Pentagon Unveils Futuristic New 'Railgun' The weapon's projectiles hit like 'a freight train': official By Neal Colgrass, Newser Staff Posted Feb 6, 2015 4:20 PM CST 79 comments Comments In this Jan. 28, 2007 photo, a test slug impacts the target after being fired from the Electromagnetic Railgun laboratory launcher, or railgun at the Naval Surface Warfare Center, in Dahlgren, Va. (AP Photo/U.S. Navy, John F. Williams) (Newser) – The Navy's latest weapon is an electromagnetic "railgun" designed to fire projectiles fast and far without using gunpowder as a propellant, the Washington Post reports. Unveiled at a Navy expo this week, the weapon uses electromagnetic impulses to shoot projectiles at up to seven times the speed of sound, creating a force so powerful that no explosive warheads are needed. The impact is like "a freight train going through a wall at a hundred miles an hour," says a top Navy official. It's also far cheaper than other missile engagement systems, and should reduce risk on surface ships because explosives aren't required, Fox News reports. How it works: The railgun draws electricity from a ship and fires projectiles using electromagnetic energy. Under the hood, a sliding metal conductor accelerated by an electrical current runs along the weapon's two metal rails, charging up magnetic fields that fire projectiles. But the gun requires 34 mega joules of power to launch a single 23-pound projectile more than 100 miles at Mach 7, and most destroyers don't have that kind of power in reserve yet, the Navy Times reports. What's more, engineers will need months or even years to link the railgun to the combat system on cruisers and destroyers. The Navy plans to give the weapon its first sea-test next year. The Navy's other cool new toy is a laser that it fired from a vessel for the first time in December.