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U.S. Navy to Deploy Rail Guns by 2011
Walter Francis writes "The U.S. Navy has apparently been busy. They have been focusing heavily on the next generation of weapons and propulsion systems, including Microwave, Laser, and Electromagnetic-Kinetic weapons, more commonly known as railguns. What specifically surprised me was the fact that the Navy plans to deploy these systems as early as 2011, on their DD(X) frigates. The range of these rail guns is estimated to be over 250 miles."
Build your own railgun Today! Kids love this one!
For a fictional view of how devastating this could be, see Niven & Pournelles 'Footfall'.
The scary part is that we could do this with current technology. It would just be horribly expensive. But once launched, the owner would have the ability to destroy any selected square meter of the Earth's surface, and there's nothing anyone could do about it (aside from shooting down the satellite).
Railgun project
Don't forget ricochet range. A projectile that skipped off the ocean (for example) could wind up somewhere much farther downrange than 30 miles.
I've seen plain old ordinary machine gun rounds do some amazing and unexpected things. I expect that scales with velocity.
Interesting point from the article - the author sees this system fitting into existing 5" gun mounts, and sees one gun as being able to deliver equivelent fire as a squadron of F18s. That means destroyers become as powerful as aircraft carriers.
How about that - the return of the battleship.
DG
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Conservation of momentum. You cannot blow a projectile into "harmless" bits, because the total momentum of the pieces remains the same. Instead of getting hit by one big projectile, you get hit by a bunch of dust, or vapor, or droplets of liquid metal. The total impact impulse will remain the same.
You also can't just deflect the projectile, because the force applied to deflect the projectile would be equally applied to the deflector device. Even if you did this via a magnetic field, the deflector would suffer damage.
There's simply not much you can do to stop a projectile moving at such velocities.
All kinds of funny in the replies (I read them all at +1 -- pity me), but not much serious.
:)
For example -- even the first generation railguns have a muzzle velocity (intentionally limited) of 2.5 km/s (which is Mach 7.5, presumably at sea-level pressure -- the article doesn't say). That's awesome for aiming, time-of-flight, and kinetic energy delivery so great you don't even need messy exposives.
But, what about the sonic boom? I mean, even a small thing crossing the speed barrier makes a noise (ref: a bullwhip) -- how loud will it be on deck with n of these things breaking the sound barrier every 10 seconds?
Will they enclose them in something, build a sound baffle of some kind, or just issue really good hearing protection devices for those working in the vicinity?
Sorry to be serious and all, but I'm just curious
everything in moderation
A friend and I started building an EM rail gun for a high school science project in 1985. We didn't even know about any military projects. We just thought it was cool to accelerate a nail using solenoids. It was years later that I found out our idea was being pursued by the military, and I looked up what I could find on the projects to see how it differed from ours. Besides bigger magnets and more power, it functions very much like what we built. In our case, the inside of the gun barrel had a "railroad track" of wires that used the metal projectile to complete a circuit and conduct electricity (through the projectile) to the correct solenoid (the one that would continue to accelerate the projectile). The only problem we had was that part of the momentum of the projectile would be thwarted by the fact that the iron in the nail would stick to the wire when current was passed through. The military solved this problem by using a tungsten rod positioned above a wad of metal foil (iron or steel). The metal foil completes the circuit and also, due to the extreme amounts of electricity, vaporizes. The foil plasma vapors are then pulled along the magnetic field just like the nail in our experiment, but without the sticking problem. The accelerating (and expanding) vapors push the projectile through the barrel, causing it to exit with astounding velocity. This kind of weapon goes through armor plating like a knife through butter.
GreyPoopon
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I was an FTG for six years (basically electrician for big guns). I can't imagine how they are going to get a fire control solution for a target 70 miles away. Without guidance, and at that distance the different weather cells between you and the target would throw the round off target.
I stood about 100 yards away from the New Jersey when she fired all guns starboard. The heat & energy from those guns was incredible. Image an order of magnitude higher. Those little aluminum FFG's would melt their superstructure with one round.
Range of 250 miles? That's impressive.
The era of the big gun pretty much ended with the battle of Midway. After that, it became obvious that aircraft carriers could both defend themselves and attack enemy shipping without need for battleships and their guns. (Or, more to the point, without big guns and the battleships needed to haul 'em around.)
But I wonder what this development means? The railgun projectile is better in several respects than a missle: cheaper, higher rate of fire, harder to spoof or shoot down, apparently more hitting power. It seems to me that this railgun is closer to carrier based aircraft in relative performance than any guns have been since before WW2.
It's almost enough to make one think that the big gun could be effective again. Envision the "bad guys" having a submarine with railguns sneaking up to within 200 miles of a carrier battle group. It could surface to rapidly launch a few dozen hypersonic projectiles at the carrier. If it could launch a big salvo rapidly enough, the carrier would be in a world of hurt. The sub probably wouldn't survive the counterattack, but to disable a carrier that's probably a good trade.
Can an effective ASW umbrella be extended to beyond the range of these guns?
Hmmm.
With reasonable men I will reason; with humane men I will plead; but to tyrants I will give no quarter. -- William Lloyd
Iirc the impact area of a sonic 'boom' is the cone created by the leading edges of the projectile, and it extends laterally away as the projectile moves at greater than mach 1 (not just while it 'breaks' the speed but at all times when it exceeds the speed). This means that the crew and the entire ship will never be in contact with the shock cone, so it will essentially make no noise at all during travel. It will make noise im sure as its fired, but probably nothing compared to a gunpowder projectile.
Am i right, or has high school physics failed again? (or rather did i fail physics...)
jeff
What I meant is that it is much smaller than cannons of comparable power -- of which there really aren't any. Being able to fit something with that much range and power on a destroyer is a big step forward.
A cruise missle isn't really that small -- currently they are fired only from destroyers and cruisers, or large submarines. Each missile is large, having to carry both the fuel and the warhead. While the rail gun itself is larger than a cruise missle and launcher, each rail round is much smaller and much safer since it isn't a mix of high explosives and rocket fuel waiting to be hit by enemy ordinance. And if its speed you want, then the limiting factor is mass, and you can get a lot more rounds for less mass with a rail gun.
I don't see what the distance to the target has to do with its value... Why spend half a million destroying a warehouse when you can use a comparitively free lump of metal?
All in all, I think rail guns are a vastly positive improvement in weapon mobility. I don't see missles as having any advantage, outside of extra range.
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Probably not, but from the articles I've been reading, they're having one hellva time with barrel friction at this stage of development. Every shot is quite literally ripping the barrel apart. Once they nail that down , it'll just be a matter of inflight guidance. Other fun facts-- Did you know they will need to divert power from the engines to bring this thing online? Having Scotty divert power to the weapons has a whole new meaning ^_^
How prophetic of me...
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