Tank Armor?

[Dennis G]

I have a few tank questions


1) what kinda armor do the tanks use(what go's into making the metal armor?)

2) What kinds of armors do the U.S. U.K Israel Russia Germany use?

3) This one is not is not about armor but what it take to punch into the armor What kind of munitions do tanks fire looking manly for other militarys not just the US?



Is that Reactive Armor?

http://www.bharat-rakshak.com/LAND-FORCES/Army/Images2/0470.jpg


Reactive armor's protective mechanism involves producing an explosion or other such reaction when it is impacted by a weapon, "pushing back" against it. This is particularly effective against shaped charge warheads, in which the warhead directs a focused jet of molten metal against the armor; reactive armor's reaction disrupts the jet before it reaches the armor's surface.

Modern ERA such as the Russian Kontakt-5 is made up of "bricks" of explosive sandwiched between two metal plates. The plates are arranged in such a way as to move sideways rapidly when the explosive detonates. This will force an incoming KE-penetrator or shaped charge jet to cut through more armour than the thickness of the plating itself, since "new" plating is constantly fed into the penetrating body. A KE-penerator will also be subjected to powerful sideways forces, which might be large enough to cut the rod into two or more pieces. This will significantly reduce the penetrating capabilities of the penetrator, since the penetrating force will be dissipated over a larger volume of armour.

ERA bricks are used as add-on armour to the most vulnerable parts of an armoured vehicle or tank. They require fairly heavy armour on the vehicle itself, since the exploding ERA would otherwise damage the vehicle and injure or kill the personnel inside.

Recent research has produced the idea of Electric Reactive Armour, where the armour is made up of two electrically charged plates separated by an insulator. When an incoming body penetrates the two plates and closes the circuit, a high voltage jolt will supposedly vaporize the penetrator and significantly reduce the resulting penetration. It is not public knowledge whether this is supposed to function against both KE-penetrators and shaped charges, or shaped charges alone. This technology has yet to be introduced on any operational platform.




Reactive Armor Basics

Reactive armor designs are based on the assumption that dispersing the shaped charge jet, so that it impacts on a large are of the structure behind the reactive armor, will reduce the jet's penetration into it.
To achieve meaningful dispersion of a fast moving stream of copper particles it must be met with a fast moving mass of material, moving at an angle to the jet's motion. Due to exchange of momentum between the moving material and the jet, the jet will be deflected and partially dispersed.
The simplest engineering fulfillment of the above requirements is in the form of two metal plates sandwiching a layer of high explosive. This is a basic reactive sandwich. The "reactive" in the name refers to the fact that the explosive material reacts to the jet's impact and explodes, propelling the plates outwards, into the jet's path.

As can be seen in the photograph on the right, the plates (usually called "flying plates") are cut by the jet. This causes a decrease in total jet penetration of the target.

This simple design is relatively effective - it is usually about 20 times more effective that armor steel. Such designs, when deployed on main battle tanks will protect them against most shoulder launched antitank rockets.
When considering the protection of lighter vehicles, such as armored personnel carriers (APC) with their much thinner armor, or protecting tanks against heavy missiles, the simple design falls short in several respects:

Its efficiency sharply decreases if the jet impacts the flying plates at any angle different from the one for which the armor was designed.
The very fast tip of the jet penetrates the plate array before the explosive between the plates reacts, and thus is unaffected by the reactive armor.
The slug, traveling at much slower velocities arrives after the plates moved out of its way, and so is also unaffected.
The flying plate facing the vehicle impacts it with significant energy and may seriously damage a lightly armored APC.
Any friendly troops close to the event are likely to be injured by the secondary explosion of the armor.
The above problems can be solved, using advanced design techniques and special knowhow

[BMF]

yes thats' reactive armor. basically when a round hits it, it explodes out, away from the tank, defeating that attack. to defeat this, a lot of modern tank rounds (inc the U.S. HEAT) and a lot of anti-tank missiles have dual charges. 1st one explodes the reactive armor, 2nd one penetrates the tank and, hopefully, destroys it.

HEAT and SABOT rounds are the main 2 in U.S. use. heat i already explained above. SABOT rounds fire a dart made of tungsten and dep. uranium(if i remember right, im just a grunt). the dart is(again, could be wrong) 40mm, and travels at some ridiculous velocity. the dart hits its target with so much kinetic energy it penetrates an insane amount of armor(uranium is so dense it cuts through steel like its nothing) and the KE blows up the tank, as we saw in the last 2 gulf wars. As far as the armor our tanks use, it's a layered system of soft and hard steel, with composites(like kevlar) mixed in. this way the tank benefits from the ups and downs of several different types of armor, making the abrams extremely durable

[GazB]

The idea behind ERA is relatively simple.

Two plates of metal with HE between.

When a projectile hits the first plate nothing happens but as it moves through the HE it detonates it. The explosion forces the two metal plates apart... one outward into the path of the HEAT beam, or the APDSFS penetrating rod... as it moves the penetrating rod has to cut a notch through it, so it is not having to penetrate a continuous mass of metal, but it does have to cut a notch through that metal. The other metal plate hits the main armour of the tank and rebounds out into the path of the incoming warhead which the incoming warhead now needs to penetrate and also cut.
In the case of an attack with a solid penetrator if new model ERA as used in Kontact-5 then the rear plate actually guillotines off the point of the penetrator. In the case of an HEAT attack it breaks the HEAT beam into pieces which greatly reduces its effectiveness. The tip of any penetrator is the most important part... try sawing off the tip of a nail and then hammering it into wood... you will find it bends before it goes in properly. In the case of a 40mm calibre Uranium rod it takes a lot of energy on the tip to get it penetrating again... this reduces its ability to penetrate armour.

Specs for Kontact 5 are

Package mass: 3 t

Added protection, RHA rating (as stated by NII Stali):
vs APFSDS: 250 mm
vs HEAT: 600 mm

[Angus]

Armor can be discussed ad nausiem and frankly is a discussion very few are even qualified by participate in in any real capacity. So I'll just toss a few things out there that might be interesting to you. I'm no scientist and certainly no expert of armor. Be that as it may here's some random info off the top of my head as I think of it...

APFSDS = Armor Piercing Fin Stabilized Discarded Sabot

Like others said above, it's basically a rod with a pointy end and a couple fins on the back like a dart. Basically this is all that anyone uses now because HEAT is generally worthless unless you're talking about a fight between two ghetto tanks like some cold war vintage T55s sportin' about as much armor as my Chevy Suburban. ;) APFSDS is catagorized as a "kinetic energy" weapon because it relies heavily on velocity to help it defeat whatever it hits. Longer the range, the less effective, usually starting somewhere after 1000m or so. Hitting something with one of these leaves a clean little hole but lots of nastiness inside the tank.

Russian AFPSDS is generally though to use higher weight penetrators at lower velocities. They can be expected (nowadays) to have DU penetrators. The plastic sabot that guides the round out of the barrel in many Russian APFSDS rounds is argued to have too much contact area where it rides the barrel inside resulting in lower performance. As a goofy side note, the sabots break away as they leave the barrel like flower pettles. The flying bits can really give your head a good ass kicking out to about 100+ meters if you are unlucky and get hit with one.

HEAT = High Explosive Anti-Tank

Basically a shaped charge that, when detonated, focuses a blast of hot gases and red hot magma (hehe) through the target. Basic concept is that if you heat armor enough in a pin point you can weaken the materials used by having them revert to liquid state (or just really soft) in that spot. These rounds are referred to as "chemical energy" because they use explosives. Because they use explosives they're also heavier and have much lower muzzle velocity (usually less than half) of APFSDS. On the plus side though, effectiveness is not changed with range since it blows up the same when it hits the target.

The major downside is that ERA, even first generation, makes HEAT nearly worthless. The M1A1 HA (heavy armor) from the first Gulf war used various types of voodoo armor to (supposedly) completely nullify HEAT rounds. Probably all propoganda though, who knows.

HE-Frag = High Explosive Fragmenting

Pretty straightforward. This is basically a big ol' grenade for all practical purposes. It is used against infantry and very light targets that can be defeated with fragments. Interestingly, the Abrams does not carry any of this type of ammunition in it's usual combat loadout (only carries APFSDS and HEAT) which means it won't be shelling you in a city any time soon. But I guess it can still kill you with those 11,000 (not a typo) rounds of 7.62mm. The HE-Frag rounds are about as heavy as HEAT and fly with a nice arc. A 125mm russian HE-Frag weighs close to 7 pounds (warhead weight).

Armor...

Best armor is generally thought to be something made of a complex layered honeycomb. Sheets of various classified goodies go into.... well I don't know what they go into, be it a mold or a press or whatever. But either way, it's not just rolled homogenous steel anymore. When looking at armor values you will usually find them in RHA (rolled homogenous steel armor) and it an EQUIVALENT. This figure does not mean that the armor is actually 500mm thick. It only means that if you stood 500mm of RHS up and shot it perpendicular to the plate you would need something over 500mm penetration to defeat it.

On the subject of armor it should be noted that armor is more than just what's in the armor. A huge factor is the angle of the armor. Tanks are obviously not shaped like bricks, and this means that a tank shell (or rocket or whatever) being shot at it will rarely hit it perpendicular to the plate. The idea is to slant the plates (usually on forward facing portions of the hull and turret) so that you can do two things....

1) Try to deflect whatever it is that's gonna hit you. This works well against RPGs and rockets and such. Hell half the time they're stale duds left over from Gorby, but anyways....

2) By slanting the plates whatever hits it at a reasonably likely angle (i.e. two tanks on roughly equal elevation) will have to travel through the plate diagonally, thus increasing the distance the penetrator has to....penetrate. Pretty simple.

Also, tanks are incredibly heavy. To keep them from going a maximum of 5kph (or mph if you're a filthy american like me) you have to skimp on the armor on top of your turret, on the rear part of the sides, and really skimp on the back by the engine. This means that, in theory, if a ****ty T55 gets behind an Abrams and shoots it in the ass you're going to have problems. Chances of that happening? Uh...... heh!

And finally... Tank shells... Russian built equipment generally uses interchangable rounds and guns. The biggest differences between tanks like the T72A and T80BV are just systems upgrades to optics and such, and obviously more survivable hulls, engine and armor. They all use the same 125mm cannon. Interestingly, Russians seem to love missiles and many of their tanks are capable of launching ATGMs from the barrel. Handy.

Oh and one last thing... Countermeasures. Russians are unique in that they are basically pioneering active countermeasures for their armor (be it a bmp or a tank). They have systems that will use low level radar to detect and incoming missile or shells and then spray it with shrapnel from ports on the turret (ARENA). Other systems burn up IR guidance systems on common SACLOS missiles like the TOW and make them worthless (SHTORA). And the earliest systems actually shot little missiles from tube launchers to impact incoming projectiles like RPGs (DROZD I believe). Crazy crazy stuff. Btw those systems work very well.

Holy **** this was no short post!!! Ack!!!

[GazB]

I am no expert either but disaggree on a few points.

"Russian AFPSDS is generally though to use higher weight penetrators at lower velocities. They can be expected (nowadays) to have DU penetrators. "

Actually they tend to have higher velocities... up to 1,850mps (ie 1.85km/s), but their problem is not lack of velocity or weight, but lack of length. The Soviet autoloaders can't handle long rounds... if you look at it the Soviet 125mm APFSDS round comes in two pieces... one with the penetrator wrapped in propellent, and the other all propellent with a case stub. A western round is one piece and about as long as the two soviet pieces together, but the western round has the projectile taking up almost the full length of the round... the efficiency of a penetrator includes factors like the material it is made of (DU or tungsten carbide are both much better than cream cheese) but also its length to width ratio... the longer it is the more it concentrates its mass into a small area... obviousl if it is too thin it will bend to easily so there is a limit...

"Basic concept is that if you heat armor enough in a pin point you can weaken the materials used by having them revert to liquid state (or just really soft) in that spot."

At the temps and velocities we are talking about most materials act like fluids. HEAT warheads penetrate kinetically... just like an APDSFS round does. That is why HEAT rounds have metal liners to give them more substance and therefore penetrating power. Early weapons used a copper lining, though more modern systems use Talantium (spelling) and even DU.

"The major downside is that ERA, even first generation, makes HEAT nearly worthless. The M1A1 HA (heavy armor) from the first Gulf war used various types of voodoo armor to (supposedly) completely nullify HEAT rounds. Probably all propoganda though, who knows. "

Often an electrified chainlink fence was used as is used by Israelis on their tanks... this can make the peizio electric fuse on the RPG fail. Even if it doesn't fail the RPGs used by the Iraqis were of old manufacture and had penetration capabilities of around 300-350mm at ideal angles of attack. Current 105mm cal RPG rounds more than double that capability... still not enough for a front on attack on an Abrams, but adequate for side and rear shots.

"The HE-Frag rounds are about as heavy as HEAT and fly with a nice arc. A 125mm russian HE-Frag weighs close to 7 pounds (warhead weight). "

The HE-FRAG projectile fired by the 125mm Soviet gun weighs 23kgs with 3kgs of that HE. It can be used as a HE-FRAG, HE, or Frag. To use it in HE-FRAG mode the detonator is set to O for open and the safety cap is left on. If it hits a target it detonates on impact and showers the area with fragments. To use it as an HE round the detonator is set to 3(Z) or off and the round will penetrate the target before detonating... earth works, bunkers or light vehicles like APCs. For Frag mode the detonator is set to o for open and the safety cap is removed... snow, rain, or even the canvas gun cover will detonate the round... care is advised. Used in conditions of very soft ground like mud or swamp so that the round detonates before burying itself.

A new fusing system called Aniet can be used with a new timer fuse for this round. The target is lased and the time of flight is calculated then entered into the fire control system. The fuse is set as the round is loaded through the autoloader automatically, so that targets like hovering helos or ATGM teams can be engaged with airburst rounds.


"Interestingly, Russians seem to love missiles and many of their tanks are capable of launching ATGMs from the barrel. Handy. "

The point behind the missiles was that for a while the west had a huge advantage in engagement range. This was due to sophisticated fire control systems and laser rangefinders. The west could afford to make such capable tanks but the Soviets had a tradition of mass production... sophisticated computers and laser rangefinders could not be mass produced. The result was a sophisticated tank built in smaller numbers and a cheap tank almost as good but made in huge numbers.
The sophisticated tanks were the T-64s and T-80s, while the cheap tanks were the T-72s. Later the T-72s started to get almost as sophisticated as the expensive tanks with comupters and laser rangefinders.

To solve the problem of the range gap it was decided to create missiles that could be used at very long range, from tanks that haven't had too much modification... just a laser and a guidance command unit and an altered commanders sight. They made these missiles for every tank... not just their new tanks and the tanks that were fitted for these missiles carried normal ammo too. They weren't super missile tanks. Only 6-8 missiles were carried. If an enemy tank was detected at 1,000m then APDSFS rounds would be used as they were cheaper and very effective at that range.
Now that their computers and other equipment is just as capable and expensive as western systems the missiles have been retained as an anti helo weapon.

"And the earliest systems actually shot little missiles from tube launchers to impact incoming projectiles like RPGs (DROZD I believe)"

Have you seen close up images of Black Eagle... seems to be fitted with Drozd II...

[Maciek]

Often an electrified chainlink fence was used as is used by Israelis on their tanks... this can make the peizio electric fuse on the RPG fail. ????

Ther were used to detonate the RPG warhead at safe distance
HEAD warheads have to be detonated at a specjal distance to have maximum armour penetrate

[GazB]

"Ther were used to detonate the RPG warhead at safe distance
HEAD warheads have to be detonated at a specjal distance to have maximum armour penetrate"

I heard they made the fuse fail... ie resulted in a dud round that wouldn't go off (presumably until the self destruct operated).

[Herrmannek]

https://hosta.atsc.eustis.army.mil/cgi-bin/atdl.dll/accp/in0546/lsn2.htm

ANTIARMOR WEAPONS, PART I

IN0546, Edition B

April 1996

United States Army Infantry School
Fort Benning, GA 31905-5593


....(3) Limitations. The RPG-7V requires a well-trained and experienced gunner to accurately estimate ranges and lead distances for moving targets. Crosswinds as low as seven miles an hour can complicate the gunner's estimate and reduce first-round-hit probability to 50 percent at ranges beyond 180 meters. An RPG projectile screen of chain-link fence will completely neutralize 50 percent of the rounds and degrade the penetrating capability of the remaining rounds. Reloading and reaiming the AT grenade launcher takes a minimum of 14 seconds. The RPG-7V has a conspicuous signature: flash, smoke, and noise. The unprotected gunner is extremely vulnerable to suppressive fires....

[GazB]

"An RPG projectile screen of chain-link fence will completely neutralize 50 percent of the rounds and degrade the penetrating capability of the remaining rounds."

Thanks herrmannek... we were both right... approx 50% duds and 50% premature detonation.