The US Navy has handed out a $12m contract to Texan academics to carry out research into electromagnetic hypervelocity railguns.

According to the Pentagon contracts feed:

The Institute of Advanced Technology at the University of Texas, Austin [will] perform railgun assessment including laboratory testing and scalability between small and medium scale launcher, pulsed power assessment and conceptual prototyping and assessment of electromagnetic railgun contractor development items including advanced containment launcher and pulsed power systems.

Railguns work by driving a conductive armature down a pair of rails, with heavy electric current flowing through the armature from one rail to another. This generates magnetic forces which push the armature along the rails. The armature may be the projectile itself, may be attached to it, or may merely be a driving sabot intended to drop off after clearing the end of the gun "barrel".

The advantage of a railgun is that it can potentially deliver much higher muzzle velocity than a normal chemically-powered cannon. This could offer the prospect of guns able to throw their hypersonic shells hundreds of miles. As the incoming projectiles would still be moving at many times the speed of sound at impact, they would also be very hard to defend against.

One of the very few sorts of battle machinery where the necessary amounts of 'leccy might be available will be the next generation of warships, which are expected to use electrical transmissions in their propulsion. Thus one can see why it's the US Navy - not the air force or someone - pushing this technology. Railguns able to deliver unstoppable hypersonic strikes from afar, perhaps also able to pick merely-supersonic missiles or planes out of the sky with ease, might also restore the surface warship to its lost dominion over the seas.

There would also be logistic benefits: instead of needing to ship dangerous explosive warheads and gun propellants about, all the supply chain would have to handle would be inert projectiles and fuel for the ship's engines.

For now, though, the best the Office of Naval Research has been able to achieve is an admittedly-impressive ten megajoule laboratory test shot (vid above). The ONR wants to see 64 MJ before actually looking to put anything into service.

Then there are other problems: existing launch rails only last three or four shots, and squashing down a steady supply from a ship's engines into ultra-brief 64 megajoule pulses* isn't a simple matter.

This is presumably where the Texas Uni boffins come in. ®

Bootnote

*The proposed Zumwalt-class destroyers, cancelled last year, were to have used 80 megawatt gas turbine prime movers and electric drives. If fitted with ONR's desired 64-MJ railguns, they could theoretically get off a bit better than one round per second; though this would leave no juice left for propulsion.

At the other end of the spectrum, a Nimitz-class supercarrier has twin 550-megawatt nuclear reactors. A railgun dreadnought built to the same outrageous scale would be able to ripple off 15 irresistible Mach-7 thunderbolts every second and still maintain steerage way.

Personally we'd rather see the USN (or someone, anyway) building space battlecruisers: but the concept has a certain baroque appeal.