Key Points and Summary – This piece explores a great naval “what if”: a gun duel between America’s never-built Montana-class battleships and Japan’s Yamato-class behemoths.
-Designed as larger, better-armored successors to the Iowas, the Montanas would have packed twelve 16-inch guns, heavy belt armor, and powerful engines for 28-knot speeds.
Yamato-Class Battleship. Image Credit: Creative Commons.
Yamato’s 18.1-inch guns and massive armor promised brutal hitting power and survivability.
-Yet U.S. advantages in fire control, rate of fire, crew training, and maneuverability likely would have tipped the balance.
-While carriers rendered such clashes obsolete and Montana was canceled, the article argues a Montana–Yamato showdown would probably have ended in an American win.
Montana vs. Yamato: The Battleship Duel That Never Happened
Online forums for alternative naval history are prevalent, and one question has armchair admirals wondering if a showdown between two giant classes of battleships – the American Montanas and the Japanese Yamatos – would have happened in a counterfactual historical battle.
The Montana-class battleships were designed to be huge – the largest vessels ever produced by the Navy. They were going to be bigger than even the Iowa-class of gargantuan dreadnoughts. The Montana-class would have a death-defying 12 super-strong 16-inch guns that could blast the enemy out of the water or devastatingly shell landing zones to prep for an amphibious operation.
The Montana-class Had an Ample Amount of Potential
The Montana-class would also have heavier armor to promote better survivability than the Iowa-class.
Montana-Class Battleship. Image Credit: Creative Commons.
This was going to be a valuable group of battleships. They were to be built specifically to answer Japan’s Yamato-class of battleships.
But the Montana-class was cancelled in 1943 in favor of producing more aircraft carriers, which were to become the decisive vessels in the Pacific theater in World War II.
Carriers were seen as more valuable and focused, with the ability to move a floating airport into position to attack the enemy as a better representation of modern (for the day) naval combat.
Montana-class Battleships Were Going to Be Gigantic
The Montana-class vessel would be a mighty 921 feet long. These would have been 59 feet longer than the Yamato-class “super battleships.” The Montana-class was going to be wider than the Iowa-class with a 121-foot beam compared to the 108-foot beam for the Iowas.
The Montana-class would displace nearly 71,000 tons with a full combat load. This displacement was almost as significant as the Yamato-class.
The Montana-class would be fast with a top speed of 28 knots, perfect for escorting the newer carriers. The steam turbines produced a total of 172,000 horsepower.
The Guns Were Out of This World
The Iowa-class battleships were equipped with nine Mark 7 16-inch, 50-caliber guns, mounted in three turrets of three guns each. The Montanas would use this same weapons configuration, but would add another turret of three guns at the aft of the ship. These could be fired at a rate of one round every two minutes. The Montana-class had 25 percent more guns than the Iowa-class, and that would have given the Yamato-class trouble.
The Montana-class also featured the Mark 16 5-inch dual-purpose gun. Twenty were on board for maximum firepower. These had larger 54-caliber barrels than the 38-caliber barrels of the Iowa-class.
The Montana-class also had two 40mm Bofors guns and twenty 20mm Oerlikon guns. These were effective anti-air weapons.
The Armor Was Top-Notch Too
Since the Montana-class was built for battleship-on-battleship showdowns, armor was improved, which included a 16.1 inch belt of steel protecting the hull, augmented by a one-inch layer of purpose-built advanced steel.
USS Iowa Battleship Guns. Image Credit: National Security Journal.
The Yamatos Were Also Heavily Armed
But the Yamato-class had the biggest guns ever built. They featured the 18.1-inch/45-caliber cannons that could do a number on enemy ships and ground positions. The Yamato-class also had modern and thick armor that would prevent many rooms from flooding and could take a powerful hit from another battleship like the Iowa-class or the Montana-class.
Yamato and Musashi were constructed mostly in secret to keep the United States from discovering information about their strength and prowess. Workers fashioned the steel carefull,y knowing that the battleships could one day rule the seas.
One advantage the Yamato-class had was the power in its shells. The guns fired 3,200-pound armor-piercing rounds that were designed to do a number on the Iowa-class. The shells could start a fire and ignite the magazine on enemy warships, and cause the blaze to maim and kill the sailors.
The match-up between the Yamato-class and Montana-class would have come down to the skills of individual sailors and the efficacy of the guns. Whichever vessel could fire rapidly and accurately to turn the other ship into a hulking ruin would win.
Both the Japanese and Americans were experienced at the latter stages of the war, but U.S. Navy personnel were better trained and more skilled, with higher morale.
The Yamato-class had great armor, though, likely the best protection of the war, and the battleships would be difficult to sink. The Montana-class had the disadvantage of its armor, but American shipyards were improving at designing the most protective layouts in the history of the U.S. Navy.
The Yamato-class was a shade slower than the Montana-class and less maneuverable. The Montana-class would have been more challenging to target with the massive guns, as it would have made more evasive maneuvers.
Image from the deck of USS Iowa taken by Harry J. Kazianis back in August, 2025. National Security Journal Image. All Rights Reserved.
Firing solutions would have been set first by the Yamato-class, but as the guns began to fire, the Montana-class would have moved just far enough to keep the Japanese shells from hitting the targets that had the least resistance to the armor-piercing rounds.
The Montanas also had advanced fire-control systems that could fire more shells at a faster rate than the Yamatos. This was likely the best advantage in a gunfight.
Both classes of battleships would have caused significant damage.
However, the Montana-class was never built.
Meanwhile, the Yamato and Musashi did not make much of a difference in the war.
They both mainly served on escort duty. The Yamato finally fired its big guns at shore targets in the Battle of Leyte Gulf in October 1944. In 1945, the Yamato was sent on a suicide mission with no air cover to Okinawa and sunk by U.S. Navy carrier wing aircraft, with most hands lost.
We’ll never know the outcome of a Montana-class versus the Yamato-class as ship-on-ship combat became rare toward the end of the war, but my money would have been on the Montana-class for its greater seamanship and rapid rate of fire.
This would have been a fight to the death, likely a sea battle unlike any other in history.
The showdown would have caused much damage, but the Montana-class would have come out on top in the end.
About the Author: Brent M. Eastwood
Author of now over 3,000 articles on defense issues, Brent M. Eastwood, PhD is the author of Don’t Turn Your Back On the World: a Conservative Foreign Policy and Humans, Machines, and Data: Future Trends in Warfare plus two other books. Brent was the founder and CEO of a tech firm that predicted world events using artificial intelligence. He served as a legislative fellow for US Senator Tim Scott and advised the senator on defense and foreign policy issues. He has taught at American University, George Washington University, and George Mason University. Brent is a former US Army Infantry officer. He can be followed on X @BMEastwood.
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