US Navy in new electromagnetic railgun milestone

US Navy boffins are chuffed to announce that they have managed to fire their thousandth shot from a test electromagnetic railgun, addressing one of the most serious weaknesses of such weapons: that they tend to damage or wreck themselves after only a few shots.

"A railgun weapons system must be able to launch hundreds of projectiles and withstand extreme pressures, currents and temperatures," said Captain Paul Stewart in tinned quotes issued by the Naval Research Laboratory yesterday. "Today's firing of the one-thousandth shot demonstrates Navy researchers are steadily progressing toward achieving that goal, developing a more effective and efficient future ship combat system."

The NRL railgun in question isn't a high-powered one of the sort which might one day be a combat weapon. Such test guns, aiming for 64 megajoule muzzle energy (and so far up to 33 MJ, as seen in the vid above), still need extensive refurbishment after every shot. The more durable thousand-shot test rig operated by the NRL boasts just 1.5 MJ, up from 0.5 when it first started firing. But its technology "is directly applicable to tests at large-scale power levels," according to NRL boffin Dr Robert Meger.

The USN is interested in high-power railguns as a replacement for conventional cannon and missiles for several reasons. Firstly, a heavy railgun projectile could be shot at extremely high velocity, such that it would travel over a hundred miles and arrive still going at better than Mach 5. This would make it more or less impossible to defend against using any current technology.

Secondly, hypersonic railgun projectiles could be used at shorter, line-of-sight ranges to sweep the sky of hostile aircraft and missiles – the greatest menaces faced by surface warships today.

Taken together, these two capabilities might well restore the surface combatant warship to its old dominant status as capital ship of the fleet, rather than playing second fiddle to the aircraft carrier as it has done now for generations. You can see why large parts of the USN are interested in the idea (though one might note that electromagnetic mass-drivers are actually going into service right now aboard carriers, used for launching jets).

There's a third and by no means insignificant advantage for railguns over normal munitions, too. With a railgun there's no need to carry magazines full of propellant charges and explosive warheads: the propulsion is delivered by the ship's fuel and powerplant and the projectile delivers its energy kinetically rather than explosively. This would potentially free up space aboard ships, and make them safer and more resistant to combat damage.

Even so, and despite yesterday's thousand-shot announcement from the NRL, combat railguns don't look likely to make their debut at sea for some time yet. ®