The Montana-class battleships were the final grand vision in an era when naval supremacy was characterized by big belts of steel and the roar of enormous cannons. Designed to exceed even the iconic Iowa class, they would have had heavier armor and much more firepower. On paper, they were the epitome of American battleship design, but they never moved beyond blueprints. By the time they were planned, the world had turned in a very different direction toward an entirely different concept of naval warfare.
International naval treaties dominated much of the early 20th century by imposing strict controls on battleship size, firepower, and displacement. The Montana class was intended to escape all those constraints altogether.
At a beam of 121 feet, they would have been too wide to fit through the original Panama Canal locks, so plans were considered to expand the canal to allow them to pass through. Their size indicated the Navy’s desire to construct ships that focused exclusively on protection and firepower at the cost of the speed of the Iowa class.
The project was initiated before U.S. involvement in World War II, as Congress authorized the initial two ships in 1939. In line with custom, the design emphasized resistance and shock power more than anything else.
If finished, they would have had the most extensive armor ever installed on an American battleship, to resist the deadly 2,700-pound Mark 8 “superheavy” shells—ammunition that previous classes were not designed to fight against.
The Montanas would have worn an armor belt over sixteen inches thick, sloped to add to the resistance, with a second belt worn underneath to resist dive shells intended to go below the waterline. On top, the decks were multicapped to take punishment from plunging naval fire as well as armor-piercing bombs.
The turrets themselves were constructed as fortresses, having faces over twenty-two inches thick and barbettes of up to twenty-one inches, and were the most heavily armored in U.S. naval history.
The defensive design went below the waterline, too. A four-layer torpedo protection system alternated between liquid-filled and air-filled compartments to absorb and spread the energy of underwater explosions.
It was one of the most thorough systems in its era, designed to make sure that the ship was able to absorb a hit and continue firing. In every detail, the Montana class was designed to be a warship capable of withstanding punishing damage while continuing to fire overwhelming levels of firepower.
Despite all promises, these behemoths were never constructed. As the Second World War advanced, priorities turned towards aircraft carriers and fast battleships capable of keeping up with them. The Montanas, too slow for carrier task forces and too costly at a time of pressing requirements, were left in the dust.
They exist as designs on paper, a vision of steel and might that never touched the sea. Today, they remain as a reminder of the day battleship supremacy peaked, just ahead of the world shifting into the new era of naval warfare.