Milestone reached in Navy railgun tests

Posted by Emma Woollacott

The US Navy has completed an important step in the testing of its Electromagnetic Railgun, which uses no explosives and can potentially reach targets 20 times farther than conventional weapons.

The US Naval Research Laboratory Materials Testing Facility says it's carried out the one-thousandth successful firing of its Electromagnetic Railgun, which it hopes can be used in future on board Navy warships.

"This test demonstrates continued advances in armature development, rail design, and barrel materials used in high power railgun launch," says D. Robert Meger of the NRL.

"Firing up to 15 shots per week on the laboratory's experimental railgun, researchers at NRL perform detailed testing and analysis of rails and armatures, providing S&T expertise to the Navy program that is directly applicable to tests at large-scale power levels."

A railgun is a form of single turn linear motor. Magnetic fields generated by high currents driven in parallel conductors, or rails, accelerate a sliding conductor, known as an armature, between the rails.

One problem, though, is that at launch, the heat created by the high currents and friction, or viscous heating generated at the sliding interface, is enough to melt most metals - including the armature material.

Many of the 1,000 shots taken so far have been designed to test different barrel designs and to quantify the damage caused by this heat.

"A railgun weapons system must be able to launch hundreds of projectiles and withstand extreme pressures, currents and temperatures," says NRL commanding officer Captain Paul Stewart.
 
"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."