Quote:
Originally Posted by ArmySGT.
What is Rolled Homogenous Armor?
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Rolled homogeneous armor (RHA) is a type of armor armor vehicles made of a single steel composition (thus 'homogeneous') as compared to cemented or layered armor using different compositions in different parts of the plate, which RHA is 'worked' by rollers applying pressure while the plate is hot.
It was the primary tank armor from the 1930s until the 1980s (and later for non-tank AFVs).
Quote:
Originally Posted by ArmySGT.
What is Layer Composite Armor?
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Composite armour is a type of vehicle armour consisting of layers of different material such as metals, plastics, ceramics or air. Most composite armours are lighter than their all-metal equivalent, but instead occupy a larger volume for the same resistance to penetration. It is possible to design composite armour stronger, lighter and less voluminous than traditional armour, but the cost is often prohibitively high, restricting its use to especially vulnerable parts of a vehicle. Its primary purpose is to help defeat high explosive anti-tank (HEAT) rounds.
There are several flavors of this, including British-developed Chobham armor used by the British and Americans.
However, because governments are cagey about just how tough their layered armor is, modern shell penetration is sometimes expressed in RHA equivalent, as the resistance of RHA is more consistent.
The US Army (among others) use Depleted Uranium (DU) in their penetrators 9since the late 1980s), as these are dense, allowing more mass in the volume of the penetrator - meaning it hits harder.
Quote:
Originally Posted by ArmySGT.
Why is the first one obsolete since the mid 1970s?
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HEAT rounds (and AT Missile warheads) began to become the primary tank vs tank round in the 1960s & 70s, since the race for bigger guns to defeat armor was reaching the point where bigger guns wouldn't fit in a tank. (Yes, you could make a tnk beig enough, but then the vehicle weight soared and the energy needed to move it rose....
Then APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) rounds were developed; these are kinetic kill rounds that fire a penetrator (think very tough spear that is much thinner than the round's diameter) at high speed.
Reactive armor is supposed to try to defend against these by blowing up the penetrator before it hits the tank's armor.
There is lots more detail than this; search the internet for more detail.
Uncle Ted