The Navy Railgun

[redhawk0]

I'm not sure this truly classifies as a military rifle...but I'll put it here anyway.

I have had the privilege of being on the military base where this thing is tested. I was in a parking lot about 100 yards from the gun when they set it off one afternoon for a test firing. I didn't see much...but I sure felt it. It felt like I was hit in the chest by a hammer. There were some very tall spruce trees between me and the test range. Those trees bent to a 45* angle then immediately sprang back to upright when they set it off. It was certainly an experience I'll never forget. Ever hear a little kid say "do it again"....yeah...I'm like that kid.

Enjoy.....

redhawk


https://www.youtube.com/watch?v=58MmOpSm4LY

[DougGuy]

Many years ago I read a detailed article and video about the railgun. It fires a 2oz. nylon projectile with a metal base, or at least it did back then, no idea how far they have progressed by now, but then when it fired, pressure inside the barrel would rise to 10,000 atmospheres absolute. Ten thousand time the atmospheric pressure at sea level? That's a LOT! I don't know that the Marianas trench gets that high at the bottom.

I was fascinated with this thing. It went through something like 15 sheets of 1" thick steel plate. Problem was that the capacitor bank was so large they couldn't mount it on a vehicle.

[Winger Ed.]

Met a guy once that was working on the Star Wars stuff back in the Regan years.
They had something that went so fast, metal wouldn't work as a projectile.

They were experimenting with ceramics.
Not the kind your coffee cup or flower pots are made of, stuff like one of the auto makers was developing,
and had built a running car engine with that didn't have any metal in it.

That was 30-odd years ago. There's no telling what has been developed since then.

[redhawk0]

When I was there, they were firing with 2 projectiles. One was an aluminum projectile (non-magnetic)...behind it was a sacrificial slug of iron. The iron slug would evaporate from the heat generated when it moved that 7 lb aluminum projectile at Mach-7. They would shoot instrumentation as well to see how the electronics responded with being fired with such force. (I worked with the Electrical guys...geniuses for sure). They would shoot it out over the ocean and recover the electronics from 5-8 miles out....then do analysis/failure analysis on it.

redhawk

[MUSTANG]

Many years ago I read a detailed article and video about the railgun. It fires a 2oz. nylon projectile with a metal base, or at least it did back then, no idea how far they have progressed by now, but then when it fired, pressure inside the barrel would rise to 10,000 atmospheres absolute. Ten thousand time the atmospheric pressure at sea level? That's a LOT! I don't know that the Marianas trench gets that high at the bottom.

I was fascinated with this thing. It went through something like 15 sheets of 1" thick steel plate. Problem was that the capacitor bank was so large they couldn't mount it on a vehicle.

10,000 atmospheres would be 147,000 psi. (One atmosphere at sea level is 14.7 psi above vacuum).
The Marianas Trench is about 36,037 feet deep. 10,000 atmospheres would be 330,000 feet (every 33 feet depth in Ocean is an additional atmosphere).

Did not find a citation for it; but my potentially flawed memory says that chamber pressure on a 16" Naval Gun is about 60,000 PSI. That would mean the cited rail gun operates at about 225% the pressure of a 16" Naval Gun (If my memory is reasonably close). The rail gun at 147,000 psi may be a little large.

[bmortell]

what do you mean by pressure it dont work like a normal gun by making pressure?

[MUSTANG]

what do you mean by pressure it dont work like a normal gun by making pressure?


Agree with you; not sure with you where the Pressure comes from. There WILL BE a pressure wave from the projectile moving through the air, not sure what the value of the air displacement wave will be. My knowledge of rail guns is limited to scientific experiments such as: the "Youth of America" conducting experiments (they must have fond memories of Sam Colt, Hiram Maxim, and John Browning)


https://youtu.be/KMT97bqaOdM

Obviously the "Science Experiment" failed to reach velocity levels and performance of DoD based research efforts. But; in the video one can see the ejecta from the rail following the projectile. Although the aluminum projectile penetrated a steel door and glass window, it failed to exit the interior door upholstery.

[GregLaROCHE]

How loud is it? Equivalent to the same size Howitzer?

[RU shooter]

Ok who's gonna try a cast bullet in one of them ! Lol with gas check of course might even need to powder coat it :-?

[charlie b]

The military has been working on railguns since the late 60's/early 70's. The early ones had many operational technical issues, such as explosive switches, a nonconductive projectile with a sacrificial base and aiming issues at longer ranges. The engineering work and technical advances that have been made over the last 50 years has brought it almost to the point it can be 'fielded'. All the Navy needs is a ship with enough electrical energy generation and storage to fire the thing.

There is a big shock wave(s) that creates a severe pressure differential and blast type effect, including the sound like an explosion.

[redhawk0]

charlie_b....yes...it really didn't go "Bang"....it was a sound of going supersonic. A sonic boom really. And you are correct...their biggest obstacle, when I was there, was making the capacitance bank small enough that it would fit on a ship. They could fit it on a ship but not much else...including sailors. From the looks of some of the declass videos...they may have been able to overcome that obstacle now.

The aiming issues at longer range is what the group I worked with had been developing using the electronics guidance systems at those speeds. I haven't been to that base in about 5-6 years so great strides have been reached just since then.

In any event...it sure is a cool concept. And even more impressive when you're actually there when they touch that thing off.

redhawk

[nightwolf1974]

OK, I need one now!! LOL!

[flyingmonkey35]

You would have the curverture of the earth to deal with at those speeds and distance.

As for power any nucular ship could handel it.

But i see these more as a space based wepon. shoot that down from orbit and good bye city. With no radioactive waste.

Could even fire it at oncoming metor.

Best of all at those speeds no leading of the barrell even the iron shot would be trace amounts.


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[popper]

IIRC they already have one ship board. Kinda same performance as rail gun catapult. Not very well.

[MrHarmless]

IIRC they already have one ship board. Kinda same performance as rail gun catapult. Not very well.

The electromagnetic catapult is more of a coil gun than a rail gun. Very similar to a staged version of maglev trains. More efficient than steam, much less wear and tear, although efficiency doesn't really matter when you've got a nuclear power plant on board.

It's still experimental, so much like the CV-22, it's definitely going through teething pains in terms of mean time between failures, but in time it will absolutely prove superior. The level of control and precision is just something you can't get out of steam for launching things like UAVs.

[Milsurp Junkie]

As far as the pressure, there is a huge force trying to push the rails apart. The main challenges with rail guns are the rails...they wear out quickly, and needed to be replaced after a few shots. This was 20+ years ago, so maybe they figured that out by now.

[Milsurp Junkie]

I am wondering when they are going to tie in the landing hooks to the catapult and do regenerative braking like a hybrid car?

[charlie b]

Space to ground you still have aero heating. And, don't need a rail gun, just drop a rock. The space based railguns were considered for shooting ICBM warheads (and satellites), not ground targets.

The newest aircraft carrier uses electric for catapult and recovery both, IIRC.

Just because a boat is nuke powered does not mean it has a huge excess of electrical power. It is limited by the generators installed in the ship.

[popper]

Guess they moved the test range from Patuxent river facility?

[charlie b]

FWIW, many of the current artillery/gun ballistic computers take into account earth curvature, changes in elevation and rotation of the earth during the flight of the shot.

The current generation of guided munitions with high speed processors and sensors are making a lot of that kind of stuff not as important.

[flyingmonkey35]

FWIW, many of the current artillery/gun ballistic computers take into account earth curvature, changes in elevation and rotation of the earth during the flight of the shot.

The current generation of guided munitions with high speed processors and sensors are making a lot of that kind of stuff not as important.Plane and simple distance + elevation. It sounds like it can shoot in a straight line over the horizen on open water. Eventulay with out uplifit it would just hit water with out loosing speed or drop.

I could be wrong as im a computer scienets not a rocket one. Computers are harder.

Also im a former cannoneer from the army.
So i understand a littel bit about direct/ indierct fire from a cannon.

I was in when the computers took over the calculations.

We went from stop and fire for effect bieng 3 hours to 30 seconds. And started hiting a soada can every time. With a howetzer.




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[JSnover]

The electromagnetic catapult is more of a coil gun than a rail gun. Very similar to a staged version of maglev trains. More efficient than steam, much less wear and tear, although efficiency doesn't really matter when you've got a nuclear power plant on board.

It's still experimental, so much like the CV-22, it's definitely going through teething pains in terms of mean time between failures, but in time it will absolutely prove superior. The level of control and precision is just something you can't get out of steam for launching things like UAVs.

I actually worked on that system. Provided mechanical support during testing on EMALS (ElectroMagnetic Aircraft Launch System) at NAS Lakehurst along with it's compliment AAG (Advanced Arresting Gear). Certainly troublesome but when the kinks are worked out it really will work. My understanding is there are two ships outfitted with it at this point, sea trials incomplete.
Steam is still the dominant system but EMALS and AAG offer a broader weight/speed capability.

[popper]

Both are based on moving electromagnetic field. Like the old SEATAC levitating train. There was a plan at one time to make a hiway with that principle. IIRC Musk is using it.