indian Express]] |access-date=11 January 2010}}</ref><ref>{{cite magazine |url=http://www.hinduonnet.com/fline/fl2414/stories/20070727000806200.htm |title=NAM and Nimitz |date=14–27 July 2007 |magazine=[[Frontline (magazine)|Frontline]] |access-date=11 January 2010 |url-status=usurped |archive-url=https://web.archive.org/web/20101209044846/http://www.hinduonnet.com/fline/fl2414/stories/20070727000806200.htm |archive-date=9 December 2010 |df=dmy-all}}</ref>

In May 2013, ''George H.W. Bush'' conducted the first carrier-borne end-to-end at-sea test of the Surface Ship Torpedo Defense System (SSTDS). The SSTDS combined the passive detection of the Torpedo Warning System (TWS) that finds, classifies, and tracks torpedoes with the hard-kill capability of a Countermeasure Anti-Torpedo (CAT), an encapsulated miniature torpedo designed to locate, home in on, and destroy hostile torpedoes.<ref>[http://www.navy.mil/submit/display.asp?story_id=74665 First Carrier Countermeasure Anti-Torpedo Launched] {{Webarchive|url=https://web.archive.org/web/20150727112816/http://www.navy.mil/submit/display.asp?story_id=74665 |date=27 July 2015}} – Navy.mil, 6 June 2013</ref> This was to increase protection against wake-homing torpedoes like the [[Type 53 torpedo|Type 53]] that do not respond to acoustic decoys. The pieces of the SSTDS were engineered to locate and destroy incoming torpedoes in a matter of seconds; each system included one TWS and 8 CATs. Initial operational capability (IOC) was planned for 2019, and all aircraft carriers were to be outfitted by 2035.<ref>[http://news.usni.org/2013/06/20/navy-develops-torpedo-killing-torpedo Navy Develops Torpedo Killing Torpedo] {{Webarchive|url=https://web.archive.org/web/20151208120511/http://news.usni.org/2013/06/20/navy-develops-torpedo-killing-torpedo |date=8 December 2015}} – News.USNI.org, 20 June 2013</ref><ref>{{usurped|1=[https://web.archive.org/web/20151208094936/http://defensetech.org/2013/10/28/navy-deploying-new-anti-torpedo-technology/ Navy Deploying New Anti-Torpedo Technology]}} – Defensetech.org, 28 October 2013</ref><ref>[http://www.navyrecognition.com/index.php/news/defence-news/year-2015-news/march-2015-navy-naval-forces-defense-industry-technology-maritime-security-global-news/2495-us-navy-continues-work-on-torpedo-warning-systemcountermeasure-anti-torpedo-system.html US Navy Continues Work on Torpedo Warning System/Countermeasure Anti-Torpedo System] {{Webarchive|url=https://web.archive.org/web/20151208174617/http://www.navyrecognition.com/index.php/news/defence-news/year-2015-news/march-2015-navy-naval-forces-defense-industry-technology-maritime-security-global-news/2495-us-navy-continues-work-on-torpedo-warning-systemcountermeasure-anti-torpedo-system.html |date=8 December 2015}} – Navyrecognition.com, 12 March 2015</ref> The Navy suspended work on the project in September 2018 due to poor reliability of the components; hardware, already installed on five carriers, is to be removed by 2023.<ref>[https://www.dote.osd.mil/Portals/97/pub/reports/FY2018/navy/2018sstd_tws_cat.pdf?ver=2019-08-21-155651-040 Surface Ship Torpedo Defense (SSTD) System]. ''[[Director, Operational Test and Evaluation|Office of the Director of Test and Evaluation]]''. FY18 NAVY PROGRAMS.</ref><ref>[https://www.thedrive.com/the-war-zone/26347/the-navy-is-ripping-out-underperforming-anti-torpedo-torpedoes-from-its-supercarriers The Navy Is Ripping Out Underperforming Anti-Torpedo Torpedoes From Its Supercarriers]. ''The Drive.com/The War Zone''. 5 February 2019.</ref>

===Carrier air wing===
{{Main|Carrier air wing}}
[[File:USS Harry S. Truman (CVN-75) flight deck.jpg|thumb|An [[F/A-18 Hornet]] launches from the flight deck of ''Harry S. Truman''. Other aircraft are stored on deck.]]

In order for a carrier to deploy, it must embark one of ten Carrier Air Wings (CVW).<ref group=Note>Although there are ten carrier air wings in the U.S. Navy, they are numbered between CVW-1 (USS ''Enterprise'') and CVW-17 (USS ''Carl Vinson'').</ref> The carriers can accommodate a maximum of 130 F/A-18 Hornets<ref>"[http://www.fas.org/man/gao/nsiad98001/ns98001.pdf Navy Aircraft Carriers: Cost Effectiveness of Conventionally and Nuclear-powered Carriers] {{Webarchive|url=https://web.archive.org/web/20111018083346/http://www.fas.org/man/gao/nsiad98001/ns98001.pdf |date=18 October 2011}}</ref> or 85–90 aircraft of different types, but current numbers are typically 64 aircraft. Although the air wings are integrated with the operation of the carriers they are deployed to, they are regarded as separate entities. As well as the aircrew, the air wings are also made up of support personnel involved in roles including maintenance, aircraft and ordnance handling, and emergency procedures. Each person on the flight deck wears color-coded clothing to make their role easily identifiable.<ref>{{Cite web |title=RAINBOW JERSEYS: A Guide to the color-coded wardrobe on a U.S. Navy Flight Deck |url=https://www.history.navy.mil/content/dam/nhhc/news-and-events/multimedia%20gallery/Infographics/FINAL_RainbowJerseys_highres_PDF.pdf |url-status=live |archive-url=https://web.archive.org/web/20230314105120/https://www.history.navy.mil/content/dam/nhhc/news-and-events/multimedia%20gallery/Infographics/FINAL_RainbowJerseys_highres_PDF.pdf |archive-date=2023-03-14 |access-date=2023-05-24 |publisher=[[Naval History and Heritage Command]]}}</ref>

A typical carrier air wing includes 36-48 [[Boeing F/A-18E/F Super Hornet|F/A-18E or F Super Hornet]]s as strike fighters, split between 3-4 squadrons; up to 12 [[F-35C]]s, contributed by a squadron of Navy or Marine aviation; 4–8 [[Boeing EA-18G Growler|EA-18G Growlers]] for electronic warfare; 4–6 [[E-2 Hawkeye|E-2D Hawkeyes]] for [[airborne early warning]] (AEW), 1-3 [[C-2 Greyhound]]s used for logistics (to be replaced by [[MV-22 Osprey|CMV-22 Osprey]]s); and a Helicopter Anti-Submarine Squadron of 6–8 [[SH-60 Seahawk|MH-60R and MH-60S Seahawks and 'Knighthawks']], respectively. Marine [[F/A-18C/D|F/A-18C or D Hornet]] squadrons are also sometimes deployed in place of [[Super Hornet|F/A-18E/F Super Hornet]] and/or [[Lightning|F-35C]] squadrons. Future aircraft planned for operation from ''Nimitz'' and future classes of aircraft carrier include the [[MQ-25 Stingray]], and two squadrons of [[F-35C]], replacing a [[Super Hornet|F/A-18E/F Super Hornet]] squadron. Aircraft previously operated from ''Nimitz''-class carriers include [[F-4 Phantom]]s, [[A-5 Vigilante|RA-5C Vigilante]]s, [[F-8 Crusader|RF-8G Crusader]]s, [[F-14 Tomcat]]s, [[S-3 Viking]]s, [[EA-3B Skywarrior]]s, [[EA-6B Prowler]]s, [[A-7 Corsair II]], and [[A-6E Intruder]] aircraft.<ref>Lambeth 2005, p. 89{{cite book |title=American Carrier Air Power at the Dawn of a New Century |last=Lambeth |first=Benjamin |year=2005 |publisher=RAND Corporation |isbn=0-8330-3842-7 |page=138}}</ref>

===Flight deck and aircraft facilities===
[[File:US Navy 090529-N-1062H-042 Supply and deck department Sailors transfer cargo in the hangar bay of the aircraft carrier USS George Washington (CVN 73) during a replenishment-at-sea.jpg|thumb|The hangar of ''George Washington'' during a replenishment at sea, 2009]]

The [[flight deck]] is angled at nine degrees, which allows for aircraft to be launched and recovered simultaneously. This angle of the flight deck was reduced slightly compared to previous carriers, as the current design improves the airflow around the carrier.<ref name="Friedman p316"/> Four steam [[Aircraft catapult|catapults]] are used to launch fixed-wing aircraft, and four [[arrestor wire]]s are used for recovery. The two newest carriers, ''Ronald Reagan'' and ''George H.W. Bush'', have only three arrestor wires each, as the fourth was used infrequently on earlier ships and was therefore deemed unnecessary.<ref>Polmar 2004, p. 111</ref>

This [[CATOBAR]] arrangement allows for faster launching and recovery as well as a much wider range of aircraft that can be used on board compared with smaller aircraft carriers, most of which use a simpler [[STOVL]] arrangement without catapults or arrestor wires. The ship's aircraft operations are controlled by the air boss from Primary Flight Control or Pri-Fly. Four large elevators transport aircraft between the flight deck and the hangars below. These hangars are divided into three bays by thick steel doors that are designed to restrict the spread of fire.<ref name="Fire Protection"/>

===Strike groups===
{{Main|Carrier strike group}}
[[File:George Washington Carrier Strike Group.jpg|thumb|alt=Four warships sailing alongside ''George Washington''|The ''George Washington'' carrier strike group in the [[Caribbean Sea]], 2006]]

When an aircraft carrier deploys, it takes a Carrier Strike Group (CSG), made up of several other warships and supply vessels that allow the operation to be carried out. The armament of the ''Nimitz'' class is made up only of short-range defensive weapons, used as a last line of defense against enemy missiles and aircraft. As with all surface ships, an aircraft carrier is particularly vulnerable to attack from below, specifically from submarines. An aircraft carrier is a very expensive, hard to replace, and strategically valuable asset, and therefore it logically has immense value as a target.<ref name="Stevens, p. 24">Stevens 1998, p. 24</ref>

As a result of its target value and vulnerability, aircraft carriers are always escorted by at least one submarine for protection. The other vessels in the Strike Group provide additional capabilities, such as long-range [[Tomahawk (missile family)|Tomahawk]] missiles or the [[Aegis Combat System]], and protect the carrier from attack. A typical Strike Group may include, in addition to an aircraft carrier: up to six [[surface combatant]]s, including [[guided-missile cruiser]]s and [[guided-missile destroyer]]s, used primarily for [[anti-aircraft warfare]] and anti-submarine warfare, and [[frigate]]s/[[guided-missile frigate]]s, prior to their retirement from USN service. Guided missile frigates will again accompany CSGs when the Navy commissions the [[USS Constellation (FFG-62)]], the lead ship of the [[Constellation-class frigate|Constellation-class]].{{cn|date=March 2025}} Also making up part of the group is one or two [[attack submarine]]s for seeking out and destroying hostile surface ships and submarines and an [[Fast combat support ship|ammunition, oiler, and supply ship]] from [[Military Sealift Command]] to provide logistical support.<ref name="Stevens, p. 24"/> The numbers and types of vessels that make up each strike group can vary from group to group, depending on deployments, mission, and availability.<ref>Polmar 2004, p. 37</ref>

===Design differences within the class===
While the designs of the last seven ships, beginning with ''Theodore Roosevelt'', differ slightly from those of the earlier ships, the U.S. Navy considers all ten carriers a single class.<ref name="Navy.mil CVN"/> When the older carriers come in for [[Refueling and Complex Overhaul]] (RCOH), their nuclear power plants are refueled, and they are upgraded to the standards of the later carriers. Other modifications may be performed to update the ships' equipment.<ref name="Navy.mil CVN"/><ref name='NorthropGrumman-Refueling and Complex Overhaul'>{{cite web|title=Refueling and Complex Overhaul|publisher=[[Northrop Grumman Shipbuilding]]|url=http://www.sb.northropgrumman.com/products/acfleetservices/|access-date=19 April 2008}}{{dead link|date=February 2018 |bot=InternetArchiveBot |fix-attempted=yes}}</ref>

The ships were initially classified only as attack carriers but have been constructed with anti-submarine capabilities since ''Carl Vinson''. These improvements include more advanced radar systems and facilities enabling the ships to operate aircraft in a more effective anti-submarine warfare role, including fitting common undersea picture (CUP) technology, which uses [[sonar]] to allow for better assessment of the threat from submarines.<ref name="ASW"/>

''Theodore Roosevelt'' and later carriers have slight structural differences from the earlier ''Nimitz'' carriers, such as improved protection for ordnance stored in their [[Magazine (artillery)|magazines]]. Other improvements include upgraded flight deck ballistic protection, first installed on ''George Washington'', and the [[high-strength low-alloy steel]] (HSLA-100) used for constructing ships starting with ''John C. Stennis''.<ref name="Polmar 113"/><ref>{{cite web |url=http://www.defenseindustrydaily.com/costing-the-cvn21-a-did-primer-01624/ |title=Costing the CVN-21: A DID Primer |date=19 December 2005 |publisher=Defense Industry Daily |access-date=27 December 2009}}</ref> More recently, older ships have had their flight decks upgraded with a new non-slip material fitted on new-build ships to improve safety for crew members and aircraft.<ref>{{cite web |url=http://www.surfacetechnologiescorp.com/projects/USS-Nimitz/ |title=USS Nimitz Flight Deck |publisher=Surface Technologies Corporation |access-date=2 January 2010 |archive-url=https://web.archive.org/web/20090731113036/http://surfacetechnologiescorp.com/projects/USS-Nimitz/ |archive-date=31 July 2009 |url-status=live}}</ref><ref>{{cite web |url=http://www.navy.mil/search/display.asp?story_id=51351 |title=Truman Flight Deck Receives New Non-Skid |author=Lt. Katharine Cerezo |date=20 February 2010 |publisher=U.S. Navy |access-date=13 March 2010 |archive-url=https://web.archive.org/web/20100722085105/http://www.navy.mil/search/display.asp?story_id=51351 |archive-date=22 July 2010 |url-status=dead}}</ref>

The last carrier of the class, ''George H.W. Bush'', was designed as a "transition ship" from the ''Nimitz'' class to the replacement {{sclass|Gerald R. Ford|aircraft carrier|4}}. ''George H.W. Bush'' incorporates new technologies, including improved propeller and bulbous bow designs, a reduced [[radar cross-section]], and electronic and environmental upgrades.<ref>{{cite web|url=http://www.irconnect.com/noc/press/pages/news_releases.html?d=165151|title=Press Release|publisher=[[Northrop Grumman Shipbuilding]]|date=11 May 2009|access-date=27 March 2010|archive-url=https://web.archive.org/web/20090521131119/http://www.irconnect.com/noc/press/pages/news_releases.html?d=165151|archive-date=21 May 2009|url-status=live}}</ref><ref>{{cite web|url=http://www.sb.northropgrumman.com/bush/design_enhancements.html |title=Design Enhancements |publisher=Northrop Grumman Shipbuilding |access-date=28 May 2010 |url-status=dead |archive-url=https://web.archive.org/web/20091113050807/http://www.sb.northropgrumman.com/bush/design_enhancements.html |archive-date=13 November 2009}}</ref> The ship's cost was $6.2&nbsp;billion. The earlier ''Nimitz''-class ships each cost around $4.5&nbsp;billion.<ref>{{cite web |url=http://www.foxnews.com/story/0,2933,479087,00.html |title=Aircraft Carrier Named the USS George H.W. Bush Commissioned |date=10 January 2009 |publisher=[[Fox News Channel]] |access-date=14 January 2010 |archive-url=https://web.archive.org/web/20121021164246/http://www.foxnews.com/story/0,2933,479087,00.html |archive-date=21 October 2012 |url-status=dead |df=dmy-all}}</ref> To lower costs, some new technologies and design features were also incorporated into USS ''Ronald Reagan'', the previous carrier, including a redesigned [[Flight deck#Full length|island]].<ref>{{cite web |url=http://www.sb.northropgrumman.com/Reagan/About_the_Christening/Media%20Link/reagan_press_kit.pdf |title=Ronald Reagan (CVN 76) Christening: Advanced Media Kit |publisher=Northrop Grumman Shipbuilding |access-date=27 December 2009}}{{dead link|date=February 2018 |bot=InternetArchiveBot |fix-attempted=yes}}</ref>