A First Look at America’s Supergun

A First Look at America’s Supergun, by .

The weapon is called a railgun and requires neither gunpowder nor explosive. It is powered by electromagnetic rails that accelerate a hardened projectile to staggering velocity…

The railgun projectile … gains speed as it travels the length of a 32-foot barrel, exiting the muzzle at 4,500 miles an hour, or more than a mile a second.

“This is going to change the way we fight,” said U.S. Navy Adm. Mat Winter, the head of the Office of Naval Research. The Navy developed the railgun as a potent offensive weapon to blow holes in enemy ships, destroy tanks and level terrorist camps. The weapon system has the attention of top Pentagon officials also interested in its potential to knock enemy missiles out of the sky more inexpensively and in greater numbers than current missile-defense systems — perhaps within a decade. …

Wires splay out the back of the railgun, which requires a power plant that generates 25 megawatts—enough electricity to power 18,750 homes. … The railgun faces many technical barriers before it is battle ready.

The age of the gun faded after World War II, hampered by the limited range and accuracy of gunpowder weapons. Missiles and jet fighters dominated the Cold War years, prompting the Navy to retire its big-gun battleships. The railgun—and its newly developed projectiles—could launch a new generation of the vessels.

“Part of the reason we moved away from big guns is the chemistry and the physics of getting the range,” said Jerry DeMuro, the chief executive of BAE Systems, a railgun developer. “The railgun can create the kind of massive effect you want without chemistry.”

The Navy’s current 6-inch guns have a range of 15 miles. The 16-inch guns of mothballed World War II-era battleships could fire a distance of 24 miles and penetrate 30 feet of concrete. In contrast, the railgun has a range of 125 miles, officials said, and five times the impact.

“Anytime you have a projectile screaming in at extremely high speeds — kilometers per second — the sheer kinetic energy of that projectile is awesome,” Mr. Work said. “There are not a lot of things that can stop it.”