The Nimitz Class aircraft carriers are the largest warships ever built. With over 6,000 personnel, the carrier has a displacement of 102,000t, and a flight deck length of 332.9m. All seven nuclear-powered Nimitz class carriers have been built by Newport News Shipbuilding, based in Virginia. The Nimitz air wing consists of 74-86 aircraft. The flight deck measures 333 x 77m and is equipped with four lifts, four steam-driven catapults and four arrester wires. The carrier is capable of launching one aircraft every 20s. The nuclear-powered carrier has two General Electric pressurized water reactors driving four turbines of 260,000hp (194MW) and four shafts. There are four emergency diesels of 10,720hp (8MW). The first of class, USS Nimitz, was commissioned in 1975. The latest, USS Ronald Reagan CVN-76, was commissioned in July 2003.