Rail Guns: An Old Idea Now Becoming A Reality

v.1.0 June, 2004

 

Source: Excerpted from www.military.com

 

SUMMARY

 

A projected naval rail gun with a 2.5km/sec muzzle velocity could deliver a guided projectile with an impact velocity of Mach 5 to targets at ranges of 250 miles, at a rate greater than 6 rounds per minute.

A test demonstrated that a rail gun projectile's kinetic energy could create a 10-foot diameter crater, 10 feet deep in solid ground, and achieve projectile penetration to 40 feet - 3 to 5 times more effective than current guns.

 

Rail gun projectiles are smaller and easier to store: a standard AGS magazine holds 1,500 rounds; a rail gun magazine could hold 10,000 rounds in the same amount of space.




 

Gunpowder, as we know it, may soon become outdated. Make way for the rail gun, a device that substitutes electromagnetic (EM) propulsion for gunpowder, with devastating results in speed and kinetic power.
 
An EM projector (i.e. rail gun) uses electrical energy to accelerate projectiles to extreme velocities. How fast? Tests conducted at the University of Canberra were able to accelerate a 16-gram projectile down a 5-meter barrel at 250,000 gravities, for a muzzle velocity of 5,900 meters per second. Loosely translated, that is an acceleration from 0 to 13,000 miles per hour in the span of 0.2 seconds.This also translates to an enormous amount of kinetic energy, at a fraction of the mass needed for a normal bullet. A quick comparison: an anti-armor projectile shot from a rail gun at 3,000 m/sec (almost twice the speed of current kinetic energy penetrators) would only need to be roughly one-fifth of the mass of a standard projectile to deliver the same amount of destructive force. Electromagnetic-power also has the advantage of stealth: Reduced logistics (rounds can have a smaller weight and volume), and the lack of chemical propellant means it will be difficult for opponents to track.

How are these impressive speeds reached? A rail gun is essentially two parallel conductive metal plates through which an electrical current is passed. This electrical current creates opposed linear magnetic fields along the axis of the rails. The projectile itself is placed between the rails, and a "driver" (armature) is placed behind the projectile. The function of the armature is to close the circuit between the two rails. When the rails are energized, a third magnetic field is created in the armature which is repulsed by the fields created in the rails, thus "driving" it down the barrel. The energy required to drive projectiles at useful velocities is enormous; peak power outputs are measured in millions of amperes.

 
 The Navy has grabbed the most press with its rail gun experiments but the Army Research Laboratory (ARL) and Lockheed Martin are developing an Electromagnetic (EM) Gun System in a two-phase program. The first phase (scheduled to conclude in 2005) is centered on a medium caliber gun demonstration, and demonstrating a single rotating power supply. During Phase II (2005-2007), EM technologies will be integrated into an armament test-bed, utilizing a large bore gun.

Fired at hyper velocities (10-100 kilometers/second), projectiles weighing a fraction of a gram have enormous destructive potential, and could be fired using the stored energy of a standard armored vehicle power plant. In addition to combat (especially anti-armor and hard target applications), EM research is also looking into using rail gun technology to deliver supplies over long distances. Launched from a 100m ramp, a 300-pound aerodynamic supply package could be "shot" over intervening terrain and remotely guided to a designated landing area. The concept is sound -- it only remains to develop the correct technology.