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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.
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
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.
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?
No, you're mistaken ... that's the USS-Nokia. ;-)
Lost at C:>. Found at C.
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.
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.
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.
I suspect it's compression rather than friction doing most of the heating. Much like an orbital reentry vehicle - the gas within the shockwave starts to glow long before it contacts the vehicle itself.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
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
Energy is not the issue – it is the rate of fire. Diesel engines power the supper capacitors, they discharge to fire the gun, and then fill them up again. I have read that this cycle might be measured in minutes instead of seconds. How big of an issue that it will be is a big question.
That depends on how many capacitor banks you've got, yes? Or possibly the sustained power output of the generators, though that's perhaps more of an issue for sustained firing. (Naval ships are pretty big; you can fit a lot of capacitors and generators in there.)
What I'm impressed at is that they can fire the railgun multiple times instead of needing to strip it down and rebuild it each time. That was always the problem with the early railguns; they'd be fine firing once but after that would be so burned up from the currents that they'd be unable to take a second shot on any reasonable timescale. They were cool, but not practical weapons. I'm guessing that that must've been solved, and the result is that pure kinetic weaponry starts to make sense again for ship-level encounters.
"Little does he know, but there is no 'I' in 'Idiot'!"
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.
23 lbs = 10.5 kg
Mach 7 = 5300 mph = 2382 m/s
KE = 0.5mv^2 = 59.6 MJ
The ship in question has four 9100 kW diesel engines (12,200 hp).
Assuming you have a big enough capacitor, the output from just one diesel engine should be enough to power a round every 6.5 seconds. There are conversion and efficiency losses, so probably every 15-20 seconds is more realistic.
Also note that 59.6 MJ is about equivalent to 14 kilos of TNT. So the energy yield of this will be on the order of a high explosive round from a 5 inch shell (which weighs about 30 kg), assuming the projectile doesn't pass entirely through the target.
Smaller diameter projectiles have more drag per unit mass and slow down faster due to air resistance. It's called their ballistic coefficient.
The practice for howitzer-like weapons like railguns is to fire their projectiles in a high arc to get them out of thick atmosphere as fast as possible to reduce air friction. They still won't hit their target at anything like their muzzle velocity even after they recover some kinetic energy on the way back down to target from the top of their parabolic arc.
The ballistically efficient shells from the late-model 15" US Naval rifles had a muzzle velocity of about 3500 feet/second and a flight time to target at maximum range (25 miles or so) of a couple of minutes. Their velocity at impact was half that of their muzzle velocity. I don't see these railgun projectiles achieving anything like that performance as drag increases roughly as the square of velocity and their ballistic coefficient will be a lot less.
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!