Armour Protection
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Steel Armour: 
The most basic kind of armour, is made with steel, rolled or cast. In the beginning it was just close to a boiler plate, thick enough to stop bullets and splinters, but with the evolution of antitank guns and armour piercing rounds, it became into a carefully alloyed thick homogeneous layer of hardened steel. Later, as hardness and toughness run in opposite directions, armourers developed the face hardened steel concept to keep unaffected the toughness of the remaining thickness.Face hardened steel plates can be produced in two ways:
- as a surface carburized, tempered steel (the dominant type).
During WWII, germans got a mayor shock when the soviet T-34 tank (top right) with his very sloped frontal armour appeared on the eastern front, as it could withstand every german tank gun in service. Evidence of this is the similarly shaped design of the german tanks of the next war generation: The Panther and the Tiger II. For compairson purposes, the definition of "rolled homogeneus armour"(RHA) is used to express the armour protection in equivalent terms. Most tanks in SA show their frontal armour sloped in the vecinity of 35 degrees. Best example is the peruvian T-55 with his sloped 150 mm frontal armour.
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Spaced Armour: 
First introduced by germans during WWII, the so called "Schürzen", consisted of 5 mm armour plate skirts, separated from the tank body. They were intended to detonate chemical energy warheads prematurely, spreading the jet, thus preventing armour penetration. Of course, this depends on the size and shape of the striking warhead.
The only case in SA is the Chilean Leopard 1v-Ch, fitted with a Blohm & Voss add-on armour around the turret and gun mantlet (see right picture). This amour consist of 20mm steel plates, two face fiber reinforced rubber coated, separated a small distance from the basic armour and mounted on shock absorbers. The plates are drilled with holes of small caliber, as in a seeve. Small caliber projectiles (IFV guns) hiting the edges of the holes will be affected by oblique-forces suffering from deviation, tumbling and eventually scattering effects, reducing their penetration capability.
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Multilayer & Composite Armour: 
This armour type follow the general principle of "any projectile will be defeated be the right combination of obstacles". In this sense, different kind of layers are used between two or more plates of steel armour:1) Against Shaped Charges: a layer of heat absorbing chemicals (like rubber, plastic, etc.) followed by a high melting point ceramic composite is used. Heat absorbing chemicals takes energy from the jet and the ceramic layer prevents from melting, thus stopping or deviating the weakened jet. The back steel plate provide mechanical support. 2) Against Squash Head Rounds: A layer of deformable plastic followed by mild steel provide shock absorbing capacity. Also, anti-spall liners (a kevlar or ballistic nylon liner fixed to the inner side of armour)and internal compartmentalization of the tank will help reducing damage and preventing crew form serious injuries. 3) Against Kinetic Projectile: Standard steel armour, embedded of heavy hard metal (tungsten or depleted uranium) rods, blocks or mesh. So, kinetic projectiles entering the steel will strike these elements and shear because of the violent course deflection, loosing much of his mass and therefore momentum. Although, this is the preferred type of armour of modern tanks, no examples of this kind of armour has been actually fitted to SA armor, with the exception of some APCs, like chilean M113 command post vehicles in the form of passive appliqué armour. During the last stages of the cold war, the front composite armour of the soviet T-72A(M1) MBT was considered a major threat to western gun makers. After the fall of the Soviet Union, many former East-German tanks were tested at Haide by NATO before being scrapped: T-72M1 Shooting Test at Haide Explosive Reactive (ERA): 
First implemented and tested by Israelis (Blazer ERA) in the Lebanon campaign, this kind of armour involves covering the tank most exposed surfaces with metal containers filled with explosives. Mainly intended against hollow charges, when the jet strikes, the explosive detonates, disrupting the jet with the blast. Recent developments, like the russian Kontact-5 (right picture), also increase protection against kinetic energy projectiles thanks to deflection or shattering effect of the blast on them.Main drawback is the damage caused to the tank itself by means of the massive activation of ERA bricks in terms of radio or other electronic devices failure. In this sense, low level fuel/air bomb explosions may be an effective way to disable ERA protected tanks. No examples of this kind of armour in SA.
Armour Protection Ranking: Intended for tanks with gun caliber >90mm, based on size and type (space means significant distance): 1st place: M60A3 & T-55 (front armour only)
2nd place: Leopard 1v-Ch
5th place: TAM VC |
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The next step, involved the sloping of the plate, as this condition not only favors the bouncing of the projectile, but increase the length of the penetration path by 1/sin of the sloping angle as illustrated. In order to normalize to some extent the proyectile core against the armour plate, solid shots were capped with a soft metal jacket.