Ship attack anyone?
New gun...
Ahhh - but will it fit on Victory (probably the only `boat` to survive the next tranche of Camerons follies) and will it demast the frenchies as well as chain shot?
These and other questions....
These and other questions....
Join Date: Aug 2004
Location: warwickshire
Posts: 115
Likes: 0
Received 0 Likes
on
0 Posts
What really amazes me is the gun recoil....or lack of it.
Clearly, the recoil is more linear along the 'barrel' than a traditional explosive given, but we are accelerating a 5kg projectile to 5,000m/s ish.
Clearly, the recoil is more linear along the 'barrel' than a traditional explosive given, but we are accelerating a 5kg projectile to 5,000m/s ish.
Buccaneers - 1978 Footage
Wander00,
There you go (but Kings of Leon soundtrack instead of Vangelis).
Great aircraft, great crews, great times !
There you go (but Kings of Leon soundtrack instead of Vangelis).
Great aircraft, great crews, great times !
Last edited by RAFEngO74to09; 1st Mar 2012 at 16:55.
Join Date: Apr 2010
Location: London
Posts: 7,072
Likes: 0
Received 0 Likes
on
0 Posts
Giblets
Wikipedia say:-
" 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). 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."
I'll bet
Wikipedia say:-
" 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). 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."
I'll bet
Isn't this where someone (please!) reposts the 4 Buccaneers low level over the sea, to the background of Vangelis!!
One or two PPRuNers might just recognise the dashing young fellows who appear in the end credits!
Join Date: Feb 2009
Location: Jungles of SW London
Age: 77
Posts: 354
Likes: 0
Received 0 Likes
on
0 Posts
Fox3WheresMyBanana
Shielding is highly conductive, dissipating the external field as eddy currents.
That's a copper box to you, chief.
That's a copper box to you, chief.
A mobile MRI is basically a 40ft trailer with a 15,000 Gauss magnet inside, but the field will barely extended outside the sides of the van. A few Gauss maybe, but not much. That's because of about three tons of steel sheets on either side of the magnet. The copper box round round an MRI is the Faraday cage, to shield the magnet from external radio frequencies and the outside world from the magnet!
In the Lenz Effect, a copper plate, about 30cm x 37.5cm x 3mm stood on end at the end of the patient table will, if released, fall over. No brainer. But if stood on the table in the bore of the magnet, it will fall over if released - s'gravity innit? - but it will take about forty seconds to do it! It is a really cool demonstration of the power of an MRI magnet.
Doubt if the power for a rail gun will be a battery, you can't discharge it fast enough, more like capacitor banks, charged from the reactor/ generator and 'fired' into the magnet coils. I'm not sure if it would be possible to use superconducting magnets, because it would be hell on wheels (or impossibly expensive) to keep the LHe around the coils from quenching.
My use for the railgun would be to slowly accelerate loads to escape velocity over, say, twenty miles and up a mountain. I was always a fan of Issac Asimov.
Roger.
Join Date: Jan 2012
Location: .
Posts: 2,173
Likes: 0
Received 0 Likes
on
0 Posts
My use for the railgun would be to slowly accelerate loads to escape velocity over, say, twenty miles and up a mountain. I was always a fan of Issac Asimov.
An interesting use for Shap or Beattock....?
An interesting use for Shap or Beattock....?
Thread Starter
Navaleye - very interesting.
Thanks for the input Landroger,
see http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA386044
for part of the US Army's research.
I shall amend "copper box" to "mostly copper box" to keep you happy.
Reminds me of H2G2 entry for Earth being amended from "harmless" to "mostly harmless".
Still a nifty weapon once they can get it into production.
Thanks for the input Landroger,
see http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA386044
for part of the US Army's research.
I shall amend "copper box" to "mostly copper box" to keep you happy.
Reminds me of H2G2 entry for Earth being amended from "harmless" to "mostly harmless".
Still a nifty weapon once they can get it into production.
Why in the name of Cthulhu does this board's SW render the acronym formed by "Light Amplification by Stimulated Emission of Radiation" as "l@ser"?
Slight thread creep, but does anybody remember that great stirrer of world effluent, the Iraqi 'Supergun' or pipeline, dependent on whether it was intelligence experts or ordinary eyes upon it.
Sat on the airfield at Lyneham for god knows how long - Looked like a pipeline to me.
Sat on the airfield at Lyneham for god knows how long - Looked like a pipeline to me.
Join Date: Feb 2009
Location: Jungles of SW London
Age: 77
Posts: 354
Likes: 0
Received 0 Likes
on
0 Posts
F3WheresMyBanana
Thanks for the link, as riveting as most scientific papers are! I think the 'shielding' they were trying to design/quantify/ research, was against an EMP, I think and not 'shield' a magnet. Two different problems, but with common areas of interest.
We use steel shielding to concentrate the magnetic field - sort of squeezing it through an easier path - to reduce the strength of any stray fields. Say, into a public corridor is quite common. We cannot expose 'the public' to as much as 5 Gauss.
At the same time, all MRIs are surrounded by a Faraday cage - often copper, but sometimes aluminium - to prevent stray RF frequencies, like police/ fire/ambulances, ATC and the aeroplanes themselves, even ships on the Thames operating radar, never mind the BBC et al, getting in to the sensitive receivers in the system. Conversely, the cage also protects people and the BBC from 20Kw bursts of RF energy at Medium wave frequencies, that are used to 'excite your protons'.
A rail gun like that one, would produce an enormous EMP and the shielding would have to be quite special - both magnetic shielding and electromagnetic shielding.
As you say, a nifty bit of kit though.
Roger.
We use steel shielding to concentrate the magnetic field - sort of squeezing it through an easier path - to reduce the strength of any stray fields. Say, into a public corridor is quite common. We cannot expose 'the public' to as much as 5 Gauss.
At the same time, all MRIs are surrounded by a Faraday cage - often copper, but sometimes aluminium - to prevent stray RF frequencies, like police/ fire/ambulances, ATC and the aeroplanes themselves, even ships on the Thames operating radar, never mind the BBC et al, getting in to the sensitive receivers in the system. Conversely, the cage also protects people and the BBC from 20Kw bursts of RF energy at Medium wave frequencies, that are used to 'excite your protons'.
A rail gun like that one, would produce an enormous EMP and the shielding would have to be quite special - both magnetic shielding and electromagnetic shielding.
As you say, a nifty bit of kit though.
Roger.
Thread Starter
Landroger - thanks for the further detail. Very educational.
BEagle - thanks for the memories. Used to borrow this video endlessly in flying training. Had ex-Bucc QFIs throughout, got offered Buccaneer...and finally ended up flying on Open Gate out of Gib in the F3, escorting or trying to catch the b#ggers. Odd to think it's all to be done by rail gun 'death-rays' soon.
BEagle - thanks for the memories. Used to borrow this video endlessly in flying training. Had ex-Bucc QFIs throughout, got offered Buccaneer...and finally ended up flying on Open Gate out of Gib in the F3, escorting or trying to catch the b#ggers. Odd to think it's all to be done by rail gun 'death-rays' soon.
Join Date: Aug 2005
Location: Edinburgh and 3C
Age: 72
Posts: 195
Likes: 0
Received 0 Likes
on
0 Posts
LowObservable:
It seems the adbots pick it up and offer to sell the bloody things so that scrotes can buy them with their drugs money and try to blind pilots for fun.
Why in the name of Cthulhu does this board's SW render the acronym formed by "Light Amplification by Stimulated Emission of Radiation" as "l@ser"?