Key Points – The Montana-class, planned as the US Navy’s ultimate battleships and successors to the Iowa class, were authorized in the early 1940s but never built.
-Designed to be significantly larger and more heavily armed, with twelve 16-inch guns (three more than Iowas) and superior armor capable of withstanding comparable firepower, they sacrificed some speed (28 knots vs. Iowa’s 33).
-However, the strategic shift during World War II towards aircraft carrier dominance led to the cancellation of all five planned Montana-class battleships before any keels were laid, prioritizing Essex-class carriers and continued Iowa-class production instead.
Monatana-Class: A Battleship Like No Other
The Montana-class battleship was a planned class for the United States Navy, intended as the successor to the Iowa class authorized under the 1940 “Two Ocean Navy” building program and funded in Fiscal Year 1941. These battleships were the last of their kind ordered by the US Navy.
They were better armored and operated with superior firepower but were slower. Five were approved for construction during World War II. The program was later canceled to continue production of Essex-class aircraft carriers and Iowa-class battleships before any Montana-class keels were laid.
The Montana-Class Battleships, Firepower Incarnate
With a planned displacement of 60,500 tons (70,000 tons fully loaded), each would have been nearly a third larger than the preceding Iowa class—the final battleships actually completed by the United States.
The ships were to be 903 feet long, with a 121-foot beam and a 36-foot draft. The Montana would have seen the displacement rise to over 72,00 tons with a full load.
The Montanas were to carry twelve 16-inch (406 mm)/50 caliber Mark 7 guns, three more than the earlier Iowa class. They were carried in four three-gun turrets. Secondary armament was also improved.
Twenty 5-inch (127 mm)/54 cal Mark 16 dual-purpose guns housed in ten two-gun turrets along the superstructure. These guns, designed for the Montana class, were intended to improve the effective range over the shorter-barreled 38 caliber Mark 12 guns in service.
From Dr. Brent Eastwood, “The Montana, Ohio, Maine, New Hampshire, and Louisiana would have boasted 25 percent more firepower than the already lethal main battery of the Iowa class.”
Each Montana-class battleship would have carried an anti-aircraft armament of thirty-two 40 mm (1.6 in) Bofors guns and twenty 20 mm (0.79 in) Oerlikon guns. The Bofors guns would be carried in eight quadruple mounts, while the Oerlikon would have been mounted individually.
However, the number of Bofors and Oerlikon mounts would have increased considerably had the ships been built since the design was completed before the carrier threat was fully realized.
Each battleship could carry three floatplanes, which would have been launched with two aft catapults. The aircraft would have been used for reconnaissance and gunnery spotting.
Armor Protection
Protection against underwater weapons and shellfire was also greatly enhanced. They would have been the only new World War II-era U.S. battleships to be adequately armored against guns of the same power as their own. The armor was 22.5 inches at its thickest.
Propulsion
The Montana-class was designed for a slower maximum speed than the swift Iowa-class to achieve these advances in armament and armor. For propulsion, the vessel would have relied on eight Babcock & Wilcox water-tube boilers, good for 172,000 horsepower, which would have turned four screw propellers. Behind the two inboard screws, the Montana would have featured two rudders.
Curiously, the much heavier Montana-class would have been less powerful than the 212,000 horsepower of the Iowa-class—however, the Montana class design allowed for more subdivided machinery spaces. The top speed was expected to be around 28 knots, and the range was 15,000 nautical miles.
Myths About the Montana-class Battleships
Many myths about the Montana class abound that the Navy has tried to put to bed, but they persist. A few of the myths follow. She was just a stretched Iowa-class with an extra gun turret. She was a ship designed to be a Yamato killer.
And don’t forget the Panama Canal story. The Montana-class Ignored the Panama Canal Restrictions. Right? Wrong, kinda. The US had plans to expand the Panama Canal locks to 140ft. Construction was meant to be completed around the same time the Montana ships came into service.
However, there was a requirement that ships had to fit under the Brooklyn Bridge to get to the New York Navy Yard. That IS true.
As to the Yamato story, at the time of the Montana-class’ design in 1939, no one in US intelligence believed that the Yamato was anything but a normal-sized battleship. That realization didn’t come until the war had already started.
The design was not an elongated Iowa-class battleship. While the two shared the same main gun, the Montana-class carried a much more powerful secondary armament. The Montana-class would have carried a more powerful 5″/54 model rather than the older 5″/38.
Firing a heavier shell at a higher velocity, the Montana-class would have enjoyed much greater anti-surface firepower than the Iowa-class.
The armor on the Montana-class was much improved. It was designed to go toe-to-toe with heavily armed battlewagons.
Would it have been the best battleship ever built? Most definitely. But the timing was off a bit. The era of the battleship was ending just as she was being designed.
About the Author:
Steve Balestrieri is a National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing on defense, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in other military publications.
Fighter Jet Fails
Greg Hollkier
May 27, 2025 at 7:58 pm
I believe that the Montana Class would have carried 18-inch guns instead of the 16-inch guns mentioned in the article. Please correct if I am wrong