Montana-class battleship

A model of a Montana-class battleship, 1944
Class overview
Name	Montana-class battleship
Builders	New York Naval Shipyard Philadelphia Naval Shipyard Norfolk Naval Shipyard
Operators	United States Navy
Preceded by	Iowa class
Succeeded by	None
Planned	5
Completed	0
Cancelled	5
General characteristics (Design BB67-4)
Type	Fast battleship
Displacement	Standard: 63,221 long tons (64,240 t) Full load: 70,965 long tons (72,104 t)
Length	921 ft 3 in (280.8 m) loa
Beam	121 ft 2 in (36.9 m)
Draft	36 ft (11 m)
Installed power	8 × Babcock & Wilcox water-tube boilers 172,000 hp (128 MW)
Propulsion	4 × geared steam turbines 4 × screw propellers
Speed	28 knots (32 mph; 52 km/h) maximum
Range	15,000 nmi (17,300 mi; 27,800 km) at 15 kn (17 mph; 28 km/h)
Complement	Standard: 2,355 Flagship: 2,789
Armament	12 × 16 in (406 mm)/50 cal Mk 7 guns 20 × 5 in (127 mm)/54 cal Mark 16 guns 10–40 × Bofors 40 mm (1.6 in) anti-aircraft guns 56 × Oerlikon 20 mm (0.79 in) anti-aircraft cannon
Armor	Main belt: 16.1 inches (409 mm) Bulkheads: 18 inches (457 mm) forward, 15.25 inches (387 mm) aft Barbettes: 21.3 inches (541 mm), 18 inches (457 mm) aft Turret face: 22.5 inches (572 mm) Main deck: 7.05–7.35 inches (179–187 mm)
Aircraft carried	3 × floatplanes
Aviation facilities	2 × aft catapults for launch of seaplanes

The Montana-class battleships were planned as successors of the Iowa class for the United States Navy, to be slower but larger, better armored, and with superior firepower. Five were approved for construction during World War II, but changes in wartime building priorities resulted in their cancellation in favor of continuing production of Essex-class aircraft carriers and Iowa-class battleships before any Montana-class keels were laid.

Their intended armament would have been twelve 16-inch (406 mm) Mark 7 guns in four 3-gun turrets, up from the nine Mark 7 guns in three turrets used by the Iowa class. Unlike the three preceding classes of battleships, the Montana class was designed without any restrictions from treaty limitations. With an increased anti-aircraft capability and substantially thicker armor in all areas, the Montanas would have been the largest, best-protected, and most heavily armed US battleships ever. They also would have been the only class to rival the Empire of Japan's Yamato-class battleships in terms of displacement.

Preliminary design work for the Montana class began before the US entry into World War II. The first two vessels were approved by Congress in 1939 following the passage of the Naval Act of 1938. The Japanese attack on Pearl Harbor delayed the construction of the Montana class. The success of carrier combat at the Battle of the Coral Sea and, to a greater extent, the Battle of Midway, diminished the perceived value of the battleship. Consequently, the US Navy chose to cancel the Montana class in favor of more urgently needed aircraft carriers as well as amphibious and anti-submarine vessels.

Because the Iowas were far enough along in construction and urgently needed to operate alongside the new Essex-class aircraft carriers, their orders were retained, making them the last US Navy battleships to be commissioned.