Zumwalt-class destroyer

USS Zumwalt sailing in 2016
Class overview
Name	Zumwalt class
Builders	Bath Iron Works, Ingalls Shipbuilding
Operators	United States Navy
Preceded by	Arleigh Burke class
Succeeded by	Arleigh Burke class Flight III DDG(X)
Cost	$22.5 billion program cost (FY15)[1] $4.24B per unit (excl R&D) as of 2016[2]
In commission	15 October 2016[3]
Planned	32
Completed	3
Cancelled	29
Active	2
General characteristics
Type	Guided-missile destroyer
Displacement	15,656 long tons (15,907 t)[4]
Length	610 ft (190 m)[4]
Beam	80.7 ft (24.6 m)
Draft	27.6 ft (8.4 m)
Propulsion	2 × Rolls-Royce MT30 gas turbines (35.4 MW (47,500 hp) each)[5] driving Curtiss-Wright electric generators[6] 2 × Rolls-Royce RR4500 turbine generators (3.8 MW (5,100 hp) each)[5] 2 × propellers driven by electric motors Total: 78 MW (105,000 shp)[5]
Speed	30 kn (56 km/h; 35 mph)[4]
Complement	147 +28 in air detachment[4]
Sensors and processing systems	AN/SPY-3 Multi-Function Radar (MFR) (X band active electronically scanned array)[7]
Armament	20 × Mk 57 VLS modules, 4 cells per module, 80 launch cells total[8] Each cell can contain: 4 × RIM-162 Evolved SeaSparrow Missiles, 1 × Tomahawk, 1 x SM-6, or 1 × RUM-139 vertical launch anti-submarine rocket 2 × 155 mm (6 in)/62 caliber Advanced Gun System (functionally inoperable; only a nominal ammunition supply exists)[9][10] 2 × 30 mm (1.2 in) Mk 46 Mod 2 Gun Weapon System[11]
Aircraft carried	1 × MH-60R helicopter 3 × MQ-8 Fire Scout VT-UAVs[4]
Aviation facilities	Flight deck and enclosed hangar for up to two medium-lift helicopters

The Zumwalt-class destroyer is a class of three United States Navy guided-missile destroyers designed as multi-mission stealth ships with a focus on land attack. The class was designed with a primary role of naval gunfire support and secondary roles of surface warfare and anti-aircraft warfare. The class design emerged from the DD-21 "land attack destroyer" program as "DD(X)" and was intended to take the role of battleships in meeting a congressional mandate for naval fire support.^[12] The ship is designed around its two Advanced Gun Systems (AGS), turrets with 920 round magazines, and unique Long Range Land Attack Projectile (LRLAP) ammunition.^[9] LRLAP procurement was canceled, rendering the guns unusable,^[9] so the Navy re-purposed the ships for surface warfare.^[13] Starting in 2023, the Navy will remove the AGS from the ships and replace them with hypersonic missiles.^[14]

The ships are classed as destroyers, but they are much larger than any other active destroyers or cruisers in the U.S. Navy.^[15] The vessels' distinctive appearance results from the design requirement for a low radar cross-section (RCS). The Zumwalt class has a wave-piercing tumblehome hull form whose sides slope inward above the waterline, dramatically reducing RCS by returning much less energy than a conventional flare hull form.

The class has an integrated electric propulsion (IEP) system that can send electricity from its turbo-generators to the electric drive motors or weapons, the Total Ship Computing Environment Infrastructure (TSCEI), automated fire-fighting systems, and automated piping rupture isolation.^[16] The class is designed to require a smaller crew and to be less expensive to operate than comparable warships.

The lead ship is named Zumwalt for Admiral Elmo Zumwalt and carries the hull number DDG 1000. Originally, 32 ships were planned, with $9.6 billion research and development costs spread across the class. As costs overran estimates, the number was reduced to 24, then to 7; finally, in July 2008, the Navy requested that Congress stop procuring Zumwalts and revert to building more Arleigh Burke destroyers. Only three Zumwalts were ultimately built. The average costs of construction accordingly increased, to $4.24 billion,^{[1][17][18][2]} well exceeding the per-unit cost of a nuclear-powered Virginia-class submarine ($2.688 billion),^[19][20] and with the program's large development costs now attributable to only three ships, rather than the 32 originally planned, the total program cost per ship jumped. In April 2016 the total program cost was $22.5 billion,^[2] $7.5 billion per ship. The per-ship increases triggered a Nunn–McCurdy Amendment breach.^[21]