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 ImotekhTheStormlord wrote:

 purplefood wrote:

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

Now why do you have to make it all horrible?
Also, not sure that'd be a good idea...

Pssshaww. I find your lack of faith disturbing.

Few problems cannot be solved by the proper application of nuclear weapons.

The only issue would be if the railgun had a slight malfunction the nuke would go off in the wrong place and nukes aren't things that should go off in the wrong places...

 purplefood wrote:

 ImotekhTheStormlord wrote:

 purplefood wrote:

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

Now why do you have to make it all horrible?
Also, not sure that'd be a good idea...

Pssshaww. I find your lack of faith disturbing.

Few problems cannot be solved by the proper application of nuclear weapons.

The only issue would be if the railgun had a slight malfunction the nuke would go off in the wrong place and nukes aren't things that should go off in the wrong places...

There are more issues than that. ICBMs exist for a reason.

Nevertheless, just imagine the explosion.

 ImotekhTheStormlord wrote:

 purplefood wrote:

 ImotekhTheStormlord wrote:

 purplefood wrote:

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

Now why do you have to make it all horrible?
Also, not sure that'd be a good idea...

Pssshaww. I find your lack of faith disturbing.

Few problems cannot be solved by the proper application of nuclear weapons.

The only issue would be if the railgun had a slight malfunction the nuke would go off in the wrong place and nukes aren't things that should go off in the wrong places...

There are more issues than that. ICBMs exist for a reason.

Nevertheless, just imagine the explosion.

Well imagining is more fun.

I hate to rain on people's parade, but I'm going to hit you with some knowledge.

According to our friend Wikipedia: "China produced 51,000 tonnes of tungsten concentrate in 2009, which was 83% of the world output. In the prelude to WWII China's production of tungsten played a role as China could use this leverage to demand material assistance from the US government."

Already, the great Satan is falling behind in this tungsten arms race!

Obviously, they could use some other hard material, but as far as the USA is concerned, there's a Tungsten gap already.

If world war 3 breaks out with railguns firing tungsten, I'm ditching krispy kreme donuts for the thoughts of Chairman Mao.

Sorry America, I like your food and your films, but Chinese tungsten scares me more

Why use tungsten when all the depleted U-235 you have lying around is more than sufficient for a railgun?

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

THE LA-LI-LU-LE-LO?

Railguns are nice because they generate little to no heat, but I'll be damned if I'm giving up my PPCs.

Weird, it doesn't look anything like onee-sama...

 Krellnus wrote:
Why use tungsten when all the depleted U-235 you have lying around is more than sufficient for a railgun?

Tungsten has the highest melting point of any element, more than three times higher than that of depleted uranium. Also, depleted uranium is depleted because it has a relative lack of U-235, so "depleted U-235" is an oxymoron.

Why even attach nukes to it when you can just drop metre long rods of tungsten from orbit?

 mega_bassist wrote:

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

THE LA-LI-LU-LE-LO?

A Metal Gear?

 AlmightyWalrus wrote:

 Krellnus wrote:
Why use tungsten when all the depleted U-235 you have lying around is more than sufficient for a railgun?

Tungsten has the highest melting point of any element, more than three times higher than that of depleted uranium. Also, depleted uranium is depleted because it has a relative lack of U-235, so "depleted U-235" is an oxymoron.

I meant U-238, long day, but as long as I know what I meant eh?

My point was though, you have this fairly dense metal, with a reasonably high melting point already laying around, there is no reason to go out of your way to get a modestly better material at the job you want to do, it would be akin to updating your computer hardware every six months instead of every couple of years, yeah you get a bit of performance improvement, but nothing worth writing home about for the amount of money you would have spent obtaining it.

The round has to complete the circuit though, I'm not sure how conductive DU is compared to W.

 AlmightyWalrus wrote:
The round has to complete the circuit though, I'm not sure how conductive DU is compared to W.

Complete the circuit? I am not sure what you are on about, railguns work by rapidly changing magnetic flux to induce an opposing magnetic field in the round, causing it to accelerate along the gun and towards the target.

 Krellnus wrote:

 AlmightyWalrus wrote:
The round has to complete the circuit though, I'm not sure how conductive DU is compared to W.

Complete the circuit? I am not sure what you are on about, railguns work by rapidly changing magnetic flux to induce an opposing magnetic field in the round, causing it to accelerate along the gun and towards the target.

Pretty much this. And given the fact that they're using a sabot, you can just make the sabot out of iron in order to fling the things.

Don't they destroy themselves after a few shots due to the massive electromagnets tearing the barrel/gun apart? Maybe that was hyperbole I read a few years ago.

They do generate a lot of friction as the shot goes down the barrel. It actually turns the surfac into plasma, hence the fire you see in the video.

Thus the inner surface does need to get replaced regularly. but thats not a new problem with firearms. The first machine guns needed t have their barrels replaced quite often because the weapons cyclic rate wasabove the tolerence of the barrel.

 Grey Templar wrote:
They do generate a lot of friction as the shot goes down the barrel. It actually turns the surfac into plasma, hence the fire you see in the video.

Thus the inner surface does need to get replaced regularly. but thats not a new problem with firearms. The first machine guns needed t have their barrels replaced quite often because the weapons cyclic rate wasabove the tolerence of the barrel.

Yeah, barrel warping is pretty common, but I thought it was far more dramatic in Railguns due to the colossal magnets. I haven't actually watched the video, mind due (at work) but that's going off what I saw a few years ago.

I would assume since we are actually putting one of these on a ship this coming summer the Navy has durability mostly figured out. I am no electrical engineer but I think you could do some tricks with magnetic fields to reduce the stress on the machinery at the cost of increased power (or just make the firing mechanism out of something non magnetic so it experiences 0 force whatsoever). The weapon obviously jumps when fired so they must have some kind of recoil damper in there as well.


By the way Tungsten is not magnetic at all. Again I am afraid that magnetic phenomena are very much outside my realm of expertise, but I believe that you need either the barrel or the sabot to be magnetic in that situation. From what I can see in the video I think they are using a magnetic sabot.

 ImotekhTheStormlord wrote:
The next step is to upsize the device and attach a nuclear warhead.

Don't need nuclear head it would only complicate things and there are already delivery system's for that, (it is called a submarine)

If the railgun technology becomes more understood speed is all you need, if you have an orbital delivery system that can increase the speed of the payload. even if the speed is marginally close to light speed the impact would be devastating.

Earth after impact

 dementedwombat wrote:
I would assume since we are actually putting one of these on a ship this coming summer the Navy has durability mostly figured out. I am no electrical engineer but I think you could do some tricks with magnetic fields to reduce the stress on the machinery at the cost of increased power (or just make the firing mechanism out of something non magnetic so it experiences 0 force whatsoever). The weapon obviously jumps when fired so they must have some kind of recoil damper in there as well.


By the way Tungsten is not magnetic at all. Again I am afraid that magnetic phenomena are very much outside my realm of expertise, but I believe that you need either the barrel or the sabot to be magnetic in that situation. From what I can see in the video I think they are using a magnetic sabot.

Since I'm on my phone at the moment, I'll give you the footnote version.
The round of a railgun does not need to be magnetic, just a conductor, due the nature of electricity and magnetism. When a changing current is present in a conductor it creates a changing magnetic field, however, the converse is true, so the presence of a changing magnetic field induces a changing current, which produces its own magnetic field that is equal and opposite to the inducing field (conservation of energy), this drives the two conductors away from each other, a railgun uses several electromagnets in succession to fling out the projectile at absurd velocities.

 purplefood wrote:

 Iron_Captain wrote:
I want a railgun! Where can I order one?
What I am doubting however is the usefulness of a railgun on a ship when ships can already fire missiles.

The ability to put a hole in something from very far away is always useful.
I imagine once they have fully worked it out it will be able to fire faster than a ship firing missiles. It's also a 5kg (Or there abouts) tungsten block travelling at mach 7. It's not going to be stopped, and probably not even seen...
There's also the fact that it is much cheaper to shoot 10 of these than it is to shoot a single missile.
Missiles can also be shot down, distracted and generally led astray.

Hmm, sounds like it'd make a nice anti-aircraft gun. Considering all the counter-measures we seem to have vs. missiles and how fast this goes it could probably work. Maybe....

 Krellnus wrote:

 AlmightyWalrus wrote:
The round has to complete the circuit though, I'm not sure how conductive DU is compared to W.

Complete the circuit? I am not sure what you are on about, railguns work by rapidly changing magnetic flux to induce an opposing magnetic field in the round, causing it to accelerate along the gun and towards the target.

I like how 'tesla' (his avatar) said this ;P.

 flamingkillamajig wrote:

 purplefood wrote:

 Iron_Captain wrote:
I want a railgun! Where can I order one?
What I am doubting however is the usefulness of a railgun on a ship when ships can already fire missiles.

The ability to put a hole in something from very far away is always useful.
I imagine once they have fully worked it out it will be able to fire faster than a ship firing missiles. It's also a 5kg (Or there abouts) tungsten block travelling at mach 7. It's not going to be stopped, and probably not even seen...
There's also the fact that it is much cheaper to shoot 10 of these than it is to shoot a single missile.
Missiles can also be shot down, distracted and generally led astray.

Hmm, sounds like it'd make a nice anti-aircraft gun. Considering all the counter-measures we seem to have vs. missiles and how fast this goes it could probably work. Maybe....

A smaller version perhaps. Using the full size railgun to shoot down a plane would be like swatting a fly with a sledge hammer.

At the speeds it would be launched at, you could fire something only a few ounces in weight and it would rip through any type of aircraft like it was cardboard.

The obvious problem is that if its detected you could easily avoid it just be altering heading or speed by even a small amount. and it would be useless at targeting an erratically moving plane. That's at long range of course. At close distances where the plane might not be able to take responsive action it would be deadly.

 Krellnus wrote:

 dementedwombat wrote:
I would assume since we are actually putting one of these on a ship this coming summer the Navy has durability mostly figured out. I am no electrical engineer but I think you could do some tricks with magnetic fields to reduce the stress on the machinery at the cost of increased power (or just make the firing mechanism out of something non magnetic so it experiences 0 force whatsoever). The weapon obviously jumps when fired so they must have some kind of recoil damper in there as well.


By the way Tungsten is not magnetic at all. Again I am afraid that magnetic phenomena are very much outside my realm of expertise, but I believe that you need either the barrel or the sabot to be magnetic in that situation. From what I can see in the video I think they are using a magnetic sabot.

Since I'm on my phone at the moment, I'll give you the footnote version.
The round of a railgun does not need to be magnetic, just a conductor, due the nature of electricity and magnetism. When a changing current is present in a conductor it creates a changing magnetic field, however, the converse is true, so the presence of a changing magnetic field induces a changing current, which produces its own magnetic field that is equal and opposite to the inducing field (conservation of energy), this drives the two conductors away from each other, a railgun uses several electromagnets in succession to fling out the projectile at absurd velocities.

So, just to clarify, the magnets are pushing away rather than pulling towards? I always though it functioned by having sets of magnets that run up the barrel that pull the projectile forwards, and turn on then off in succession, increasing the projectiles velocity. It makes a whole lot more sense that it pushes rather than pulls. I probably should have done some actual research rather than harass poor Dakka members with inane questions.

 Grey Templar wrote:

 flamingkillamajig wrote:

 purplefood wrote:

 Iron_Captain wrote:
I want a railgun! Where can I order one?
What I am doubting however is the usefulness of a railgun on a ship when ships can already fire missiles.

The ability to put a hole in something from very far away is always useful.
I imagine once they have fully worked it out it will be able to fire faster than a ship firing missiles. It's also a 5kg (Or there abouts) tungsten block travelling at mach 7. It's not going to be stopped, and probably not even seen...
There's also the fact that it is much cheaper to shoot 10 of these than it is to shoot a single missile.
Missiles can also be shot down, distracted and generally led astray.

Hmm, sounds like it'd make a nice anti-aircraft gun. Considering all the counter-measures we seem to have vs. missiles and how fast this goes it could probably work. Maybe....

A smaller version perhaps. Using the full size railgun to shoot down a plane would be like swatting a fly with a sledge hammer.

At the speeds it would be launched at, you could fire something only a few ounces in weight and it would rip through any type of aircraft like it was cardboard.

The obvious problem is that if its detected you could easily avoid it just be altering heading or speed by even a small amount. and it would be useless at targeting an erratically moving plane. That's at long range of course. At close distances where the plane might not be able to take responsive action it would be deadly.

The key word here being is detected. I know battleships aren't exactly known for being sneaky by any means and the idea is pretty hilarious. However if you're miles and miles away and you shoot this at a plane they probably wouldn't even know you were a threat until it's too late. I'm sure aircraft could take evasive maneuvers but each shot is going so fast the planes would have to 'matrix dodge' out of the way and hope it's enough.

I dunno I'm not as smart as all you guys with experimental technology and a lot of other things. I'd just imagine considering the speed of these bullets that depending on how fast they go you could probably make a great anti-aircraft gun with it. It is experimental and I'm sure in the future it'll be a very real threat to aircraft.

 Krellnus wrote:

 dementedwombat wrote:
I would assume since we are actually putting one of these on a ship this coming summer the Navy has durability mostly figured out. I am no electrical engineer but I think you could do some tricks with magnetic fields to reduce the stress on the machinery at the cost of increased power (or just make the firing mechanism out of something non magnetic so it experiences 0 force whatsoever). The weapon obviously jumps when fired so they must have some kind of recoil damper in there as well.


By the way Tungsten is not magnetic at all. Again I am afraid that magnetic phenomena are very much outside my realm of expertise, but I believe that you need either the barrel or the sabot to be magnetic in that situation. From what I can see in the video I think they are using a magnetic sabot.

Since I'm on my phone at the moment, I'll give you the footnote version.
The round of a railgun does not need to be magnetic, just a conductor, due the nature of electricity and magnetism. When a changing current is present in a conductor it creates a changing magnetic field, however, the converse is true, so the presence of a changing magnetic field induces a changing current, which produces its own magnetic field that is equal and opposite to the inducing field (conservation of energy), this drives the two conductors away from each other, a railgun uses several electromagnets in succession to fling out the projectile at absurd velocities.

Ah yes, I distinctly remember the experiment from my General Physics 2 class where a magnet fell more slowly when dropped through an aluminum tube. Even though aluminum is not magnetic it still produced a changing electric field in response to the magnet. Confused the heck out of me when I saw it happen then too...

Also in response to the aircraft idea, railgun projectiles can have a very small radar signature and they do move very fast. I would imagine that an aircraft might not even be able to pick them up on sensors until it's too late.

 Sparkadia wrote:
So, just to clarify, the magnets are pushing away rather than pulling towards? I always though it functioned by having sets of magnets that run up the barrel that pull the projectile forwards, and turn on then off in succession, increasing the projectiles velocity. It makes a whole lot more sense that it pushes rather than pulls. I probably should have done some actual research rather than harass poor Dakka members with inane questions.

No. You're thinking of a coilgun. A railgun creates a circuit through the round, that extends into a magnetic field. The current running through the round interacts with the magnetic field to create a force forwards along the rails.

 AlexHolker wrote:

 Sparkadia wrote:
So, just to clarify, the magnets are pushing away rather than pulling towards? I always though it functioned by having sets of magnets that run up the barrel that pull the projectile forwards, and turn on then off in succession, increasing the projectiles velocity. It makes a whole lot more sense that it pushes rather than pulls. I probably should have done some actual research rather than harass poor Dakka members with inane questions.

No. You're thinking of a coilgun. A railgun creates a circuit through the round, that extends into a magnetic field. The current running through the round interacts with the magnetic field to create a force forwards along the rails.

Yeah, you're thinking gauss rifle.

 Sparkadia wrote:
So, just to clarify, the magnets are pushing away rather than pulling towards? I always though it functioned by having sets of magnets that run up the barrel that pull the projectile forwards, and turn on then off in succession, increasing the projectiles velocity. It makes a whole lot more sense that it pushes rather than pulls. I probably should have done some actual research rather than harass poor Dakka members with inane questions.

Well, strictly speaking, it is both the magnets and the projectile both pushing away from each other. Basically all a railgun simply comes down to being a linear accelerator that uses magnetic fields and induction, rather than the repulsion of like electric charges to push a projectile out of one end of the accelerator, although that is not entirely accurate.

To put some numbers on the railgun for my fellow dakkaites (using the numbers on wikipedia):

If you have a 3.2 kg projectile and accelerate it to mach 7 (~2 400m/s) it will impact with a force of 7680N and will impart a kinetic energy of 18 432 000J, for comparison a kilogram of TNT will detonate with an energy equal to 4 184 000J. So basically shooting something with a railgun imparts about 4.5 times the energy of 1kg of TNT (so about the energy of 4.5 kg of TNT) and has two added benefits, you don't have to be close, and you lose less energy when transferring kinetic energy then you do when exploading (since the explosion expands in a sphere).

 dementedwombat wrote:
Also in response to the aircraft idea, railgun projectiles can have a very small radar signature and they do move very fast. I would imagine that an aircraft might not even be able to pick them up on sensors until it's too late.

Ah, see, this is a possibility that gets me chubbed over the F-35 that nobody else seems to get the appeal of. With a little beauty like this on your side, small radar signatures don't mean much.