Kamis, 14 Juni 2012



The concept of the railgun has been around since the early 1900s, when a French inventor patented a design for his "electric apparatus for propelling projectiles." It's basically a linear motor in which two parallel rails are connected to a power supply, upon which is placed a conductive projectile that acts as an armature. This completes the circuit, resulting in a powerful Lorentz force that propels the projectile along the rails and sends it toward a target. Railguns are promising as weapons because the projectiles travel at such high velocities that they don't need to contain explosives to do serious damage.

They have a few practical problems, however, as they eat up a lot of current and generate huge amounts of heat. Plus, the rails tend to disintegrate quickly. Early models essentially self-destructed in the process of firing a single round. Nevertheless, the US Office of Naval Research (www.onr.navy.mil) has spent the better part of a decade working on designs that hold together long enough to be practical. They recently tested the first of two commercially-built models, and it looks like a major step forward. The system — built by BAE Systems (www.baesystems.com) — has been run through a series of low energy shots in preparation for upcoming full-scale testing.

 The amazing thing about this weapon is that we're talking about 32 megajoules of power which can expel large objects at speeds of 4,500 to 5,600 mph. By comparison, an M16 rifle generates a muzzle velocity of a little over 2,000 mph.) One megajoule is enough energy to toss out a one ton object at 100 mph. The Navy's short-term goal is to demonstrate a weapon that shoots a distance of 50 to 100 nautical miles. The next goal is "to develop thermal management systems for both the launcher and pulsed power to facilitate increased firing rates of up to 10 rounds per minute." To see it in action, just search for "BAE electromagnetic railgun" on YouTube. ▲