The Electromagnetic Railgun

February 28, 2012 6:22 PM

The Navy has spent seven years testing out the components of a way-futuristic weapon: a shipboard cannon that blasts bullets over vast distances at hypersonic speeds using bursts of electricity. ... The Navy released video of the first tests, viewable above, on Tuesday. The dramatic mini-inferno in the wake of the slug fired from the railgun is the result of “1 million amps flowing through” the gun, said test chief Tom Boucher, the hypersonic speed of the shot, and the actual aluminum of the bullet — “reactive in the atmosphere” — burning off.
posted by Trurl (143 comments total)

The way the air lenses around the projectile is amazing.
posted by Threeway Handshake at 6:28 PM on February 28, 2012 [3 favorites]

Are shipboard cannon even relevant any more? And if so, in what way is this thing superior to a regular weapon?
posted by kavasa at 6:31 PM on February 28, 2012

I'm not exactly desperate to work for the military industrial complex...but man, how do I apply for a job working on this?

And I don't know, maybe you could make a bigger version that launches space craft out of an evacuated tube built into a tall mountain...that would have peacetime applications right?
posted by Chekhovian at 6:33 PM on February 28, 2012 [2 favorites]

I will admit that using the latin for "speed kills" is cute in a callous, military sort of way.
posted by kavasa at 6:33 PM on February 28, 2012 [10 favorites]

I'm torn. On the one hand: the cool-as-fuck engineering with this and seeing a classic SF trope become a reality. The other hand: the knowledge that we have spent billions of dollars on it which could've been spent better and last but not least, the fact that, if used, this will be employed in wars I don't want to happen and almost certainly, at some point, kill innocent civilians.
posted by zardoz at 6:34 PM on February 28, 2012 [33 favorites]

Perhaps if it fails, it can be rebranded as an antimatter generator.
posted by underflow at 6:35 PM on February 28, 2012 [1 favorite]

Railguns are cool. Needs more cl_railtrailcolor though.

On the other hand, I am surprisingly worried about these rounds missing their targets. In general I don't like the idea of rounds hitting anything other than their intended target, but this thing? Flying for hundreds of miles in a few minutes? Man, what if it like, hits the water at just the right angle, and goes skipping off like the world's deadliest stone?
posted by m0nm0n at 6:36 PM on February 28, 2012 [3 favorites]

Well, for one, you'd no longer need to carry around massive amounts of explosives on your ship.
posted by Threeway Handshake at 6:37 PM on February 28, 2012 [6 favorites]

I will admit that using the latin for "speed kills" is cute in a callous, military sort of way.

Too bad they couldn't conjucate the verb correctly (eradicat). Never mind the fact that eradico means "to pull up by the roots" instead of "kills"....
posted by zeugitai_guy at 6:38 PM on February 28, 2012 [24 favorites]

*conjugate (What an unfortunate word to screw up...)
posted by zeugitai_guy at 6:39 PM on February 28, 2012 [19 favorites]

This is amazingly fucking cool and I hope it never gets off the ground. Railguns are truly amazing pieces of work and hyperkinetic weapons are so sci-fi that I don't even miss my jetpack. At the same time, having yet another delivery system for killing lots of people is something that I'm not in favor of.

So I hope this dies in about 5 years, after they come up with a way to use it to facilitate space launches.
posted by Hactar at 6:39 PM on February 28, 2012 [2 favorites]

I can't be the only one who said to himself, "Head-shot!" right?
posted by fijiwriter at 6:39 PM on February 28, 2012 [6 favorites]

Are shipboard cannon even relevant any more?

I think the blog post where I found this explained it best:

"Because RAILGUN, that’s why."
posted by Trurl at 6:40 PM on February 28, 2012 [4 favorites]

Impressive
posted by hellojed at 6:40 PM on February 28, 2012 [2 favorites]

I'm damn near a pacifist but I love our crazy ass military technology sometimes. My brother in law is an A-10 pilot and he gave me a shell casing from the big gun on that thing. Apparently they use them as shot glasses. I guess I've heard the phrase "depleted uranium" too many times to go for that, but still damn cool to have.

Anyway, what exactly is the practical use of a naval rail gun? Blowing up other navies? Attacking targets on shore? Shooting down missles or air targets? What?
posted by furiousxgeorge at 6:40 PM on February 28, 2012

So where's my Ion Cannon then?
posted by Slackermagee at 6:41 PM on February 28, 2012 [1 favorite]

Anyway, what exactly is the practical use of a naval rail gun? Blowing up other navies? Attacking targets on shore? Shooting down missles or air targets? What?

Standing off targets way, way over the horizon at speeds faster than many missiles can achieve, without the drawbacks that guided missiles have.
posted by ZeusHumms at 6:42 PM on February 28, 2012 [3 favorites]

Wow, they plan to get these things to fire up to 100 nautical miles. Apparently current cannons go 13 miles.

They are pretty much going to be able to replace expensive shells and cruise missile with cheap hunks of metal no?
posted by Ad hominem at 6:44 PM on February 28, 2012 [2 favorites]

Anyway, what exactly is the practical use of a naval rail gun?

This, mostly.
posted by Kadin2048 at 6:48 PM on February 28, 2012 [26 favorites]

I've said it once, I'll say it again: if you think this is cool/complex, you should take a look at your own nervous system some day; this thing looks like it could ruin a lot of nervous systems.
posted by The White Hat at 6:51 PM on February 28, 2012 [12 favorites]

Do I get to talk about my adventures with (well, okay, near) the railgun at Dundrennan Range again?
posted by scruss at 6:51 PM on February 28, 2012

The dramatic mini-inferno in the wake of the slug fired from the railgun is the result of... the actual aluminum of the bullet — “reactive in the atmosphere” — burning off

Note that metallic aluminum is extremely reactive with oxygen. The reason aluminum appears so stable is that a very thin layer of aluminum oxide immediately forms around it, creating a shell that protects against further corrosion.

I think what may be happening here is that the current used to launch the slug burns off the aluminum oxide layer (Al2O3 is an insulator), exposing the metallic aluminum core, which then reforms exothermically as it exits the barrel, resulting in a flaming trail of awesomeness.
posted by dephlogisticated at 6:52 PM on February 28, 2012 [7 favorites]

Are shipboard cannon even relevant any more? And if so, in what way is this thing superior to a regular weapon?

From what I understand the idea is that the projectile comes in faster than a missile, much smaller and harder to detect, and therefore active defenses have a much lower chance of intercepting it. Further, since it has a practical range of 100 miles, vs the 13 or so max for conventional cannon, it might change the balance of naval power away from carriers again.
posted by sotonohito at 6:54 PM on February 28, 2012 [6 favorites]

Impressive

Meh. Insignificant next to the power of the force.
posted by The World Famous at 6:55 PM on February 28, 2012 [15 favorites]

Evidently the greater speed of the projectile is enough to substantially increase the amount of damage it does compared to conventional firearms.
posted by XMLicious at 6:56 PM on February 28, 2012

Oh, man, I'm glad the military finally solved the problem of "How do we get a destructive projectile from point A to point B real quick?" Now no more sore backs from troopers having to physically carry big balls of lead thousands of miles to drop on the bad guy's head.
posted by tumid dahlia at 6:56 PM on February 28, 2012 [7 favorites]

Are shipboard cannon even relevant any more? And if so, in what way is this thing superior to a regular weapon?

Surely it'd be useful for destroying incoming cruise/anti-ship missiles, if nothing else.

I can see another upside... it's an electric gun! Good for the environment, versus those nasty combustion guns! But seriously, reading the linked article, it sounds like the Navy really wants this gun, including for lighter ships that don't have a sufficient power supply, so they'll need to develop dense battery technology. If the next few billion we spend on this weapon results in vastly improved batteries, then it'll be the best use of military budget in some time. Better than chemical bombs Afghanistan anyway. And let's face it, they'll be spending the money anyway.
posted by amorphatist at 6:59 PM on February 28, 2012 [6 favorites]

Last I heard, they were talking about 200nm range, not 100. And I haven't actually plotted it out, but they had claimed a 200nm range means the shell gets fired into a ballistic arc that takes it up 90 miles. Also, the largest battleship cannons (Imperial Japanese Navy ships Yamato and Musashi) had 18.1" guns that could fire 26 miles. They often engaged closer just because it was problematic to be spotting where the rounds landed that far over the horizon, even with the armored observation posts high in the masts of the battleships.

Naval shore bombardment will probably not go out of style anytime soon, but it until the 1940s it only went on for coastal towns. With a 200nm rail gun, well, it's time to head for the mountains.

The ships may need satellite images or a forward controller to move the shots, but some of that can be automated as long as the lines of communication are open between the local observer and the ship with the railgun.

The question is where the ships will get all this power. Sometimes (e.g. Aegis) the weapons-system gets so expensive that the ship cannot also have an expensive nuclear power plant.
posted by Sunburnt at 7:01 PM on February 28, 2012 [1 favorite]

1. The sheer speed of this compared to a regular explosively fired round turns you into the fastest gun on the sea. Other ships auto-magically become your bitches.
2. The amount of energy in one round turns you into a one shot one kill artist. It hits you faster and goes through more hull metal, deeper into the ship.
3. Your ship can be faster, dependent on the weight of batteries and/or generators used. Also use less crew, an unfortunate trend.
4 Raining fire from those magical distances with your man-carryable (I'm saying relatively small) shell doesn't really inspire fear compared to the regular car-sized shells from the big gun. Still a neat trick tho'

(all invalidated if Phalanx don't get that sea-skimming cruise missile)
(removes defense industry engineer hat)
posted by djrock3k at 7:02 PM on February 28, 2012 [2 favorites]

(all invalidated if Phalanx don't get that sea-skimming cruise missile)

I was under the impression that those missiles can also engage in a terminal pop up and ballistic descent that basically leaves all point defenses uselessly holding their dicks in their hands.

But even if not, you can always salvo fire huge waves of cheap smart missiles...surface ships, not the place to be in the next war, even if you have awesome railguns...
posted by Chekhovian at 7:11 PM on February 28, 2012

Anyway, what exactly is the practical use of a naval rail gun?

If you make the barrel long enough (so you can accelerate slowly enough to keep the g-forces manageable) LEO transport.

You probably thought ballistic missiles were for delivering nuclear weapons too, didn't you.
posted by Kid Charlemagne at 7:17 PM on February 28, 2012 [3 favorites]

I am not so great with the physics and whatnot. Whenever I watched old movies, I could never understand how a cannon works. So, you shoot this big steel ball, and it hits near someone and the person goes flying through the air? Huh? Why would that happen. Well, then I saw that MythBusters story about their errant cannonball shot and realized these things have a LOT more force than I ever imagined.

Oh, and once I was about to go hiking at Storm King Mountain near West Point. They had to close the mountain (the MOUNTAIN!) because apparently they found a bunch of civil-war-era cannonballs lodged in the mountainside that hadn't exploded. Apparently a cannon salesman or something on the opposite bank of the Hudson would fire shots at the mountain for a sales pitch.

So, after all that, I thought I had a better understanding of these things, but then I just watched this railgun thing.

What the hell was that all about?

What is that thing they fired? That thing that looked like the femur from a short aluminum robot? That is the bullet? And when they shot it, wasn't it flying all wonky? Does that not matter? Is that the thing that can fly so far? The wonky robot femur? Why not a simple cylinder? Or a rocket shape? And where did it go? And doesn't anyone else want to know what it looked like when it got there?

Also, how does one use 1.21 gigawatts of power to fire a robot femur all at once? Is it, like, stored up somehow? I mean, I get a bill from Con Edison in the summer that makes me cry, and I get that my non-energy star AC drains a lot of power, but would it be possible to plug something in that can just quickly use electricity in one shot? Can't you only draw a maximum amount of power from the flow (again, I don't know physics stuff)? Is it like a flashbulb on a camera, where it sorta builds up and then pops? And if so, wouldn't you just need a big battery? And if you just needed a big battery, wouldn't it just be easier to use a regular ol' rocket-style missile in the first place which is basically the same thing?
posted by This_Will_Be_Good at 7:18 PM on February 28, 2012 [5 favorites]

You don't have to worry about unexploded ordinances if the ordinances aren't explosive. That's one positive.
posted by the jam at 7:21 PM on February 28, 2012

Kadin2048 -- so, if you look a bit more closely at the stock chart you linked to, I am guessing that the railgun was fired at 2:06 today?
posted by This_Will_Be_Good at 7:22 PM on February 28, 2012 [3 favorites]

Well, for one, you'd no longer need to carry around massive amounts of explosives on your ship.

Maybe not, but you still need an energy source for the railgun.

Further, since it has a practical range of 100 miles, vs the 13 or so max for conventional cannon, it might change the balance of naval power away from carriers again.

Which is good because... wait, who actively fields aircraft carriers for more than just show anymore?

The sheer speed of this compared to a regular explosively fired round turns you into the fastest gun on the sea. Other ships auto-magically become your bitches.

Sure, but today the most active naval threats are Somali pirates masquerading as fishing boats, and North Korean boats fucking around with the South Koreans. Sure, maybe Iran has some naval power and maybe there's a chance of going to war with them. But you could probably plug up the Persian Gulf by carefully scuttling the mothball fleet.
posted by b1tr0t at 7:25 PM on February 28, 2012

Also, how does one use 1.21 gigawatts of power to fire a robot femur all at once? Is it, like, stored up somehow?

A compulsorator.
posted by mullingitover at 7:28 PM on February 28, 2012 [3 favorites]

> Which is good because... wait, who actively fields aircraft carriers for more than just show anymore?

The US carrier fleet is hardly for show. If another navy had a rail gun the US would simply keep its carriers out of range since any jets it carried would have a much greater range than 100 miles.
posted by Burhanistan at 7:32 PM on February 28, 2012 [3 favorites]

Are shipboard cannon even relevant any more?

If you're talking about current guns, then no. They're basically just big artillery.

And if so, in what way is this thing superior to a regular weapon?

Current naval guns are a difference in degree, not kind, from the guns that were on the HMS Victory at Trafalgar, i.e. a steel tube, open at one end, that you load with powder that propels a shot. Current guns can fire explosive shells upwards of fifty miles. Which is awesome, but peanuts compared to your standard cruise missile, which is why there are no battleships in active service in any fleet on the planet.

But railguns are an entirely different kind of thing. The projectiles being fired are lighter, and more like cannonballs than explosive shells, but they're being fired at speeds around 5,400mph. A nineteenth-century twelve-pounder cannon could hit about 1,000mph, and the 16" Mark 7 guns on American battleships only gets up to 1,700mph. So we're talking something three times as fast as the most powerful gun in history.

This means two things. First, it means that your range has just gone way up. Fifty miles seems to be the maximum range for conventional guns, not because we hit some kind of materials science or design wall, but because that's all the power we can get out of gas expansion in a terrestrial atmosphere. The shot is only going to move as fast as the explosion that powers it, and there's an upper limit. So extending range is a big deal.

But second, because the shot is moving so damned fast, the gun's accuracy goes up, particularly with respect to moving targets. Cruise missiles only go about 550mph. Railguns can achieve velocities ten times that. And that Somali pirate masquerading as a fishing boat? Now you can drop a bullet on him from over the horizon, and because it's only going to take about five seconds to get there, you can probably hit him at that range. Really, this would let the Navy go after these sort of smaller, less organized targets much more efficiently, because it no longer needs to launch a few tons of steel powered by several more tons of gunpowder, or assign expensive and limited aircraft, to go after a few speedboats. They can just shower a literal hail of bullets from hundreds of miles away.
posted by valkyryn at 7:35 PM on February 28, 2012 [21 favorites]

Maybe not, but you still need an energy source for the railgun.

Which is only one of several really big problems that still need solving before this can be made operational. Other problems include designing a firing mechanism that can actually fire multiple shots in a row & making a barrel that won't melt under the heat of repeat fire. So yeah, let's not scrap those explosive-based guns quite yet. Still, very cool to have gotten this far.
posted by scalefree at 7:37 PM on February 28, 2012

If another navy had a rail gun the US would simply keep its carriers out of range since any jets it carried would have a much greater range than 100 miles.

Actually, a practical railgun might be a pretty effective deterrent for a carrier fleet. As soon as the carrier gets within about a hundred miles of the railgun, the carrier is dead. But the carrier has to rely on its air escort for protection at that range, and this protection is finite. I'm reminded of the Battle of Midway, which was significantly decided on the basis of which fleet's planes found the other carriers first. This are slightly different now, what with satellite surveillance and radar, but the idea still holds: planes are awesome, but they can only kill so many targets, only so many targets at once, and only those targets you know about. The advantage of a railgun is that it can basically hit any target in its range until it runs out of ammo.
posted by valkyryn at 7:40 PM on February 28, 2012 [2 favorites]

I was just thinking about this. Sure, maybe this is useless against a guy in a zodiac. Maybe these projects are giant make-work boondoggles of negligible practical value in the real world. Our defense budget is still a way for the government to pump huge amounts of funds into the economy, some of it even cutting edge research. We did get the interstate highway system and the Internet because of it and modern silicon valley is build on the roots sunk there by cold war military contractors.

Of course it would be nice if we could put all those funds and cutting edge resources into civilian space exploration, or developing energy sources.
posted by Ad hominem at 7:42 PM on February 28, 2012 [1 favorite]

Excess energy from the ship (e.g. when engines are not using power to move it) are stored in large capacitor banks. Electrical energy in cap banks is discharged very quickly into the rails which form a circuit due to the contact of the metal projectile with the rails. The Lorentz (j cross b) force accelerates the projectile to incredibly high velocities. The Ohmic (or resistive) heating of the rails cause the outer most layer to ablate (explode) in clouds of plasma. One downside to this approach, which is often not discussed, is that the firing of this device generates a substantial EM pulse that can potentially damage ship board radar if not properly shielded.
posted by FuturisticDragon at 7:44 PM on February 28, 2012 [2 favorites]

Railguns also become pretty useful if you move your ship powerplant design to all electric, instead of having some gas-turbine generators for electric power, and also other gas turbine generators connected to massive main reduction gears for propulsion.

Combined with the research into capacitors, and you get yourself an over-the-horizon boom and no explosives on board.
posted by the man of twists and turns at 7:46 PM on February 28, 2012

Actually, a practical railgun might be a pretty effective deterrent for a carrier fleet.

I think that job is already taken by the hoards of cheap, smart, fast, and long ranged cruise missles/drones/etc that any sensible enemy will throw at any carrier that comes close enough.
posted by Chekhovian at 7:48 PM on February 28, 2012

Yeah, the military has awesome technology, but rather than waste my enthusiasm on the military, I just choose to remember how many amazing *useful* things that could have been R&D'd with that money instead of yet another killing machine.

It's important to keep in mind that the primary mission of the US military is to provide politically-connected military contractors with unlimited cash. The lucky corporation this time is the cheerfully corrupt, murderous-dictator-friendly BAE Systems. The US military drains taxpayer money, gives scads of it to horrible, horrible corporations in the form of jaw-droppingly corrupt cost-plus arrangements, who use the profits to build their business supplying third world misery with extra helpings of misery. And all the US gets out of it is an expensive, impractical weapon that we can mount on an antiquated floating target. *blows party horn*

If this global civilization is remembered at all, it will be for the insane percentage of our human and natural resources we consumed in intraspecies military posturing and conflict, instead of exploring, understanding, and learning to sustainably interact with our universe.
posted by Salvor Hardin at 7:59 PM on February 28, 2012 [17 favorites]

Keep in mind that this is a weapon to fight a war in about 2025. Even though we have the technology to destroy the entire world many times over in 35 minutes, we must prepare for this war with newer more imaginative weapons. We are so afraid of this as yet unknown unknown that we must spend more than 80 trillion dollars between now and then just to make sure we do not fail. We must not even cut a fraction of that expenditure to care for the elderly, the hungry, the jobless, children, the very poor or the sick. Those unfortunate souls must bear the brunt of our lean times so that we can be ready for this future threat. You will not be safe otherwise. 19 maniacs with box cutters will be no match for this rail gun. It will keep you safe. The fire of its oxidizing aluminum will warm your heart, but not your home. Put on a sweater old woman and eat your cat food. We had to keep you safe.
posted by humanfont at 7:59 PM on February 28, 2012 [9 favorites]

m0nm0n: On the other hand, I am surprisingly worried about these rounds missing their targets.

Smart Bullets (mentioned third paragraph from bottom in Wired article).
posted by unmake at 8:01 PM on February 28, 2012 [1 favorite]

The other hand: the knowledge that we have spent billions of dollars on it which could've been spent better

“Every gun that is made, every warship launched, every rocket fired signifies, in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed. This world in arms is not spending money alone.

It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children.

The cost of one modern heavy bomber is this: a modern brick school in more than 30 cities.

It is two electric power plants, each serving a town of 60,000 population.

It is two fine, fully equipped hospitals. It is some 50 miles of concrete highway.

We pay for a single fighter plane with a half million bushels of wheat.

We pay for a single destroyer with new homes that could have housed more than 8,000 people.

This, I repeat, is the best way of life to be found on the road. the world has been taking.

This is not a way of life at all, in any true sense. Under the cloud of threatening war, it is humanity hanging from a cross of iron.” - Dwight D. Eisenhower
posted by hippybear at 8:04 PM on February 28, 2012 [66 favorites]

The US carrier fleet is hardly for show. If another navy had a rail gun the US would simply keep its carriers out of range since any jets it carried would have a much greater range than 100 miles.

Perhaps we can split the difference and agree that the primary task of the US carrier fleet is deterrence?

Regardless of the state of the US carrier fleet, who else has a carrier fleet that this is useful against? If no one else, then developing and demonstrating a weapon like this is exactly the thing to convince the CCCPC that a railgun is just the thing for all that research into advanced batteries and capacitors that the CAS has been doing over the last decade or two. Not that I think China would actually use a gun like that, but why remind them that they ought to have a nice shiny one of their own?

Our defense budget is still a way for the government to pump huge amounts of funds into the economy, some of it even cutting edge research. We did get the interstate highway system and the Internet because of it and modern silicon valley is build on the roots sunk there by cold war military contractors.

Sure, but both the Interstate System and early-days Silicon Valley date from a time when there wasn't all that much divergence between military and civilian hardware. I'd love to see something from the last 20 years of DoD research that has spun off into civilian life. GPS receivers might make the cut, but these days civilian devices are far more sophisticated (but perhaps less rugged) than their military counterparts. On the other hand, I'd be willing to bet that the vast majority of military IT is repurposed civilian stuff. I'm sure Microsoft and Cisco love that revenue, but it isn't like they'd be hurting without it.

Why not invest in inner-city community colleges, and teach kids how to build scalable web apps with open source software? Then they can breathe new life into the industry and government agencies around them, without having to make large cash outlays that they wouldn't be able to afford anyway.
posted by b1tr0t at 8:05 PM on February 28, 2012 [1 favorite]

Here's one way it could be a great benefit,

the Navy really, really loves its railgun

but

Another big problem: the current generation of Destroyers can’t produce the power

What does the Navy need to research? Incredibly more efficient electricity generation and storage, isn't that pretty close to 'alternative' energy?
posted by sammyo at 8:09 PM on February 28, 2012 [3 favorites]

Surely it'd be useful for destroying incoming cruise/anti-ship missiles, if nothing else.

No, you'd have to fire many of them simultaneously to create a wall that a fast-moving target would hit, not the other way around. And at ten rds/min you're not going to achieve much.

That's what the Phalanx CIWS is supposed to do: throw depleted uranium into the air with 1970's technology and hope that something hits it. Good luck with that if you have multiple targets inbound and you're on a carrier (larger area/silhouette to defend with unequal weaponry).

Whether carrier aviation or submarine warfare have seen better days or not is irrelevant to the discussion as this program has all the hallmarks of the Navy competing to be relevant against cheaper alternatives that the Air Force has come up with. With a weapon like this, you can engage ten targets a minute within a 200nm range from a sustainable single platform for a long period of time without giving away your position or motive and a small chance of actual engagement with the enemy.

Basically a destroyer could sit a hundred miles out in the Mediterranean doing figure-eights while shelling Damascus at will. Or most of China's industrial regions.
posted by jsavimbi at 8:10 PM on February 28, 2012 [2 favorites]

The other hand: the knowledge that we have spent billions of dollars on it which could've been spent better...

[...]
- Dwight D. Eisenhower

Unfortunately, with the anti-boffinistic mentality of the congress, it seems about the only way to get $$ to build the really expensive speculative future tech is via the military budget. While Ike's sentiment was spot-on, it's a bit late; the military-industrial complex already won. At least for now.

* That is, it would be lovely if NASA or another org was exploring this tech, but they're not, and the budget will be spent anyway, so I'd rather this than another nuclear sub.
posted by amorphatist at 8:10 PM on February 28, 2012

Don't assume that boats are the only place you can use a weapon like this. An orbiting railgun platform would be freaking terrifying. It might not be possible now, but I see that as the future of a weapon like this.
posted by Bighappyfunhouse at 8:11 PM on February 28, 2012 [3 favorites]

Too bad they couldn't conjucate the verb correctly (eradicat).

It's only incorrect if you think "speed kills" is the intended translation. It could be "I, speed, kill".
posted by kenko at 8:12 PM on February 28, 2012 [2 favorites]

Ok you guys convinced me that for the things we did get and the people that were employed it was ultimately not worth it. The huge amound of resources blown up and sunk to the bottom of the sea, and the incredible loss of life.
posted by Ad hominem at 8:12 PM on February 28, 2012

What does the Navy need to research?

ONR Energy Storage Program

Already ahead of you.
posted by the man of twists and turns at 8:14 PM on February 28, 2012

kavasa writes "And if so, in what way is this thing superior to a regular weapon?"

Well if nothing else it would mean you wouldn't have to fill your ships with explosives. And because of that you could haul more bullets.

XMLicious writes "Evidently the greater speed of the projectile is enough to substantially increase the amount of damage it does compared to conventional firearms."

Energy is proportional to the mass times the square of the velocity. Substantially increase is an understatement as each doubling of velocity results in a four fold increase in force.

b1tr0t writes "Maybe not, but you still need an energy source for the railgun. "

Sure, but that energy source is designed to be stable rather than designed to explode. IE: a ton of coal is a lot safer to have on board with you than a ton of TNT. Also your supply ships wouldn't have to carry explosives and you wouldn't need great big piles of explosives hanging around all your bases. Your entire supply chain benefits from handling inert chunks of aluminum rather than explosives.
posted by Mitheral at 8:23 PM on February 28, 2012 [1 favorite]

Anyway, what exactly is the practical use of a naval rail gun?

Why, doing what the Navy does best, of course: perpetuating itself through huge expenditures.
posted by indubitable at 8:26 PM on February 28, 2012 [1 favorite]

The lucky corporation this time is the cheerfully corrupt, murderous-dictator-friendly BAE Systems

Also the producers of a popular food product.
posted by dephlogisticated at 8:28 PM on February 28, 2012

You say rail gun, I say bullet train. I think it's great the national transit system is getting this kind of boost! /didn't watch the linked video
posted by Ritchie at 8:37 PM on February 28, 2012 [1 favorite]

What does the Navy need to research? Incredibly more efficient electricity generation and storage, isn't that pretty close to 'alternative' energy?

Thanks, but no thanks. We already did that once already, and it is exactly why civilian nuclear power is as dangerous as it is. Nuclear power plants were designed first for installation in cramped submarines staffed by the Navy's brightest and best trained technicians. Alternative designs that take up more physical space or require less attentive staff have ben consistently ignored.

IE: a ton of coal is a lot safer to have on board with you than a ton of TNT. Also your supply ships wouldn't have to carry explosives and you wouldn't need great big piles of explosives hanging around all your bases. Your entire supply chain benefits from handling inert chunks of aluminum rather than explosives.

I can see why you'd think that, since you are using the wrong units. Don't think of a ton of TNT (which probably has a much higher energy density that a ton of coal, but much less than a ton of uranium), think of a joule of energy. You need to have enough joules aboard the ship to operate the gun. How are you going to do that?

Hint: there's a reason why the TSA doesn't want you carrying extra batteries on an airplane. As energy densities increase, there's little practical difference between a battery, a supercapacitor and a stick of TNT.

Nuclear power is great for ships because the energy density is so high. It is also so dangerous because... the energy density is so high!
posted by b1tr0t at 8:37 PM on February 28, 2012 [3 favorites]

Over 20 years ago, during one of my first days in Marine Corps boot camp, our drill instructor stood before us and announced that he only had a short amount of time to turn us from lazy civilians into hard-hearted killers. I knew at that moment that I had made a terrible mistake. Deep below my outward bravado and machismo, I knew that I would never be a killer of any kind, much less a hard-hearted one. After a few weeks, I claimed suicidal tendencies and got kicked out of the Corps. I take great care to never claim to have ever been a Marine, not because I didn't earn the title in their eyes but because that's not who I ever was.

I've heard many otherwise rational men gleefully speak of head shots, body counts and collateral damage. I've known good men who have killed the enemy in the heat of battle for love of country and even more for love of their brother-warriors. It's not for me.

You say this technology will benefit technology. You say the money will be spent anyway. I say that as long as we lust for the blood of other human beings, we're fucked as a species.
posted by double block and bleed at 8:51 PM on February 28, 2012 [11 favorites]

Perhaps we can split the difference and agree that the primary task of the US carrier fleet is deterrence?

The primary purpose of a carrier battle group is to project power. With it, you can put a fully armed, self-contained, self-protecting airbase just about anywhere in the world.

The U.S. has more aircraft carrier deck space than the rest of the world combined.

A railgun-armed ship, however, is really meant for littoral combat, in say, support of a Marine Expeditionary Unit. Park the ship over the horizon and defend an amphibious operation 24/7, more capably and less-expensive than a carrier could with strike aircraft.

That said ... This all feels very beside the point in a world of drone aircraft getting better and better.
posted by Cool Papa Bell at 9:02 PM on February 28, 2012 [4 favorites]

> Perhaps we can split the difference and agree that the primary task of the US carrier fleet is deterrence?

No, the primary task of the US carrier fleet is to drop ordnance on third world countries.
posted by Burhanistan at 9:04 PM on February 28, 2012 [3 favorites]

I say that as long as we lust for the blood of other human beings, we're fucked as a species.

Define 'fucked' then I suppose? Humans/apes/mammals all the way on down have been murdering each other since the prehistory. And there's more of our species than ever, and we're living in the least violent time in history. How exactly are we as a species 'fucked'?
posted by amorphatist at 9:04 PM on February 28, 2012 [3 favorites]

An orbiting railgun platform would be freaking terrifying. It might not be possible now, but I see that as the future of a weapon like this.

Wasted energy. If you're already at the top of the gravity well, just give your payloads a tap to get them started. See Rods From God.

If you want to do it properly, the Moon may be a Harsh Mistress but I have it on good authority it would make an excellent platform for an offensive ballistic railgun.
posted by scalefree at 9:10 PM on February 28, 2012 [11 favorites]

Don't assume that boats are the only place you can use a weapon like this. An orbiting railgun platform would be freaking terrifying. It might not be possible now, but I see that as the future of a weapon like this.

For planetary bombardment, you wouldn't need a railgun. Just give the projectile (something dense and solid that won't burn up passing through the atmosphere) a slight push, and gravity will do all the work for you. Kinetic bombardment.

Energy efficient!
posted by His thoughts were red thoughts at 9:11 PM on February 28, 2012 [2 favorites]

instead of exploring, understanding, and learning to sustainably interact with our universe.

The US military budget for one year is equal to how much NASA has spent in its entire lifetime.
posted by stbalbach at 9:12 PM on February 28, 2012 [4 favorites]

Damn it, scalefree.
posted by His thoughts were red thoughts at 9:12 PM on February 28, 2012 [2 favorites]

How exactly are we as a species 'fucked'?

Resources.
posted by scalefree at 9:12 PM on February 28, 2012 [2 favorites]

A railgun-armed ship, however, is really meant for littoral combat, in say, support of a Marine Expeditionary Unit. Park the ship over the horizon and defend an amphibious operation 24/7, more capably and less-expensive than a carrier could with strike aircraft.

Yeah, I'm pretty sure that could take out the entire Roman Empire.
posted by His thoughts were red thoughts at 9:15 PM on February 28, 2012 [6 favorites]

How exactly are we as a species 'fucked'?

Resources.

All the more reason to develop awesome planet-escapering tech now.
posted by amorphatist at 9:16 PM on February 28, 2012 [1 favorite]

I say fucked because I'm old enough to remember a time when it was likely that the entire planet would be instantly obliterated shortly after the opening of a briefcase.
posted by double block and bleed at 9:26 PM on February 28, 2012 [1 favorite]

All the more reason to develop awesome planet-escapering tech now.

Um...this is planet destroying tech. Not the other thing.
posted by His thoughts were red thoughts at 9:27 PM on February 28, 2012

> I say fucked because I'm old enough to remember a time when it was likely that the entire planet would be instantly obliterated shortly after the opening of a briefcase.

Well, if it makes you feel better there are ICBM-laden subs on patrol right this moment.
posted by Burhanistan at 9:28 PM on February 28, 2012 [3 favorites]

How exactly are we as a species 'fucked'?

Well, one way to look at it is that our ability to concentrate potential energy has increased exponentially, while our constructive utilization thereof has stalled in the general region of "toddler with a ball-peen hammer".
posted by dephlogisticated at 9:33 PM on February 28, 2012 [4 favorites]

Basically a destroyer could sit a hundred miles out in the Mediterranean doing figure-eights while shelling Damascus at will.

Ye-es. But cities are big. I'm sure that many Damascenes might be killed by projectiles hitting an office block, but are you actually doing much damage to the city or its industrial capacity? You're never going to get pinpoint accuracy with unguided projectiles and if factories could work around bomb damage in WW2 I bet they can work around the relatively small craters made by a billet of impacting metal.
posted by Joe in Australia at 9:47 PM on February 28, 2012

You're never going to get pinpoint accuracy with unguided projectiles

There have been precision-guided artillery rounds in service for at least a decade.
posted by Cool Papa Bell at 9:53 PM on February 28, 2012

To put it in units that are probably more familiar to people, one kilowatt-hour is 3.6 megajoules. So this gun uses 6-10 kWh per shot. May not sound like much, but when you dump it all into one lump of metal, it is. Also, that's the output power-- presumably more goes in.
posted by alexei at 9:53 PM on February 28, 2012

Even though they won't be storing tonnes of propellent and explosives on ships for their guns the capacitors and/or flywheels needed to power this thing are still going to react badly if damaged.

This has the range of modern anti-shipping missile, and assuming it can be aimed accurately is going to have a much better chance of hitting its target (point defense would be useless). In fact it'll be really hard to detect, the shell's radar cross section is going to be tiny. A harpoon missile costs over $1m and you can only store a limited amount of them - ~90 max - this would probably have a much cheaper per unit cost and you'd be able to carry a lot more of them (although the energy storage would take up a lot of room too).

I don't see this being too useful in a shore bombardment role though. Aircraft and guided missiles still seem to be more effective (esp. at longer ranges).
posted by schwa at 10:07 PM on February 28, 2012

Really, these new railguns will only convince the public of their worth when the Navy kills a Transformer with testicles.
posted by Burhanistan at 10:09 PM on February 28, 2012

Really, these new railguns will only convince the public of their worth when the Navy kills a Transformer with testicles.

Do they have to use testicles to kill him? I guess they could use special aluminum-plated ones but it still seems kind of weird to me. But you know best.
posted by scalefree at 10:24 PM on February 28, 2012 [4 favorites]

Betesticled?
posted by Burhanistan at 10:35 PM on February 28, 2012

"...and if factories could work around bomb damage in WW2 I bet they can work around the relatively small craters made by a billet of impacting metal."

All that kinetic energy concentrated in one spot should make a fairly large crater. It's a more efficient way of taking the energy in one place and delivering it to another place very quickly, without the wastage of relying on chemical reactions.
posted by Kevin Street at 10:56 PM on February 28, 2012

Only when they kill him with truck nuts..
posted by rainy at 11:02 PM on February 28, 2012

33 megajoules per shot and 10 shots per minute is 330 megajoules per minute which is equal to 5.5 megawatts continuous power. This is about 7400 horsepower or the equivalent of two diesel-electric locomotives running full throttle continuously while firing.
posted by JackFlash at 11:25 PM on February 28, 2012 [1 favorite]

I'm wondering what was going on with the shape of the projectile as well.

As a weapon, it's not clear at all how this thing is practical. None of our 'enemies' have any kind of high tech weaponry. Spending all this money on hardware is completely useless for actually helping us win wars. If they actually wanted to do a lot of damage they would be focused on making things cheap. Many more predator drone type things, but for much lower costs.

The US carrier fleet is hardly for show. If another navy had a rail gun the US would simply keep its carriers out of range since any jets it carried would have a much greater range than 100 miles.

Couldn't the jets be hit by the railgun as well? The carriers are also susceptible to cruse missile and stuff like that

But second, because the shot is moving so damned fast, the gun's accuracy goes up, particularly with respect to moving targets. Cruise missiles only go about 550mph. Railguns can achieve velocities ten times that. And that Somali pirate masquerading as a fishing boat? Now you can drop a bullet on him from over the horizon, and because it's only going to take about five seconds to get there

Yeah but… why would you spend $250 million dollars on something to do that, when you can obviously just get right up next to them and just shoot them with a sniper rifle gun, let alone a regular navy weapon.

That's why the argument for this technology makes no sense on a cost basis. Who are we supposed to fight with these things?

Keep in mind that this is a weapon to fight a war in about 2025. Even though we have the technology to destroy the entire world many times over in 35 minutes, we must prepare for this war with newer more imaginative weapons.

Uh, why? No one else is investing in this kind of research. If a country has a nuclear weapons, why does it need a railgun? If it doesn't have nukes, why would it choose to develop a railgun, rather then a nuke?

Maybe this thing is just a feint to get other countries to waste money developing their own.
posted by delmoi at 11:29 PM on February 28, 2012 [1 favorite]

HOLY SHIT RIFTS IS FUCKING REAL OMG WE ARE THE COALITION!!!!

and holy fuck I have no megadamage armor, holy fuck, oh I am so fucking fucked
posted by Afroblanco at 11:29 PM on February 28, 2012 [2 favorites]

In fact it'll be really hard to detect, the shell's radar cross section is going to be tiny.

Agreed, but you will have the huge EMP generated by firing the gun. And the projectile may generate a very visible electromagnetic signature as it travels.

It is intellectually fascinating stuff, but then so are Mark Rothko's paintings.
posted by b1tr0t at 11:41 PM on February 28, 2012

"...and if factories could work around bomb damage in WW2 I bet they can work around the relatively small craters made by a billet of impacting metal."

Have you ever looked at the damage from meteors?

Once this weapon hits, all the kinetic energy left over has to go somewhere, likely there would be a large molten splash depending on what it hits and how fast it is going.

At the least it is going to be very like an explosion. I will wait for a math person to convert the kinetic energy to lbs of TNT.
posted by psycho-alchemy at 11:48 PM on February 28, 2012

Also I didn't see there backstop, the horizon looked empty.

Either the backstop is really far away or their shot vaporized.

It would be funny if they just released this to buy themselves time to solve the problem of their shot vaporizing.
posted by psycho-alchemy at 11:54 PM on February 28, 2012 [1 favorite]

But second, because the shot is moving so damned fast, the gun's accuracy goes up, particularly with respect to moving targets. Cruise missiles only go about 550mph. Railguns can achieve velocities ten times that. And that Somali pirate masquerading as a fishing boat? Now you can drop a bullet on him from over the horizon, and because it's only going to take about five seconds to get there, you can probably hit him at that range. Really, this would let the Navy go after these sort of smaller, less organized targets much more efficiently, because it no longer needs to launch a few tons of steel powered by several more tons of gunpowder, or assign expensive and limited aircraft, to go after a few speedboats. They can just shower a literal hail of bullets from hundreds of miles away.

A LITERAL HAIL? According to the Navy, the goal in 5 years is "several shots per minute" without depleting the energy stores. Maybe you meant that kind of literal that is the opposite of the meaning of literal?

planes are awesome, but they can only kill so many targets, only so many targets at once, and only those targets you know about.

This is true of any weapon operated by a human.

The advantage of a railgun is that it can basically hit any target in its range until it runs out of ammo.

...or malfunctions, and this is true of any weapon operated by a human.
posted by dubold at 12:02 AM on February 29, 2012 [2 favorites]

I know it's an instrument of destruction and so on but .... COOOOOOOOOOL
posted by GallonOfAlan at 12:40 AM on February 29, 2012

Another big problem: the current generation of Destroyers can’t produce the power

What does the Navy need to research?

No, no, no. They've already done the research. Now it's just a matter of:

YOU MUST CONSTRUCT ADDITIONAL PYLONS.
posted by ShutterBun at 2:19 AM on February 29, 2012 [3 favorites]

Psycho-alchemy asked: Have you ever looked at the damage from meteors?

The kinetic energy of an object is half its mass times the square of its velocity. A little Googling tells me that substantial meteors fall with speeds in the tens of kilometers per second. Let's say thirty kilometers per second and a weight of five kilograms - that billet looked about that weight.

E = 5/2*30000 = 2,250,000,000 joules.

The article says that they want to fire projectiles using one per cent of that energy. And obviously not all of that energy goes into velocity; is it as much as 20%? Anyway, your rail gun has a tiny fraction of the energy of a comparably-sized meteor. And even that meteor would only leave a tiny crater, a few meters across!

Of course, you're not aiming at the ground. You're aiming at a building. So what do you think happens to a roof when a small but heavy piece of metal hits it? Why, unless it hits a support it makes a small hole in the roof. And then it makes a small hole in the floor below and it keeps going. It will ultimately spend most of its energy in the ground below the building, although I suppose that a certain amount gets reflected upwards. But still, you're essentially making a very small and localised crater on one floor of one building.

Cool Pap Bell wrote: There have been precision-guided artillery rounds in service for at least a decade.

Ones without propellant? I'm sure you could make something like that, and then you'd just have to make it work without being crushed by acceleration or melted by air friction or whatever. I'm a bit sceptical, but I guess. It's certainly not something that has been used for a decade, though.
posted by Joe in Australia at 2:29 AM on February 29, 2012

Hey, it's my Dad's project on mefi!

Big secret to keeping this project funded? Let The Admiral Press The Button. My Dad's lab has become a stop on the VIP research tour and he makes sure the highest ranked visitor gets to press the button that fires the gun. Then he gives them a paperweight made from a few inch thick piece of steel that has been punctured by the railgun. The VIP puts the object d'art in their office, others see it and ask about it, and then schedule a visit of their own so they can Press The Button.
posted by robocop is bleeding at 2:48 AM on February 29, 2012 [16 favorites]

Your dad builds railguns?

Well, I guess we've figured out why robocop is bleeding.
posted by dubold at 3:18 AM on February 29, 2012 [6 favorites]

Um...this is planet destroying tech. Not the other thing.

Ahem.
posted by Kid Charlemagne at 3:41 AM on February 29, 2012

Your dad builds railguns?

Before railguns, it was plasma cannons.

Oh, and flying saucers.

Seriously, kids, SCIENCE!
posted by robocop is bleeding at 4:15 AM on February 29, 2012

Ahem.

Well, that's your fault for for using undefined acronyms!

Do you have a link or something? That sounds cool.
posted by His thoughts were red thoughts at 4:27 AM on February 29, 2012

Well, if it makes you feel better there are ICBM-laden subs on patrol right this moment.

If you want to get even giddier keep in the mind that there are British subs out there with ICBMs. Think The IT Crowd with nukes. Since I have been in the UK they have had a collision, run aground and had a murderer open fire and kill people on board these things. The charge of the light brigade has never ended.

I saw one of these of the coast of Skye a few years ago and all I could think that I was watching the death of millions gliding across a bay.
posted by srboisvert at 4:28 AM on February 29, 2012 [3 favorites]

Anyway, what exactly is the practical use of a naval rail gun?

Bombarding some Asian target far inland from friendly waters? Perhaps in a scenario where the US does not enjoy air superiority and, thus, cannot deploy manned aircraft or drones safely to the target area?
posted by Thorzdad at 5:04 AM on February 29, 2012

As a weapon, it's not clear at all how this thing is practical. None of our 'enemies' have any kind of high tech weaponry. Spending all this money on hardware is completely useless for actually helping us win wars. If they actually wanted to do a lot of damage they would be focused on making things cheap. Many more predator drone type things, but for much lower costs.

See Arthur C. Clarke's "Superiority".

numerous and straightforward > few and fancy
posted by Trurl at 5:25 AM on February 29, 2012 [2 favorites]

delmoi writes "Uh, why? No one else is investing in this kind of research. If a country has a nuclear weapons, why does it need a railgun? If it doesn't have nukes, why would it choose to develop a railgun, rather then a nuke? "

A nuclear weapon is basically a weapon of last resort and is too indiscriminate for field work. Consider for example that the US has dropped millions of pounds of explosives explosives on Iraq and Afghanistan in the last couple decades and not one nuclear weapon. Once developed no one is going to sweat using a rail gun.
posted by Mitheral at 5:33 AM on February 29, 2012 [1 favorite]

From what I've been told, a big part of the shipmounted railgun is to get the explosives off the ship. Having high explosives on board means more armor, which means bigger ships, which means more cost. A railgun can take the place of not only a ship's cannons, but a bunch of the various ship-to-shore missiles it totes around, which again can reduce the size of the ship. There is also some interest in using smaller railguns to stop attacks by smaller vessels (ala the USS Cole), but the physics doesn't really work out. Same for interdicting missiles in flight, but they'll keep working on it.

So in a way, it's an attempt to make more and cheaper. Instead of a massive battleship or frigate that requires the support of a bunch of other vessels, a railbomb ketch could be one of those support ships.
posted by robocop is bleeding at 5:35 AM on February 29, 2012

If you make the barrel long enough (so you can accelerate slowly enough to keep the g-forces manageable) LEO transport.

Note by long enough, you also mean "long enough that the muzzle is out of the atmosphere."

This thing fired a 10kg aluminum slug at 5500fps, or just over a mile a second, about Mach 8. It was traveling so fast that the aluminum was melting and then catching on fire from atmospheric friction.

Typical low earth orbit velocity is about 7.8km/sec, or well over 25,000 fps. If your craft leaves the muzzle anywhere below 50 miles above the surface, your trip will end very loudly, very brightly, very quickly, and very hot.

As as in long enough -- it's best to keep human acceleration down in the 4g range, or 40m/s². So, about 200 seconds at that to reach 8km/sec, which means you'd need an 800km long barrel.

Note that this has to be a *linear* barrel. If you tried to get to 8km/sec using a circular accelerator 128km in diameter, you'd be pulling 100g in centripetal acceleration. For a 1g centripetal acceleration, the diameter of your accelerator would be 6400km. Compare to size of Earth.

Just give the projectile (something dense and solid that won't burn up passing through the atmosphere) a slight push, and gravity will do all the work for you. Kinetic bombardment.

But then you have to boost the projectiles into LEO as well, and plus, you're limited to LEO velocity. Not that this is in any way small, but the right answer, if you want to use rail guns as a strategic weapon, is to build them on the moon, where you have plenty of mass lying around, and, as a bonus, will have rounds hitting with about 60% more velocity. Note that you don't need to generate all of that velocity, the rail gun is simply to get the projectile off the moon and into an orbit that hits the Earth in the right place.

Are shipboard cannon even relevant any more?

Fundamentally, a ballistic projectile is the hardest projectile to stop. A projectile that is being propelled only needs a little nudge to miss -- the rest of the energy for changing its trajectory comes from the projectile itself. There's no guidance system to confuse.

And, compared to a conventional cannon, one thing really jumps out -- look at the breach. It was two tiny doors, it looked like a pair of oven doors. That means that the chamber pressure of this thing is vastly lower, which is vastly easier to repair. The rounds themselves are smaller, in the sense that in a normal cannon, the round is the projectile plus the propellent, plus primer and in weapons of this scale, the case. In a railgun, the entire mass is projectile. A conventional cannon firing a projectile this size would have a much larger round.

Finally, you don't have to worry about storing propellent. Given the number of ships that have blown up because the powder magazines were hit, this is a big deal. You would, of course, still have to worry about the charges in the projectile, but modern high explosives are *vastly* more stable than the propellents we use to fire them. Getting rid of those propellents would be a big win in survivability.

Finally, though -- if I'm hitting something at 3-4km/sec with 10kg of something, I don't actually need much of a charge. There's enough KE there to do a great deal of damage. Theoretically, we could go full circle -- from solid shot, to shell, to contact fused shell, to proximity fused shell, to solid shot again.
posted by eriko at 5:52 AM on February 29, 2012 [5 favorites]

Oh yeah.

BOOM! BRIDGESHOT!
posted by eriko at 5:52 AM on February 29, 2012

Perhaps if it fails, it can be rebranded as an antimatter generator.

No, I've seen one of those, they're much bigger.
posted by eriko at 5:53 AM on February 29, 2012

If another navy had a rail gun the US would simply keep its carriers out of range since any jets it carried would have a much greater range than 100 miles.

The F/A-18C combat range is listed as only 400nm, the F/A-18E is 390nm, and that's an in-and-out bombing range, no air-to-air, no dodging around things. Keeping the carriers 100 miles offshore would *seriously* limit the FA-18C combat ability. Get the range to 150 miles, and you will have effectively taken these aircraft out of the battle, or at least seriously limited their effectiveness.

Yes, you can refuel, but that adds complications and delays strikes. This can work for a lot of missions, but for naval landings, you need the flattops close so that the attack craft can have some loiter time, and of course, so they can turn around fast after they're out of munitions or low on fuel.
posted by eriko at 6:00 AM on February 29, 2012

Anyway, your rail gun has a tiny fraction of the energy of a comparably-sized meteor. And even that meteor would only leave a tiny crater, a few meters across!

IIRC, the meteorites that leave small craters like that are only traveling at a few hundred km/h after aerobraking.
posted by ROU_Xenophobe at 6:03 AM on February 29, 2012

kavasa: "And if so, in what way is this thing superior to a regular weapon?"

Sooner or later, everyone listens to Reason.
posted by wenestvedt at 6:16 AM on February 29, 2012 [2 favorites]

Dammit, I just came in here to make a Snow Crash reference! Namely: "Ultima Ratio Regum" would have been a better motto.
posted by A dead Quaker at 6:21 AM on February 29, 2012

1) Military R&D drives advancement in basic applied science and foundation technologies. Sad, but true. The space program was essentially a military project, as was the internet. We wouldn't have satellite communications or Metafilter without military R&D.

2) As doomsday weapons go, this one is environmentally friendly. It replaces chemical propellant (the modern equivalent of gunpowder), which is toxic to manufacture, and uses aluminum slugs instead of depleted uranium or lead. It's not polluting like a cruise missile. It results in lighter and smaller ships, which require less fuel to operate and fewer resources to build.

3) It's going to represent a massive cost savings. Carrier groups are fucking expensive, and in the wake of modern submarine, torpedo and missile design, dangerously obsolete. You can replace an entire carrier group with a railgun cruiser, a drone cruisers (a ship designed to launch and retrieve drones) and an ASW ship, while projecting just as much power. Three medium sized warships, that's all. We can repurpose operational budgets for more R&D projects, or just shrink military spending outright.

Amazing times we're living in.
posted by Slap*Happy at 6:40 AM on February 29, 2012 [2 favorites]

See Arthur C. Clarke's "Superiority".

numerous and straightforward > few and fancy

Farmboys in X-wings > the Death Star
posted by Foosnark at 7:15 AM on February 29, 2012

For the people who have been asking about the shape of the projectile, I'm guessing the cup-shaped rear is to hold onto a crosspiece that bridges the two rails. The idea is, put two rails parallel to the axis of the barrel, and let current flow up one rail, across a sliding crosspiece, and down the other. The magic of E&M then throws the crosspiece forward with great force, pushing the projectile in front of it.
posted by d. z. wang at 7:25 AM on February 29, 2012

RE: The slug shape. I saw this somewhere else and they said that they use an un-aerodynamic shape in case it goes off course. If they miss, the slug won't go 100 miles farther than it was supposed to and through someone's living room.

The operational version would use a differently shaped slug that may or may not have a bunch of other crazy stuff (guidance systems, explosives, or just a solid slug).

The other advantage that I haven't seen mentioned is the noise. This thing would have long range like a cruise missile but since it travels so much faster than the speed of sound, no one will hear it coming.
posted by VTX at 7:32 AM on February 29, 2012

> The operational version would use a differently shaped slug that may or may not have a bunch of other crazy stuff (guidance systems, explosives, or just a solid slug).

I seem to recall some CGI promo videos of rail gun projectiles that exploded like cluster bombs to rain down on airfields and other installations.
posted by Burhanistan at 7:56 AM on February 29, 2012

LatinFilter: If the motto translates to "speed kills," shouldn't it be velocitas eradicat rather than eradico?
posted by the sobsister at 7:59 AM on February 29, 2012

despite the bombardment scenarios suggested above i think the main reason for this type of weapon is for air defense. having a projectile that could be accurately fired at this speed would be extremely useful in defending against airplanes and even faster things like ballistic missiles.
posted by lester's sock puppet at 8:04 AM on February 29, 2012

And, compared to a conventional cannon, one thing really jumps out -- look at the breach. It was two tiny doors, it looked like a pair of oven doors. That means that the chamber pressure of this thing is vastly lower, which is vastly easier to repair.

A railgun doesn't have a chamber in the same way that explosive-powered guns do. All the wear and tear is on the rails, where they make contact with the projectile.

Finally, you don't have to worry about storing propellent. Given the number of ships that have blown up because the powder magazines were hit, this is a big deal.

You don't need to store explosive propellent, but you do need to be carrying around the necessary energy to power the gun somehow. The ship might end up being a huge diesel bunker* or carry around an oversized naval nuclear reactor.

There is also some interest in using smaller railguns to stop attacks by smaller vessels (ala the USS Cole)

A smaller railgun might be useful for attacking the USS Cole, but would be no more useful for preventing something like the USS Cole bombing than NORAD was in stopping the 9/11 hijackings. Not useful at all.

Our current weapons systems are phenomenal. We don't need bigger guns, we need better ways to think about the threats that do (or don't) exist and how to deal with them most effectively. Railguns are crazy sexy geek-tech, but they strike me as more akin to Death Stars or Maginot Lines than actually useful weapons. Expensive and dramatic, but vastly easier to defeat than their proponents expected.


*Rather than making bigger guns, why not take some rusty old supertankers, fill them up half way with unrefined crude, and park them just off the shore of whoever you want to intimidate? It wouldn't work for landlocked countries, but total destruction of fisheries and the coastline is a terrible threat.
posted by b1tr0t at 8:15 AM on February 29, 2012 [1 favorite]

1) Military R&D drives advancement in basic applied science and foundation technologies. Sad, but true. The space program was essentially a military project, as was the internet. We wouldn't have satellite communications or Metafilter without military R&D.

Not true, just a self-fulfilling prophecy. Any large project generates ancillary research results. There's no reason those taxpayer dollars couldn't have gone into fusion energy research, a supercollider, a space mission, etc. All of those ventures have produced enormous unforeseen side benefits. Plus, instead of ending up with what is at best an expensive toy, we could have had a primary result with enormous societal and scientific benefits! I don't give the military industrial complex a scrap of credit for scientific achievements - they primarily waste blood, manpower, and treasure on projects that sometimes accidentally do some good, but never break even in societal utility.
posted by Salvor Hardin at 8:46 AM on February 29, 2012 [1 favorite]

Cool Pap Bell wrote: There have been precision-guided artillery rounds in service for at least a decade.

Ones without propellant?

Yes. If you'd have looked at the link, you'd find several examples. Here's the latest model, and this one saw service in the first Gulf War. They are GPS-enabled, finned projectiles able to adjust course in mid-flight, just like a guided gravity bomb dropped from an aircraft.

The railgun is almost certainly being designed with a mind toward firing something with similar capabilities.
posted by Cool Papa Bell at 8:59 AM on February 29, 2012

Big secret to keeping this project funded? Let The Admiral Press The Button. [...] The VIP puts the object d'art in their office, others see it and ask about it, and then schedule a visit of their own so they can Press The Button.

This is great advice, actually, with applications far broader than putting holes in things.
posted by RikiTikiTavi at 9:05 AM on February 29, 2012

"It's going to represent a massive cost savings. Carrier groups are fucking expensive, and in the wake of modern submarine, torpedo and missile design, dangerously obsolete. You can replace an entire carrier group with a railgun cruiser, a drone cruisers (a ship designed to launch and retrieve drones) and an ASW ship, while projecting just as much power. Three medium sized warships, that's all."

This is also sort of a security based argument as well. If future naval technology will be cheaper to maintain and require less hardware to do the same job, then it follows that other nations will have less trouble developing this capability for themselves. When the barrier to naval superiority is actual material, then you have to control huge resources and have a lot of money available to build all those ships and planes and keep them running, which gives the United States an advantage. But if you can achieve the same result with a lot of research into new technology and a smaller investment in material then that comparative advantage is smaller, and other countries may have less trouble building powerful navies of their own. It'll just take them longer than the US.
posted by Kevin Street at 9:08 AM on February 29, 2012

*Rather than making bigger guns, why not take some rusty old supertankers, fill them up half way with unrefined crude, and park them just off the shore of whoever you want to intimidate? It wouldn't work for landlocked countries, but total destruction of fisheries and the coastline is a terrible threat.

Like nuclear weapons this is pretty indiscriminate. Tough to intimidate Iraq/Egypt/Libya/Panama/Cuba/North Korea this way without seriously pissing off all their neighbours; many of whom are your allies and may be the reason you are there flexing your might in the first place.
posted by Mitheral at 9:22 AM on February 29, 2012 [1 favorite]

But if you can achieve the same result with a lot of research into new technology and a smaller investment in material then that comparative advantage is smaller, and other countries may have less trouble building powerful navies of their own. It'll just take them longer than the US.

Which is another reason to keep the R&D wheels in motion. By the time railgun fleets are commonplace, our network of autonomous silent torpedoes need to be shadowing hostile railgun platforms to nullify them. By the time they get their own network of autonomous silent torpedoes, we'll have stealthed active sonar and directional acoustic cannon to nullify them. And so it goes...
posted by Slap*Happy at 9:23 AM on February 29, 2012

*Rather than making bigger guns, why not take some rusty old supertankers, fill them up half way with unrefined crude, and park them just off the shore of whoever you want to intimidate? It wouldn't work for landlocked countries, but total destruction of fisheries and the coastline is a terrible threat.

I'm pretty sure the Geneva Conventions have a rule against that sort of thing. See Dresden, Firebombing of.
posted by scalefree at 10:15 AM on February 29, 2012

Like nuclear weapons this is pretty indiscriminate.

And it's also illegal by the universally recognized Conventions of War.
posted by scalefree at 10:19 AM on February 29, 2012

I think I'm going to let my eyes unfocus and drift off in to a daydream where I live in a world where nobody is investing huge amounts of time and resources into figuring out ever more exotic and powerful methods of Fucking Shit Up and Killing People, because, you know, that would be a crazy way to behave. Mmm that's some good fantasy world...
posted by nanojath at 10:51 AM on February 29, 2012

I'm pretty sure the Geneva Conventions have a rule against that sort of thing. See Dresden, Firebombing of.

Sure, but the Geneva convention didn't do much to stop the 9/11 hijackers. Picture a tanker arriving in New York Harbor. Then picture a little Iraninan flag popping out. What good is your rail gun now?

Or, picture a completely crazy US administration (impossible, I know), that decides to park tankers off population centers around the world, SPECTRE style.

Just because the Conventions or good sense forbids something, doesn't mean it won't happen. See also: Guantanamo.

I think I'm going to let my eyes unfocus and drift off in to a daydream where I live in a world where nobody is investing huge amounts of time and resources into figuring out ever more exotic and powerful methods of Fucking Shit Up and Killing People, because, you know, that would be a crazy way to behave. Mmm that's some good fantasy world...

It would be interesting to look into non-defense R&D vs defense R&D over time. As bad as the economy is, there is a lot of very active private, non-defense R&D right now.
posted by b1tr0t at 1:17 PM on February 29, 2012

Picture a tanker arriving in New York Harbor. Then picture a little Iraninan flag popping out. What good is your rail gun now?

Rail gun? Are you kidding? Dude, I can beat the Frigate level on Goldeneye 64 with slappers.
posted by The World Famous at 1:22 PM on February 29, 2012 [2 favorites]

Rail gun? Are you kidding? Dude, I can beat the Frigate level on Goldeneye 64 with slappers.

You know, I did completely overlook the impact this railgun research could have on the video game industry.
posted by b1tr0t at 2:37 PM on February 29, 2012

I never imagined these things would *actually* be controlled by a touch screen that says

"Fire" "Charge" "Abort!!" (with the exclamation marks)
posted by cacofonie at 6:12 PM on February 29, 2012

I understand that there are efforts afoot to remove the Abort command from the panel...
posted by b1tr0t at 6:48 PM on February 29, 2012

I understand that the weapons officer will be required to stare at a picture of the bullet before pressing the Abort button.
posted by Joe in Australia at 8:25 PM on February 29, 2012 [3 favorites]

Some people argue that a bullet is already a projectile, even when it is just sitting in the magazine.
posted by b1tr0t at 8:39 PM on February 29, 2012 [4 favorites]

I'm torn. On the one hand: the cool-as-fuck engineering with this and seeing a classic SF trope become a reality. The other hand: the knowledge that we have spent billions of dollars on it which could've been spent better and last but not least, the fact that, if used, this will be employed in wars I don't want to happen and almost certainly, at some point, kill innocent civilians.

I can't believe I'm the first person to point this out FTFA:

The Navy has spent $240 million on the railgun so far, and it expects to spend about as much through 2017 on tests — before buying a single one of the things.

posted by !Jim at 8:44 PM on February 29, 2012

For what the rail gun cost to develop, they could have hired Kimi Raikkonen for almost five years, or just run the entire Ferrari Formula 1 team for about 5 months. Stupid Obama. What was he thinking?
posted by The World Famous at 12:20 AM on March 1, 2012

You're not looking at the bright side: these fine steel swords are going to make totally awesome ploughshares some day!
posted by Ritchie at 2:35 AM on March 1, 2012 [1 favorite]

I can't believe I'm the first person to point this out FTFA:

The Navy has spent $240 million on the railgun so far, and it expects to spend about as much through 2017 on tests — before buying a single one of the things.

Do you find that to be remarkably high or remarkably low?

An amazing alternative energy laboratory that I used to work for recently had its funding canceled by the DoE. We could have financed that research for 240 years with what they've spent on the rail gun. We could have sent a third Mars Exploration Rover to Mars.

The US Military spends around $689 billion annually (20% of the total US budget, 25% of the non-SS budget), $274 billion of which goes to defense contractors. I would love to defund the US Military down to...say...1/20 their current budget - that would bring them down to a nice, manageable $30 billion/year.

The way things are now, there's a vicious expenditure-increasing cycle driven by a parasitic defense contractor lobby.

1. There exists a massive US military budget.
2. Defense contractors swarm to get at this money like leeches to the American groin.
3. Defense contractors are awarded massive amounts of money.
4. Fabulously rich defense contractors purchase, intimidate, or become our politicians and leaders.
5. Our politicians and leaders find ridiculous ways to fling US mil-spec feces all over the globe to justify the massive budget.
6. Other countries and organizations react negatively to a vast, belligerent US military presence around the globe.
7. Unrest, anti-American sentiment, and propaganda create a sense of permissive inevitability (or even eagerness) amongst taxpayers about increasing military expenditures.
7. Military expenditures increase (goto step 1).

Even without the defense contractors, there is a simpler cycle:
1. There is a huge US Military budget.
2. We've got to do something with this enormous military.
4. Shit, they're pissed, now we REALLY need an enormous military.
5. US Military budget grows (goto step 1)
posted by Salvor Hardin at 4:06 PM on March 1, 2012 [2 favorites]

The Navy has spent $240 million on the railgun so far, and it expects to spend about as much through 2017 on tests — before buying a single one of the things.

Do you find that to be remarkably high or remarkably low?

I find it neither, but the person I was replying to claimed we were spending billions on it. Excuse me, but if we're going to have a debate here, I'd prefer it be based on facts.
posted by !Jim at 5:35 PM on March 1, 2012

Excuse me, but if we're going to have a debate here, I'd prefer it be based on facts.

An admirable preference, which I share. I'm glad you pointed out that the Navy's rail gun adventure has cost us considerably less than billions (thank goodness).

Nevertheless, I do think the facts in this case support the idea of sending a rail gun slug directly through the DoD budget (and IJim, in case it seems like it, I'm not implying that I know your opinion). In my opinion, even as little as $240 million for this thing is a criminal abuse of taxpayer funds. It may seem like I have something against rail guns in particular. I don't. In fact I'm a physicist, and a big sci-fi nerd who loves futuristic stuff like this. INSIDE MY SCI-FI BOOKS. In a way, because this is a particularly sexy misuse of tax revenue, I feel like I should speak out especially forcefully. This is hardly an isolated DoD line-item - it's one float in a long parade of suckery.
posted by Salvor Hardin at 6:43 PM on March 1, 2012 [2 favorites]

Wow, also, I apparently can't reliably count to 8, or to 3! Outrage is a helluva drug.
posted by Salvor Hardin at 8:34 PM on March 1, 2012