The U.S. army is developing a new family of armored vehicles that are lighter, and equipped with high tech armor that, if perfected, can stop all current anti-tank weapons. Well, perhaps not all, or at least not as expected. If one of these 14 ton future tanks gets hit by a 1960's vintage 125mm Russian low tech anti-tank shell, the results could be disastrous. Those older tank shells were simply 60 pound hunks of hard steel, traveling at 3,000 feet per second. That's 270 million foot pounds, or the equivalent of the tank colliding at high speed  with an object like a large truck. The tank crew may be saved by air bags, but the equipment inside the tank would suffer considerable damage. The tank designers are trying to come up with a solution to this unforeseen, and highly likely, problem. There are still tens of thousands of Russian tanks out there with 125mm guns capable of firing these cheap, low tech, anti-tank shells.