We can haz railgun?

Navy Railgun Fires 33-megajoule Shot

Depending on the article you read the muzzle velocity is somewhere from mach 5 to mach 8 and can hit a target 110 miles away with pinpoint accuracy.

And time to target at 100 miles is just over a minute.

More pictures and video

From science fiction to science fact in our lifetime. Though I’d like to know how they’re overcoming some of the longstanding obstacles to the technology. Specifically the problem of the rails degrading due to the high energy and high temperatures generated while firing.

It’s fairly clear from the article and images that this is an experimental rig. IOW, they don’t have to worry about lifecycle on the rails. They’ll be replaced when they’re sufficiently torn up.

We’re still some way from a deployable weapon here, though this beast has some very interesting implications. Bear in mind that hitting a target at 6000mph means you’re NOT talking about a practical weapon at that range. You’re not, for instance, dropping the shot over the curve of the earth and emloying a little naval gunfire support. So… What could you hit with that combination of velocity and range? Aircraft - Very slow ones. Very LEO satelites (with the right gunnery software, tracking, and support). Not much else.

This has a way to go before it becomes a viable weapon.

I work on the base where this is being developed and tested - not at all associated with it, but I’m pretty sure I heard the test firing. Considering it’s a weapons center, I hear a lot of test firing.

My husband was involved with it for a short time. He said they have to replace the rails after every shot right now. That’s part of the R&D process - figuring out how to make it deployable. I don’t know if there are plans to make it guided, or if it’s even possible. But ya gotta start somewhere, right?

Wow. They have a gun that can fire 33 one ton-vehicles at a speed of 100 miles an hour! Finally, a use for the Smart Car – hurl them slowly at our enemies!

I believe you can put both fins (or other control devices) on such a shell, along with a small radar unit in the nose.

I would think that with the velocities involved and the time to impact that any sort of passive guidance system would be minimally effective without excessively large control surfaces.

As far as viable targets, just about any hardened bunker would be an ideal target. Weapons bunkers. No warship of significant size would be able to avoid being hit and I wouldn’t bet on it being seaworthy after being hit.

If TTI for a hundred miles is a minute and change, a target at 50 miles is going to be thirty seconds. While a fast and nimble fighter might be able to dodge a shot, I wouldn’t bet on many bombers. That’s ignoring the sparrow and elephant gun analogies.

Once the technology develops, and there are still significant hurdles to overcome, it will be a virtual sniper rifle against hard targets.

There’s only a limited amount that can be done about that; portions of the rails vaporizing is how the thing works.

I’m trying to picture how this system will hit something 100 miles away The curvature of the earth is going to be a problem. It would seem to me that a projectile would need a ballistic trajectory to hit something so far away. In that case, would kinetic energy be sufficient to kill any a hard target?

I’m thinking this thing would need to either be airborne, or if ground based be used on targets within line of sight --which would make it very vulnerable.

Is such a weapon recoilless? My gut says yes, but it’s like an airplane on a treadmill question.

How so? The just need to generate enormous magnetic fields – why would that require vaporizing anything except for the fact that the materials involved can’t handle the energy/heat?

I wonder what the electromagnetic fields inside the barrel would do to the electronics of the projectile.

I think its eventually supposed to be like a sabot munition, the rail gun projectile carries a five inch shell so far, then the thing drops off or the shell drops off and has a jdam seeker.

I’m wondering how this would work as a tank gun. Most modern anti-tank shells (like APDS) work essentially by firing a small, heavy projectile very, very fast. Railgun projectiles are even faster, and perhaps more importantly, take up much less room than a tank round, which would allow a tank to carry more ammo.

Probably not this century, unless a new means of power generation is achieved. Standard APDS rounds are good enough for the moment against the majority of the tanks in existence. I could see going to liquid propellant long before anyone went to a gauss gun on a main battle tank.


Is that true? Can a modern MBT like the M1A2 SEP or Merkava 4 penetrate its own frontal armor?

I’d venture to say no, not the long way. Thats based on reading open source material. If it were possible to go the long way on an abrams, I would say that more countries would have invested in a high velocity main gun round, instead of going with top down anti tank missiles like the bil.

Having said that, I don’t see an abrams doing a snap shot against a t90 at a couple hundred feet with the gauss gun, unless the FCS computes the range against the amperage going through the rails, and hoping it does not glance off the sloped armor at a very high speed.

I dont know enough about the merkava to venture an opinion on that vehicle, only to say that if its like the mark one merk, then the main round has to penetrate the armor and then the engine compartment, before it even gets to the meatware.


Nope. It throws mass out one end and nothing out the other, so recoil is inevitable.

It’s required because railguns work by producing an extremely powerful and hot arc between the projectiles and the rails. Not just a magnetic field. You are going to get erosion no matter what; it’s like running a super arc welder over the rails with every shot.

There’s other electromagnetic mass driving technologies that don’t have that problem, but they aren’t railguns. Railguns have the advantage of producing higher velocities than other techniques, at least at the moment.

Nitpick; I note that according to Wikipedia “gauss gun” refers to coilguns, not railguns.

Sure you could. The space shuttle orbits at over 17,000 MPH, which means it exactly follows the curvature of the earth; anything traveling more slowly than that will most certainly follow a ballistic arc back down to the surface of the earth. It won’t be a very tall arc, but you absolutely could fire a 6,000-MPH projectile on a slight incline and hit targets that are beyond the horizon.

Certainly. Mind you, it won’t be at 100 miles. It’ll be a LOT further than that. Terrain interferes, otherwise. At 6000 MPH, you’ve got basically a line-of-sght weapon. Anything over-the-horizon will be subject to intervening buildings, trees, hills and mountains… even gentle rises, in the wrong place, will mask much of the terrain. Unless, that is, you move out to supremely long ranges (where aircraft make more sense), or fire at angles that are steep exo-atmospheric ballistic arcs, and then you have to deal with things like reentry, targets having moved in the meanwhile, and all that rot.

In short, you lose the vast majority of what makes Naval Gunfire Support useful - the ability to drop rounds down on top of your target in a timely manner, AKA indirect fire. Now, you could de-tune the beast to drop your velocities to something that would be useful, but then you can get those velocities more cheaply using old-fashioned guns.

Interestingly, I just learned something about that.

I spent a recent holiday curled up with my dogs watching Tanksgiving on the Military History Channel – all day they ran programs about tanks.

One of the things they mentioned is that several Abrams tanks had to be abandoned during one of the wars in Iraq (due to loss of mobility). Rather than risk them falling into enemy hands, a decision was made to destroy them as quickly as possible, and other tanks in the unit fired their kinetic-energy APFSDS depleted-uranium rounds at them from the militarily ridiculous range of a few yards.

The depleted-uranium-mesh-reinforced armor deflected the rounds. And they were intentionally hitting weak spots, not the frontal armor. I really wouldn’t have expected the enormous penetrating power to be stopped, even by an Abrams’ armor, but they said only in two cases were the guns able to drive a round far enough into the disabled tanks to do measurable damage, despite repeated attempts. Generally offense beats armor in this day and age; I found this quite surprising.

In an unrelated incident, an Abrams that had been destroyed somehow was burning out of control, and the trapped driver could not be reached. Apparently the fire was allowed to burn itself out on the theory that the body could be recovered later. When the recovery team went in, they found the driver annoyed but very much alive, protected by halon fire suppression system and supplied with his own oxygen.

Those things are TOUGH.

Don’t know about the current versions, but I’ve heard from several sources the Gulf War-era Abrams and Challenger 2 caused serious problems during the advance on Baghdad, because when they tried to blow up the ones left behind they couldn’t penetrate the hulls from any angle.