On Tank Armor...

It is often argued in some threads that such and such a tank as the equivalent of 1000mm of steel armor or 800mm. Or that a certain tank gun can penetrate how many mm of armor at a certain range. The fact is that it doesn’t work this way. Modern tank armor cannot be described as being equivalent to a certain thickness of rolled homogeneous steel, period. There is no equivalency to speak of.

Primarily there are two kinds of threats a tank’s armor has to defeat – Kinetic Energy and Chemical Energy.

In terms of kinetic energy threats, the only kind of projectile that even has a chance at penetrating a heavy tank’s frontal arc is a long rod projectile. You cannot describe the ability to protect against them as a thickness of steel. Depleted Uranium or Tungsten-Carbide rods will pierce ordinary steel like butter and any kind of sane thickness is quite irrelevant. If you shoot the LR penetrators into a 5m block of steel they’ll simply embed themselves in it. This is not how tank armor typically stop the APFSDS-T or DU rounds. There is no armor that is say 300mm thick, but equal 1200 mm of steel and hence cause a penetrator that will go through 1000mm of steel to be stopped after 250mm of this “miracle armor” and stick out like a dart on a dart board. It doesn’t work like that. The key to stopping long rod penetrators is fracturing it on impact. If you are successful, you will have an inch or two worth of a dent and there will be practically no penetration. If you fail, the rod will most likely go right through your armor no matter how thick or thin it physically is. Generally speaking, the system employed to achieve this is a very high tensile metal face plate that is relatively thin. And their effectiveness depends highly on the penetrator itself. The US uses Depleted Uranium for this. Most others use tungsten carbide or simply face hardened steel. Tungsten carbide is actually harder than DU, but DU is sufficiently hard and is less prone to shattering than TC. In the end, 80% of the tank’s ability to stop sabot KE rounds comes down to 10 to 20mm worth of armor.

When it comes to Chemical Energy warheads, there are primarily two types – HEAT and HESH. HEAT is the more common of the two today, and despite the name the way it works has nothing to do with heat. So, you can forget about any claims that ceramic armor is superior against HEAT rounds because they do not conduct heat. This is utter rubbish. HEAT – High Explosive Anti-Tank – rounds work by focusing explosive energy down a very narrow jet. They do so using a geometrically precise reverse cone hollow charge of high explosive which when detonated uses about 2/3 of its explosive energy to force the remain 1/3 or so into a concentrated jet. This jet penetrates armor by pressure, not by temperature. Stopping HEAT rounds really comes down to either dissipating this jet or giving it sufficient room to dissipate on its own. The simplest way is to have an armor skirt a good half a meter away from the tank’s armor. This is used in WWII on many German tanks when HEAT rounds started to become commonplace. The other way is to use a reactive armor. Both explosive and ceramic composite armor (such as Chobham) are in essence reactive armor. They work by reacting to the HEAT jet and disrupting it. ERA works by itself exploding. The resulting explosive force and the metal plate thrown out by it disrupts the focus of the HEAT jet rendering it a lot less effective that it otherwise will be. Chobham type armor typically crushes under the jet. This pulverizes the ceramic layers and turns the ceramic into a high modulus cloud of pulverized ceramic. This dense ceramic dust, under tremendous pressure, is almost like a fluid. As it gushes out in the face of the HEAT jet and neutralizes its energy. HESH – High Explosive Squash Head -- warheads work by flattening itself against the armored surface like a lump of clay. When detonated, the explosive force causes transfer through the metal – like a billard ball striking another, stopping and causing the other ball to get in motion. This force causes the inside surface of the armor to buckle and detach. The armor itself hence becomes the killing mechanism, showering the occupants inside the tank with shrapnel. Again spacing works against HESH. However, ERA and composite armor in their basic form do not. As long as you have continuous armor between the outer and inner surface, HESH will most likely kill you. Again, trying to measure resistance to chemical warhead as a “thickness of steel” worthless.

To sum it up, basically, to stop kinetic energy weapons, it really comes down to a few centimeters of very hard plating. To stop Chemical Energy weapons, it is all about spacing and reactive armor (not just ERA, but passive ones like Ceramic composites as well).

The common armor concepts used in modern tanks is as follows:-

(1) Steel armor. This is cheap and easy to make. It can be a casting or made from welded plates. Heat treating can be used to harden the faces of steel armor to improve performance against kinetic energy weapons at the expense of resilience against chemical warheads. Classic tanks like the M48 and T55 uses this.

(2) Aluminum armor. This is very light. Every pound of aluminum armor is also more effective against chemical warheads as an equivalent pound of steel since aluminum is bulkier but less dense and stronger than steel by weight. The M113 uses aluminum armor – too little of it really to be of much value. The protection of the M113 was bad to the point where assault rifle rounds with steel cores will penetrate it at close range.

(3) Perforated steel armor. This involved steel armor that is in effect drilled full of holes perpendicular to the face of the armor. The holes are no bigger than half the expected diameter of the expected penetrator. This allows the armor to be 40-50% the weight of a solid block of steel, but 70% as effective against kinetic threats. It also makes the armor bulkier and full of empty space, which enhances survivability against HEAT and HESH type warheads. Usually the perforated blocks will form the core of the armor, with harden steel strike faces and/or unperforated panels capping off both ends. Advanced versions of perforated armor use hard cylinder liners for the holes to increase kinetic protection and/or ceramic fillers within for protection against HEAT rounds. Despite popular believe, the original Leopard II does not use Chobham type ceramic laminate armor, rather it uses perforated armor. Because the orientation of the holes are very important to effective protection, perforated armor does not lend itself to curved surfaces very well.

(4) Ceramic Laminates (Chobham type). This is usually a laminate of multiple layers of metal and ceramic plates. The ceramic used is usually a guarded secret, but it is speculated that Alumina (Aluminium Oxide or Sapphire), Boron Carbide (the hardest simple ceramic), and similar materials are probably used. Sometimes synthetic fibers are used to enhance the effectiveness of the metal backing plates and metal mesh is integrated into the ceramic plates to localize shattering when struck. Sometimes the term Ceramic Matrix Composite is coined to discribed laminated armor employing these advanced techniques. Because the ceramics are both very hard and crushes into a HEAT jet disrupting retro-fluid action, it is very effective against HEAT warheads. Because it is numerously layered, it is more effective against modern HEAT warheads which frequently has tandem charges to defeat ERA. When it is hit by a tandem charge, the precursor charge will not expend the entire reactive package just the top layer or two. Ceramic laminates also resist kinetic energy penetrators better than steel armor of a comparable weight though not as drastically better as they resist shaped charges from chemical warheads. Pound for pound, this is currently the most effective single armor concept though it is frequently used in conjunction with other armor concepts. Because ceramics cannot be bent into curved surfaces, tank designs using ceramic laminates also tend to be squarish.

(5) High tensile alloy faced armor. This is an arrangement common amongst state of the art tanks. Basically, it is a thin sheet of tungsten alloy or in the case of late model M1 tanks Depleted Uranium acting as the strike face of whatever the armor type is underneath. The mission of this is to fracture long rod penetrators and render them practically useless. Tungsten-carbide is actually harder than DU, but DU is also very hard and is less prone to shattering making it a superior material for penetrators and strike faces. The problem is DU dust is toxic and is very unhealthy if breathed in.

(6) ERA – Explosive Reactive Armor. This is a cheap and relative light way of protecting against HEAT projectiles. Basically it is high explosive sandwiched between steel plates which explodes when it is hit by a HEAT warhead. It is practically useless against kinetic rounds and there is no repeated strike capability making it very venerable to tandem charge warheads. But it is light, modular and easy to apply over existing vehicles. You will see this on Soviet tanks and Chinese tanks a lot. Generally it is a quick fix for tanks which does not use advanced ceramic laminate type “passive” reactive armor.

(7) Spaced armor. This is one of the oldest tricks in the book and really the only one that does not involve heavy materials and the only thing that is truly effective against HESH rounds. This can be simple slats or skirts mounted some distance off the sides of the hull or turret. It is also a feature inside the advanced construct of some tanks. An empty space is just about as good as steel in countering shaped charges and empty space is weightless. Modern internal spacings also tend to have angled baffles to channel the jet off the centerline to further increase effectiveness against chemical energy attacks.

(8) Advanced Combinations. Most of the best tanks in the world use a combination of two or more of the above.

Oh, BTW, because they offer more protection for the same weight compared to steel but takes up more space, perforated armor and ceramic laminate armor is sometimes called "Bulky Armor".

The current armor package for the M1A2 for example uses Depleted Uranium strike faces, an advanced Chobham type ceramic laminate, baffled spacing and Kevlar type supplementary backing for critical spaces. The exact thickness and construct of the laminated armor blocks are of course highly classified. I believe the core armor for the up armored Leopard 2s remain the same as the original Leopard 2’s perforated type. However, the big chunks of additional armor probably has high tensile strike faces and are probably mostly hollow – if they were not largely hollow, the Leopard 2A6 would be a lot more than 70 tons. Only the Chinese military officials will know the exact composition of the armor on the Type 98 and 99 tanks. However, if I have to take a guess I say they are using perforated armor with hardened strike faces and ERA. This will be consistent with the need for squared profiles and the modest weight of the packge.

Der Wille zur Macht!

"The protection of the M113 was bad to the point where assault rifle rounds with steel cores will penetrate it at close range."

wow


Don't try this at home lads

quoted from:
panda
"Of course we knew it would be a tuff fight. The little Viets are our tiny cousins. They are practically Chinese but only much shorter."

Gcap
"I plan on sending a letter to the Colombian DoD,On possibly buying 12-20 Mirage-2000-5 multi-role combat aircraft."

What's the Best Armoured American tank? M1A2?

Has one of the M1's been penetrated in wars?

best armored MBT has thot to hav ben chally 2. and no, the M1 has not been penetrated by the Iraqi T-72 and -55. the most that has happened is that a tread has been torn

"It was as though they were rabid. Such fury should not be contained within a human or any other living thing. You could almost see the devil cowering in their eyes as they screamed for Mughal blood when they charged forward with no regard for their own lives, running as fast as a rabbit and more deadly than any cobra I have encountered in my stay here. Woe betide the Mughals, as they were slaughtered by the thousands in this battle"

-French observer at a battle after a Guru was killed by the Mughals


Nische kar apni jeet karon



The Sikh Regiment

Indian Army's Most Decorated Regiment

What's the Best Armoured American tank? M1A2?

Has one of the M1's been penetrated in wars?

Yes. And, yes, M1A2s and M1A1 SEPs have been penetrated and destroyed in war.

However...

(1) The front armor, front quarter and side armor of the M1 family has never been penetrated in action. Infact, the US's own Depleted Uranium long rod penetrator failed to penetrate the turret front during one occasion where an another M1 tried to destroy it from about 50m away. The M1A1 was immobilized during the invasion of iraq due to multiple RPG hits to the engine exhausts and onto the tracks. There was no time to wait for a recovery vehicle because the commander of the company did not want to slow the advance. So he decided to destroy the tank. The first shot failed to penetrate the front left turret armor. Two more shots from the rear quarters and straight into rear of the turret destroyed tank.

(2) All the M1 losses thus far has been from rear and rear quarter hits to the engine compartment and to the tracks.

(3) M1s tend to burst into flames when hit int he rear quarter because diesel fuel is used as spaced armor in the rear quarters to protect the crew compartment.

(4) The crew compartment has never been penetrated so far. And no US tanker has ever been lost inside an M1 -- not counting tankers who were shot or was caught in a blast while standing exposed through the hatch or cupola of course.


Der Wille zur Macht!

very good explaination of armor, thanks

That's why the Leclerc is a hell of tank, you can rapidly customize the tank armour depending on the threat it has to face. Still I have little belief in armour. I don't believe allowing the enemy to even hit you is a reasonable philosophy. I'm the type who think active defense is more important than passive defense. For a tank to survive the battlefield it must react to incoming projectile even before the projectile makes physical contacts with the tank. It should have enough armour to protect it from the common widespread threat such as RPG without needing to react to such threat actively. This lead me to predict, we will not see anymore MBT in the richest army by 2040. The main land attack vehicle will not be more than 30 tonnes. However will see a massive evolution in the guns and the type of weapon they will carry. 10km range guns not affected by terrain constraint (with all type of ammunitions) as well as high speed missiles are necessary to adapt to modern battlefield.

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We were not given dominion over the earth; our forebears earned it in their long, nightmarish struggle against creatures far stronger, swifter, and better armed than ourselves, when the terror of being ripped apart and devoured was never further away than the darkness beyond the campfire's warmth. -Darwin

The problem with active defence is that...

(1) Most earlier ones (eg Drozd) is too slow to be effective even against high subsonic missiles and barely supersonic missiles. They also tend to have limited arc coverage.

(2) The later ones (eg Arena, Trophy, etc) is still completely useless against kinetic threats which are typically 3 to 4 times faster than a hellfire or Javelin. And long rods are very hardy against an explosive grenade or fragment shower.

(3) Most of the active defence systems rely on low power, wide coverage, millimeter wave radar(s) for cueing and activation. This is exactly what the opponent tends to jam in open warfare.

In the end, you still need good armor on a MBT. Because one of the biggest threat in open warfare is not RPG type rockets and ATGMs, but other tanks with kinetic penetrators. A 30 ton tank with small arms defeating armor only and active defence will be very vulnerable.

Having said that, I think the west has irresponsibly neglected active defence for a decade or two -- you should have both good passsive armor and active protection. But, they are starting to wake up and are aggressively developing and deploying active defence systems. The US is currently field testing four systems in Iraq.

The first is IAAPS or Integrated Army Active Protection System. This is a comprehensive setup which has all aspect infra sesnors which detects the launch of an RPG or ATGM. The system automatically deploys IR and RF jamming and physical decoys. If that fails a large boosted grenade launched towards the target bearing and detonated to kill the missile or RPG at about 30 yards.

The second is the Israeli Trophy APS which is a mature system that is proven in action, but with a lesser degree of countermeasures integration. The detection system is radar via multiple fixed field of view millimeter wave radars rather than advanced IR. The kill vehicle is also a line of sight boosted grenade, but of a smaller caliber than that used on the IAAPS.

The third is the CICM system by United Defence. This works like IAAPS, but is simpler and does not integrate RF/IR jammers and decoy launchers. It is also lighter and smaller. The main selling point is that it uses a direct kill mechanism which sends a cloud of 55 pellets fired from the intercept cannister into the path of the approaching missile/RPG instead of relying on an explosive grenade to kill it. This kill mechanism is a lot more benign to foot soldiers fighting in the vicinity of the protected vehicle. Threat detection is via an all aspect array of optical "flash" detectors and two cued millimeter wave planar array radar integrated to both sides of the launcher itself. The launcher can carry two or four kill cannisters and each cannister can fire twice (once from each end). Unlike IAAPS, the whole rig is small enough to be mounted to trucks and Humvees if desired.

The fourth system is probably the simplest. There is no grenades of metal storm pellet cannisters. There is no tracking radar or sophisticated integrated countermeasures. It is simply made up of small boxes with an air bag in it! Yes. The airbag system is very simple. The box itself as a low cost, solid state, proximity -- much like an advanced version of the kind of parking sensors you find in the bumpers of cars! If it detects a fast approach object which is faster than any vehicle, human or thrown object (say above 300km/h), it triggers the airbag to inflate! The airbag causes the RPG to either be deflected or be detonated on the airbag about a meter away from the vehicle. This prevents even a Humvee from being penetrated by RPG type projectiles. The system is not sensitive enough to respon to small arms fire and hence will not be set off by bullets.


Der Wille zur Macht!

Quote: 1) Most earlier ones (eg Drozd) is too slow to be effective even against high subsonic missiles and barely supersonic missiles. They also tend to have limited arc coverage. (2) The later ones (eg Arena, Trophy, etc) is still completely useless against kinetic threats which are typically 3 to 4 times faster than a hellfire or Javelin. And long rods are very hardy against an explosive grenade or fragment shower. (3) Most of the active defence systems rely on low power, wide coverage, millimeter wave radar(s) for cueing and activation. This is exactly what the opponent tends to jam in open warfare.

That's exactly why they have to remedy the problem. It's not like I'm the only saying this, this is a serious issue that most advance military are now considering. Give it time, a reliable system should come.


In the end, you still need good armor on a MBT. Because one of the biggest threat in open warfare is not RPG type rockets and ATGMs, but other tanks with kinetic penetrators. A 30 ton tank with small arms defeating armor only and active defence will be very vulnerable

No one is saying a 30 tonnes tanks be armed with a small arms is going to engage MBt (this is just plain stupid). A 30 tonnes fighting vehicle in the nearby future will have the firepower to devastate any MBT within a 10 km range if they invest money in new guns and new missiles as well as sensors to go with these new weaponry (an no amount of armour can deal with such firepower, this where armour goes to the drain in high intensity conflict this is the critical point you need active defense). That said, the most common threat isn't kinetic penetrators but RPG. As observed in Iraq, most enemy tanks were taken from the air or at time by attack helicopters (the threats of kinetic penetrators or tanks in general was nigh to ridiculous). Deploying long column of MBTs as Rumsfeld did was rather retarded. The enemy confused didn't quite took the opportunity to wreack havoc on such column (Many time Iraqis in pick up trucks actually engage those columns but lacking in organisation and chronic studity they failed to inflict damage, instead they attack MBTs rather than the logistical tail and thus cutting the army supplies). This could have had serious consequence, similar to what happen to the Lybians armoured facing a highly mobile chad army train by the french army to take logistical tail first, cutting the main forces from the supplies basicallt starving them out of everything.

I'm not saying armour need to be totally neglected. but armour is last to be considered in a future engagement. Priority should be firepower, intelligence, strategic and tactical mobility, active defence (very important active defence I believe has the potential to neutralise firepower). Then last you can consider armour because certainly you would have to fight in situation where you are facing guerilla forces. You are not going to use active defense each time a p!ss cheap rocket hit you, the armour need to be able to take the shock. This is where the research in armour should go. And that I'm not talking about dumb old armour, but perhaps something to force the rocket to explode before reaching the vehicle. This is how I view the battlefield should evolve.

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We were not given dominion over the earth; our forebears earned it in their long, nightmarish struggle against creatures far stronger, swifter, and better armed than ourselves, when the terror of being ripped apart and devoured was never further away than the darkness beyond the campfire's warmth. -Darwin

I think one has to understand and appreciate the fact that engaging in asymetrical warfare -- mainly guerillas and terrorist threats -- is a privilege. It is when you have the unquestionable ability to dominate the enemy in conventional warfare that you get the privilege to fight these nuisance. Hence the idea of an army, and it's equipment, geared mainly towards low intensity urban conflicts is a mistake. Because, if this is all you have and the only kind of war you can fight, then you won't even get to fight it. If the enemy can engage you in conventional warfare and stand a chance at winning, they will. And conventional warfare is a lot worse than asymetrical warfare -- casaulties will be in the hundreds of thouands not a thousand or two.

As it stands right now, the MBT -- no matter how well protected with armor -- is being outpaced by top attack missiles and air delivered ordnance. In fact, that has been the case since three decades ago. Even in the 60s and 70s, your tanks are sitting ducks once you lose ontrol of the air. You cannot provide a tank with all aspect protection. But that is not to say that you shouldn't have heavy armor, because heavy armor is a flexible and robust tool. And, it is the very presence of heavy armor that forces your enemy to deploy large ATGMs and various anti-armor equipments. It adds to their problems which is exactly what you want.

I see the continued presence of heavy tanks into the foreseeable future. But tanks will feature layered protection. Conventional advanced armor, air bags for stand off detonation, active interceptors for missile interception (possibly with the ability to intercept both horizontal and top attack weapons) and advanced IR/RF jamming and countermeasures.

I also see the development of APC sized Anti-tank vehicles with vertical launch missiles and the ability to simultaneously engage multiple targets. The same system can also probably be deployed on wheeled utlity vehicles and as towed setups.

Der Wille zur Macht!

Quote: I think one has to understand and appreciate the fact that engaging in asymetrical warfare -- mainly guerillas and terrorist threats -- is a privilege. It is when you have the unquestionable ability to dominate the enemy in conventional warfare that you get the privilege to fight these nuisance. Hence the idea of an army, and it's equipment, geared mainly towards low intensity urban conflicts is a mistake.

Actually the addition of armour as I've mentioned above is simply to counter asymmetrical threats which are simply too hard to counter due to its widespread nature. However what I was describing is mainly how to deal with conventional threats, conventional threats need to be deal with rapidly through precise and rapid application of firepower at critical points (with that vision in mind, there is little room for armour but active defense is a must, a fighting unit can actively protect itself or be protected by a specialise unit or both). But this doesn't mean you have to neglect low intensity conflict, low intensity conflicts has the potential to drain the life out of an army over a long period of time. Due to the evolving nature of war, most conventional war will eventually evolve in guerilla wars or vice versa (you don't want guerilla armies to turn in conventional ones this is a losing sign). An army needs to adapt to both type of conflicts rapidly in the near future . Vietnam for example, the viet alternate conventional and guerilla tactics, this lesson need to learn. Iraq how long did the conventional battle last? the guerilla war is still going on, with nigh to 15,000 casualties excluding those sufferring from battle fatigue and diseases (a very considerable number perhaps more than wounded bu hard to track). You wonder why the US need private contractors in Iraq? To be able to cope with both guerilla or conventional threat successfully doesn't guarantee victory as shown in Algeria, since war is simply an extension of politics at time. But dealing with both threats that can alternate is certainly a good way of winning a war.

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We were not given dominion over the earth; our forebears earned it in their long, nightmarish struggle against creatures far stronger, swifter, and better armed than ourselves, when the terror of being ripped apart and devoured was never further away than the darkness beyond the campfire's warmth. -Darwin

Quote: I see the continued presence of heavy tanks into the foreseeable future. But tanks will feature layered protection. Conventional advanced armor, air bags for stand off detonation, active interceptors for missile interception (possibly with the ability to intercept both horizontal and top attack weapons) and advanced IR/RF jamming and countermeasures

By 2050, the most advance and richest armies would not field any MBT in the conventional sense. But most third world countries will still field them. The reason being simply the system used by rich armies are beyond the capability of poorer armies to deploy.

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We were not given dominion over the earth; our forebears earned it in their long, nightmarish struggle against creatures far stronger, swifter, and better armed than ourselves, when the terror of being ripped apart and devoured was never further away than the darkness beyond the campfire's warmth. -Darwin

dwightlooi thanks for the good info.

Do you think the MAIN purpose of armour is to protect the Crew or the Tank itself?

I was always wonder if enemy is going to stop the tank they just need to attack the tracks and why bother with the frontal armor?

Also: we will almost NEVER see tanks vs tanks battles more in modern warfare, so the chance to face the Frontal armor of a enemy tank is not any big more.

"As observed in Iraq, most enemy tanks were taken from the air or at time by attack helicopters "

yes, that's the case for the USA but not for any other country. Just name me one country that can field hundreds of planes/helicopters anywhere at any given time besides the USA?

Imo, tanks look irrelevant but that's just because we're thinking that every country has the capabilities of the US, that's not true in the real world.
But I do agree with Eryx that tanks will become less relevant in the future but I believe they will still play their role.


Don't try this at home lads

quoted from:
panda
"Of course we knew it would be a tuff fight. The little Viets are our tiny cousins. They are practically Chinese but only much shorter."

Could some one provide sources for this summery of armor types etc.

Many that live deserve death. And some die that deserve life. Can you give it to them? Then be not too eager to deal out death in the name of justice, fearing for your own safety. Even the wise cannot see all ends.