Armour piercing technology

34534654

New Member
on the wikipedia I found three diferent type of AP technology:
shot and shell penetrator
shaped charge penetrator (HEAT warhead in RPG for example)
kinetic energy penetrator (armour-piercing fin-stabilized discarding sabot used in main battle tanks).

Kinetic energy AP uses narrow and long darts made of high density & strength material fired from a cannon of big diameter using a sabot.
Material used can be depleted uranium, that due to friction heats up and burtsts after inpact destroying everything inside the armour.

shape charge technick uses high explosive that is fired by a detonator that is ignited by a pressure switch (normaly piezzo element) when a projectile hit the target. This high explosive super heats up the metal infront of it (normaly copper) to for plasma gas that is directed to a narrow point using special funnel at the top of the warhead. This super heated gas travels at the speed of up to 25M and cuts through the armour like a welding machine.


but I really don't understand how shot and shell penetrator works. In the scheme found on wikipedia it is made of light weight balistic cap, steel alloy piercing shell with high exlosives underneath it and a fuse at the end that fires the explosive at just the right time.

I can understand 2nd Newton's law of action and reaction, but I think that firing up the explosives in this warhead won't produce much trust, I think it will react much like a rocket motor. As far as I understand this I can compere this with firing up a bullet out of the gun barrel which will have two openings. I believe that in a experiment like this, both bullet and a cartridge case will accelerate in an opposite direction, where both will theoreticaly recieve only a half of released energy.
 

Wooki

Defense Professional
Verified Defense Pro
on the wikipedia I found three diferent type of AP technology:
shot and shell penetrator
shaped charge penetrator (HEAT warhead in RPG for example)
kinetic energy penetrator (armour-piercing fin-stabilized discarding sabot used in main battle tanks).

Kinetic energy AP uses narrow and long darts made of high density & strength material fired from a cannon of big diameter using a sabot.
Material used can be depleted uranium, that due to friction heats up and burtsts after inpact destroying everything inside the armour.

shape charge technick uses high explosive that is fired by a detonator that is ignited by a pressure switch (normaly piezzo element) when a projectile hit the target. This high explosive super heats up the metal infront of it (normaly copper) to for plasma gas that is directed to a narrow point using special funnel at the top of the warhead. This super heated gas travels at the speed of up to 25M and cuts through the armour like a welding machine.


but I really don't understand how shot and shell penetrator works. In the scheme found on wikipedia it is made of light weight balistic cap, steel alloy piercing shell with high exlosives underneath it and a fuse at the end that fires the explosive at just the right time.

I can understand 2nd Newton's law of action and reaction, but I think that firing up the explosives in this warhead won't produce much trust, I think it will react much like a rocket motor. As far as I understand this I can compere this with firing up a bullet out of the gun barrel which will have two openings. I believe that in a experiment like this, both bullet and a cartridge case will accelerate in an opposite direction, where both will theoreticaly recieve only a half of released energy.
Normally a good idea to post a link, so we can see what you are talking about.

The explanation for the shaped charge defeat mechanism is incorrect. Nothing "heats up" per se. The speeds involved are too fast for heat to be transferred. There is no "funnel" at the top of the weapon. It works by this simple process: Take a triangle made up of some material (plastic if you want too) and place it on it's side and remove the base like so ...... < .......

Now line the outside of the triangle with explosive.

Set off the chemical reaction and the material that makes up the triangle has no where to go. As it is physically impossible for one atom to be in the same place as another atom, they all decide to move out the open face of the triangle at enormous speed. This in turn forms the "jet" you hear about.

That is basically how shaped charges work.

The pressure at the tip of the "jet" is reliant upon the force of the material behind it, so if you break this extremely thin stream of material that is being forced into the armor, you can defeat the weapon.

That is the underlying principle of reactive armors and how they work.

cheers

w
 

34534654

New Member
  • Thread Starter Thread Starter
  • #3
Shaped charge - Wikipedia, the free encyclopedia
Kinetic energy penetrator - Wikipedia, the free encyclopedia
Armor-piercing shot and shell - Wikipedia, the free encyclopedia

Set off the chemical reaction and the material that makes up the triangle has no where to go. As it is physically impossible for one atom to be in the same place as another atom, they all decide to move out the open face of the triangle at enormous speed. This in turn forms the "jet" you hear about.

That is basically how shaped charges work.
So shaped charges are based on the same physical principle of action and reaction as AP shell (if the term is even correct). By the description on wikipedia I previously thought that this jet stream is in infact one that cuts through the armour. So if I am understanding you right if top of this warhead (top of the triangle) will be opened (damaged durring penetration), thrust that is created by the jet stream will be significantly reduced and projectile will fail to penetrate?

Back to the AP shells that wasn't jet explained. Based on my understanding I will say that AP shells use same principle of action and reaction as shaped charges to gain forward thrust so it can penetrate the armour (is this correct)? But unlike with shaped charge where pressure of the jet enables that thin top of the warhead isn't simply squashed against the armour, AP shell uses metall alloy piercing head that makes penetration possible. This "shell" on the bottom also has a shape of inverted bell (much like nozzle in the rocket motor) so it can transforms most of the released energy from the high explosives and created necessary thrust.

another AP technology used in antimateriel rifles like Barrett M82
Raufoss Mk 211 - Wikipedia, the free encyclopedia
video demonstration of M82 firing different rounds
[ame="http://www.youtube.com/watch?v=-NCJFI7T6Zc"]YouTube - USMC Instructional video - m82a1 sasr sniper rifle[/ame]
as far as I could understand this video, AP mk211 did penetrate 1" homogenous armour but did not leave the armour plate on the other side while 0.50 caliber SLAP round did leave the armour plate. But as this instructor said before, SLAP round could not be fired from this gun, but can be from others (maybe he thought of M2 Browning).

So what does this mean as on wikipedia Saboted light armor penetrator - Wikipedia, the free encyclopedia SLAP round is described pretty much same as does the scheme for mk211 AP round show also found on wikipedia.
 
Last edited:

Wooki

Defense Professional
Verified Defense Pro
By the description on wikipedia I previously thought that this jet stream is in infact one that cuts through the armour.
Yes, that is correct
So if I am understanding you right if top of this warhead (top of the triangle) will be opened (damaged durring penetration), thrust that is created by the jet stream will be significantly reduced and projectile will fail to penetrate?
Maybe
Back to the AP shells that wasn't jet explained. Based on my understanding I will say that AP shells use same principle of action and reaction as shaped charges to gain forward thrust so it can penetrate the armour (is this correct)?
No. The AP "Shot and shell" you are referring too is Ballistically Capped Armor Piercing, used in WW2. Ballistic cap means a wind shield to give the projectile better aerodynamic performance. When the round struck the target it used it's inertia to penetrate the armor. As you increase the velocity the strain on the projectile exceeds the round's mechanical strength and it shatters. So to correct this you use any number of graduated hardness "bands" techniques to stop the projectile from shattering upon impact and let it's mass and Length to Diameter ratio do the rest of the work to penetrate.

But unlike with shaped charge where pressure of the jet enables that thin top of the warhead isn't simply squashed against the armour, AP shell uses metall alloy piercing head that makes penetration possible. This "shell" on the bottom also has a shape of inverted bell (much like nozzle in the rocket motor) so it can transforms most of the released energy from the high explosives and created necessary thrust.
No, That is incorrect. The round penetrates and then explodes as per normal behind the armor.
as far as I could understand this video, AP mk211 did penetrate 1" homogenous armour but did not leave the armour plate on the other side while 0.50 caliber SLAP round did leave the armour plate. But as this instructor said before, SLAP round could not be fired from this gun, but can be from others (maybe he thought of M2 Browning).

So what does this mean as on wikipedia Saboted light armor penetrator - Wikipedia, the free encyclopedia SLAP round is described pretty much same as does the scheme for mk211 AP round show also found on wikipedia.
I don't understand the question. If a round comes out the other side of a piece of armor, it is said to have penetrated. If it does not come out the other side, it has not penetrated. If it does not come out the other side, but the armor flakes off at the back, then sometimes this is written up as "behind armor effects" and in some circles this is also regarded as having penetrated the armor.

I'm not a teacher. I would suggest you obtain a copy of "The Illustrated Encylcopedia of Ammunition" by Ian V. Hogg It is a lot more definitive then wikipedia, especially if you are having trouble understanding Wiki-English.

cheers


w
 

eckherl

The Bunker Group
Verified Defense Pro
The goal for shaped charge warheads is not to enter and exit a armored target, the real damage comes from either behind armor effects or by spalling effect, even our neat KE rounds tend to inflict more damage to a heavy armored target if it bounces around inside. There have been cases where vehicles hit by KE or armor piercing rounds that enter and exit have done minimal damage to a vehicle and its crew.
 
Top