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The Science of Rail Guns
i09 ^ | 3/20/2012 | Keith Veronese

Posted on 03/20/2012 9:44:57 PM PDT by U-238

Ubiquitous in science fiction, rail guns are a hot area of military research in real life too. But will we ever really get to use them the way people in science fiction do? And could rail guns be used for a non-violent reason — inexpensively launching payload into space?

Halo Reach ends with your Spartan taking up a mounted rail gun to destroy an incoming Covenant ship. Rail guns are the basis for a funny aside in Mass Effect 2. They're used in Babylon 5 and Stargate Atlantis and The Last Starfighter. And they're a devastating hand-held weapon in the Metal Gear Solid and Quake series. Now, let's discover the real science behind rail guns. Ejecting pieces of metal at phenomenal velocities The initial theory leading to modern rail guns owes itself to Louis Octave Fauchon-Villeplee, an early 20th Century French scientist who was awarded the patent, Electric Apparatus for Propelling Projectiles. The patent proposed passing current through two strips of aluminum, with an induced force pushing a metal block forward.

Modern rail guns typically make use of two metal rails, a movable armature, and a power supply. Current passes from a positive conducting rail, over the armature, and to a negative conducting rail, creating a magnetic field in the process that sends a projectile resting on or within the armature forward. Laboratory conditions produced velocities of up to 9 kilometers per second using small mass projectiles; nearing the velocity needed for an object on the surface of the planet to escape the gravitational pull of Earth.

(Excerpt) Read more at io9.com ...


TOPICS: Foreign Affairs; News/Current Events; Technical
KEYWORDS: banglist; electromagnetic; miltech; physics; projectile; railgun

1 posted on 03/20/2012 9:45:08 PM PDT by U-238
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To: U-238

Could they, in principle, be effective replacements for bullets and gunpowder?


2 posted on 03/20/2012 10:03:39 PM PDT by Jonty30 (What Islam and secularism have in common is that they are both death cults.)
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To: Jonty30

They’re testing ship-based platforms right now. A few obstacles have to be overcome, like heat dissipation, structure fatigue and power supply.


3 posted on 03/20/2012 10:10:01 PM PDT by lurk
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To: Jonty30

Yes.You would not to expend a spent cartridge from the breech.You can develop a railgun rifle.

http://www.tquad.com/


4 posted on 03/20/2012 10:11:45 PM PDT by U-238
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To: Jonty30

Stationary Gun Platform yes. Power requirement are huge doubt batteries/mobile generator will ever be able to keep up. Not at least in my lifetime.


5 posted on 03/20/2012 10:23:45 PM PDT by Bailee
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To: lurk

It would be such an advantage, if they ever overcome these issues. Not having to carry fuel would leave so much more room for ammunition.


6 posted on 03/20/2012 10:28:38 PM PDT by Jonty30 (What Islam and secularism have in common is that they are both death cults.)
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To: U-238
Yes, but that shell casing is a convenient, "throw-away" heat sink.

Something the caseless cartridge experimenters learned.

7 posted on 03/20/2012 10:28:40 PM PDT by Trailerpark Badass
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To: U-238

I think Newton’s third law of something pushing back with the same force that it pushes forward could be a problem as well.


8 posted on 03/20/2012 10:33:55 PM PDT by Jonty30 (What Islam and secularism have in common is that they are both death cults.)
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To: Trailerpark Badass

You are right about the caseless cartridge and experiments


9 posted on 03/20/2012 10:34:27 PM PDT by U-238
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To: Jonty30

If they are discussing a railgun rifle maybe they have a prototype or close to one that we are not aware of.


10 posted on 03/20/2012 10:36:11 PM PDT by U-238
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To: Jonty30

Science Fiction always becomes science fact.


11 posted on 03/20/2012 10:39:00 PM PDT by U-238
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To: Jonty30
Could they, in principle, be effective replacements for bullets and gunpowder?

It all boils down to the size of the power source, and the reduction of resistance. Resistance equals heat, which requires size and complexity and weight to dissipate. Power sources for weapons are usually rather bulky.

But if you could create a zero-point energy source running a small, room-temperature-frictionless electromagnetic levitation bubble areound your rail gun projectile...

... that would be, like, awesome.


12 posted on 03/20/2012 11:04:42 PM PDT by Talisker (He who commands, must obey.)
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To: Jonty30

With railguns, most of the recoil is actually perpendicular to the direction of the projectile, trying to force the rails apart in both directions. If the rails are bound to each other, the forces net against each other, and basically there is no recoil.


13 posted on 03/20/2012 11:33:16 PM PDT by Boogieman
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To: U-238
You would not to expend a spent cartridge from the breech.You can develop a railgun rifle.

You may end up expending a power supply though.

A use once and discard capacitor may be the power supply of choice for a rail gun.

Capacitors are able to discharge much more quickly than batteries and so would be a preferable source of portable power for a rail gun.

14 posted on 03/21/2012 12:18:14 AM PDT by Pontiac (The welfare state must fail because it is contrary to human nature and diminishes the human spirit.)
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To: Pontiac

But that is where we are heading?All you need is a reliable power source and you have a portable rifle.


15 posted on 03/21/2012 12:26:57 AM PDT by U-238
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To: Talisker

I agree


16 posted on 03/21/2012 12:30:54 AM PDT by U-238
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Just imagine a portable railgun rifle with special laser sighting in the hands of a sniper.


17 posted on 03/21/2012 12:34:54 AM PDT by U-238
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To: U-238
All you need is a reliable power source and you have a portable rifle.

I wouldn’t go so far as to say that, but I would say that the power supply may well be the biggest hurdle.

Talisker makes good points on conductors. Making a conductor capable of handling the currents required to launch a projectile at 5000 fps and survive to do it a second time is a major hurdle.

What we may see first is a man portable shoulder fired rail gun anti-tank weapon that is used once and discarded.

Materials that can survive the high current loads are the major problem to overcome in a man portable rail gun. This is why I think a disposable man portable weapon will be the first on the battle field.

It may take high current room temperature superconductors to make a rail gun battle rifle a reality.

18 posted on 03/21/2012 12:48:35 AM PDT by Pontiac (The welfare state must fail because it is contrary to human nature and diminishes the human spirit.)
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To: Pontiac

I agree with you.Good Post


19 posted on 03/21/2012 12:56:26 AM PDT by U-238
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To: Pontiac

It would be a great battlefield rifle.


20 posted on 03/21/2012 1:01:11 AM PDT by U-238
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To: U-238
It would be a great battlefield rifle.

Eventually.

I wouldn’t be at all surprised if the first few examples were worse than useless.

Every new technology suffers from a certain amount of failure when it first enters the wilds of the real world.

Considering the messiness of the battle field it is hard to imagine the first battle tested electric battle rifle being an unalloyed success. Water, sand, mud, ice all are enemies of electrical equipment and all are found on the battle field. But given time and the ingenuity of Americans they will be defeated and the American soldier will have a rail gun battle rifle.

21 posted on 03/21/2012 1:37:08 AM PDT by Pontiac (The welfare state must fail because it is contrary to human nature and diminishes the human spirit.)
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To: Boogieman
basically there is no recoil

That is a violation of the law of conservation of momentum. True, there are forces acting sideways trying to bend the rails out, but there is a force trying to shorten the rails, as well. The gun cannot push the projectile forward without the projectile pushing back on something.

This is not like RPG where the projectile has a rocket driving it forward unless you have vaporized metal moving in the opposite direction as the projectile.

22 posted on 03/21/2012 3:00:50 AM PDT by Right Wing Assault (Dick Obama is more inexperienced now than he was before he was elected.)
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To: Pontiac

So we’re probably looking at a rifle with a really big extension cord going to a portable nuke plant?


23 posted on 03/21/2012 3:12:51 AM PDT by ROCKLOBSTER ( Celebrate Republicans Freed the Slaves Month.)
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To: U-238

where did they use a rail gun in Babylon 5?


24 posted on 03/21/2012 4:15:14 AM PDT by camle (keep an open mind and someone will fill it full of something for you)
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To: Pontiac

>It may take high current room temperature superconductors to make a rail gun battle rifle a reality.

If you can pull this off, you’ve also solved the power source issue. You can use a superconducting loop as a form of ‘battery’ or maybe capacitor might be a more appropriate term.


25 posted on 03/21/2012 4:39:49 AM PDT by drbuzzard (different league)
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To: U-238

———rail guns are a hot area of military research -——

Translation....... sacred cow

Rail gun research should be abandoned and unused obligated funds returned to the treasury. Rail guns are a boondoggle that has lived on and on and failure after failure to actually produce.


26 posted on 03/21/2012 4:57:53 AM PDT by bert (K.E. N.P. +12 ..... Crucifixion is coming)
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To: lurk

Ghostbusters Proton Pack Backpack ?


27 posted on 03/21/2012 5:05:55 AM PDT by Joe Boucher ((FUBO) Hey Mitt, F-you too pal)
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To: camle
where did they use a rail gun in Babylon 5?

When the Centauri were bombarding the Narn homeworld. (Although they were called mass drivers...)

Yes, I'm a sci-fi geek. :-)

28 posted on 03/21/2012 5:06:47 AM PDT by Jonah Hex ("To Serve Manatee" is a cookbook!)
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To: U-238

Cool article.

“Ubiquitous in science fiction...”

Not one example from a book..? Man I really am behind the times! When someone says “science fiction,” books are the first thing I think about, not movies, TV or video games.

Freegards


29 posted on 03/21/2012 5:36:47 AM PDT by Ransomed
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To: bert
Rail guns are a boondoggle that has lived on and on and failure after failure to actually produce.

Substitute the Airborne Laser (which mercifully has finally been cancled) for "rail gun" and the above is actually true.

30 posted on 03/21/2012 6:10:08 AM PDT by Strategerist
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To: U-238

I came on this thread expecting something about Big Bertha and here you all are talking about electrical dooflackies.


31 posted on 03/21/2012 6:16:37 AM PDT by mitch5501 ("make your calling and election sure: for if ye do these things ye shall never fall")
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To: Jonah Hex

got it, thanx. i remember g’kar was not pleased. neither was sheridan.


32 posted on 03/21/2012 6:47:25 AM PDT by camle (keep an open mind and someone will fill it full of something for you)
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To: Right Wing Assault

Well, obviously it doesn’t violate conservation of momentum, it’s just that the device is designed to transfer the momentum in such a way that you don’t see the classic backwards recoil.


33 posted on 03/21/2012 7:45:18 AM PDT by Boogieman
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To: U-238
Rail guns are the basis for a funny aside in Mass Effect 2. They're used in Babylon 5 and Stargate Atlantis and The Last Starfighter. And they're a devastating hand-held weapon in the Metal Gear Solid and Quake series.

Awright, which one of you cappin' rookies forgot to put Keith Laumer's Bolo novels on the list? [Not only railguns as Bolo *Hellbore* main gun armament, but *smart* guns at that....]


34 posted on 03/21/2012 2:56:02 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: U-238
Rail guns are the basis for a funny aside in Mass Effect 2. They're used in Babylon 5 and Stargate Atlantis and The Last Starfighter. And they're a devastating hand-held weapon in the Metal Gear Solid and Quake series.

Awright, which one of you cappin' rookies forgot to put Keith Laumer's Bolo novels on the list? [Not only railguns as Bolo *Hellbore* main gun armament, but *smart* guns at that....]


35 posted on 03/21/2012 2:56:20 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: U-238; Squantos; Travis McGee
Just imagine a portable railgun rifle with special laser sighting in the hands of a sniper.

The immediate problem is that the relatively immense power source involved for powering the weapon would be immediately detectable by sensors, negating the sniper's stealth advantage. That's already becoming a problem in sniperville with conventional small arms, hence the proliferation of suppressor/silencer mounts on sniper rifles.

Will we return to the crossbow as a sniper tool? A kinetin-energy launched silent weapon with a terminally guided fire-and-forget projectile, with the effect of a 40mm M203 or GP-30 grenade once it gets there? Stay tuned.

36 posted on 03/21/2012 3:01:14 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: archy
Don't forget "Eraser" with Ahnold.


37 posted on 03/21/2012 3:36:16 PM PDT by Future Snake Eater (Don't stop. Keep moving!)
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To: archy

My weapons of choice were an will always be a M79 and a TRW built M1A . Those were my eras fire an forget tools. Albeit a love for the M82A1 Barrett an raufaus recipe fodder did exist the last few years of my career.....

Rail guns ...... Phft....


38 posted on 03/21/2012 5:30:27 PM PDT by Squantos (Be polite. Be professional. But have a plan to kill everyone you meet)
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To: Squantos
Albeit a love for the M82A1 Barrett an raufaus recipe fodder did exist the last few years of my career.....

Rail guns ...... Phft....

Happy news for you: on one range I frequent, the 800-meter targets are two-foot long sections of railroad rail. painted orange and hanging from a short section of chain. And at least twice I've let fly at them with an M82A1/ M107A1, which punches right through if it hits on the bottom web of the rail. IS a rail gun....You have to have on to be with it in this Twenty-First Century....

39 posted on 03/23/2012 12:29:26 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: Future Snake Eater
Don't forget "Eraser" with Ahnold.

Nor the one Mycroft used for Moon-to-Earth bombardment in Heinlein's The Moon Is a Harsh Mistress. Somebody oughta make a movie....


40 posted on 03/23/2012 12:33:56 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: archy; Squantos
What is all the hubbub about rail guns? Hitler had those huge guns on rails back in the ‘40s...

{:0)

41 posted on 03/23/2012 12:38:08 PM PDT by MileHi ( "It's coming down to patriots vs the politicians." - ovrtaxt)
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To: U-238

bflr


42 posted on 03/23/2012 12:44:58 PM PDT by Captain Beyond (The Hammer of the gods! (Just a cool line from a Led Zep song))
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To: MileHi
What is all the hubbub about rail guns? Hitler had those huge guns on rails back in the ‘40s...

The mounting of siege ordnance on railcars dates back to the U.S. Civil War, [War for Northern Dominance] at least:


43 posted on 03/23/2012 1:37:29 PM PDT by archy (I'd give my right arm to be ambidextrous!)
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To: archy
I always thought those pieces were funny looking, so large around for the bore size. Was the metal brittle?
44 posted on 03/23/2012 2:10:59 PM PDT by MileHi ( "It's coming down to patriots vs the politicians." - ovrtaxt)
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