Nimitz-class aircraft carrier

USS Nimitz (CVN-68)
Class overview
Name	Nimitz class aircraft carrier
Builders	Newport News Shipbuilding Company
Operators	United States Navy
Preceded by
Succeeded by
In commission	May 3, 1975
Planned	10
Completed	10
Active	USS Nimitz USS Dwight D. Eisenhower USS Carl Vinson USS Theodore Roosevelt USS Abraham Lincoln USS George Washington USS John C. Stennis USS Harry S. Truman USS Ronald Reagan USS George H. W. Bush
General characteristics
Displacement	Template:Nimitz class aircraft carrier displacement
Length	Overall: 1,092 feet (332.8 m) Waterline: 1,040 feet (317.0 m)
Beam	Overall: 252 ft (76.8 m) Waterline: 134 ft (40.8 m)
Draft	Maximum navigational: 37 feet (11.3 m) Limit: 41 feet (12.5 m)
Propulsion	2 × Westinghouse A4W nuclear reactors (HEU 93.5%) 4 × steam turbines 4 × shafts 260,000 shp (194 MW)
Speed	30+ knots (56+ km/h; 35+ mph)
Range	Unlimited distance; 20–25 years
Complement	Ship's company: 3,532 Air wing: 2,480
Sensors and processing systems	AN/SPS-48E 3-D air search radar AN/SPS-49(V)5 2-D air search radar AN/SPQ-9B target acquisition radar AN/SPN-46 air traffic control radars AN/SPN-43C air traffic control radar AN/SPN-41 landing aid radars 4 × Mk 91 NSSM guidance systems 4 × Mk 95 radars
Electronic warfare & decoys	AN/SLQ-32A(V)4 Countermeasures suite SLQ-25A Nixie Torpedo Countermeasures
Armament	16–24 × Sea Sparrow or NATO Sea Sparrow missiles 3 or 4 × Phalanx CIWSs or RIM-116 Rolling Airframe Missiles
Armor	Unknown
Aircraft carried	=85-90 fixed wing and helicopters

The Nimitz-class supercarriers, a line of nuclear-powered aircraft carriers in service with the United States Navy, are the largest capital ships in the world, and are considered to be a hallmark in the superpower status of the United States of America. These aircraft carriers are numbered with consecutive hull numbers starting with CVN-68. The letters CVN denote the type of ship: "CV" is the hull classification symbol for aircraft carriers, and "N" indicates nuclear-powered propulsion. The number after the CVN means that this is the 68th "CV", or large aircraft carrier.

Nimitz (CVN-68), the lead ship of the class, was commissioned on May 3, 1975. George H. W. Bush (CVN-77), the tenth and last of the class, was built by the Newport News Shipbuilding Company, and entered naval service on January 10, 2009. The George H.W. Bush is the first transition ship to the new Gerald R. Ford class, the first ship of which began construction in 2007 and will incorporate new technologies including a new multi-function radar system, Electromagnetic Aircraft Launch System (EMALS), volume search radars, an open architecture information network, and a significantly reduced crew requirement. To lower costs, some new technologies were also incorporated into the Ronald Reagan, the previous carrier to the George H.W. Bush.

By tonnage, the Nimitz-class warships are the largest aircraft carriers built so far, holding the world record for displacement of any naval war vessel. Nimitz Class Nuclear-Powered Aircraft Carriers have a displacement of 102,000t, and a flight deck length of Template:M to ft.

Design and construction

The ten Nimitz class aircraft carriers were constructed between 1968 and 2006 at Newport News Shipbuilding Company, in Newport News, Virginia. They were ordered to supplement the aircraft carriers of the Kitty Hawk class and USS Enterprise, in order to increase the size and dominance of the US Navy. In total, the construction of each ship was around US$4.5 billion each.

The design of the final seven ships (from Theodore Roosevelt) is slightly different to that of the earlier ships, although the US Navy nevertheless regards them as a single class. As the older Nimitz carriers come in for Refueling and Complex Overhaul (RCOH), they are upgraded to the standards of the latest ships.

Design

All ten Nimitz class aircraft carriers have an overall length of Template:M to ft and a maximum displacement of 98,235–104,112 tons full load. They have a beam at the waterline of Template:M to ft and the maximum width of their flight decks is 76.8–78.4 m (252 ft 0 in – 257 ft 3 in). The ships' companies can number up to 3,200, as well as an air wing of 2,480. Due to a design flaw, ships of this class have inherent lists to starboard when under combat loads that exceed the capability of their list control systems.

All ships of the class are powered by two A4W nuclear reactors with four propellor shafts, which can produce a maximum speed of over 30 knots (56 km/h) and maximum power of 260,000 bhp. As a result of the use of nuclear power, the ships are capable of operating continuously for over 20 years without refuelling, and are predicted to have a service life of over 50 years. Their annual service costs are around US$160 million each.

The ships were designed to be improvements on previous US aircraft carriers, in particular USS Enterprise and the Forrestal class supercarriers, by using a more modern design. In addition, the two reactors on Nimitz class carriers take up less space than those on the Enterprise, which uses eight, meaning there is more interior space. This, along with a more generally improved design, means that Nimitz class carriers can 90 percent more aviation fuel and 50 percent more ordnance when compared to the Forrestal class carriers. The US Navy has also stated that the carriers could withstand three times the damage sustained by the Essex class inflicted by Japanese air attacks during World War 2. The hangars an 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 US aircraft carriers since World War 2, after the fires caused by Kamikaze attacks.

The carriers were constructed, like most modern ships, by welding together pre-assembled "blocks", containing the ship's plumbing and electrical supplies, and which can weigh up to 800 tons. These are assembled in the dry-dock before the ship is fully fitted out. The Nimitz class also have bulbous bows in order to improve fuel effieciency by reducing hydrodynamic drag.

Aircraft carried

The maximum number of aircraft the carriers can accommodate is 85-90, although current numbers are closer to 64, including 48 tactical and 16 support aircraft. Aircraft currently in operation on Nimitz class carriers include: F/A-18C/D Hornet / F/A-18E/F Super Hornet, EA-18G Growler, EA-6B Prowler, E-2 Hawkeye, C-2 Greyhound, S-3 Viking, SH/HH-60 Seahawk, and T-45 Goshawk (non-combat aircraft, used only for training missions) for many missions including self defense/interception, land attack/close-air support, electronic warfare, maritime strike and air crew training. The ships have four aircraft elevators to transfer aircraft between the hangars and the flight deck.

Armament

In addition to the aircraft carried onboard, the ships also carry either three or four NATO RIM-7 Sea Sparrow missile launchers, designed for defense against aircraft and anti-ship missiles. They also carry either three or four 20 mm Phalanx CIWS missile defense cannons. The USS Ronald Reagan has none, having been armed with the RIM-116 Rolling Airframe Missile system during construction, two of which have also been installed on the Nimitz, George Washington, and the Ronald Reagan. These will be installed on the other ships as they return for Refueling Complex Overhaul (RCOH).

Service history

The first ship of the class Nimitz first deployed to the Mediterranean sea on May 3, 1975.

In order to bring the older ships up to the more modern standards of the newer ones, as well as to refuel their nuclear power plants, they undergo a Refueling Complex Overhaul (RCOH). The Nimitz was the first ship of the class to undergo her initial refueling, during a 33-month RCOH at the Newport News Shipbuilding Company in Newport News, Virginia, in 1998. The Dwight D. Eisenhower was next, completing its RCOH in 2005. The Carl Vinson began its RCOH in late 2005, and completed its post-overhaul sea trials in July 2009. The fourth of the class, the Theodore Roosevelt entered drydock in August, 2009 to begin its RCOH.

Ships

The United States Navy lists the following ships in the Nimitz class:

USS Nimitz at sea near San Diego, CA.

USS Nimitz (CVN-68)

The USS Nimitz was laid down at Newport News Shipbuilding Company, in Newport News, Virginia, on June 22, 1968. The ship was launched on May 13, 1972 and commissioned on May 3, 1975 by then president Gerald Ford. Since her construction, she has participated in a number of deployments and operations, including Operation Evening Light, Operation Desert Storm, Operation Southern Watch and Operation Iraqi Freedom. In August 1981, during a deployment in the Gulf of Sidra, near Libya, the ship was involved in the shooting down of two Libyan aircraft by two US F-14 Tomcats in what became known as the Gulf of Sidra incident.

The ship began a Refuel Complex Overhaul (RCOH) on 2 March 1998, which lasted three years, until 25 June 2001. Nimitz remains in commission, as of 2009, and is based at Naval Air Station North Island in San Diego, California.

With George Washington behind

USS Dwight D. Eisenhower (CVN-69)

The USS Dwight D. Eisenhower was laid down on August 15, 1970 and was launched on October 11, 1975. After her commissioning on October 18, 1977, the ship was initially deployed as part of the U.S. Atlantic Fleet. Other deployments and operations include Operation Eagle Claw, Operation Desert Shield and Operation Desert Storm, Operation Uphold Democracy, Operation Southern Watch, Operation Deny Flight and Operation Enduring Freedom.

The ship has undergone two complex overhauls: one between 1995 and 1997, and her RCOH between 2001 and 2005. She remains commission and is based, as of 2009, at the Naval Station Norfolk in Norfolk, Virginia.

Returning from Operation Enduring Freedom

USS Carl Vinson (CVN-70)

The USS Carl Vinson was laid down on October 11, 1975 and was launched on March 15, 1980. The ship was commissioned on March 13, 1982, and in 1983, she began an eight month deployment which would relocate her to her homeport of Naval Air Station Alameda in California. Her other deployments include Operation Southern Watch, Operation Desert Storm, Operation Desert Fox, Operation Enduring Freedom and Operation Iraqi Freedom.

Carl Vinson underwent RCOH between 2005 and 2009. She is stationed until 2010 at Naval Station Norfolk, Virginia, but it was announced in 2009 that the ship would be based at NAS North Island in San Diego as the flagship of the newly established Carrier Strike Group 1 as of 2010.

USS Theodore Roosevelt (CVN-71)

USS Theodore Roosevelt (CVN-71)

USS Theodore Roosevelt was laid down on October 31, 1981 and was launched on October 27, 1984. The ship was commissioned on October 25, 1986 and, since then, has engaged in operations and deployments including Operation Desert Shield, Operation Provide Comfort, Operation Deny Flight, Operation Southern Watch, Operation Deliberate Force, Operation Allied Force, Operation Enduring Freedom and Operation Iraqi Freedom.

Theodore Roosevelt is based as of 2009 at Naval Station Norfolk in Norfolk, Virginia and began RCOH in August 2009. The price for the ship's RCOH is reported to be US$ 2.4 billion.

In the Gulf of Alaska

USS Abraham Lincoln (CVN-72)

USS Abraham Lincoln was laid down on November 3, 1984 and was launched on February 13, 1988. The ship was commissioned on November 11, 1989 and since then, has participated in operations and deployments including Operation Desert Shield and Operation Desert Storm, Operation Fiery Vigil, Operation Southern Watch, Operation Restore Hope, Operation Vigilant Sentinel, Operation Enduring Freedom and Operation Unified Assistance. In 2006, the ship underwent a refit at Puget Sound Naval Shipyard. She remains in active service, as of 2009, and is based at Naval Station Everett in Everett, Washington.

USS George Washington

USS George Washington (CVN-73)

The USS George Washington was laid down on August 25, 1986 and was launched on July 21, 1990. The ship was commissioned on July 4, 1992 and has participated in operations including Operation Decisive Endeavor, Operation Southern Watch, Operation Enduring Freedom, Operation Iraqi Freedom and Operation Vigilant Resolve. While being transferred to her current homeport at Yokosuka Naval Base, Yokosuka, Japan, the ship suffered a serious fire which cost $70 million in repairs.

Heading home to Bremerton, WA

USS John C. Stennis (CVN-74)

USS John C. Stennis was laid down on March 13, 1991 and was launched on November 11, 1993. The ship has participated in Operation Southern Watch, Operation Enduring Freedom, Operation Iraqi Freedom and Operation Noble Eagle since her commissioning on December 9, 1995. She remains in active service and is beased at Naval Base Kitsap in Bremerton, Washington.

USS Harry S. Truman alongside oiler USNS John Lenthall (T-AO-189)

USS Harry S. Truman (CVN-75)

USS Harry S. Truman was laid down on November 29, 1993 and was launched on September 7, 1996. The ship was commissioned on and has participated in Operation Southern Watch, Operation Iraqi Freedom as well as providing aid after Hurricane Katrina. The ship underwent a dry-docked planned incremental availability (DPIA) refit throughout 2006 at Norfolk Naval Shipyard. She remains in service, based at Naval Station Norfolk in Norfolk, Virginia.

USS Ronald Reagan

USS Ronald Reagan (CVN-76)

USS Ronald Reagan was laid down on February 12, 1998 and was launched on March 4, 2001. After her commissioning on July 12, 2003, the ship departed her homeport of Naval Air Station North Island in San Diego, California on Jan. 4, 2006 on her maiden deployment to conduct naval operations in support of Operation Iraqi Freedom and Operation Enduring Freedom, as well as to conduct maritime security operations (MSO) in the Persian Gulf.

USS George H. W. Bush underway from Naval Station Norfolk.

USS George H.W. Bush (CVN-77)

The final ship of the class, USS George H.W. Bush was laid down on September 6, 2003. The ship was launched on October 9, 2006 and was commissioned on January 10, 2009. The final cost of construction was reported to have been US$6.2 billion. As of 2009, the ship is undergoing post shakedown availability (PSA) involving maintainence and training before she enters fully operational service in 2010.

Future

The ships were designed to have a fifty-year service life. The US navy are building a new class of supercarriers named the Gerald R. Ford class, the first of which is expected to enter service in 2015. These ships are intended to replace USS Enterprise, and will not immediately replace the Nimitz class, but operate alongside them.

See also

• List of aircraft carriers
• List of naval ship classes in service
• Supercarrier

External links

• Nimitz Class project page on Naval-technology.com
• GlobalSecurity article on Nimitz Class carriers
• Naval Vessel Register page for USS Nimitz