jimbow8 Wrote:I always thought that it was dependent on the fumes. My grandpa said he used to light a cigarette and then throw the match into a bucket of gasoline. The match would only extinguish, no flame, no explosion. I assumed it was a well ventilated area, so there were no fumes hovering.
That may be Jim. The area being well ventilated that is. I've dropped lit matches into a puddle of gas and the same thing happened . . . nothing. It probably has to do wth the concentration of fumes, the temperature of the fumes, as well as the temperature of the flame.
You hear someone say, "Put out that match . . . can't you smell gas." Well yeah, you can smell gas, but for the fumes to be concentrated enough to cause an explosion, the smell of the fumes would be strong enough to make you barf. (An automobile engine uses heat of compression as well as a spark to ignite the fuel/air mix, and that heat of compression is pretty high. The heat of compression in a Diesel Engine is high enough to ignite the fuel without a spark. That's why they're called Compression Ignition engines.)
Shooting a bullet into a gas tank most likely wouldn't cause an explosion because:
1. The bullet would have to be almost melting-point hot to ignite the gas, and it would have to hit high on the tank where the vapor is.
2. If the bullet hits the tank in the area that has liquid in it, it's not encountering a fuel/air mix, and would therefore cause only a major splash inside the tank. At Knob Creek machinegun shoots they often shoot at barrels of "stuff" that explodes, . . . but it's not gasoline. It's something considerably more volitile. And even then they're most likely shooting tracers, which have an extremely hot chemical
burning at the base of the bullet.
A high power rifle bullet (.308/30-06) travels at 1,841 miles per hour. It would pass completely through a two foot wide gas tank in three quarters of one thousandth (0.00074) of a second -- not long enough to transfer much heat. And copper or lead doesn't cause much of a spark when it hits thin sheet metal.
I've heard of a TV program called "Myth Busters," this might be an interesting subject for them to play with.
When I get the chance, I'm going to try it with bullets traveling at 2,216 miles per hour, and jacketed pistol bullets traveling between 852 and 1,057 miles per hour.
Ken V.