The Navy is researching rail guns because they would weigh less than conventional ones and — since they rely on electromagnetism rather than chemical propellants — eliminate the need for a dangerous magazine of explosives. The result: a lighter, more lethal ship. A combat-ready rail gun would fire Mach 5 projectiles over 200 miles with pinpoint accuracy, hitting targets within 5 meters.
The first video is a Discovery Channel report detailing the rail gun concept, its destructive capabilities, and the challenges ahead. The second shows the actual test firing of the Navy magnetic rail gun at the Dahlgren Proving Ground in 2006. Since that video was shot, velocities have reached 5,640 mph.
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In February 2008, the US Navy completed a 10-megajoule test fire — the first time a projectile was fired at 8,270 feet per second (5,640 mph). The gun was firing at only a third of its potential power. The target photo below was made available through the kind consideration of Raymond Allen, Electrical Engineer at the Naval Research Lab.
The Naval Surface Warfare Center Dahlgren Division test used just some of the potential 32-megajoule capability — itself only half the 64-megajoule target for the final weapon. The Navy plans a shipboard rail gun, potentially aboard the next-generation cruiser CG(X), between 2020 and 2025. The Marine Corps is particularly interested for over-the-horizon fire support.
Actual rail gun target — courtesy Raymond Allen, Naval Research Lab
Q1. What is a rail gun and how does it work?
An electromagnetic rail gun uses electrical energy to accelerate projectiles to extreme velocities. Rail guns do not require chemical propellants or explosive warheads — freeing magazine space and reducing ship weight. The high-velocity kinetic impact of a solid metal round can have an explosive effect, and the uniform propulsion provides far greater accuracy.
Q2. Why is this technology being pursued by the Navy?
The system has the potential to provide responsive, long-range, accurate, high-volume naval surface fire support. Range could extend more than 200 nautical miles — compared to 13 nautical miles for the current Mk 45 5″/54 system. Estimated firing rate: 6 to 10 rounds per minute.
Q3. At what stage is the program?
Currently in the science and technology phase under the Office of Naval Research (ONR).
Q4. Are there prototypes in development?
BAE Systems and General Atomics are under contract with ONR as part of the Innovative Naval Prototype Program, developing a 32-MJ rail gun (Mach 7) as an intermediate step toward a 64-MJ tactical system deployable on naval surface combatants.
Q5. How long before a weapon system is fielded?
At least another 15 years from the time of writing to field a viable rail gun weapon system in the fleet.
Q6. What are the advantages of rail guns?
Extended range — over 200 nautical miles vs. 13 nautical miles for current guns
Higher velocity — hypersonic speeds in excess of Mach 7 (5,550 mph)
Safer ammunition handling — no explosive propellants or warheads
More rounds aboard ship — additional space for ordnance or other uses
High angle of trajectory — can engage targets on reverse slopes in defilade
Q7. Specific technical applications?
Cannot be discussed for reasons of national security and classification.
Q8. How do rail gun projectiles destroy targets?
By kinetic energy only. The tremendous velocity on impact releases enough energy that explosive rounds are unnecessary — and leaves no dud rounds to endanger civilians after a conflict.
Q9. What is the Navy's budget?
Total ONR Innovative Naval Prototype rail gun program budget: $237 million, FY06–FY11.
Q10. What types of targets can it engage?
Three rounds are planned: a unitary round for hard targets (bunkers, buildings); a rod-dispensing round for vehicles; and a pellet-dispensing round for personnel.
Q11. Primary partners: BAE Systems, Boeing, Charles Stark Draper Lab, General Atomics, Department of Energy (Lawrence Livermore), US Naval Academy, Naval Postgraduate School, Naval Sea Systems Command, NAWC Rhode Island, NSWC Carderock, NSWC Dahlgren, and the United Kingdom.
Q12. Is this developed for a specific platform?
No. With deployment planned for 2020–2025, integration could occur on new vessels or by retrofitting existing platforms.
Q13. Major scientific hurdles?
Four key areas: bore and containment system materials; projectiles; pulsed-power network; and ship integration.
Q14. Will the projectile have internal guidance?
Yes.
Q15. How does it compare with current weapons?
Compare with the SR-71 (Mach 3.5 maximum, 2,500 mph) and the Space Shuttle at two minutes into ascent (approximately 3,000 mph). The rail gun projectile arrives at Mach 5+.
Q16. Electromagnetic pulse effects on personnel and equipment?
All DoD and industry-standard safety procedures for electromagnetic radiation are in place at test facilities. An operational shipboard system would likely be unmanned. Electromagnetic emissions are being monitored throughout the program.
Q17. How does a non-explosive projectile cause damage?
At Mach 5 impact speed, kinetic energy alone destroys the target. Thousands of fragments — each traveling at lethal velocity — are created on impact.
Update: February 18, 2009
BAE Systems announced a $21 million deal with the US Navy to build a new, more powerful prototype electromagnetic rail gun for ONR. The target: a 64-megajoule hypervelocity weapon capable of lobbing projectiles 200 miles and having them arrive at Mach 5+. Solid metal shells, no explosive propellants — significant logistics advantages for fleet supply. The new prototype was expected to begin testing in 2011.
