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Navy Gets 8-Megajoule Rail Gun Working
prototypo writes "The Free Lance-Star newspaper is reporting that the Navy Surface Warfare Center in Dahlgren, Virginia has successfully demonstrated an 8-megajoule electromagnetic rail gun. A 32-megajoule version is due to be tested in June. A 64-megajoule version is anticipated to extend the range of naval gunfire (currently about 15 nautical miles for a 5-inch naval gun) to more than 200 nautical miles by 2020. The projectiles are small, but go so fast that have enough kinetic punch to replace a Tomahawk missile at a fraction of the cost. In the final version, they will apex at 95 miles altitude, well into space. These systems were initially part of Reagan's SDI program ("Star Wars"). An interesting tidbit in the article is that the rail gun is only expected to fire ten times or less per day, presumably because of the amount of electricity needed. I guess we now need a warp core to power them."
But I was thinking, is this a possible way to launch orbiting vehicles? I first think no, as the initial force necessary to 'shoot' something into orbit would probably destroy any delicate instruments needed for a working satellite.
However, this seems very interesting as an Anti Satellite/"Star Wars" platform. If they can get the software working to intercept, this should (scaled up version) be able to knock out satellites, ballistic missiles, etc - shouldn't it?
It could be worse, it could be Monday.
if you can only fire 10 per day.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
I'm a member of the NRA, I didn't see this in the last catalog.
What happens to the projectiles in these things? Such a gauss density I would assume, beyond simply the accelleration of the projectile has to be considerable. The coin shrinker is only 1600-2500 J
Assuming 2500 J in a space of 3 mm does to an object the size of a quarter, 8 mega Joules would have an equivilent magnetic density spread over a gun 96 metres in length. Or me math is fscked...
A feeling of having made the same mistake before: Deja Foobar
An interesting tidbit in the article is that the rail gun is only expected to fire ten times or less per day, presumably because of the amount of electricity needed.
If only we knew when lightning was due to strike some sort of a clock tower? Surely, then, we could harness the power needed.
If that doesn't work, perhaps some new technology involving trash?
The Free Lance-Star newspaper is reporting that the Navy Surface Warfare Center in Dahlgren, Virginia has successfully demonstrated an 8-megajoule electromagnetic rail gun.
Yeah, but can you headshot with it from the far platform on the Longest Yard?
The theory of relativity doesn't work right in Arkansas.
by June they'll get the quad-damage powerup working?
So, do the electrical power requirements for this mean that the Navy will once again be building nuclear-powered ships?
Insisting on "correct" English is like saying that there is only one, definitive recipe for chili.
I have *never* understood how railguns work. Here is an explanation, although it still leaves me frowning and making funny shapes with my fingers all stretched out.
One presumes there are sonic booms associated with this. Anyone know if they're louder or quieter than the explosions associated with heavy ship artillery?
Nostalgia's not what it used to be.
How many million-dollar cruise missiles are you firing a day?
Most likely it will end up as an augment. One of the virtues of this system being, though, it can set up a shot quicker than a Tomahawk.
Has anyone else found out about these guys?
It's an old site but it's still just as awesome. I almost considered trying this out myself but I'm not exactly sure if such a thing is legal.
It will allow the US Navy to miss targets from much further away.
Once I was a four stone apology. Now I am two separate gorillas.
The Navy isn't estimating a price tag at this point, with actual use still about 13 years away.
I think they mean deployment, unless the Navy knows something Congress doesn't. Which wouldn't surprise me.
Did you read the original post? It says it can go up some 90 miles before coming back down. If thats not an arc, I dont know what is.
Perhaps a sufficiently high arc can disguise this as a meteor* strike if it goes unannounced and unnoticed by radar.
*Meteorites leaves evidence. Meteors can explode in midair.
Cool to think about....
Basically, its a magnetic rail gun for launching space-craft into orbit. And in order to avoid the crushing G-forces involved, it has to be hundreds of miles long. So, while it may not be economically or politically viable, it is technically feasible. We know how to build a launch loop, as opposed to a Space Elevator, which can't be constructed with current technology.
-Sean
32 megajoules is less than 9 kilowatt hours.
Heat might be more of an issue. That would be over 30,000 BTUs, or a 60 degree rise in a quarter ton of cooling water.
A 32-megajoule version is due to be tested in June. A 64-megajoule version is anticipated to extend the range of naval gunfire (currently about 15 nautical miles for a 5-inch naval gun) to more than 200 nautical miles by 2020.
Nobody will ever need more than a 64 Megajoules rail gun.
With this new rail gun technology, the US Navy now has a serious fire support asset in its Iowa and North Carolina class battleships. All they have to due is overhaul the power generation systems to handle these things and an Iowa class battleship would be capable of launching 90 16" projectiles and 200 5" projectiles a day via modifying the the main and secondary batteries for rail gun tech. In much more significant terms a Iowa class battleship would be able to deliver a broadside salvo of 9 16" rounds and 10 5" rounds on a target. Thats a lot of firepower!
Running a few quick calculations shows that power is not likely the cause of the delay between firings. If you have 10kW to power your system, you can fire a 64MJ blast every 1.78 hours. If you have 100kW, time to fire is only 10.7 minutes. Obviously for the smaller railguns the power requirements are even less. I'm no expert on how much power is actually available on those big boats, but somehow I doubt that 100kW is out of reach.
I believe that the time to fire is more likely dominated by the maintenance issues - making sure that the rails are perfectly straight, the warhead is correctly placed, etc. If you're off by even a little bit that sucker could destroy the railgun on the way out, costing you millions and making it inoperative until you're back home.
augment your senses: http://sensebridge.net/
Come on, if you could fire a projectile 200 miles, you could just mount these on coastlines, serviced by ground-based power plants. True, it wouldn't replace navies ENTIRELY, but it would suddenly become extremely UN-economical to have one with even the slightest capability to get near a shoreline. Pushing back aircraft carriers 200 miles would severely reduce the flight time of the planes, which now have to fly a lot farther just to get to the coastline, let alone targets inside countries.
On the plus side, land-locked countries can now hunt whales for food. :)
I like to place meaningful quotes in my sig, so people will know that I know what meaningful quotes are.
I'm almost positive the main issue is not electricity generation but rail friction. The best rail guns I'd heard of until today needed completely overhauling after each test firing because the rails themselves are damaged so badly as the projectile passes. Coil guns are better in this respect, as the projectile doesn't have to touch the coils...
qntm.org
Its advantages are obvious - each round is cheap, it doesn't get lost and end up as a technology or a munition 'giveaway' (or bad press), and as the article says, reaction time can be rapid. It means that the next class of boats are merely floating powerstations with all the 'goodies' held far away from the action. Besids, a rail gun is not just line of sight, as with any ballistic weapon, unless you can see over the horizon. I guess the main limiting factors in use would be those of ablation - both to the rail and projectile.
a 60 degree rise in a quarter ton of cooling water
A cubic foot of seawater weighs approximately 64 pounds. A quarter ton, or 500 pounds, means this thing would raise less than 8 cubic feet of seawater by those 60 degrees. (A cubic foot of fresh water is 62 pounds, so the difference is negligible) That's a miniscule amount of global warming that this thing will add to the ocean each time it fires. And with entire oceans to heat up I doubt the Navy is too concerned about that environmental impact.
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...these would almost replace Navies.
I believe a Navy does a lot more than just throw shells at buildings. That aside, you'd probably have a hard time hitting an even slightly moving ship with one of these at any range, let alone finding the ship in the first place without any of your own. After all, if the ship makes a slight random adjustment to course every six minutes or so (travel time of the shell at maximum range), then they're reasonably safe--especially if we assume that each gun could only fire at the maximum noted rate of ten shots a day, which means they get a shot every few hours or they blow all their shots in a few hours. Mounting these on shorelines is a waste.
Excellent point. Here's a quick reference from the Wiki article:
Full-scale models have been built and fired, including a very successful 90 mm bore, 9 MJ (6.6 million foot-pounds) kinetic energy gun developed by DARPA, but they all suffer from extreme rail damage and need to be serviced after every shot. Rail and insulator ablation issues still need to be addressed before railguns can start to replace conventional weapons.
Being able to launch one is a great accomplishment. The question is: Where will it hit? Unlike a Tomahawk, it's unlikely you can install a GPS receiver in the "bullet" because of the high launch g-forces, so using terminal guidance is probably out. You'd have to rely on the initial launch trajectory, which at a range of 200+ nautical miles, means the result will likely be a miss, rather than a hit.
Of course, if they get the rate of fire up high enough...
Chip H.
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During a 5-second 'shot', when the stored energy was released, the motor, generator and flywheel would go from 480 to ~100 rpm, and dump 960 mega joules of energy into the coils of the experiment. You could feel the vibration in your feet anywhere you stood at the site, all the CRT's images would collapse due to the intense magnetic field generated. Then it was another twenty minutes before they could do it again.
Slashdot's name? When my compiler sees
I think it's great that research is being undertaken since this could be useful for other applications, but am I the only one scratching their head as to why the military is making a big push for these?
I assume a gun like this would go onto a destroyer. I can't think of the last time a destroyer was used in any meaningful way in combat since WW2. If I remember correctly, the only reason the navy even keeps destroyers is because congress forces them to. I guess you could put it on a tank or something, but most conflicts that are fought now are on the ground and are more guerilla tactics than formal engagements. It's being shown in Iraq and Afghanistan that all the fancy new technology that the military keeps buying doesn't really mean squat when it comes to fighting a war.
Am I missing something here?
Shoot 11 missiles at the ship, when everyone else shoots 10.
Wait a second... I guess the country who has the most prolific use of satellite for military is the states. So could this technology comes back and bite our own ass?
From the above, I'm assuming they have a reasearch project underway that would directly translate into launch survivability for the hardware. I'm not a electrical or mechanical engineer, but I'm going to guess that electronics embedded in high-impact composite ceramics (a la tank armor) might be the ticket here. The rocket engine and the fuel are another story. My understanding is that solid rockets are relatively simple construction (compared to liquid) so they would be the best candidate for survial. Pretty much every weld or joint I can think of would come apart under those kind of forces, so the fewer parts the better.
This reminds me of a proof-of-concept model built by by Dr. Emmett L. Brown, except he was capable of creating greater acceleration using only twenty-one gigawatts of electricity, and he utilized flux-capacitor technology which did not require overhauls after every use.
100kW is around 134 hp. There are motorcycles capable of generating more power than that, and a single cylinder of a ship's diesel makes more than that, too.
boldly going forward, 'cause we can't find reverse
Hmm, I wonder if, instead of nuclear missiles, we could just have nuclear generation powered railguns that could lob comet-like projectiles, thereby have the same kind of initial devastating effect, but without all the problems of nuclear fallout and radiation.
I mean, it's true that nuclear weapons have basically brought peace to modern nations through the principle/doctrine of mutually assured destruction (thats why, for example, all of Europe isn't Soviet Union now -- Russia forced to stop taking over stuff and be peaceful or else get nuked).
Maybe a new doctrine of mutually assured destruction through the crushing of cities through colossal projectiles with ungodly kinetic energy would still provide the umbrella of traditional MAD, but without that tiny little problem (which will never go away as long as there are nuclear weapons) of the potential of some lunatic dictator, who cares more about being in power than he cares about whether or not the rest of life on planet gets wiped out by radiation poisoning, getting his hands on nuclear weapon.
Take the example of the M-1 Abrams. The main gun on this tank is stabilized in some way to allow accurate shooting while on the move. I'm not sure of the details behind this, but I'm sure mounting the railgun on some actuators controlled by some gyros will be able to minimize the pitch from the ocean.
HARP died because Remo found out it was all a scam.
Actually it's the other way around, the sound of the shell makes very little sound compared to the crack of the bullet.
from wikipedia:
Another important factor in sound signature suppression is the muzzle velocity of the ammunition. In weapons firing supersonic bullets, most often rifles, the supersonic bullet itself produces a loud and very sharp sound as it travels downrange. This is often referred to as a ballistic crack. For this reason, it is more difficult to hush the sound signature of these firearms effectively. Subsonic ammunition reduces sound report, but has a lower velocity than supersonic ammunition and is thus less lethal and has a shorter range.
Man is the lowest-cost, 150-pound, nonlinear, all-purpose computer system which can be mass-produced by unskilled labor.
Wow, 200 posts, and not one complaint about railgun campers. I guess nobody plays Quake anymore.
"Times have not become more violent. They have just become more televised."
-Marilyn Manson
I WANT ONE! (The other 10% are holding out for the 64 megajoule model).
[Insert pithy quote here]
"Electric" does not mean "electronic." EMPs will affect ICs, but if I were to build the same thing with a crapload of vacuum tubes, it would survive a blast without a problem. It is the delicate nature of ICs that lead them to be affected. I have a nice old VW Bug that would survive an EMP without a problem. The radio might have a problem (though it is all transistor, no tubes and no ICs, and I haven't really paid much attention to how well transistors survive an EMP because it isn't really relevant), but everything else will work fine, including the headlights and electric ignition. If the EMP was strong enough, it could cause the starter and alternator to fail, but at those levels, the car would likely have to be close enough to the blast that the mechanical pieces would be affected (the EMP is the least of your worries if the vehicle is vaporized).
Given the most simplistic versions of this, it could be an all-mechanical firing mechanism (some guy in a room throwing a huge switch). I expect that it could be integrated into the ships systems with ICs, but they would be hardened, and if it is done the "military way" then there will be a manual way of doing it in an emergency. A diesel engine that charges a flywheel and supplies power to this thing would be completely unaffected by an EMP. But I wouldn't want to be the guy that flips the switch on this.
Learn to love Alaska
The most surprising thing to me was the terminal velocity of a lead bullet--around 80mph. I would have expected higher from such a dense metal.
The kinetic energy of the recoil will be precisely equal to the kinetic energy of the projectile.
With that said, the Navy has had decades of experience in dealing with guns that make your whole battleship slew sideways when fired. There are ways to absorb and/or re-direct the recoil.
Clear, Dark Skies
The army has successfully tested self guided howitzer shells. The electronics have withstood 16,000Gs. I think they can make electronics that can withstand a railgun.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
Use the rail gun to launch a big, heavy projectile into orbit.
Attach projectile to giant bungee cord.
Attach giant bungee cord to object you want in orbit.
Give object giant scissors.
Expanding on this, you could tie one object with several rubber bands to several projectiles.
paintball
Apparently this gun will fire a Ford Taurus at 380mph.
Does anyone know if Clarkson or Hammond have expressed an interest ?
You can have very strong mangetic fields without them leaking all over the place - you just need to give them a preferential path to flow though. You'd have to assume they've covered that base - after all it would improve their efficiency to be using high permeability cores rather than free air.