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Navy Debuts New Railgun That Launches Shells at Mach 7
Jeremiah Cornelius writes: "The U.S. Navy's new railgun technology, developed by General Atomics, uses the Lorentz force in a type of linear, electric motor to hurl a 23-pound projectile at speeds exceeding Mach 7 — in excess of 5,000 mph. The weapon has a range of 100 miles and doesn't require explosive warheads. 'The electromagnetic railgun represents an incredible new offensive capability for the U.S. Navy,' says Rear Adm. Bryant Fuller, the Navy's chief engineer. 'This capability will allow us to effectively counter a wide range of threats at a relatively low cost, while keeping our ships and sailors safer by removing the need to carry as many high-explosive weapons.' Sea trials begin aboard an experimental Navy catamaran, the USNS Millinocket, in 2016."
...but at least part of the future is here already.
"Our opponent is an alien starship packed with atomic bombs," I said. "we have a protractor"
...Can someone who is explain where the big fiery explosion out of the railgun is coming from, if this thing is electromagnetically driven?
In Soviet Russia, Chuck Norris will still kick your ass.
Can it be efficiently powered, though? It always seemed like the power draw was the main issue with these kinds of guns, effectively limiting them to a few shots.
It's a "Small-waterplane-area twin hull" or SWATH, not a catamaran. http://en.wikipedia.org/wiki/S...
-73, de n1ywb
www.n1ywb.com
"They are firing, sir!"
"Prepare the counte...."
Seriously... 100 mile range? At 5000mph? That range doesn't add up to me, but regardless, whoever is on the receiving end of this bad boy doesn't stand a chance to defend themselves
That's not even a 75mm railgun size. Can I fit it on my Velator? :)
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Just speculation but, when you propel something to mach 7, friction becomes a real issue. The SR-71 had a titanium body if I recall correctly, to help deal with temperatures it encountered at Mach 3. It is quite possible that the projectile is very hot and is igniting materials that have lower ignition temperatures.
HA! I just wasted some of your bandwidth with a frivolous sig!
Railgun $25,000 a round versus $1,000,000 a round for missiles.
Cost on just purely physics level, is rather irrelevant. It is economics that are the limiting factor.
Mount a downsized version on the A10.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
At last the US Navy, for so long the joke of the high seas, will become a force to be reckoned with.
how many pairs of boxer shorts should you own?
Well, judging form the pictures, this is the one disposable razor I wouldn't want to be shaved with.
Ezekiel 23:20
The railgun might fit, but where are you going to put the nuclear reactor to power it?
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Not to nitpick (well.....yah, I'm nitpicking), but both General Atomics and BAE Systems Railguns will be tested on the USNS Millinocket. BAE Systems actually got the Phase II contract, whereas General Atomics did not.
Link: http://breakingdefense.com/2014/04/navys-magnetic-super-gun-to-make-mach-7-shots-at-sea-in-2016-adm-greenert/
Full Disclosure: I nearly got to work on the GA RailGun system and I know some people who are on it. It's a better design than the BAE one but BAE got the contract.
Actually, do we know that there's any burning going on at all? I believe the light from a fire is not directly emitted by the chemical reaction, it's a result of the combustion gasses glowing from the heat. In which case just heating even an inert gas sufficiently will cause it to glow similarly. And the immense high-speed compression from a mach-7 projectile traveling down a confined tube should generate plenty of heat.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
So we're back to throwing rocks.
We just throw them very, very fast. :)
I do not fail; I succeed at finding out what does not work.
I likely takes a lot more electricity than that because the rail gun isn't going to be very energy efficient. I think I saw a large bank of capacitors in the background of the indoor photo. You wouldn't need such large capacitors, or so many of them, if it was only using 7.2kWh. Also the railgun is also firing a sabot of some sort that contains the 23 pound projectile. Regardless the article already pointed out that it is far cheaper to shoot than the chemically propelled shells. What I really want to see though is impact testing, I want to see things disintegrating explosively as a result of being hit by this thing.
Perhaps one of the big benefits of a naval railgun is that it's so difficult to defend against. Old-fashioned anti-ship missiles can be disabled or destroyed by the defending ship's close-in defenses. This is because the incoming missile is filled with sensitive electronics, guidance systems, explosives, fuel, turbojet engines, stabilizing fins, etc, and is very likely to be damaged or destroyed if hit by a 20mm round from the defending ship's CIWS missile defenses.
However, how do you shoot down a hunk of metal traveling at mach 7 toward your ship? It wouldn't make any difference if you hit it with a 20mm round from the goalkeeper or phalanx. The projectile would just keep flying toward the ship and strike it anyways. Besides, how would you even hit something which is so small and traveling at mach 7.
It doesn't seem there would be any good defense against this.
Many!
Imagine if you didn't need to handle explosives like Cordite as propellents anymore. This will reduce storage space and make a battleship's gun turret a while lot safer place to work. One small spark won't set off a magazine anymore.
"Muzzle velocity" is higher, so the distance you can throw something is a bit further, like 5x further. If you can fire further, you have a huge advantage because you can hit your opponent before he can shoot at you. Or if you are doing ground support, you can fire further inland.
I'm assuming a rail gun will be faster to reload. Might take some time to recharge the power supply, but surely we can fire faster than a Mark 7's 2 rounds a minute. More pounds and rounds on the target than your opponent is always better.
Finally, it may be possible to more strictly control forces on the shell when firing it, which may make it possible to put more technology IN the shells, and still get very high velocity. Imagine a shell that can adjust it's flight path, even slightly, which means you can fire in the general direction you want, then fine tune the aim in flight. (I assume they don't do that now..)
Issues to watch out for: First, Rail guns tend to have tracks (rails) and said rails usually have difficulty with wear due to the huge forces and high speeds involved. Hopefully they have engineered the better materials. Second, power supplies for rail guns have to be designed to provide HUGE impulse powers with power generation systems wanting to be running at steady state. You have to match the two. Finally, weapons like this usually mean you have to redesign the whole weapons system, a process that literally takes decades.
Go Navy, this is worth the R&D money..
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
according to the experts at yahoo answers, there isn't recoil in the traditional sense, but there is recoil because physics and also it somehow forms babby.
I doubt the capacitors are actually much of a risk either - after all there's no need to have them charged until right before you fire. It'll only be that brief window when they've got a large charge but haven't yet fired that they'll be dangerous. Unlike missiles, conventional explosives, propellants, and fuel which are all a continuous danger as long as they're on board.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
F=MA. M = big, A = very fast, therefore F = big very fast!
So, teaching in current mathematics has come to this?
We're doomed.
Faster! Faster! Faster would be better!
It's got a ways to go.
Tolerances causes more cost than you think, and documentation around military contract is generally at least half the cost of anything. It's not the contractors taking the piss (what, are you in OZ or UK?), but the government being stupid in supporting the military industrial complex.
Learn to love Alaska
I think the big problem with something like that would be two fold. It would have to be mammoth in size, not just huge. That is becausethe impactor would have to receive all of it's velocity before release, instead of like an ICBM that throttles up once it is in the much thinner upper atmosphere. Missiles don't throttle up until they are at significant altitude because the forces of friction would destroy them at lower altitudes. A rail gun munition would have to be big enough that it could have an effective amount of mass left after literally burning it's way through the lower atmosphere.
The other problem is how do you aim such a thing? Your loop is already going to be absurdly large so that you can gradually alter the path of the projectile to keep it going in a circle. Any point at which there is a relatively sudden change in direction is going to have to be massively reinforced and I really don't even know how you'd achieve altering the projectiles direction at these speeds without it just ripping through the sidewalls. The rail gun in the article shoots at around 5000mph, which comes out to a relatively puny 1.38 miles per second. Ballistic missles need to be going about 2.5 mi/s when they are at low earth orbit altitudes on the way up, so it'll need to be going faster than that when it leaves the launch facility. Can you imagine what it would take to change the course of what would probably have to be a multi ton projectile hurtling through a tube at speeds significantly above 2.5 mi/s? We'd probably need a "barrel" many miles long.
What might be more possible would be a launch facility with several independant guns which can shoot in say 8 differing directions. Then use a projectile that is capable of guiding it's own course, probably using solid fuels, once it has been launched.
Friction with and compression of the air yield heat.
Enough heat turns air into plasma.
Plasma has a tendency to glow brightly in the yellow-red range.
Il n'y a pas de Planet B.
Why the hell does an inert slug encased in a discarding sabot cost twenty grand?
The only way these get cheap is if we have to make a lot of them to fight a war. Be thankful we only have to deal with low-rate peacetime economics where the development costs of unique tooling gets amortized across a small number of prototype rail gun slugs creating a big per-unit price tag that causes fools to go apoplectic.
Maw! Fire up the karma burner!
let's see 23lbs @ 7333 fps is about 169,000 ft lbs or about 229,000 joules each second. If the projectile hits the target for about 1/500th of a second that's more or less 1.2 GigaWatts.
F=MA. M = big, A = very fast, therefore F = big very fast!
So, teaching in current mathematics has come to this?
We're doomed.
If somebody asks whether accelerating a 23-lb mass to Mach 7 would push the thing accelerating it backward, we may have to go back to F=ma. And defining m=big and a=very fast seems appropriate. So, yeah, F=big very fast. Not perfect grammar, but at least it paints a picture for our friend who has yet to hear of Newton.
He's getting rather old, but he's a good mouse.
I'm betting that $25K per shot includes the cost of launcher maintenance.
Even for military use, 10kg of solid projectile material shouldn't bill out at $25K.
Depends, is the target a bridge or a building?
Striking moving targets from 100 mile range is ballsy, even for the Navy.
The same reason that space vehicles and meteors burn the atmoshere when they encounter 'air' at high velocities.
The same thing that destroyed the space shuttle "Columbia"with damaged heat tiles on the wing edge when it re-entered.
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
The navy will secretly transport it to the moon, there the speed will be enough.
Yes, but who're you going to crew it with, convicts? They'll just build another one and throw rocks at us.
You're special forces then? That's great! I just love your olympics!
QUAD DAMAGE
and now...and now...and now...it just keeps coming
My God can beat up your God. Just kidding...don't take offense. I know there's no God.
Probably includes cost of rail maintenance- most artillery pieces need to be re-barreled at some interval as well.
love is just extroverted narcissism
Ex Vietnam era Navy Vet. The "shell" fired is part rocket. This extends the range but uses a smaller warhead. They even had a small version for the 5 in guns my destroyer carried.
And if there is any place that knows about jerk, it's /. :)
The Kruger Dunning explains most post on
I'll add that I just read that 155mm rounds cost $50,000 each. So it's even cheaper than conventional artillery.
Citation please.
The new GPS radar guided Excalibur perhaps. But no a standard HE round.
http://en.wikipedia.org/wiki/M...
The max range of a 155 round is a lot shorter than some are indicating.
16000 yards or about 9 miles for the howitzer. It is necessary to
not confuse naval guns with army howitzers. Since I am an Army guy
I will not worry about naval guns beyond acknowledging that "guns" have
longer range but the max is about 23 miles.
Rail guns are interesting as kinetic weapons. The projectile must be
something dense and durable. One guess would be tungsten, or tungsten carbide, depleted
uranium perhaps. Depleted uranium amo is commonly jacketed with gliding metal to protect
the barrel for sure. I wonder if U has sufficient strength as is for a rail gun acceleration profile.
There is a big gap between modern guns ~25 miles and cruise missiles, both range and cost.
Perhaps this is the true goal of a rail gun.
http://www.g2mil.com/8inchguns...
Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities; Truth isn't. Mark Twain.
There is a youtube video where the weapon is initiated (fired isn't quite appropriate as there is no fire involved) and you can definitely see the barrel recoil within the gun base. The M114, 155mm howitzer firing the M107 he projectile masses at 43Kg and has a muzzle velocity of 564 m/s resulting in at least 24252 Kg*m/s of recoil; the railgun fires a 10 Kg projectile with a muzzle velocity of 2235 m/s resulting in 22350 Kg*m/s or 8% less recoil (power) than a howitzer; 1.3678128e7 J vs. 4.995225e9, but 365 times more energy.
Apocalypse Cancelled, Sorry, No Ticket Refunds
30MJ is about 2,000kW electrical for one round per second. Not that much power at these energy levels.
Not much room needed for the projectiles, less danger of a powder room exploding, fine. But none of this seems to even mention: what is generating the massive amount of electrical energy required per shot? Not to mention rate of fire - how much time is needed to generate that power for each shot? That this is a very quiet elephant in the room implies it's pretty bad on both counts.
Depends. How far can your target move in that time. Likely, less than a mile, and since ships don't turn on a dime, they're highly likely to be proceeding on a vector over the coarse of the projectile's flight. So, just like duck hunting, you aim in front of them appropriately, only with computers doing the math for you.
Just another day in Paradise
Yeah - Go pedantics! Big can be size, weight, importance, etc... Knee-jerking "big"=="size" is like saying that the "shortest" route home means plowing through walls, cars, etc, rather than going to my car and taking the "quickest" route home. Yes, "fast" is "speed", but when you're referencing F=ma, I think that "getting something big to move fast" implies changing the velocity of a given mass. How close to Kindergarten do we need to get?
Well, I'm arguing with an AC on an article a day old that will probably never be read. Maybe a day of Kindergarten is what we all need.
He's getting rather old, but he's a good mouse.