US Navy announces sea trials for electromagnetic railgun

US Navy announces sea trials f...
Artist's concept of a ship equipped with a railgun turret (Image: US Navy)
Artist's concept of a ship equipped with a railgun turret (Image: US Navy)
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US Atomics railgun (Image: US Navy/John F. Williams)
US Atomics railgun (Image: US Navy/John F. Williams)
BAE Systems railgun (Image: BAE Systems)
BAE Systems railgun (Image: BAE Systems)
Artist's concept of a ship equipped with a railgun turret (Image: US Navy)
Artist's concept of a ship equipped with a railgun turret (Image: US Navy)
Railgun combat scenario (Image: US Navy)
Railgun combat scenario (Image: US Navy)
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Watching old war movies, we expect firing a navy gun to be accompanied by a deafening bang and a dramatic cloud of burnt powder. This being the 21st century, the US Navy has other ideas as it prepares to install and test a prototype electromagnetic railgun on a Spearhead-class joint high speed vessel (JHSV) in 2016 as part of a program to develop the naval artillery of the future.

Modern missiles are miracles of range, accuracy and lethality, but they are also incredibly complex and expensive with a single shot costing millions of dollars. Old-fashioned projectile weapons are cheaper, but also much less effective. They have shorter ranges, less accuracy, and still need dangerous-to-handle propellants to fire them. According to the US navy, what is needed is something with an effectiveness comparable to that of a missile, but with costs per round less than that of conventional naval artillery.

This is where the EM railgun comes in. It uses electromagnetic force to propel a warhead instead of a chemical propellant. The idea has been around since at least the 1920s and the principle has been suggested and even experimented with for every application from sidearms to levitating trains to moving asteroids, but it’s only been in recent years that the principle has moved from proposition to practicality.

BAE Systems railgun (Image: BAE Systems)
BAE Systems railgun (Image: BAE Systems)

The EM railgun is basically an electric motor that’s been folded out and laid flat. Like an electric motor, the railgun uses an alternating electromagnetic field to pull along an armature. In this case, the armature is a sliding metal conductor that holds a projectile and is held between two conductive rails. Instead of whizzing around in a circle as in a motor, the electromagnetic field shoots the armature along the length of the rails, building up to hypersonic speeds. When it reaches the end of the rail, the armature releases the projectile, which flies toward its target.

The stats for such a weapon are impressive the current prototypes built by companies such as General atomics and BAE Systems can fire an aerodynamic shell at speeds of Mach 7.5 (5,700 mph / 9,200 km/h), which can reach the horizon in 6 seconds and has much greater range than conventional guns, having a reach of 110 nautical miles (126 mi / 203 km). Furthermore, the projectile has so much kinetic energy that it doesn’t need to carry high explosives to destroy its target.

Railgun combat scenario (Image: US Navy)
Railgun combat scenario (Image: US Navy)

One particular advantage of the EM railgun is that it costs orders of magnitudes less than conventional missile systems. This doesn't just keep the bean counters happy, it also makes the enemy unhappy because while they’re lobbing missiles at a million dollars a round, the railgun is shooting back at only a few thousand dollars per round. That means a lot more firepower available to commanders, and thus more flexibility in how to respond to threats, with the Navy saying that railguns would be effective against against enemy warships, small boats, aircraft, missiles and land-based targets.

The 2016 test deployment will be the first sea trial of a railgun. It will use a JHSV vessel because its cargo space and topside are readily available for installing the gun, and since the JHSV is a non-combatant ship, a permanent weapon installation isn’t required.

US Atomics railgun (Image: US Navy/John F. Williams)
US Atomics railgun (Image: US Navy/John F. Williams)

The prototype EM railgun is the result of testing and the development by the US Navy and private companies since 2005 at the Naval Surface Warfare Center in Dahlgren, Virginia, and the Naval Research Lab. Phase I of the program concentrated on developing a 32 megajoule muzzle energy proof-of-concept weapon and a 100-nautical mile projectile. Phase II, currently under way, concentrates on making the EM railgun fire at 10-rounds per minute and being able to handle the heat and stresses of rapid firing.

The plan is to design projectiles for the railgun that will be compatible with powder guns, so a future deployment will be easier and allow missiles to be saved for major threats. Based on the success of the tests, the Navy will eventually decide on which class of ships to deploy the EM railguns.

The video below shows a railgun in action.

Source: US Navy

Navy to Deploy Electromagnetic Railgun Aboard JHSV

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It's interesting that the few articles I've seen on this over the last week or so always compare the rail gun to missles on a piece by piece basis, i.e. they look at one missle being equivilant to one rail projectile, and totally discount the complete system.
How much R&D has gone into this, which will have to be ammortized across each system?
How much will it cost to refit existing ships to use this weapon?
How much will it cost to build a new ship around this weapon when the Navy determines that it will actually be the best course of action?
Unfortunately, the governments (military) idea of saving money is not the same as that of a normal person. One only has to look at the program to moth-ball the A10 in favor of the F35 to see this.
The biggest advantage is the inert ammunition can't blow up and sink the ship. The capacitors only store enough energy for a single shot.
railguns dont use alterneting current, but direct current. railgun != linear motor
Michael Wilson
I'm more interested in the non-military applications for this....Imagine cheap space launches costing thousands instead of millions for lobbing durable goods (read: goods not affected by g-force) into space.
Alex Aricci
Bear in mind this is a prototype of a new technology with historically a lot of teething problems; IIRC typically mass production alone brings down costs by a factor of ten; costs will go down even further as newer versions are introduced while performance goes up (which happens with every new technology, aircraft, automobiles, jet engines, 3D printers, electronics, etc., etc.) Not to mention the significant side benefits of a much faster projectile, which will probably happily penetrate reinforced bunkers and tanks (hell, a sock would make a pretty deep gouge in your average building at Mach 7) being an inert fast piece of lead with a ton of momentum even if you can react fast enough it's going to be really, really difficult to stop. Not to mention railguns are a fairly viable method of launching mass into space, a project like this is probably the only way that option will ever become feasible to explore.
This thing is even faster than a M1A2 tank sabot round. 10 rounds per minute will ruin your day, oh and that lovely little aircraft carrier over there, in no time at all. Bravo!
I sort of agree with Rt1583. They use something the cost of the Tomahawk missile as budget justification and compare it to the cost of a solid kinetic only round but there are a lot of problems with that comparison. Railgun is far far more similar to a powder projectile than a long range missile and those are already cheap.
The only reason they avoid that comparison is because it would be harder to justify funding. The biggest issue is the Tomahawk actually has midcourse correction where a Mach 7 kinetic round would be more like aiming long range artillery. You would need someone close to the target giving trajectory corrections. Another issue is if you fire missile payload at powder detonation speeds there is some risk of detonation in the tube (A tank sabot round is a little over Mach 5). It would be extremely difficult to accurately hit a target at missile range with missile payload.
It would suffice as a formidable competitor to powder kinetic weapons today but it takes up more room and there would be no real cost savings. It no doubt takes an extremely large amount of power to fire and that amount of electricity has to be much more difficult to store at sea than the mostly simple powder packs used on ships today.
As a side note about the A10, I really wish they could just make an updated version of it cheaply instead of shelving the platform. I can't imagine it would be that hard to make minor improvements on it to keep it around.
@RelayerM31 I can't speak to kinetic used on ships but M1A2 tank rounds cab be loaded in about 5 seconds which puts it in the same range of about 10 rounds a minute.
Grant Bugno
Is there any reason why this couldnt shoot a missile? Would save on 200 miles of rocket fuel plus the acceleration loses and have the advantage of missile guidance to be more accurate for moving targets. But the space idea is awesome too. Using nuclear reactor powered spacestations to shoot objects would save on getting fuel out of the atmosphere
Jon A.
The best way to come up with an updated A10 is to change the rules to allow the Army to fly it. They love the A10, but the Air Force has always hated it.
Noel K Frothingham
Grant, using a rail gun with a launch to launch a conventional missile defeats the purpose of the rail gun. A conventional missile could not withstand the acceleration forces. The EMD equipment that might be used to put an object into LEO may share a basic operating principal with a railgun, but any similarity ends there.
Diachi, the price tag of a single Tomahawk cruise missile IS in excess of $1,000,000. Check Janes.
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