A Railgun Cannon. What’s Next Star Destroyers? |
How many games have you played that featured a railgun as a weapon? I’m guessing just a few under a thousand. From Halo to Stargate to the movie Eraser, railguns are just as much a part of the sci-fi genre as bad acting and large-chested blue aliens. Now however, railguns are no longer science fiction. They are a reality for the US Navy.
The Navy demonstrated its new toy at the Naval Surface Warfare Center. The weapon uses electromagnetism to propel non-explosive projectiles to high speeds. The new weapon should increase the range of US Navy vessels as well as decrease the cost. The railgun is expected to replace the expensive Tomahawk missile saving the Navy a lot of money. Because of the speed of the projectile launched from such a weapon, it might be a cheap and efficient way to shoot down incoming missiles.
“It’s pretty amazing capability, and it went off without a hitch,” said Capt. Joseph McGettigan, commander of NSWC Dahlgren Division. He continued, “The biggest thing is it’s real–not just something on the drawing board.”
According to Wikepedia, “A Railgun is a type of Magnetic Accelerator Gun (MAG) that utilises an electromagnetic force to propel an electrically conductive projectile that is initially part of the current path.”
Don’t look for a hand-held model anytime soon. The full version, meant for Navy destroyers, will require an enormous amount of electrical energy to fire. The next generation of Navy destroyers are built to be all electrical, allowing for energy to be diverted from the engines to the railgun as needed. The gun would be able to fire a 40 pound projectile up to 6 times a minute. The projectile would actually leave earths orbit and reenter under satellite guidance. The force of the impact would destroy targets with no chemical explosive needed.
TAGS: electromagnatism, guns, Magnets, railgun, railgun cannon, Weapons
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“The railgun is expected to replace the expensive Tomahawk missile saving the Navy a lot of money.”
i dont think a rail gun would be a suitable replacement for the Tomahawk.
The biggest drawback for a railgun is the power supply, same thing with a weapon-capable LASER. Next is Newton’s third law, where you’d have to keep in mind that as much as is exerted on that 40-lb slug, pretty much the same amount is exerted on the device/ship/etc that fired it. It would only be a replacement for the Tomahawk if it was just as accurate, about as expensive to build, field, and maintain, and if the target’s destruction called for a kinetic energy strike as opposed to a high-explosives delivery (compare shooting a watermelon with a .22 and sticking a firecracker in it, which will destroy more of it?)
What jim bob fails to realize is that, while it is true that the same force will be exerted upon that 40 pound slug (and the navy is actually using 7 pound projectiles, not 40), the effect that will have upon a projectile vs a ship weighing in somewhere around 50,000 tons will be vastly different. Conventional guns work under the same laws of physics.
Additionally, the kinetic energy of a projectile traveling at that speed is equivalent to that of a Tomahawk Missile. So when that projectile hits the ground, it’s still going to cause a huge amount of damage.
Yeah, Jason is right, not to mention that even though the force exerted is negligible to a water based platform as large as a destroyer, there is far less force applied than you would think on the object firing. In rail guns most of the force is applied on the rails themselves as they fire according to most recent theory, not on the base of the object they are attached to while firing (wikipedia’s current entry). Also, force equals speed multiplied by mass. They will be using pretty massive projectiles are higher speeds than that of a Tomahawk. They will definitely do as much damage. The power issue is the most important one longterm. If they are going to have to have their engines entirely powered off to fire these it may change the tactical and manuvering situation for them in an intense combat situation.
In the year or so since this article was written wikipedia has been updated:
“In February 2008 the US Navy tested a magnetic railgun; it fired a shell at 5,600 miles per hour using 10 megajoules of energy. Its expected performance is over 13,000 miles per hour muzzle velocity, accurate enough to hit a 5 meter target from 200 nautical miles away while shooting at 10 shots per minute. It is expected to be ready in 2020 to 2025.”
with that proposed speed and accuracy, what’s easier to hit? A Tomahawk? or a railgun projectile?
Coilguns have no recoil. I would think that railguns would be the same, since they are similar. You are comparing it to a regular gun, where energy causes matter to push against matter, hence the recoil. In a rail gun, it is only energy pushing/pulling against the matter.
SiriS – what the f*#k are you talking about? Go back to high school and review conservation of momentum.
As to the railgun – the problem, as far as I understand, is that firing the projectile vaporizes the rails. How do they deal with that problem?
Just to be accurate, MOMENTUM is mass time velocity, FORCE is acceleration times mass.
As for the power issue, the answer may be ultracapacitors. They can be charged and then left that way until the railgun needs to be fired and then the capacitor can discharge the needed energy to the gun.
Sorry to nitpick, but Halo doesn’t have railguns.
Nitpicker- Actually, if you read Halo: Fall of Reach, all of their ships are equipped with railguns. It is how they attempt to repel the covenant invasion. Aside from the ships, they also have orbiting railgun installations. If you play through the first level of Halo 2, and get to the part with the outside of the ship, you will notice that there is an enormous railgun firing at the armada
HALO has a railgun??
To whomever is still confused regarding the “kickback” of a railgun:
Please look up your B-force math (B = magnetic force in Maxwell’s equations). You will find that they operate in two dimensions; one is circular (and occupies two dimensional spaces), the other is linear and is opposed to the circular dimension. This is not to be confused with the TRANSMISSION of the electromagnetic force which happens via bi-dimensional waves of alternating electric field and magnetic field propagation.
A railgun DOES have some amount of kickback, but since it is not using percussive force (such as a gun or cannon) to accelerate the loan a slightly modified set of rules apply. In fact, a very SMALL amount of force is ultimately transfered in the direction opposite to launch. The induction of the field through the projectile happens almost entirely in the circular component of the B-field vector (i-hat and j-hat for those inclined).
As far as practice, yes, this has a history of destroying the cannon’s rails. This, however, is principally based on extreme-limits testing. I ASSUME that they will not be operating this gun in a manner that destroys itself.
For all of the skeptics out there, regarding engineering:
The folks who design these weapons are a good deal more educated than you or I. Having worked for a military/aerospace contractor as an engineer, I grasp the incredible amount of theory that must support a design before a prototype is even considered.
If the gun exists, it freaking works. The question is whether or not it works to the same degree as “Advertised.”
Do not mistake the picture for one of the actual rail gun. I assume it will be a water/phase-change cooled cannon with either multiple barrels (think vulcan cannon or gattling gun) or it will be immensely thick with huge cooling fins on the outside to aid in heat dissipation.
Regarding the kinetic energy released from a falling projectile and its usability:
Keep in mind that escape velocity is a constant. It does not depend upon angle of launch nor does it depend upon mass (wind resistance does play a role ultimately). If these are satellite guided projectiles, I would assume they have a non-zero minimum of control surfaces on the projectile. Terminal velocity is invariably slower than escape velocity, but terminal velocity is much more dependent on wind resistance than escape velocity. A large portion of energy wasted to wind resistance would be regained upon reentry in the form of heat energy.
Even a non-explosive projectile would be devastating when heated and dropped at terminal velocity.
Also, keep in mind that the Tomahawk is a cruise missile. So whatever use you had imagined in your head, it is predominantly for removing fortified enemies (tanks, infantry, and small bases), and is usually air-burst. Dropping a 40-lb, satellite-guided, superheated chunk of metal from space WILL WORK JUST F**KING FINE!
An untrained eye will DEFINITELY mis-recognize the rapid release of kinetic energy as a conventional explosive warhead. There will be incredible heat, noise, and rapid expansion of air.
This is one step better than dropping 40-lb meteorites on the enemy at will.
Damn it! Gauss… not Maxwell. Sorry.
Not to nitpick again, but the idea of making a real rail gun is hardly “new” at all.
Anyone ever hear of “Star Wars” (not the movie, the actual army initiative).
Read up on it here: http://en.wikipedia.org/wiki/Strategic_Defense_Initiative
The technology has been around for over 20 years.
Wouldn’t an EMP of some kind just rape the US Navy?
InSoMniaK604: The armed forces hardened their equipment against EMPs back during the Cold War, just for that reason. Seeing as the Soviets had nuclear arsenals to rival ours, we wanted to be prepared for that. Now, civilian equipment would likely be destroyed, yes.
look i may not be as smart as many of you folks but rail gun technology seems to be a bit unlikely to work by 2020-2025. while yes it may work in firing a slug but in order for the weapon to be used effectively wouldn’t it require to shoot out multiply rounds per minute rather then having it use as an artillery cannon. because here its saying the rail will act as a cheaper tomahawks. and aiming the weapon will require a advance targeting system to fire it. perhaps a supercomputer is require to process the targeting data.
the article mentioned converting more ships to electronic battlecruisers. is that smart? it may be fancy but wouldn’t that increase the effectiveness of electronic warfare? we could get to a point where some nerd on a decent computer posed more of a threat than a battle ready fleet or an entire battalion of soldiers.
the whole idea of an emp being a problem is childish and scifi at best. Even if a large enough one could be produced, due to the extreme magnetic fields created by the rail gun itself farraday cages would no doubt be integral to its design, shielding it from electromagnetic pulses.
how stupid are you people that picture is from star gate atlantis
Naval Warfare Center????…not unless the center is on the City of Atlatis. The photo is from the TV show Stargate Atlatis in the Sci Fi Channel. Nice Try
I believe, that the technology is ready. Origionally back in the starwars project, the materials they had were inferior to what was available now, the developments in electronics and materials has led in advancements to make this weapon, viable for combat. While they initialy set the project aside.. that’s exactly what they did, set it aside. To get back to it later. Meantime, many people have made small model EM systems that worked just fine. *EM bullettrains anyone?* I had a friend who had a small two rail system built out of spare parts in his barn. I read a story of a college student building one with his teachers assistance for a school project.
Military simply has the funding to get the proper materials, put them together in precision, and have vessels large enough to power them. The technology all exists. It’s just scary when they are all brought together, and you can really Reach out and touch someone. Almost quite literally without noise, and with them not being able to detect it.
Not to say that a good enough system couldn’t detect it.. however. Unlike a tomahawk, You can’t spoof the shell, you cannot shoot it down, and you certainly can’t do much to protect yourself from it.
This same technology I hope, will be used to send space shuttles into orbit someday.
I’m sorry but I came across this article and no one (maybe a few) knows what they’re talking about. First of all railguns are not new. They’ve been around for a while. Someone was correct earlier about the rods being vaporized. Only some of it is vaporized when it is shot due to the magnetic force converting some of the slug into plasma; the rest burns up due to friction because we’re talking really freaking fast.
And secondly magnetism does not violate Newtons laws. Mysterious magnetism pushes rod, mysterious magnetism pushes gun. Anyone ever held two magnets near each other? They’re both repelling. If you put a magnet on the ground and a magnet above it, the magnet above pushes the one on the ground down and vice versa.
Saying that the impulse is in a circular motion makes absolutely no sense. The laws of the conservation of momentum state that the sum of all changes in momentum are zero. Guess what the sum of impulses in a circle are: zero! Guess what the impulse on the rod if: REALLY BIG! That means the total change in momentum would be non-zero and would violate a fundamental law. Fail.
Just because you took a physics class and know the name of Gauss and Maxwell doesn’t mean you know what you’re talking about.
Just to be clear… Halo doesn’t feature any railguns. They use MAC (Magnetic Acceleration Cannon) guns, which are an upscaled Gauss cannon. Similar in concept to a railgun but mechanically different.
if it is true that the projectile flies into orbit then it should be able to fire at intercontinental ballistic missiles such as that which north korea seems so intent on makeing
the idea of a railgun is way older than starwars. Documents we(the U.S.) captured from the Nazis after world war 2 theoriezed on the possiblity of a magnetic anti-aircraft gun. However, engineers discovered that each battery would need the amount of power used by Chicago, and the idea was abandoned.
umm.. dont know that much about pysics, but becuse the bullet is being pulled by magnetic coils, and as it reaches each coil that coil turns of, there wouldent realy be that much recoil would there?
First-off, there are no railguns in Halo. The weapons used by UNSC starships and orbital defense platforms are Magnetic Accelerator Cannons, which is a badass-sounding name for “really massive coilgun that will ruin your day”.
A railgun works by sending the electrical current THROUGH the projectile itself (thus causing the immense heat release, and partial vaporization of both the projectile and the rails into plasma.
A coilgun uses a series of electromagnetic coils that wrap around the barrel of the weapon, and a ferromagnetic kinetic impactor. The coils generate tremendous EM fields that pull the impactor along the barrel; as it reaches the first coil, that coil shuts down, and the next one is powered up; and so on for the entire length of the weapon. Repeat the action with powerful enough EM fields and a fast enough coil firing sequence, and you can easily accelerate the round to impressive speeds.
In both cases, the advantage is that there is no chemical combustion/detonation that propels the round; this means no hot gases, no combustion residue, no spent casings, and increased efficiency.
The only problems we have is an atmosphere, which creates significant drag on the impactor. Otherwise, railguns/coilguns are IMO chillingly powerful and effective weapons. The expected performance of a warship-level railgun is to deliver 302760000 Joules of energy on impact.
That means you being hit by two EMD GP50 125-ton locomotives plus a few railcars.
At 100 miles per hour.
Falling from space.