What's a Railgun?

(Image credit: U.S. Navy's Office of Naval Research (ONR))

What's literally faster than a speeding bullet and more powerful than a locomotive? A railgun a technology that launches projectiles with such power that it ignites the air around it.

A gun launch system that uses electricity and magnetic force to fire world record-breaking shots, the railgun's technology was originally designed to arm ships with long-range kinetic energy warheads while eliminating the hazards of high explosives.

The electromagnetic railgun, which is described as a game-changing war-fighting and disruptive technology by the U.S. Navy's Office of Naval Research (ONR), made history on Dec. 10 when it released a 33-megajoule shot at the Naval Surface Warfare Center Dahlgren Division.

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The 33-megajoule shot means the Navy can fire projectiles at least 110 nautical miles, placing sailors and marines at a safe standoff distance and out of harm's way, and the high velocities achievable are tactically relevant for air and missile defense, said chief of naval research Rear Admiral Nevin Carr in an ONR press statement. This demonstration moves us one day closer to getting this advanced capability to sea.

A megajoule is used to measure the velocity at which mass travels. For example, a 2,240-pound (one-ton) vehicle moving at 100 miles per hour equals one megajoule of energy. That means the railgun's 33-megajoule shot gives off enough energy to move 33 cars at 100 mph. [Watch the railgun in action.]

The railgun circuit is battery-powered and consists of a movable conductor atop two conducting rails in a magnetic field . To fire a projectile, an electric pulse is sent to the railgun, which creates an electromagnetic force that accelerates the projectile to a record-breaking Mach 7.5 speed seven-and-a-half times the speed of sound.

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Remy Melina was a staff writer for Live Science from 2010 to 2012. She holds a bachelor’s degree in Communication from Hofstra University where she graduated with honors.