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Navy test fires railgun: Video

Re: Navy test fires railgun: Video

hmmm thats neat - never heard of a "rail" gun - so if this catches on how far behind it do you think will be a "sniper" rifle railgun?

In theory you should be able to do the same thing just smaller right?
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Intrepid4576</div><div class="ubbcode-body">hmmm thats neat - never heard of a "rail" gun - so if this catches on how far behind it do you think will be a "sniper" rifle railgun?

In theory you should be able to do the same thing just smaller right?</div></div> The rail gun is probably the easy part. The power source, that's not easy.
 
Re: Navy test fires railgun: Video

kinetic energy (K) = 41297307.891906 joule
kinetic energy (K) = 39142.295442799 british thermal unit
kinetic energy (K) = 9863692.531744 calorie
kinetic energy (K) = 2.5775740998598E+26 electronvolt
kinetic energy (K) = 4.1297307891906E+14 erg
kinetic energy (K) = 30459331.16815 foot-pound
kinetic energy (K) = 41297307.891906 newton-meter
kinetic energy (K) = 0.39142141576693 therm
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Alaskaman 11</div><div class="ubbcode-body">would some math guy please do the math on the foot ponds of energy with a 40 lb round doing 7000 fps. </div></div>

30,458,430.5 ft-lbs

By comparison a 175gr SMK @ 2600fps is 2626 ft-lbs.
 
Re: Navy test fires railgun: Video

http://www.foxnews.com/scitech/2012/02/2...intcmp=features

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I got trace!</div></div>
grin.gif
 
Re: Navy test fires railgun: Video

Per this website: http://billstclair.com/energy.html

A 40lb (280,000gr) traveling 5000mph (7330fps) and a diameter of 6" (wild guess) has 33,403,108 ft-lbs of energy!

Now I have no idea how to mathematically check that number, but I plugged in some numbers for 308, 338LM, 300wm, and 50BMG and the energies listed matched very closely to those listed on Wikipedia.

And we all know Wikipedia is never wrong......
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Krav69</div><div class="ubbcode-body">Good.

Now hurry up and aim it at some-----

Quickly. </div></div>

I don't suppose you much care which ones?
 
Re: Navy test fires railgun: Video

Just had a brief about this from their program manager. This video is only the tip of the iceberg. The rail gun is going to be a hell of a weapon and will undoubtedly be a favorite of ground pounders based on its range and quick strike ability as well as its decreased damage radius and CEP.

Josh
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mac the knife</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Intrepid4576</div><div class="ubbcode-body">hmmm thats neat - never heard of a "rail" gun - so if this catches on how far behind it do you think will be a "sniper" rifle railgun?

In theory you should be able to do the same thing just smaller right?</div></div> The rail gun is probably the easy part. The power source, that's not easy. </div></div>

Actually it's the other way round. Our capacitor technology has been growing by leaps and bounds while our material sciences has been a rough slog to find something that will perform how they need it to. The biggest issue right now is they turn into giant arc welders and the slug gets welded to the rails after a few shots as it heats up and the tolerances change. Being able to overcome that is an awesome feat of engineering and it looks like they're well on their way to fixing it. The last time I did any research on it, they were looking at using superconductors cooled by nitrogen to keep the system stable.

If you guys want to play around with something like this, you can make a Gaussian cannon out of a disposable camera, some copper wire, and an empty thread spool. They're a lot of fun and it's a great science project to do with kids.
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HPCR59</div><div class="ubbcode-body">Why does stuff like this get out? IMO, the general public (i.e. the entire world) does not need to know about projects like this. </div></div>

It's to let people like me know that at least some of my tax dollars are going to general American Badassery rather than being completely squandered by ri-tahrds in government.
 
Re: Navy test fires railgun: Video

Not exactly the same thing, but operates the same. Coil guns were really fun to make when I was growing up. Saw a video somewhere on the net where a larger version was made and had around the same power as a 9mm from a handgun.
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pointblank4445</div><div class="ubbcode-body">Seems like an odd projectile design. </div></div>

That is just what pushes the projectile. This video shows the various armatures that are used to push the projectile down the barrel. The actual round is a sabot with the pointy projectile that is on the center of the table at the beginning of the below video. You can see the sabot separation in the shots near the end of the video.

The one they are showing in the original video is the scaled down version they are looking to fit to platforms. The big one in the video below is the 30ft long research gun. They can take it apart to try different rail shapes and types. That is the reason for all the different armature types on the table in this video.

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/bkYQwIeXGdI"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/bkYQwIeXGdI" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>

Josh
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gathert</div><div class="ubbcode-body">Nooooope. (Chuck Testa). There is no actual explosion so recoil is negligible, for something of that size anyway. The projo is constantly being pushed forward by an invisible force and doesn't have any pressure built up behind it, ergo no recoil. </div></div>

I really hope you're joking here, because you just ignored several key laws of very basic physics. Recoil is not caused by gasses expanding from the end of a gun, it's caused by the Force(capital f here, as in mass times acceleration) that is counter to that which is acting on the bullet. Accelerating objects impart an equal and opposite force on ANYTHING projecting them, regardless of the power source, be it compressed air, twisted rope, bent wood, gunpowder, or magnetic fields.

Five seconds on wikipedia about railguns would have brought you this little tidbit "The recoil force exerted on the rails is equal and opposite to the force propelling the projectile. The seat of the recoil force is still debated. The traditional equations predict that the recoil force acts on the breech of the railgun. Another school of thought invokes Ampère's force law and asserts that it acts along the length of the rails (which is their strongest axis).[7] The rails also repel themselves via a sideways force caused by the rails being pushed by the magnetic field, just as the projectile is. The rails need to survive this without bending, and must be very securely mounted."
 
Re: Navy test fires railgun: Video

There has to be oneheckuvan EMP at work there.

Makes me wonder about EM shielding and innocent bystanders (my very own Pacemaker/Defibrillator for instance).

Greg
 
Re: Navy test fires railgun: Video

There has to be oneheckuvan EMP at work there.

Makes me wonder about EM shielding and innocent bystanders (my very own Pacemaker/Defibrillator for instance).

Greg
 
Re: Navy test fires railgun: Video

Remember the total mass of the gun system and mount versus the mass of the projectile. Reason that recoil doesn't rip it apart is that you just have so much more mass in the gun itself.

As for man-portable version. Once they get those sci-fi micro-fusion reactors the size of a 9v working, maybe. For now, I'll pass on the 2,500 ton backpack I'd need to tote around with the 512" barreled rifle.

I'm wondering if the Navy is regretting cancelling the CGN program at this point...
 
Re: Navy test fires railgun: Video

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">There has to be oneheckuvan EMP at work there.

Makes me wonder about EM shielding and innocent bystanders (my very own Pacemaker/Defibrillator for instance).

Greg </div></div>

Greg,

They told us there is not an issue. He referenced the cameras and other sensing equipment by noting how it does not fail or go crazy during shots.

As for recoil, he said it is considerable, but it will always be less than a weapon using explosive propellant for the same level of energy.

Josh
 
Re: Navy test fires railgun: Video

Thanks; I tend to be sensitive to such issues.

I also understand the newer A/C carriers coming out of the drydocks will be configured with catapults based on similar principles.

Good point about the cameras; I should have caught that.

Greg