
What?
Shirley anybody who knows anything about fires would know not to pour a liquid accelerant into a pit if said accelerant gives off a vapour which is heavier than air?
So you might forgive the plods, but firefighters being that stupid? Help!
Firemen and police officers in New Jersey blew themselves up last week in an "orange mushroom cloud of fire and debris" which created a "deafening boom felt miles away". The unfortunate public-safety operatives had been attempting to light a bonfire at a high-school rally. According to the South Jersey Courier-Post, kids at …
It can be done I was taught to do so in the RN although it has to be done carefully and it also has to to be a small fire e.g. an oil drip tray the secret is to use a fine spray of water and keep it moving fan wise front to rear and not to allow it past the spray of water,taught to me at HMS Ganges Shotley Gate near Ipswich.
You're corrected. It's a light oil. It burns with a very yellow/orange flame and gives off black smoke when burned at standard atmospheric pressure and when soaked into wood. They should have used a blow torch to ignite plain diesel+wood. I thought that part of the country used fuel oil for house heating, thus would know more about how to get 'er lit.
Normally, diesel vapor needs to be compressed w/ oxygen in order to explode. However, liquid diesel fuel burns quite nicely. Many years ago while working in the Rocky Mountains of Colorado to clear huge snags of trees piled up by bulldozers clearing the forest for a new interstate highway we would use diesel as an accelerant to help burn 50 ft. tall piles of green wood. Probably the most dangerous job I ever had - climbing 50 ft up on a pile of trees with a honkin' big chain saw to cut up the trees to drop them into the fire in the center of the pile. The pay was good, and I was a 20-something in my "immortal" youth, but looking back in hindsight I think I must have been out of my bloomin' mind! :-)
diesel vapour will *spontaneously* combust if you compress it, but a big old flame will do the job in either case. (diesel in liquid form is pretty safe to have a match around but in this case the liquid formed fumes and built up in the confined space under the bonfire == recipe for an explosion.)
All Diesel needs for ignition is something hot enough.
In Diesel engines that heat is achieved by compression instead of the spark plug used in a gasoline engine.
Liquids don't compress (that's why hydraulics work) but gases do. And when you compress them, the energy used to do so gets converted into heat.
How does one go about getting the job of "Comedy-explosions Correspondent", and what qualifies one for the job? Explosive wit? Devastating good looks? A burning desire for the facts? Ebullient personality? Booming great laugh?
With all that in mind, how did Lewis get the job?
And when do I start?
a pyramid of kerosene soaked pallets.
a volatile accellerant spreads a flame front over the entire surface.
a cone of unburned fuel collects inside the pile, heat vaporizes the kerosene and raises the temp of the unburned gasses, but all oxygen is consumed by the outer cone of flame so there is a superheated core of hydrogen rich fuel..
a shift in the pile lets air enter. ignition follows...more photos please!
ISTR in the boy scouts, we used one match and a properly built fire..
if he were in a hurry, a pro would use thermite or magnesium shavings.
these days i make my light shows with the three Ls, Lasers, Lenses, and LEDs
You, sir, are talking quite a bit of twaddle with regards to what happened inside that pile. Kerosene or diesel doesn't spontaneously convert into hydrogen under those conditions; it just vapourises, making it a whole lot more flammable in its own right, but that vapour still consists of the same hydro*CARBON* chains as found in the fluid. And it's exactly that relatively heavy kerosene or diesel vapour that can stay contained inside a pile of shipping pallets, possibly resulting in a conflagration as kindly demonstrated by those intrepid firesta^H^H^Hfighters; hydrogen would just whiff off upwards, it being so much lighter than air.
according to http://en.wikipedia.org/wiki/Diesel_fuel
"The average chemical formula for common diesel fuel is C12H23, ranging approximately from C10H20 to C15H28." ...so diesel is 2/3 hydrogen molecules.
but i did make that unclear, the hydrogen continued to be bound to the carbon until ignition.
there is more hydrogen in a gallon of diesel fuel than there is in a gallon of Liquid Hydrogen.
Long ago, I poured a litre of diethyl ether onto a soon to be bonfire. I wanted to see how well ether 'crept' (in the words of various chemistry teachers). I approached with a very long stick, with a flaming brand at the end, until it met the vapour front. It didn't explode, but the garden around the bonfire was instantly transformed into a pool of fire. The bonfire caught nicely too!
Unlike the firemen, I was expecting the outcome. However, if I did it again, I'd probably wear some eye and ear protection.
Diesel has to be got well-warm to evaporate, and a small naked flame can lack the energy to get things going. But, with a few slight variations in additives, the same oil is used in diesel engines and oil-fired heating.
If there had been something hot left from previous attempts to start the fire, even diesel oil could have produced a vapour cloud. And if there was nothing quite hot enough to ignite it...
With petrol, that dangerous in-between stage is room temperature, or lower, which is what makes it so dangerous. But any liquid fuel chucked onto a smouldering fire is dangerous.
(I imagine Lewis would recommend something quite different for starting a fire. A thermite reaction?)
So firemen think a clever way to light a bonfire is to sling diesel all over it? I sure hope they never invite me to one of their BBQs... it must be carnage.
"Hey Bob, the barbie's dying down a bit... sling another bucket of petrol on it will ya?"
"No problem Bill, I am a fireman after all!"
*WOOOOOOOF*aaarghburnscreamdie
I've seen a small-scale demo of putting water on an oil fire, it's impressive. You do not want to be close.
As for diesel, you can ignite it without compression if you get it hot enough. Eventually it'll start giving off vapour, at which point it can be as explosive as any of the short-chain hydrocarbons.
That's the sort of enormous bang that Los Alamos Fandom were renowned for in the 1980s (and for all I know ever since). I remember their mortar during the fireworks display at one of the BECCON SF conventions... The police came as people reported that the nearby Ford Tractor Plant had blown up! And some of the plastic from that device cleared the hotel and appeared in the car park.
And the year that BECCON took on the National Mantle and decamped to Birmingham - that year they had airspace allocated to them by Birmingham International Airport. Now that was real class.
Paris - of course (work it out for yourselves - its not tough).
of my time in the RAF. It was bonfire night and a nice big pile had been erected near married quarters.
The station firer team were in charge and it would appear that they had decided to light the pyre with a well aimed Very flare.
Trouble was - it bounced off - an landed in the uncovered box containing all the fireworks.
flames for .......
The article implied that the explosion was both a fuel-air explosion and a "Bunker Buster". I think the author is mixed up about the two.
It probably was a fuel-air mixture explosion but it was not a "Bunker Buster". A fuel-air bomb is a surface effect weapon. It sprays fuel into the air as it is going down and then sets off an explosion that consumes the fuel using the oxygen in air as its oxidant. It explodes at or near the surface.
A Bunker Buster is a deep-penetration shaped charge weapon that includes its own internal oxidant. It explodes after it has penetrated beyond the reach of air's oxygen.
Actually, it's BOTH of them. You see, fuel-air bombs are a type of thermobaric explosive. Thermobarics have a unique characteristic that make them killer in caves and bunkers--one hell of a shock wave. Modern bunker-busters, while possessing heavy and hard heads allowing them to penetrate into the ground, are now being fitted with thermobaric warheads so that, once they get through, they deliver the maximum punch.
Will you lot please stop waffling on about diesel and read the story again. Diesel was not the only liquid they used, so whether or not diesel gives off a flammable vapour is irrelevant.
Oh and diesel will definitely burn. It was one of the materials burnt on starfish decoy sites during WWII. IIRC they used diesel, paraffin and wood fires to give three visibly different types of fire for added realism.
Oh and on the subject of the Darwin awards. Firstly twitter for idiots is twitter. Secondly a significant number of stories that make it to the Darwin awards are not true.
I never can understand why barbecue fuel is made from almost-impossible-to-light material.
Why the fuc*k we don't just recycle old sofa's? I remember at school being told that "a house can be set on fire by a carelessly dropped cigarette on a sofa".
So, use sofa-stuff. For effective ignition, I guess the cigarette can't be strategically placed, but must be dropped carelessly, possibly lobbed over the shoulder, as you would do with spilt salt.