|MadSci Network: Engineering|
Doug, That's a good question. I can't tell you how the latest fuzes work, but I can give you the basics. First of all, a fuse is a device for communicating fire. A fuze is a device used to ignite and explosive charge. The spelling is important. Proximity fuzes were developed after the second world war, when many improvements were made to the U.S. arsenal. The first proximity fuzes were of differing designs, including timed fuzes which were activated when the round was fired and pressure fuzes, which operated like a barometer. The reason behind their development was simple. An explosive, if it is not shaped like a cutting charge, will expand in all directions, a sphere. If the bomb hits the ground one half of the energy will be wasted into the ground, making a crater. If the weapon is exploded before it hits the ground, more than 80% of the energy is directed outward, causing a great deal more damage. These days fuzes are of electronic design, based on the pressure fuze concept and being minutely adjustable or they are controlled by the firer, being detonated when the weapon has reached a desired location. Modern fuze designs are military secrets, but you could probably figure it out by deduction. The funny thing is, many millions of bombs were dropped with contact fuzes that set them off when they hit the ground. These bombs did not need fuzes. Three hundred pounds of RDX or Napalm tendtoexplode when you drop it from five thousand feet at four hundred miles an hour, even if it hits jell-o.
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