D.U. is a very good material since it has a high density and and at the same time very strong and hard but at the same time not brittle. That means excellent penetration capabilities. And in addition to this the D.U. fragments will start to burn after penetration causing secondary damage to the target which will lead to a higher kill probability.

Other countries that have limited access to DU us heavy metal such as wolfram carbide and similar alloys that also have good penetration capabilities.

The difference between them is that Wolfram Carbide is very expensive to create but easy to machine into ammunition. DU is relatively cheap but on the other hand very hard to manufacture. This makes them comparable in price.

But the two materials are equally dangerous after penetration when inhaling dust since wolfram Carbide is toxic when inhaled.

There is currently no other alternative to material for use in anti-tank ammunition and high-capability armor piercing rounds than just Wolfram alloys and DU.

Let's say the tank crew is locked in their tank -- and they know that the enemy foot soldiers are clambering all over the tank. The crew doesn't want that. I think I was told about modern tanks firing a grenade upwards then it exploding. This had the effect of killing the unwanted enemy scrambling over the tank, but not harming the tank because of its armor. Have you ever heard of such a thing? If not -- what do tank crews do if there are 5 enemy personnel scrambling around on the roof and they want rid of them? On modern tanks there are some ways to prevent enemy soldiers to climb "onboard".

1. Speed makes it hard to get on the tank. Its though to get up when a tank is still moving, imagine when it is driving along in 10 km/h

2. A tank is never alone. Another tank can easily hose the other tank with machinegun fire to get rid of soldiers climbing on top.

3. There are systems like the French Giat Galiz that can fire smoke grenades as well as high explosive grandes that detonate right outside the tube covering the tank in shrapnel.

An enemy that has the chance to climb up on a tank is doing something that can easily be described as suicide. It would be much better to sneak up within close range and fire an rpg or place an explosive device. Which would in any scenario, be classified as suicide attempt.

I have quite a few clients who were in tanks in Vietnam. Several have signs of brain injury, without history of trauma - other than being in tanks during combat. Is there any evidence that the violent shaking of the head or impact of sound waves could have produced brain injury in these veterans?

I cannot confirm or deny, just speculate This was a question that I have never encountered before. I have never heard of such a connection with brain damage & tanks.

High noise can lead to tinnitus (high pitch noise & ringing in the ears) which in turn can lead to problems and unhealthy. Violent shaking and bouncing in tanks with helmets on could cause stretched neck muscles and I guess, in theory, more severe injuries.