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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.
http://www.eve-online.com/ They have a wealth of knowledge with warp cores, power requirements and railguns. I forsee great things for all... just don't use Minnie BPOs.
One of the 187.
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.
All we do is park one of these badboys off the coast of Iraq and blast the Insurgent bases to smithereens. Score one for the good guys.
..more like ZPM.
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.
High energy physics, baby! Makes me all weepy...
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.
Okay, now we just need some legs for this beauty, don't we?
Soon to replace the BFG in Doom.
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.
ought to be enough for anybody.
Great! And how will this weapon solve the Iraq debacle or get rid of suicide bombers?
All it needs is 1.21 gigwatts
why it increases in powers of two? Maybe, then, it should be mibijoules, so that we know for sure that we're getting our money's worth for each kibidollar of taxes?
I can assure you, the best way to get rid of dragons is to have one of your own.
Please RTFA: even the summary states that the projectiles will reach up to 95 miles of altitude. They're not just firing the thing into the air willy-nilly--that projectile is, yes, being arced to its destination. 5-inch cannon shells must arc to reach the extent of their range, so why not these projectiles?
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/
From the TFA "... will extend it's range to more than 200 miles and strike a target that far away in six minutes". So that's 200 miles in 360 seconds, or 2000 miles / hour. That's not really all that fast, it's a muzzle velocity of ~2933 fps, and the projectile weighs 3.2 kg
Yeah, it's a lot more than a bullet, but I don't see how something that size at that speed takes out a building. Or am I missing something?
Where are the screenshots!
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.
Well, if you look at the summary, it says:
Travelling 200 nautical miles, and reaching a peak height of 95 miles, I would say they plan on having something which both covers distance, and can be lobbed onto the target.
So, I think both of your issues are addressed in the summary. They will be able to shoot farther than they can now, and do it at pretty high altitudes.
Cheers
Lost at C:>. Found at C.
is IRAN!
Richard Steven Hack - This sig is TOO GODDAMN SHORT TO DO ANYTHING USEFUL WITH! MORONS!
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.
But then aren't most of that amazing speed (and thereby, kinetic energy) lost, or do these projectiles have guidence to steer them over the curvature of the earth, not relying on gravity?
The rotation and curvature of the Earth. Accurate long range ballistics can be demanding mathematically.
In traditional artillary tolerances in gun tubes, rifling bands, propellant charges and shell mass also have an impact; which is why it is usually used for area fire. But as other posters have pointed out, GPS and/or laser and/or radio guidance can help out.
putting the 'B' in LGBTQ+
Now, what happens to birds when you fire a gazillion of these things into sky. On a cautionary note - please keep it away from Dick Cheney.
You will never have experience until after you needed it.
it's not line of sight. Note the "suborbital" phrase in the summary?
The cesspool just got a check and balance.
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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.
From TFA: "Railguns are also portrayed in the "Stargate" TV series and in many video games, including "Halo 2."" Halo2? What that article really needed was a Quake II shout out. Damn kids...
95 miles altitude? reenter from out of atmosphere ? while carrying complex electronic for GPS navigation?
Most movies and documentaries attest that, when reentering from space, the communication between NASA and the space crew is off , due to excessive heat on the vehicle; and that gizmo is supposed to navigate out of GPS, while free falling at the highest possible speed (to maximize impact damage)?
I hope they did their math correctly, and computed the heat of air friction correctly... otherwise the navy will sport the first artificial falling star generator in history
64-megajoules is 17.8 kilowatt-hours. Even assuming the gun is only 10% efficient, that isn't so much power. To put it another way, to fire the gun every 64 seconds at 10% efficiency takes 10 megawatts, or 13000 horsepower. Destroyer turbine engines put out considerably more power than that. What am I missing?
How do they plan on keeping the thing stable enough to hit targets accurately 200 miles away at sea?
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.
How are they going to deal with the fact that they are trying to mount these things on ships that are floating in the middle of the ocean and are subject to the rise and fall of the waves? I have to imagine that the angle of the barrel in relation to the horizon has to be changing by a pretty significant amount of degrees.
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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Just to put things in perspective, a tomahawk is capable of flying 1,500 miles, and then passing through a 1 meter square window (through which of course the wings cannot follow) and detonating its payload, which can be high explosive, a tactical nuclear warhead, an EMP device, or any of another broad assortment of items.
Granted the commanders don't expect a tomahawk to be that accurate more than one time in ten, but they seem to do it about half the time.
Tomahawks can also do things like be programmed to follow waypoints. You can fly one up a canyon (it uses a combination of GPS and other data, including bitmap images of the target and points along the way) and hit a target that isn't reachable by a simple ballistic trajectory. So they're not going away any time soon, we'll just use a lot less of them. A tomahawk can fly around a building and blow up a shorter one behind it, a railgun projectile can't.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
They should propably also contact this guy for proper bridge design, wich would be a logical 3rd. step...
...sorry:
640Kjoule is enough for anyone.
Mastering the English language is fucking easy: all you have to do is to put an f* word in every fucking sentence.
I built one back in the early 70's as a science fair project. It shot pennies at a very high velocity, high enough to go right through the back wall of the garage. It worked on a slightly different principal as the Navy one. Instead of using the magnetic field to propel the projectile, it used a piece of copper foil folded accross the penny, connecting to a pair of copper rails about a quarter inch appart. When a car battery was connected accross the 2 rails, the copper foil is vaporized, shooting the penny out the far end at a high velocity. It was a blast.
cd pub
more beer
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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
It's about time! This is the option that I've really been waiting to put in my battlemech.
I've pretty much given up on the cup holder, though.
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?
As soon as they can fire more than 5 per day, the civilian-tech generator will be driving my car.
0-to-60 in 4 seconds, with no noise, on railgun tech. Yeah baby!
668: Neighbour of the Beast
I'd use it to disable overly loud car stereos.
"You'll get nothing, and you'll like it!"
Shoot 11 missiles at the ship, when everyone else shoots 10.
Wouldn't a nuclear blast - tactical or otherwise - OR an EMP device fry a ships ability to fire these? Can someone clearify?
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Possibly not. Keep in mind destroyers can also be used to defect incoming missiles directed toward carriers. I'd imagine this rail gun system could be integrated with whatever replaces AEGIS, which was the system used to use massive automated machine guns to intercept incoming projectiles.
Possibly overkill, but I'd imagine a smart system could also intercept crazy suicide bombers, as in the case with the USS Cole.
So, what's the recoil of one of these things going to be like? And, how will that effect a boat?
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?
Take a look at these two quotes from the article:
Because the gun uses electricity and not gunpowder to fire projectiles, it's safer, eliminating the possibility of explosions on ships and vehicles equipped with it. The projectile fired yesterday weighed only 3.2 kilograms and had no warhead. Future railgun ordnance won't be large and heavy, either, but will deliver the punch of a Tomahawk cruise missile because of the immense speed of the projectile at impact.Now, wait a second. If the projectile delivers that much energy, then the railgun must be handling that much energy plus some. If somehow that railgun were to mishandle the energy, say if there were some kind of short or some component failure, then that Tomahawk cruise missle punch could happen at the railgun instead of at the target.
I'd HARDLY say that is "...eliminating the possibility of explosions on ships..."!! I hope the Navy brass aren't buying that line!
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.
What's the recoil on one of these suckers? Since there's not an actual explosive reaction, I'm not sure if it would be all that much, but given that actual ballistic output of the thing I'd imagine that if there were recoil it could be a bitch to deal with...
It could be a power issue related to charge time, It might require that much power to run, however each shot could use more power then that overall by charging up large capacitors.
Personal Website
256 megajoules ought to be enough for anyone...
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
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Not getting this, are you? You shoot it up at a very steep angle, sort of like a howitzer. It clears the atmosphere fairly quickly losing some of its kinetic energy. it coasts through its trajectory and comes back down where it grinds through the atmosphere losing a bit more, but retaining a good amount since I'm betting the projectiles will be extremely aerodynamic, sort of like the rods in the old proposed Thor satellites. At that point it impacts and destroys things transfering most of the kinetic energy to waste heat.
this is my BOOMSTICK!
Shouldn't be too hard for a ship in LEO to capture such a payload - after all, it has a known and predictable trajectory.
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.
It's been a given that any electromagnetically launched spacecraft would be equipped with maneuvering rockets -- indeed, most of the catapult designs that have been floated around have the vehicle firing rockets relatively soon after launch. It's basically an issue of payload -- the railgun will fire fairly lightweight projectiles at very high speed; adapting the technology for a multi-k-kilo vehicle should be possible, but there are going to be huge tradeoffs in terms of velocity and secondary propulsion requirements. And. as you note, some way of applying delta-V once at the preferred altitude.
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.
Unless it has GPS tracking or control, there is no way that a shell fired over 200 miles, with an apex of 95 miles up, at over 2000fps, would have any of the necessary accuracy to make it worth it. Wind resistance, air currents, and the rise and fall of the ship by a mere half inch would throw off the trajectory to be not feet or yards off-target, but miles.
Another field where electricity is good. So in the next world war 3 there will be no polution :)
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
Garnett compared that force to hitting a target with a Ford Taurus at 380 mph. "It will take out a building," he said. Warheads aren't needed because of the massive force of impact.
UM...only 380 MPH? How fast were those planes going on 9/11?
I WANT ONE! (The other 10% are holding out for the 64 megajoule model).
[Insert pithy quote here]
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It's the stress of the launches on the rails that limits how many can be launched. I bit a small test rail gun and the amount of stress on the rails is signifcant, so much so that you would have to replace the rails after almost every launch. It's actually significant that the rails can be used ten times.
When can I buy one, and will it enable me to insta-kill every n00b caught in a ladder?!
Is there any particular reason why these (proposed) guns are all rated at powers of two?
Surely that system has no use outside binary computing...?
Nobody else has this sig.
Using the Extended Range Guided Munition 5" MK45 Mod 4 Naval guns have a range of approximately 60 nautical miles, not the 15 mentioned in the summary.
It has been a while, but sometime last year I sat in an airplane next to a guy working on a railgun presentation.
I did not get to read all that much over his shoulder, but I know the speed of these projectiles is measured in kilometers per second. My memory is kind of fuzzy, but the number 3.2 KMps keeps popping into my head. Also, I remember there being two different diameters of projectile, one of which was 38mm. I was about a year ago though, so I don't remember all the details.
A sabot round? The projectile being the actual round with the rails being the Sabot - ejected by the force of the plasma? Use an asymetrical round to ensure orientation, use 1/2 the surface as one pole & the other half as the other, all focusing on the rails themselves. Might be able to buy you enough surface area to avoid welding the sabot to the chamber.
Now we have something to fight off the Cylons!!!!
We need one of those MS-style TCO reports.
Engineering is the art of compromise.
6 minutes, 200 miles. Is ~2000 MPH, but it's also going 95 miles up
I know this isn't the best way to look at it but figure 1/2 way is 100 mile and 95 up a2 + b2 = c2 so
it's 137 * 2 , up and down, so 274 so we are more like 2740 MPH.
But it's an ark so maybe more like 4000 MPH. to really cover the 200 Mile trip.
but then it would be essentially free falling from 95 miles upright?
Wouldn't it evenually hit a terminal velocity from air resistance?
And what about air resistance going up?
Does anyone know the math to figure out how fast it would be travelling on exit and impact?
How much energy is really imparted into the projectile? and how much is turned into heat at the gun site?
I know I am not up do doing the math without a week of research at the library, but my gut instinct tell me that anything far past the horizon (50 miles) would have little more impact then a small meteor falling down.. Right?
John
I am always doing that which I can not do, in order that I may learn how to do it. - Pablo Picasso
This would be perfect for Chinese ... One billion of ships with this inexpensive guns with one Chinese ...
per each each ship
No one could stand against such Beowulf cluster !!!
ehy, I got yer megajewels right 'ear!
Metal.. Gearrr...?
He compared the process to charging up a battery on the flash of a digital camera, then pushing the button and "dumping that charge," producing a magnetic field that drives the metal-cased ordnance instead of gun powder.
So if it were possible to track the shell at those speeds, if you had an important building to defend, could you not use a magnetic field pulse to defend against it? I understand it would be pretty much impossible to create a field with the same strength for an entire building, but you don't need to stop the shell cold, just slow it down enough so that the entire building is destroyed.
http://bike.stu.ph/rides - free GPS routes available for Garmin, Magellan, GPX and Google Earth
How cool would that be?!?! Duplicate and mobilize the current version, take them to Afghanistan and use them for cave busters. No more multi-million dollar bunker-buster missiles to worry about. At $1-2K each we could fire these puppies all day long into every cave they got. No more cave-rats...
SPOILER ALERT!
For those of you who never played it (or its Gamecube rerelease), the Metal Gear was built with the intent of launching nuclear weapons using a railgun, sidestepping the Strategic Arms Reduction Treaty requirements calling for the elimination of ICBMs.
What sound do people on rollercoasters make? Hint: it's not Xbox 360.
...the US Navy is looking to hire the guy who lent his voice to Unreal Tournament to add "MMMMMMMMONSTER KILL!" to ship audio.
A little while ago there was a proposal to launch small orbiting "parasols" that would reflect solar heat and help stop global warming (http://earthobservatory.nasa.gov/Newsroom/MediaAl erts/2006/2006110323537.html). As proposed, they would be spacecraft with circuitry, but the proposal did call for electromagnetic launching (i.e., railguns). I would think you could also send reflectors without circuitry; they would be reflective chaff, and they would need more frequent replacement, but what the heck. Railguns are loads cheaper than rockets.
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
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And yet, I know that many, many people will be so enamored with the sexy-sounding hype that they will be pleased to have their hard-earned taxes spent on it. It fits in so well with The War on Terror and other sucker-stories that our Hypnotoad representatives have been feeding us.
...are we scared yet?
I assure you that the energy expended in getting fission products into the sun exceeds the extracted energy from said spent fission products by a large margin.
So no, sending shit into the Sun is NEVER A SOLUTION.
Thanks.
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
Ye gods. Just what sort of fucking ultra-morons have we got reading slashdot these days ? People who think a megajoule is a huge amount of energy, rather than enough to boil a kettle ? People who think we need to give ships nuclear reactors to give projectiles the energy of "a Ford Taurus at 380 mph".
Retards. Absolute fucking retards.
Alright, I built a Coca Cola rail gun and I used 1493 gallons of Classic Coke and it blew up because you forgot that food Calories are kilocalories. You really only need a twelve-pack. OK, maybe a whole case because building a rail gun is thirsty business.
A megajoule (MJ) is a unit of "work" - one watt for a duration of one second. 1 kWh = 3.6 MJ, which means that 16 MJ is less than $1.00 of electricity if you get it from the power grid. The engines on jet fighters and the like generate megawatts of power on takeoff - not as electricity, but as physical power to get the aircraft off the ground.
A pound of TNT releases 1.9MJ of energy when it explodes.
The main problem is - hopefully this is obvious - creating a mechanism that can create, contain, and release megajoules, and making it small and portable. (Excluding of course "mechanisms" like sticks of TNT or, more to the point, pounds of gunpowder.) The USAF Airborne Laser works in the megajoule range, but the energy is released with a megawatt-class laser over seconds, not a fraction of a second as it has to be in a railgun.
The platform for the still-experimental Airborne Laser is a 747 and it carries chemical fuel for only 2-3 dozen shots, so obviously anything resembling publicly-known existing technology for a railgun system will have to go on something the size of a ship, or if on land, several trucks. The Army has a new power system, the MEP-PU-810A/B, that can generate a little under a megawatt from a single tractor-trailer sized unit.
A Navy official suggested to us that we replace Cruise missiles with railguns on a few ships here as an evaluation. I was skeptical at first but he explained the benefits of using it for our day-to-day enemy shooting. So I decided to let him install the railgun over 5 ships to see how the ship crew got on. Besides, our Navy warfare manager had been using one in his submarine and it seemed to work fine, why not try it on our battleships ?
Once he'd got the machines up and running we let the crew try it out. It all seemed fine to start with: shooting score was pretty good and the crew could still do their work as normal.
Alas it did not stay that way. After a few days, I had lost count of the number of complaints received from both crew and officials who could not find things they were used to or tasks they could not perform that they previously could with our Cruise missiles. The final straw came when one crew member lost several hours of duty when the railgun suddenly had an error shooting against an enemy ship, and sent the barrel miles away from the target.
Needless to say, the railgun team offered no support whatsoever. I made the official remove the railgun from our ships and lets just say he's no more sailing with us anymore
...you could hit anyone, anywhere, on short notice.
All is Number -Pythagoras.
The Quake 4 Railgun is like 30-Megajoules
We need more Jiggawatts!
Ginga no Rekshiya Mata Each page.
i didnt read anythign that actually specified rail or coil gun, i imagine they use rail gun cause it sounds cool, but i would think a coil gun to be more effective in a naval sized application
Chris
...an Iraqi teenager blows your goddamn legs off with 20 bucks of explosive in a coffee can.
There's an audible "crack" as a bullet passes over your head. That's the sonic boom. It's not deafening, but you can definately hear it. I know this from being in the "butts" on various rifle ranges. The "butts" are where the targets are. Essentially, concrete bunkers that allow people to lift the targets up and down so that the shooter can have each shot marked to them (using a big pointy arrow, really).
What you hear is the "crack" of the bullet passing overhead, immediately followed by the thump as it hits the earth embankment behind the target. You can tell when it's your target that's been hit (since the crack is immediately above you) - and you have to listen for it, the thump doesn't give you enough directional hints to tell if it was your target or the target next door.
If this thing has an apogee of 500,000 feet, it can shoot down satelites. For a moment, just think about how huge that capability is. Considering how much data is shuffled around via communication satelites, being able to deny a nation state that capability is huge.
Yes Francis, the world has gone crazy.
Could anyone explain to me if using one of these mega-powered rail guns would create a feasable means to build underground tunnels? I mean it seems like something with this much power (and using the right projectile/drillhead/whathave you) could put some serious hurt on a mountain in close-range proximity, but what if it was put underground, how could this be used to build tunnels?
Tunnel building is a slightly OCD interest of mine.
Government seems to love coming up with new and "wonderful" ways to kill indiscrimitantly at lower cost.
The nuclear bomb is the biggest of such atrocities. Now it can be done even cheaper. Nevermind how you are expected to aim such a high-velocity long-distance projectile with no guidiance system with any level of accurcacy to make it worhwhile, anyway.
Maybe we can grab this bad boy, get to the moon, and do an actual "The Moon is a Harsh Mistress" scenario...:-D
Ruby Neural Evolution of Augmenting Topologies
http://www.youtube.com/watch?v=o735Fg7-Yzc&mode=re lated&search=
Unfortunately the energy required will make us all blocky and polygonal.
To put the range of this weapon in U.S. centric perspective, a ship armed with one of these guns off the Pacific coast could hit targets as far inland as Reno, NV. One off the Atlantic coast could hit Pittsburgh, PA. That's pretty darn impressive.
I like my beverages with warning labels!
Aren't most ships made out of metal, these days? What would be the possible side effects of such a strong magnetic pulse in proximity to, let's say, hull plating? Magnetized ships seem like a bad idea when you think about the composition of land mines (metal) and other munitions. Anyone more of an expert in this area?
- Sometimes you're the pidgeon, sometimes you're the statue.
You mean something like this http://www.metalstorm.com/
A game has objectives and is competitive, anything else is just play
This strikes me as a good design—after all, if the rail gun had a quick recharge time, it'd be far too easy to respawn camp.
"Waaa! UN! The US won't even let us get out of our docks! Ban them!"
Your bank is insolvent.
Taking Money Back
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
In this development stage, this looks like a joke.
;-)
32 MJoules is the energy equivalent of app. one litre (app. a quarter gallon) of Gasoline, or 12 kg of TNT.
By comparison, a cruise missile would carry half a ton of explosives.
Furthermore, in order to survive the firing, this needs to be a very tough and compact projectile.
Therefore, it would probably just make a nice hole in any target, disappear 30 feet into the ground and dissipate its energy down there.
Most of that energy will be released as heat to the soil.
The damage it does would be comparable to the occasional meteorite that wrecks a car or crashes through the roof and the bathroom of a house while the family sleeps - we are certainly not talking about anything on the size that took out the dinosaurs 65m years ago
The problem with this railgun, just as with an ordinary gun, is that the ship firing it feels a shock of the same magnitude as the ship that is being hit. To increase the damage inflicted, shells were filled with explosives.
Apparently this gun will fire a Ford Taurus at 380mph.
Does anyone know if Clarkson or Hammond have expressed an interest ?
I've scanned through the many comments, and every one seems to be discussing the technical aspects of this weapon. Whilst this is may be inevitable on a "news for nerds" site, I think I need to remind you that this is a device for killing human beings — people like you, me, your parents, your friends.
I recently read a Slashdot article on alleged biochemical weapons in North Korea, and barely a comment regarded the exciting technical aspects of such weapons. The discussion was about how terrible it was that they existed.
All this is despite the fact that NK's weapons are purely defensive (they would doubtless love to annex SK, but they know that it would be suicide) and the USA's weapons are purely offensive (no power could hope to openly confront that country, which is currently engaged in the occupation of a conquered nation and is actively threatening to attack others).
First off, the summary author says something to the effect that he was guessing that the 10x a day firing limitation would be because of the energy required - much more likely is because of the heat produced by the armature (which contains the tungsten projectile) would warp the rails.
Second off, some people have mentioned guidance systems for the projectile - from what I can see, the projectile would be moving at such speeds air friction would melt most any guidance package...
100 tons of titanium a day sounds great... but what are you going to do with it once its in Earth orbit? Look up in the sky and say "Its a bird, its a plane, no, its a big rock of titanium?" You then have to send a craft up to actually GET the freaking stuff, and the cost of getting the vehicle up there and back is more than the value of the titanium! NASA mission costs run, what is the number, $7,000 per kg of payload? The price of *milled* titanium is about $10 a pound! What are you going to do with the $3,165 loss per pound, make it up on your market-flooding, price-cratering volume? And that is assuming your Magical Moonbase generates processed and milled titanium for free!
(Please, spare me "Well, we'll do it for almost free with our space elevator!" There is no free lunch in physics. The potential energy of an object in earth orbit is high, and if you don't want that potential to be kinetic when you bring it down, you're paying an energy cost. What are you going to pay it with, fusion? Great, then we only require *three* sci-fi technologies to make our Magical Moonbase profitable.)
Help poke pirates in the eyepatch, arr.
See page 7 of http://www.onr.navy.mil/about/conferences/rd_partn er/2006/04thursday/dandrea_inp_track.ppt
The navy can probably put more than one gun on a ship using a common electrcity source. Assuming that the 10 shots per day comes from the damage done to the gun with each shot "multiple barrels" can increase the number of shots allowed each day. I would assume that main cost with the rail gun comes from the source to power it.
An engineer who worked on this project back in the day came and talked to my department. (General Engineering at UIUC) His part of the big picture was developing a switch that could handle this kind of power without blowing up as the contact is made. I believe they got it to work by pumping enough current through a disk of aluminum a few feet in diameter that it would vaporize, driving a slug which made the actual contact and carried the big current.
Yeah, I'm sure DARPA and company are *real* impresses with the tags on this article.
Come on? A Quake tag after millions of dollars in research? There should be a uber-weapon tag too!
Besides, what exactly does a video-game have to do with a fictional video game? I think the rail gun idea came before quake.
Great, we just got Mini-me to stop humping the laser. Now we have to get him off the rail gun, too?
I'm gonna need some crackers...
A problem with a high speed projectile is that it tends to make a small, deep hole. In WW1, the only thing the big rail mounted German gun did, was to upset an apple cart in Paris.
Oh well, what the hell...
He's not talking about firing it into orbit. Railgun on moon: fires at earth. Slug uses parachutes, guidance fins, or some other crap to prevent it causing huge craters on impact.
I knew they'd listen to reason.
Why bother, there are plenty of Titanium mines on earth. Turning it into metal is the hard part.
I'm voting for "some other crap", where "some other crap" is technology which is contrary to the laws of physics. Even if the slug has NO velocity relative to the earth when it starts to get pulled down by gravity (which would be a nice trick, considering its not powered and there is nothing between the moon and our outer atmosphere to slow it down), its going to start accelerating quickly. All a parachute does is increase your air resistance. Ah, slight problem -- for a lot of the descent there is no air! By the time there is air, you're AT REENTRY SPEEDS! I sure hope your parachute likes things hot, hot, hot, because if it gets reduced to a crisp you now have the world's largest bullet approaching the earth at about 13 kilometers a second! (Sidenote: parachute surface area needs to be proportional to mass.
Guidance fins?! Great idea. You've now got a big metal bullet with plasma eating at the edges... with guidance fins. Of course, its still not powered, so it comes in at whatever angle of attack it comes in on. That is going to generate blowtorch-hot plasma at an arbitrary point on the surface of the slug, which may or may not be hot enough to liquify your titanium. For comparison, the space shuttle sees 1650C at points, and it has the luxury of picking its angle of entry and firing thrusters to act as a partial brake before having to bleed off the rest through air friction and lift. The melting point of titanium is about 1660C (citations vary -- I've seen as high as 1800. Either way, you're going to have some interesting deformation of the metal at those temperatures. Hope you have those guidance fins securely attached at a point that doesn't deform or liquify.)
Help poke pirates in the eyepatch, arr.
Arcing a 5" projectile, you going to lose most of the kinetic energy. I can't see how arcing a 5" projectile can compare to 1000lb warhead on a tomahawk missile.
Have you ever been to a turkish prison?
What does all of this mean for Sealand? Will Sealand dominate the North Atlantic?
In the film "Eraser," Arnold Schwzenegger uncovers a plot to sell a railgun to terrorists.
Railguns are also portrayed in the "Stargate" TV series and in many video games, including "Halo 2."
don't forget the ever-better 'perfect dark' for the n64, btw i'm not looking forward to a weapon like this. getting sniped 200 miles away doesn't taste right.
They are talking about using guided munitions for these weapons, and with the velocity they fire at, you'd need to be aiming at some agile little vessel to miss. Also from what I gather from the posts above, the rate of fire limitation isn't power supply, its maintenance and ensuring the rails are not damaged by the firing. This is the same problem faced by vulcan cannons and the like, dealt with by multiple barrels in rotation. With that in mind you could stack a few clusters of fifty of these things all up your coast and have a fire rate of 500 a day per cluster, assuming you don't simply have removable rail components, which will push up your fire rate even further. These would also serve a significant anti-aircraft and anti-missile role, not to mention anti satellite.
That would be a significant threat to any navy or airforce.
What he can't kill, he has sex on. Trent.
Brand new ways to kill people!
That's just what we need!
Since we keep taking weapon ideas out of science fiction, why not just get it over with and unleash a nice big batch of grey goo on the Earth? At least it'll be quick.
I have always had a passion for the railgun concept.
(Next up the Hellbore cannon... I can dream)
What about the pressure wave this thing generates?
Uh - Nasa and company have been using aerobraking since the beginning of the space program. More than 40 years ago, the took a MANNED capsule, decelerated is just barely below orbital velocity, slowed it via aerodynamic drag, then dropped the thing into the ocean on parachutes.
Doing the same with big chunks of metal, with all the technological advances that we've seen since the 1960's, does NOT sound like an inherently impossible task...
Don't tell me to get a life. I had one once. It sucked.
I'd love to see one, but it would have to be incredibly tiny, or sail in an incredibly large navel, no?
Chat with other atheists http://secularchat.org
Aerobraking does not scale well, which is why the space shuttle (100 tons) has to put a heck of a lot more effort into it than the Mercury capsules (1.5 tons) did. (Incidentally, about a third of that weight is heat shielding, because otherwise the metal portions would catastrophically deform on reentry.) I don't doubt that you can use the space shuttle to retrieve whatever the heck you want -- for $7,000 a kg. "All those technological advances" which are *required* to get a body down in one piece from outside the atmosphere just can not be done for $10 a pound of payload.
Help poke pirates in the eyepatch, arr.
If it doesn't use a magnetic field to propel the projectile, it's not a rail gun. It sounds like you built some kind of electric spud cannon. Which is still pretty cool. Depending on the toxicity of copper vapor.
Either that or you did build a rail gun, with copper-clad penny sabot projectiles, and there is a pile of copper foil somewhere in or near your garage to this day.
Can you be Even More Awesome?!
I think the reason for the 10-shot-per-day limit is due to the stresses imposed on the rails. From what I understand, they have a tendancy to warp when used.
-ubuntu others as you would have others ubuntu you.
>> ZPM
no kidding. i was going to post the same thing
warp core.. sheesh, that's so yesterday
music - http://www.subatomicglue.com
which by the way, here's the obligitory zero point module link
zero point modules generate power using zero point energy of course.
that's energy from the quantum foam
music - http://www.subatomicglue.com
A Navy gun (the 5" variety I suppose) has around 10 MJ of launch energy. One destroyer (using a single gun) can fire about 20 rounds per minute (5 Inch/54-caliber (Mk 45) lightweight gun)
Now, one Arleigh Burke destroyer has some 75MW of shaft power (4 gas turbines). Assuming it can direct a third of this power to projectiles (considering all the losses), one ends up with enough power to launch more than one projectile a second.
Assuming the launch power (to the projectiles) is at around 10% of total engine power, one can have about the same rate of fire.
Now, where there is energy lost? Well, conversion to electricity (let's say for our purposes, conversion to electricity is as good as conversion to shaft horsepower); electricity storage; energy lost in capacitors; gun efficiency.
Let's say electricity storage (energy lost as it is stored) is of little concern. The capacitors have (if I remember) at most 50% efficiency (you must supply double the energy as compared to what you get out of them). Gun efficiency is unknown (not mentioned in the article).
So, what one ends up? For every launched ordnance, the ship must cool the electric components, for an effect equal to the launch energy. Thanks God for all the cool seawater around!
n/t
Did you ever notice that *nix doesn't even cover Linux?
I don't think any sci-fi fan worth his salt who likes moon railguns firing titanium at the earth wouldn't also imagine a space elevator.
demi
This is not a guided missile, that means the trajectory should be calculated beforehand and an exact launch is needed otherwise even a 1/1000 deviation at the start point will mean a 100 meter miss at a 100 km shoot.
Great. So you periodically launch re-entry heat-shield modules up to the moon where they are affixed to the titanium before being flung at our atmosphere. The heat-shields protect the titanium to the point where the parachute can safely slow its descent. Now we're talking Apollo-era technology.
Why in the world do you think we've got to send something up to catch the titanium and bring it back down? An why on earth do you assume it would have to be the space-shuttle?
Oh, and remember, each launch doesn't have to be 100 tons of titanium. Ten 10-ton launches would work just as well. Or 20 5-ton launches, or even 100 1-ton launches.
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Comment removed based on user account deletion
I'm just stoked that I'm going to get my new 32-megajoule rail gun and my new iPhone in the same month!
I'm just sayin'.
...possible damage to the ship? The change in momentum at firing time is greater than the change in momentum at impact time (due to wind resistance along the entire flight path). So if this thing can demolish buildings at impact, how do they prevent it from demolishing the ship, not to mention the weapon itself at launch? Even a really, really long launch tube isn't going spread the momentum over a very long period of time. I'd love to see what kind of dampeners they're considering.
If the sea level rises, that means more area covered by water, which means the Navy's importance increases. That also means less coast-line, so the Coast Guard's prowess deminishes. It also means less land area, so the Army suddenly becomes unnecessary. That leaves the Air Force. Nobody really cares about the Air Force as it is because the Navy's air force could kick the Air Force's Air Force. And the Marines? SEALs can take care of them. Moral of the story: Don't piss off the Navy
FYI: The railgun under development is anticipated to fire up to 10 rounds per minute aboard Naval ships or other platforms. The Electromagnetic Launch facility at Dahlgren, Va., can fire Railgun 6 to 10 times per day. See retraction: http://fredericksburg.com/News/FLS/2007/012007/011 82007/252002
Correction - Date published: 1/18/2007
The railgun being tested at the Naval Surface Warfare Center in Dahlgren is expected to be able to fire six to 10 rounds a minute. The system is expected to be ready for deployment between 2020 and 2025. A story in yesterday's paper was incorrect on those points.
It is the policy of The Free Lance-Star to correct factual errors in a timely fashion. We welcome your calls at 540/374-5400.
The article quotes one of the generals as saying the projectial is "like a ford taurus hitting the target at 380 mph" Ford taurus weigths 1383 kg (http://en.wikipedia.org/wiki/Ford_Taurus) and 380 mph -> 169 m/s
1383*169 => 234937.402 kgm/s. Projectial weighs 3.2 kg => it hits the target at 73417.9381m/s. This seems extremely high
I feel like I'm off by an order of magnitude. Guess it would be better to work off of the projection that the projectial can reach 95 miles into space to calculate initial speed.
It probably depends on the target. A HEAT round only penetrates a target with what is probably a pencil-sized stream of plasma. Even a sabot round is only a few inches across. Either will give a tank a very bad day.
Against buildings it might not be a great weapon (unless you drop 50 of these at a time at 1 meter intervals - that would make a mess). Against equipment it will probably be very effective - I doubt a radar, SAM battery, or vehicle would survive a direct hit (granted, you need a very accurate shot - since you need a direct hit unlike most bombs/etc - GPS might not be enough). If you can fire 1000 rounds for the cost of a cruise missile you could still wipe out a building for comparable cost (1000 randomly-fired rounds hitting a building will almost certainly collapse it - or make it useless in any event). And without blast effects you don't kill as many civilians - bullets are safer than bombs.