Fire guys ain't as dumb as they look. Mix detergent with water and you reduce surface tension. It soaks in better. So, some types of foam are really just soapy water.
Years ago there was a fish based foam. Many years ago. Did not smell good.
Not so long ago, some places changed over from one type of foam to another. They were not compatible. If they got mixed, they formed something that looked like Play Do.
But, the foam IN the fire could be either a closed cell or open cell foam. Closed cell would be like Styrofoam, open cell is like the yellow seat cushions, will soak up water readily if it hits it.
Instead of just insulting somebody else, could you explain why water isn't the answer in this case? Most of us aren't chem majors, which I'm sure gives you that one reason to fell superior to the rest of us.
Not a chem major here, but presumably it's for the same reason you don't throw water onto an oil/cooking fire, and instead smother it with a lid. The foam the firefighters use is probably some dense, squishy, sprayable version of a lid.
But hey yeah lets just continue to question the decisions of the dudes who do this literally every day. Water, yeah, I'm sure that never occurred to them for some reason.
Water can actually be used to put out oil fires; it's sprayed on as a mist rather than a stream. The mist extinguishes the fire rising from the oil before the water can sink through the oil, as a stream of water would do.
Had Gary C written "Why not just use water, wouldn't that work?" instead of a snarky obviously ignorant "perhaps then it wouldn't take days to get the fire under control," then adamg's comment is on the money.
But look, its a professional fire department. They know about fighting fires. Taking the snarky ignorant position deserves to be called out.
They've tried 3 alarms worth of engines and ladder trucks + the bldg sprinkler system for 12 - 18 hours.
The water simply hits an object and runs off. The material is essentially impenetrable and water proof. FireFoam (not a brand name) will coat and smother similar to fighting an aircraft fuel fire. I wouldn't want to be the insurance company that gets that bill.
Well, not being a chem major or a professional firefighter and generally being ignorant about everything, I feel the need to speak out and voice my opinion.
When "they" were proposing railroading millions of gallons of ethanol through the city, a big concern was the fact that there was not enough fire-fighting foam around to address a spill. Ethanol fires (basically alcohol fires) can only be put out with foam. It also is a question of special apparatus and training to use it and MassPort was basically it for the region.
So there are fires that will just get spread around if you spray them with water so foams are used to smother them. And I don't get the sense that they blast the foam out like an Ibiza rave, but that it's more like it's dribbled onto it - which might explain why it is taking so long to get this thing under control. Given that the ethanol proposal was canned (for now), cases like this serve to highlight that perhaps our local emergency response capacities are a bit unprepared for the types of chemicals and scenarios that are out there.
Also, most fires are have a point where firefighters can move in, open walls and ceilings, toss out furniture that's in the way and make access for the water to hit the burning materials. Burning foam is forcing them away from the building even with extra air supply trucks to keep the men breathing.
The bottles they wear have ~20 minutes of air given various exertion levels. Some have more but they get heavier still. There's about 2000psi in a bottle and that takes alot of steel or fiberglass to keep air in the bottle. Having to walk with all the gear on across a parking lot and into a building means, by the time you get there, it's time to come out.
There are certain universal worldly bits of wisdom pertaining to chemicals. For instance , dont mix bleach with ammonia , and dont put water on a petroleum fire. Capice ?
Foam smothers a fire - sits on it, while water runs off.
DEP also has air and runoff water sampling going on - they may want to prevent more toxic runoff and/or toxic air emissions, and foam may help that by sitting on/smothering the fire.
...is essentially styrofoam. If you read the article and do some easy google-ing, you'll see that the company makes foam products including coolers, packaging foam, & pool noodles. Obviously the foam used in firefighting is not styrofoam. It is a product that mixes with water in the engine, and is pumped through the hoses and our onto a fire through a speical nozzle that allows the foam to expand. The way foam works partly by cooling the fire, and mostly by smothering it, therefore depriving it of oxygen. I submit for your education & entertainment the following videos:
In this one, the two groups of firefighters you see first are merely spraying water on the sides of the tank, solely in an effort to keep the tank (relatively) cool. Then the third group begins directing foam on the open top.
Comments
Best Line Ever
I know there's a good reason, and different kinds of foam, but that just tickled me no end.
Suldog
http://jimsuldog.blogspot.com
Thanks
Obviously, that struck me as kind of weird, too. I realize the firefighting foam is different from the stuff that's on fire, but ...
Surface tension
Fire guys ain't as dumb as they look. Mix detergent with water and you reduce surface tension. It soaks in better. So, some types of foam are really just soapy water.
Years ago there was a fish based foam. Many years ago. Did not smell good.
Not so long ago, some places changed over from one type of foam to another. They were not compatible. If they got mixed, they formed something that looked like Play Do.
But, the foam IN the fire could be either a closed cell or open cell foam. Closed cell would be like Styrofoam, open cell is like the yellow seat cushions, will soak up water readily if it hits it.
Breaking down the surface tension helps.
Here's a thought
Instead of using foam on foam, how about spraying the burning foam with some water? Perhaps then it wouldn't take days to get the fire under control.
Not a chem major I see
Oh well - just another of millions who thinks he's being smart when he's being really quite ignorant. I guess that is what keeps Drumpf in votes.
OK, smart guy
Instead of just insulting somebody else, could you explain why water isn't the answer in this case? Most of us aren't chem majors, which I'm sure gives you that one reason to fell superior to the rest of us.
Not a chem major here, but
Not a chem major here, but presumably it's for the same reason you don't throw water onto an oil/cooking fire, and instead smother it with a lid. The foam the firefighters use is probably some dense, squishy, sprayable version of a lid.
But hey yeah lets just continue to question the decisions of the dudes who do this literally every day. Water, yeah, I'm sure that never occurred to them for some reason.
Water can actually be used to
Water can actually be used to put out oil fires; it's sprayed on as a mist rather than a stream. The mist extinguishes the fire rising from the oil before the water can sink through the oil, as a stream of water would do.
I'm with (a different) anon on this one
Had Gary C written "Why not just use water, wouldn't that work?" instead of a snarky obviously ignorant "perhaps then it wouldn't take days to get the fire under control," then adamg's comment is on the money.
But look, its a professional fire department. They know about fighting fires. Taking the snarky ignorant position deserves to be called out.
They've tried 3 alarms worth
They've tried 3 alarms worth of engines and ladder trucks + the bldg sprinkler system for 12 - 18 hours.
The water simply hits an object and runs off. The material is essentially impenetrable and water proof. FireFoam (not a brand name) will coat and smother similar to fighting an aircraft fuel fire. I wouldn't want to be the insurance company that gets that bill.
Foam Alone
Well, not being a chem major or a professional firefighter and generally being ignorant about everything, I feel the need to speak out and voice my opinion.
When "they" were proposing railroading millions of gallons of ethanol through the city, a big concern was the fact that there was not enough fire-fighting foam around to address a spill. Ethanol fires (basically alcohol fires) can only be put out with foam. It also is a question of special apparatus and training to use it and MassPort was basically it for the region.
So there are fires that will just get spread around if you spray them with water so foams are used to smother them. And I don't get the sense that they blast the foam out like an Ibiza rave, but that it's more like it's dribbled onto it - which might explain why it is taking so long to get this thing under control. Given that the ethanol proposal was canned (for now), cases like this serve to highlight that perhaps our local emergency response capacities are a bit unprepared for the types of chemicals and scenarios that are out there.
Also, most fires are have a
Also, most fires are have a point where firefighters can move in, open walls and ceilings, toss out furniture that's in the way and make access for the water to hit the burning materials. Burning foam is forcing them away from the building even with extra air supply trucks to keep the men breathing.
The bottles they wear have ~20 minutes of air given various exertion levels. Some have more but they get heavier still. There's about 2000psi in a bottle and that takes alot of steel or fiberglass to keep air in the bottle. Having to walk with all the gear on across a parking lot and into a building means, by the time you get there, it's time to come out.
There are certain universal
There are certain universal worldly bits of wisdom pertaining to chemicals. For instance , dont mix bleach with ammonia , and dont put water on a petroleum fire. Capice ?
Could be more to it than that
Foam smothers a fire - sits on it, while water runs off.
DEP also has air and runoff water sampling going on - they may want to prevent more toxic runoff and/or toxic air emissions, and foam may help that by sitting on/smothering the fire.
I was just kidding....jeesh!
I wasn't questioning the firefighting intellect of the firemen.
And in my own defense, may I quote from the WBZ story:
“We’ve been having trouble getting water to the scene of the fire,” said Chief Pasdon.
The foam that is burning....
...is essentially styrofoam. If you read the article and do some easy google-ing, you'll see that the company makes foam products including coolers, packaging foam, & pool noodles. Obviously the foam used in firefighting is not styrofoam. It is a product that mixes with water in the engine, and is pumped through the hoses and our onto a fire through a speical nozzle that allows the foam to expand. The way foam works partly by cooling the fire, and mostly by smothering it, therefore depriving it of oxygen. I submit for your education & entertainment the following videos:
https://www.youtube.com/watch?v=_Dss-79jodk
In this one, the two groups of firefighters you see first are merely spraying water on the sides of the tank, solely in an effort to keep the tank (relatively) cool. Then the third group begins directing foam on the open top.
Self expanding foam on tanks
https://www.youtube.com/watch?v=OxLPvNdv2t4
Foam in aircraft hangars:
https://www.youtube.com/watch?v=8csL5Y2_pnE