Posted on 02/28/2012 8:40:36 PM PST by DogByte6RER
Navy fires up fully-weaponized railgun prototype
At the end of last month, the Navy got an early Valentine's Day present in the form of a prototype fully-weaponized naval railgun. And on Tuesday, it released a video of its first shot, which we're officially filing under "things not to get in the way of."
This prototype weapon, developed by BAE Systems, fires inert aluminum slugs out of a 40-foot barrel using nothing but megajoules of raw electricity. The giant gout of flame you see in the picture (below) comes from a combination of about a million amps of energy, the hypersonic speed of the round, and the aluminum in the bullet reacting with the atmosphere.
The ultimate goal here is to fire 10 rounds per minute with 32 megajoules of energy each, sending them between 50 and 100 miles downrange with flawless GPS-guided accuracy, at a speed that's so high that when the rounds hit their target, they'll be carrying the equivalent amount of destructive force as a Volkswagen Beetle traveling at 100 mph.
32 times over.
In the video of the test (YouTube link posted below), you'll notice that the payload (the "bullet") is decidedly not streamlined. We know that Boeing has been developing some mean-looking streamlined railgun rounds, but apparently the Navy doesn't want to use them in these tests for fear of accidentally losing control of one and hitting the White House or something, instead opting for brick-like rounds that don't go nearly as far.
In April, General Atomics will deliver a prototype of their railgun design, "Blitzer," to the Navy so that it'll have two of these monsters to play around with. And by 2017, which is another way of saying a quarter of a billion dollars from now, the Navy might actually be ready to start thinking about deployment.
I think the moon is the only place where solar panels can be effectively used without wasting space and energy.
Install these there and you go yourself a nice launching pad for outer space probes.
If we didn't invent, make, use, and sell new and better ways to kill people then the entire USA economy would collapse.
I guess that explains why Obama is cutting military R&D.
Seems like rather than keeping things secret, now we have to let the world know our latest tech developments and plans.
The kinetic energy is Mass * Velocity * Velocity / 2.
Mp * Vp * Vp/2 = 32 * Mvw * Vvw * Vvw/2.
solving for Vp yields
Vp=100 Mph * sqrt(32* 2000/20) ~= 5657 mph ~= 8300 feet/second.
No wonder it smokes.
(Yes I know pounds is not a mass unit, but since only the ratio counts it doesn't matter what units are used, as long as they are the same for both masses)
The 1300’s built to 1776’s were pretty damn fast.
Ping
I’ll wait for the laser version, thank you.
Just think about what they could do with one of these guns two miles long, that fired subatomic particles - in space.
(SLAC)
Seems like some missed this:
“.. at a speed that’s so high that when the rounds hit their target, they’ll be carrying the equivalent amount of destructive force as a Volkswagen Beetle traveling at 100 mph.”
As in—”32 times over.”
The article doesn’t give a price for the gun but it sounds like the ammo would be pretty cheap (aluminum blanks).
getting there, but not quite that fast. Or potentially as massive.
In the video, the clip from the down-range aimed camera shows the projectile yawing from side to side as it responds to aerodynamic forces on its tail.
The yaw frequency in the video looks like it’s about 1/3 hz. That’s after it’s been slowed down by a factor of, like, 200 or 300 (very rough estimate there).
That means that, in free flight, that projectile is wobbling at between 60 and 100 hz. Magnitude of yaw looks to my eye to be maybe 30° peak-to-peak.
Now look at the size of the projectile as that Navy engineer puts it in the breech. It’s got to weigh 10-20 lbs.
For those of you with some mechanical background, just imagine the torque necessary to get an object of length ~16 inches, weighing, say, 15 pounds, oscillating through ±15° at 60 or 70 hz
Then consider that that thing doesn’t really have fins in the normal sense. It just as a sort of wide tail, hewn from a block of aluminum by the look of it.
We’re talking some serious speed here.
In case you were wondering about what I would like for my birthday..................
Actually, the kinetic energy in a hardened slug traveling at those speeds is pretty impressive.
Think of the penetrator from an M-1 tank APFSDS round. It’s only a chunk of depleted urainium (IIRC, it weighs around 20 lbs) but it’s going about 5000 fps when it leaves the barrel. Yet it easily slices through Russian main battle tank armor several miles away and routinely causes a catastrophic secondary explosion that blows the tank’s turret off of the hull. There have been instances where the impact alone was sufficient to tear the turret off.
The rail gun’s velocity is even higher, so, even with a smaller mass round, the force of its impact is tremendous.
The real engineering achievement of the operational rail gun will be in its electrical system. The objective is to have it charge, discharge (fire), and reload/recharge over 30 times per minute. And each shot has 32 megajoules of energy. Producing, storing, and managing the sequenced discharge of that much electrical energy, that fast, is not easily done.
(APFSDS = armor piercing, fin stabibized, discarding sabot)
Actually, the kinetic energy in a hardened slug traveling at those speeds is pretty impressive.
Think of the penetrator from an M-1 tank APFSDS round. It’s only a chunk of depleted urainium (IIRC, it weighs around 20 lbs) but it’s going about 5000 fps when it leaves the barrel. Yet it easily slices through Russian main battle tank armor several miles away and routinely causes a catastrophic secondary explosion that blows the tank’s turret off of the hull. There have been instances where the impact alone was sufficient to tear the turret off.
The rail gun’s velocity is even higher, so, even with a smaller mass round, the force of its impact is tremendous.
The real engineering achievement of the operational rail gun will be in its electrical system. The objective is to have it charge, discharge (fire), and reload/recharge over 30 times per minute. And each shot has 32 megajoules of energy. Producing, storing, and managing the sequenced discharge of that much electrical energy, that fast, is not easily done.
(APFSDS = armor piercing, fin stabibized, discarding sabot)
The “bullet” may be pretty cheap, but the “powder” sounds pretty pricey.
Imagine the capacitors necessary to store and release such power. Cooling of the gun may not be the only thing limiting the firing rate. Those caps would take time to charge.
But think of your electric bill.
They had better fast track mounting and preparation of this gun fast. World war three is coming within weeks to months, IMHO
Hey, Rodney King got up to 85mph in an Hyundai.
The railguns were supposed to be installed in the Zumwalt class destroyers, which are 50% larger than the Arleigh Burkes, and are actually the size of early American Dreadnaughts or late WW2 cruisers. I don’t know how we are supposed to use railguns until we have better batteries and capacitors.
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