Re: [MV] 'Electric armour' vaporizes anti-tank grenades and shell s

From: Dave Ball (vought@msn.com)
Date: Mon Aug 26 2002 - 00:33:49 PDT


All...
Ok we are talking conventional armour not DU or other need to now stuff that
might or might not be in use and anti tank launchers (RPG-7) and it is as
advanced as throwing a manual switch to the inner plate if you should see a
skinny with a rocket on the CRT.
The plasma jet does penetrate the insulation of the second layer though and
in all the info I have dug up there is no one saying if it is a one time
only.
I will read more later I have printed a couple of articles. The below was a
British website with the street info of course...

Dave

Boffins at Britain's Ministry of Defense have invented an electric 'force
field' designed to protect armoured vehicles against anti-tank grenades.
The 'electrical armour' is designed to vaporise copper projectiles released
from grenades on impact before they are able to penetrate a tank's inner
hull, the Daily Telegraph reports. The idea is to make tanks less vulnerable
to anti-tank launchers, such the RPG-7, which is commonly and cheaply
available in the world's trouble spots, such as Afghanistan.
When armaments like RPG-7 grenades hit a tank, a "shaped-charge" warhead
blasts a jet of hot copper into a target at around 1,000mph - capable of
slicing through a foot of conventional solid steel armour.
The new electric armour is based on a highly charged capacitor connected to
two separate metal plates on the tank's exterior. The outer (armour-plated)
plate is earthed while the insulated inner plate is live.
When the crew of a tank feel they are under danger, they switch on current
to the inner plate, using the tank's internal power supply.
If the tank is unfortunate enough to be hit by a grenade, the jet of copper
produced will penetrate both the outer plate and the insulation of the inner
plate completing a circuit, which results in the discharge of the capacitor
and the vaporisation of most of the copper.
The Telegraph reports that despite the high charge generated by the system,
the "electrical load on the battery is no more than that caused by starting
the engine on a cold morning".
It sounds bizarre, but the paper reports that in a recent demonstration an
armoured personnel carrier protected by the system withstood repeated
attacks by rocket grenades that would normally have destroyed it many times
over.
Boffins hope to develop the armour further and fit it in Britain's next
generation of tanks and armoured personnel carrier. The Pentagon is also
reportedly showing a keen interest in work on the technology
----- Original Message -----
From: "Steve Grammont" <islander@midmaine.com>
To: "Dave Ball" <vought@msn.com>; "MV" <mil-veh@mil-veh.org>
Sent: Sunday, August 25, 2002 10:44 PM
Subject: Re: [MV] 'Electric armour' vaporizes anti-tank grenades and shell s

> Dave
>
> >Was the link to the story that was released to the media on Electrical
> >Armour given I may have missed it and I would like to read about this
> >because what I have heard so far does not jive with common physics
although
> >it is very interesting.
>
> I am pretty sure John is correct. A shaped charge is only effective if
> it maintains its form and impacts the armor at an agreeable angle. WWII
> US Bazooka rounds were known to be totally ineffective against highly
> sloped armor, for example, because the round would tip JUST enough on
> impact that its jet would not be effective. Also, the Germans found that
> even mesh wire screen was good enough to defeat man launched hollow
> charge rounds. All you apparently need to do is get it to detonate in a
> favorable way and the plasma jet can't do what it was designed to do.
>
> So the theory of defeating hollow charge rounds through manipulation of
> the conditions under which the round detonates is sound and supported by
> a wide body of practical application in WWII (in particular). That means
> the only question here is if the interference with the copper is enough
> to cause the round to "fail" to an extent necessary for the inner armor
> to survive contact with the plasma jet.
>
> >I would like to know how the Armour depletes the energy and gas from the
> >penetrator/slug and spalling from that penetration and causes the second
> >layer to vaporize the penetrator without the contents of the tank having
> >there brain drip out there ears from the pressure.
>
> I dont think there would be any problems with pressure within the vehicle
> since the whole thing is happening outside.
>
> Also remember that the "slug" in the case of a hollow charge round is not
> in and of itself designed or capable of causing much (if any) damage to
> armor. Therefore it poses no risk to the inner armor provided it is at
> least thick enough to defeat the round in question (i.e. 2mm of armor
> ain't going to stop a spitball <g>). Also spalling is not something that
> I think can be caused by a hollow charged round. Spalling can only be
> achieved through accelerated dense masses of a size greater than the
> width of the armor (taking into consideration the materials of both shot
> and armor) striking the inner armor. Splintering, from a partial
> penetration, would not happen at all from a hollow charge round even if
> it penetrated since the plasma is designed to liquify the armor, not
> splinter it.
>
> My knowledge of armor and ballistics is mostly WWII based, but the basics
> are pretty much the same now as they were back then.
>
> Steve
>



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