New 'electrical active' Armour to defeat hand held anti-tank rounds

Unusual source, but a start point for those interested in such things. Sounds
vaguely feasible to me.

http://www.theregister.co.uk/content/54/26728.html

                                        TTFN
                                                Jon

The Register usually doesn't cover the defense industry, but they will cover
anything odd in the "technology" field. For a quirky look at the IT world, I
love the Reg.

> Jonathan White wrote:

> Unusual source, but a start point for those interested in such things.

> Sounds vaguely feasible to me.

Michael Llaneza schrieb:
> The Register usually doesn't cover the defense industry,

It's not entirely news. A year ago, the Observer already reported these
experiments. The design described in the Observer seems more complex the one
in the Register, but I don't know if these are actual differences in the
technical design or the journalist's understanding of it.

See:
http://www.observer.co.uk/international/story/0,6903,539143,00.html

Does anybody have an idea about how good it would be against kinetic energy
penetrators? As these are metal, too, they should have some effect.

Guess we need one more armour category in DS2 beyond ablative and
reactive ;-)

Greetings

On Tuesday, August 20, 2002, at 02:59 PM, KH.Ranitzsch@t-online.de
wrote:
> http://www.observer.co.uk/international/story/0,6903,539143,00.html

> Does anybody have an idea about how good it would be against kinetic
I'm obviously not privvy to the research but basic physics allows us to have a
guess. I suspect the charge difference is very good at disrupting

the copper jet partly because copper is a very good conductor (duh) and
partly because the jet is in in liquid/gaseous form and therefore quite
easy to disrupt from the nice jet shape that's required to get best
penetration. If the penetrator was still solid and was made out of a metal
that was much less conductive, the charge difference probably wouldn't be
enough to pump enough energy into the penetrator to blow it apart. Even if it
did, you'd just end up with a 'shotgun' penetrator rather than a solid block
which might not help all that much.

One obvious side effect would be it would be good for keeping infantry off
your vehicle. From now on all soldiers will be supplied with new army boots
with rubber soles:).

> Guess we need one more armour category in DS2 beyond ablative and
And all tank maintenance engineers will be called 'sparky':).

                                        TTFN
                                                Jon

Jonathan White schrieb:
> On Tuesday, August 20, 2002, at 02:59 PM,

I guess Oerjan would be the one who might best comment on this. A
recent posting on the www.tank-net.org forums claimed that the
penetrator jet of a hollow charge is not actually liquid or gaseous, but still
a solid.
http://63.99.108.76/ubb/Forum3/HTML/000246.html
The warhead liner is deformed by the charge into what is, effectively, a solid
penetrator not too dissimilar to a KE round. I am inclined to believe this.
Certainly I don't believe the 'gaseous' or 'plasma' or
'burn-through' variants of the explanation of how a hollw-charge
warhead works. Photos of hollow-charge damage I have seen all show
rather clean small holes, which is not what I expect from a liquid hitting an
object.

Greetings

> KH wrote:

> >http://www.observer.co.uk/international/story/0,6903,539143,00.html

Kinda-sorta. You could say that "HEAT jets are solid just like KE
projectiles", but it is more accurate to say that both HEAT jets *and* KE
projectiles behave more or less like fluids - the differential equations

which govern their behaviour when they hit armour look far more like those
used for fluid dynamics than those used for solids.

However, they do have different shapes. KE rounds (and EFP slugs) are
relatively short and fat (modern APFSDS rounds "only" have L/D ratios of

30:1) compared to HEAT jets, which makes the HEAT jet far more vulnerable to
lateral stresses. (Which is why early ERA types could defeat HEAT but

not KE while modern reactive armours are effective against both - the
early types weren't strong enough to stop KE.)

> Photos of hollow-charge damage I have seen all show

Never seen a narrow high-pressure water jet cut through a sand bank?
(...or
the hull of a small boat, for that matter... <g>)

Later,

> Does anybody have an idea about how good it would be
It is not a liquid or a solid but a plasma ( states of matter are solid,

liquid, gas, plasma and superconductor now(more?)). It is an ionized gas which
is first cousin to a blow torch and "burns"
through. Since it is ionized it can be effected by an E/M field and I
suspect the plan is to disrupt the jet (like a blow torch that is not adjusted
properly) rather

then actually stopping it.

Kinetic rounds should not be effected in that the inertia of kinetic rounds is
so high that it would be like stopping a cannon ball with a tennis racket.

Before you start striping off armor this is not the only chemical round that
there is. The British used a shaped charge (fire a BB gun at a window and
you'll see the effect) called a APSH
 (APSH - armor piercing squash head) which passed the inertia but did
not penetrate. I also talk with someone who talked about a solid penetrator
that would be accelerated when the round hit the vehicle. I got the impression
that the penitrator was expensive and unstable so hadn't been continued.

Scott Siebold schrieb:
> >

Err... not quite. A superconductor is not a 'state of matter' in the same
sense as the others. A superconductor is a solid that happens to have no
resistance to electricity. Just as solids can vary in colour, density, heat
conductivity etc. Materials of different color are not defined as different
'states of matter' in the strict definition of that term.

Only in very loose wording could you say that superconductivity is a
state of matter - but then so would be metallic conductivity,
semiconductors and insulators.

As Oerjan and the web forum contribution I quoted earlier noted, a HEAT jet is
not a plasma.

> It is an ionized gas which is first cousin to a blow torch and

This is a good explanation of a plasma, but apparently, it's not what a HEAT
warhead does.

> Before you start striping off armor this is not the only

Another definition problem. A 'Chemical round' is generally taken to be loaded
with a chemical weapon, e.g.nerve gas. In a looser sense, all explosives
(except nukes) are 'chemical weapons' in that the explosion is a chemical
reaction. But nobody refers to them that way. A HEAT warhead is just an
especially sophisticated type of explosive warhead, not a 'Chemical Weapon' in
the strict sense.

> The British used a shaped charge (fire a BB gun at a window and

My understanding of an APSH was that it is a 'normal' grenade with thin walls
so that the explosive material is squashed flat against the armour. When it
then explodes, not only the inertia, but also the energy of the explosion is
efficiently transferred to the armour.

Greetings

> The British used a shaped charge (fire a BB gun at a window and

Isn't this what is usually referred to as HESH - High Explosive Squash
Head? A round that squidges against the target on impact, then detonates and
sends a shockwave through the armour, causing chunks and splinters to spall
off the inner face and do a Magimix job on the unfortunate crewmen.

IIRC (and my knowledge on this is rusty), they are not particularly
velocity-dependant and were thus used quite a bit for lower velocity
guns such as the old 76mm on the Scorpion CVR(T). I think their range and
accuracy is relatively poor, but when they hit they can be quite effective
killers.

> It is not a liquid or a solid but a plasma ( states of matter are

then actually stopping it.

Does this mean the armor/field would reduce the effect of DFFG fire?

> Scott Siebold wrote:

[On HEAT jets]

> It is not a liquid or a solid but a plasma ( states of matter are

Sorry Scott, but this is complete bullshit. If you believe this, I'm afraid
that you have been thoroughly fooled by someone :-( The HEAT jet is
solid metal under so high a pressure that it "almost behaves like" a fluid; it
is nowhere near hot enough to form a hot plasma and there's no electrical
charge which could ionize it at lower temperatures.

> Before you start striping off armor this is not the only chemical round

> that there is. The British used a shaped charge (fire a BB gun at a

David's and Jon's descriptions are right on the mark here. HESH/HEP is
not
a "shaped charge" warhead - that particular term refers to the "inverse
cone" type of shape which focusses the blast - but it could quite
accurately be called a "deformed charge" warhead <g>

Metallic KE rounds would be vulnerable to this type of electric armour as well
*if* the voltage is high enough... but achieving that extreme voltage
may be a tad tricky :-/

***
> KH wrote:

> Another definition problem. A 'Chemical round' is generally taken to be

Correct. What Scott meant was a "Chemical *Energy* round" ("CE round" for
short): one which uses chemical energy (ie., high explosives) rather than the
rounds own kinetic energy to damage the target.

Regards,

> It is not a liquid or a solid but a plasma ( states of
Ah yes quite. Ther are 5 "states" of matter and one of those states is
"superconductor". I didn't make this up but it was in one of those 200 level
physics classes I had to take in collage. A material that is in the
superconductive state "ACTS" differently then matter in the other states.

An intersting side issue is glass is a high desity liquid which is slowly
moving (glass
that is 100+ years old is actually denser at the base then at the top).

Denser? Or just thicker?

on 02.8.22 3:48 PM, Scott Siebold at gamers@ameritech.net scribbleth:
> An intersting side issue is glass is a high desity liquid which is

> Scott Siebold wrote:

> "superconductor". I

Ok, lets just kill this thread outright. Before anyone starts arguing over how
many states of matter there are, or if glass is a liquid, I suggest you read
the information at:

http://www.urbanlegends.com/science/glass.flow/index.html

http://www.ualberta.ca/~bderksen/florin.html

http://www.lassp.cornell.edu/sethna/OrderParameters/BrokenSymmetry.html

> classes I had to take in collage. A material that is in the

only electrically

> (glass that is 100+ years old is actually denser at the base then at

"Thicker" (distance across the base) not "denser" (more mass per cubic
centimeter)

> --- Scott Siebold <gamers@ameritech.net> wrote:

Not very likely, I would suggest that somebody was trying to make a point and
the '5th' state of matter is only useful in that reguard.

In the 2000 years since the anchients defined the universe to be earth, air,
fire, and water; we have progressed to the point where the universe is made up
of solids, gases, energy and liquids, isn't progress wonderful.

Bye for now,

[quoted original message omitted]

You are indeed correct here. The HESH round 'folds' against the surface and
then detonates, fragmenting the internal structure and sneding it blasting
through the internal spaces of the tank, dicing any organic material ont he
way. This is fairly easily defeated by using ERA (Explosive Reactive Armour)
which is fitted to the outside of the vehicle and detonates as soon as the
round impacts, focusing the blast away from the vehicle skin.

This new 'electric' armour is designed to defeat the shaped charge rounds (not
KE rounds) by setting up a massive voltage differential between the

armour plates.  As the shaped-charged round detonates, it releases a jet
of
'plasma-like' molten metal (which would normally slice through the
vehicle
skin and blast-incinerate everything inside), the plasma 'makes' the
electrical circuit which then disrupts the plasma jet to such an extent that
its effectiveness is significantly degraded. Hopefully to such an extent that
the poor saps inside don't get toasted.

> Simon Brodie wrote:

> You are indeed correct here. The HESH round 'folds' against the

ERA defeats HESH by acting as a spaced armour, but a simple stand-off
plate
works just as well - you don't need any explosives for this.

> This new 'electric' armour is designed to defeat the shaped charge

<sigh> There is nothing "plasma-like" about the metal jet from a HEAT
round.

> (which would normally slice through the vehicle skin and

That's the theory, yes. The practise is usually somewhat different, unless
the warhead is very big - particularly that "everything" bit :-/

> the plasma 'makes' the electrical circuit which then disrupts the

Once again, there is no such thing as a "plasma jet" from a HEAT warhead.
Fortunately for the operation of this electrical armour, metal doesn't need to
be in a plasma state in order to close a circuit.

Regards,