|
Written by Samovar88
|
|
Wednesday, 28 November 2007 |
|
Trailblazers
Episode #86
Original air date 10/31/07
Trailblazers
The Myth: Based on Hollywood movies, will a gun shot into a gas tank cause a burning trail of gas that will actually reach the bad guy’s car and go up into the gas tank causing an explosion?
Experts: Frank Tabor supplying .22 caliber and .44 caliber weapons
Memorable and quotable moments: The animation of Jamie as an action hero, the robotic gasoline application “firebug”.
Jamie: Kinda dark in here, maybe we need to light a fire.
First test: The burning rates of 3 different fuels
Gasoline burns consistently about 3.17 miles per hour. Jet fuel has a traveling rate of zero due to lack of fast vaporization and diesel is the same as jet fuel.
Second test:
The guys fire two different bullets to see what the size of the hole is. They determine that the size of a .22 cal. bullet hole is about ¼” and the size of a .44 cal. bullet hole is about 5/8”.
Third test: Small scale remote fire trail lighting.
Jamie’s “firebug” is a small remote control car designed with a squirt bottle of gasoline and gravity feed hose attached. Jamie directed the car, Adam lit the trail and the team was able to light a perfect fire trail behind the vehicle. Jamie said “Extremely dangerous. You can’t do this at home. You may have an R.C. car, you may have some gasoline, but you could die, you could burn your house down. We have the fire extinguishers, we have EMTs, we are prepared, you’re not. Don’t try this at home.”
Full scale test: Pickup truck with isolated, suspended gas tank, driven indoors leaving a trail of gas that will be lit. Adam created a steel rig to isolate and suspend a gas tank from the rear of a pickup truck. A gravity fed hose lead from the gas tank with 2 nozzle sizes matching the approximate sizes of the two bullet holes. A rope connected the hose to the cab of the truck so the driver could raise and lower the hose. First they tried the nozzle that was the size of a .22 caliber bullet hole. Jamie was driving while Adam was watching. As Adam said, “You can pretty much push a car faster than gasoline burns.”
Then they tried it with the .44 caliber bullet hole sized nozzle. The flames were allowed to catch up to the truck by accident. The observation was made that the closer the flame to the truck, the more the gasoline was vaporizing, causing an increase in the speed of combustion.
Next, they tried the same test outside. At a slow speed, the gasoline trail burned continuously. However, at 20 miles per hour, the trail became small and the flame burned out. Then, the truck was stopped, the flames were allowed to reach the tank, but there was no explosion. As the gas vaporized, the flames grew more intense, enough to catch the mounted camera on fire. The team then opened more ports in the gas tank to reach the “butter zone” of air flow for gasoline combustion, above 1.4% and below 7.6% vapor to air.
Result: There was very vigorous burning but no boom.
Myth: BUSTED
The Myth: Will a jump-start of a heart burn a wired bra?
Memorable moments: Tory getting fitted for a bra “Once again making my family proud.” Tory asked “Is this as disturbing as I think it is?” Grant’s answer, “It’s more disturbing than you think it is.”
Action: The Build team used Grant’s defibrillator from an earlier myth. Then they applied 360 joules of electricity in the recommended defibrillation positions on the chest of the ballistics gel torso with the under wire bra. There was no burn. The team then exposed a small portion of the wire and placed the “paddles” in contact with the wire, which created a burn.
Result: PLAUSIBLE
The Myth: Will a defibrillator cause a piercing to spark?
Action: The paddles were applied very close together and touching the barbell of the piercing on the ballistics gel torso.
Result: The coating was removed from the barbell, a burn occurred. PLAUSIBLE, but unlikely.
The Myth: Can you catch and stamp out a lit fuse of gunpowder and will the powder keg really go boom?
The experts: Sgt. J.D. Nelson of the Alameda Bomb Range.
First they tested the burn rate of black powder. When they just dumped a line of black powder out and lit it, it went up very quickly. When there was a controlled amount in a line, it did not burn quite as fast.
At the Alameda Bomb Range, Adam and Jamie lay down chip-board panels as a track for the test. They lay a controlled 80 foot trail of gunpowder, leading to an empty keg. Adam easily outruns the flame and kicks out the trail. Jamie tries the same experiment but is given an extra challenge by Adam knocking him out of the way and pulling at his suspenders.
Result: CONFIRMED :
Gratuitous BOOM: Will a trail of gunpowder burn all the way to a keg full of gunpowder and cause the keg to explode? YES. “Yet another thing not to try at home” said Jamie. PLAUSIBLE
|
Episode Descriptions 
