Opening the Nozzle in Smoke

Replies to This Discussion

Permalink Reply by Russ Chapman on February 2, 2011 at 8:52pm

I agree with John.  When you use fog,,,you have to get near the job.  My crews with smoothbores? We start our attack from a safe distance. Use the tool.  Water damage?  This may sound bad, and believe me, we use the stream till the fire is darkened down or the heat is knocked down, but lately, water damage is the last thing I am worried about.

Russ Chapman said:

John, I don't know any firefighters that have been killed by steam.  I do know MANY  firefighters, myself included who have spent time in a burn ward due to steam.  Our fire load is drasticlly different.  We use many more petroleum products. Again, as I said in my original post, I will be happy when they put this penciling thing to bed.

John Ceriello said:

Russ, why is there fire load different? Same question to you, do you know any firefighters that have been killed by steam, what about civilians?

Russ Chapman said:

Brother Pierre

I am sorry.  We have a totally different fire load than you.  Fog for interior attack burns too many firemen.  This will not work here.

Pierre-Louis LAMBALLAIS said:

Hi US guys, :)

 

My answer is the one we teach in many countries: use fog not solid stream. Why? In order to cool something, water has to increase in temp then evaporate. That's physics. In order to do that, water must have a large contact with heat. The more the contact is, the better is the transformation of water so the better is the cooling effect. The problem is that this transformation of state (from liquid to gas) create steam which will burn you.

The "3D" method is the result of this study: when you see accident, you see that they always happen between the main entrance and the seat of the fire. Because there is air movement: from outside to inside for air (so oxygen), and from inside to outside for smoke (so fuel). In order to go to the seat of fire , you must go "under" a mix of fuel and O2. In order to avoid ignition of that, you can "refresh" the smoke and dilute it. I remember a test we've done in a flashover container, with heavy black smoke: a gas detector was used and after only 2 or 3 minutes, the poor gas detector was shouting as the level was far more over 1000ppm. After 2 or 3 pulses, the level was down to 700ppm.

The problem is that smoke is a gaseous fuel. A "3D" fuel. If you use a solide bore against a chair, the chair will stop the water. But the smoke will not. That's because water you flow with the solid bore is "heavy" and goes far. Just take a stone, and launch it. It goes far. Break the stone in small pieces and launch it: it's not going so far. The challenge of the 3D method is to cool the smoke, but without touching wall nor ceiling. If you touch them, the water will turn to steam. And at 400°C, water expand 3000 times when turned to steam. So the steam will push down the smoke and burn you.

What you say here, is that you go into the house, without using the nozzle and wait to crunch on the floor to use it. Logical, because as you are using solid bore, each time you try to cool the smoke, the result is a poor cooling effect (poor contact surface and poor time of contact between water and smoke) and a high steam production (as the water strike the ceilling, and expend). So in order to avoid that, you just go in without flowing water.

 

Our method is different: even if we have just a little smoke layer, we pulse. So we never wait to suffer heat, as we cool before that.

Do we create water damage? No. Do we create excess steam? No. Just see this video: this is a demonstration of the progression method, used in many countries:

http://www.dailymotion.com/video/x38tg8_progression_tech

Just look the cloud of water: the nozzle is fully opened and immediatly closed. The time of opening is about 1/3 of a second. The nozzle is a 135GPM one, but used at about 40GPM. This mean the nozzle, in one pulse, flow only 40/180 = 0,22 gallons of water. The pattern is about 60° wide. And as you can see the cloud of dropplets don't go too high (the container is 2,50m hight, so 8 feets, like a common ceilling), and the cloud go in front of the guys, cooling the location where they progress on. Notice also that, as the contact between water and heat is very important, we have a high level of water transformation. We compute it's about 90% of water used as a cooling effect, as a solide bore against smoke has only a max of 20%. This mean that, while opening a solid bore nozzle against smoke, you will have 80% of the water on the ground. If you open you nozzle at 135GPM, during 10 seconds, you flow

22,5 gallons, and you'll have 80% on the floor, so 18 gallons. And you cool with only 20% so with 4,5 gallons. And this is what we see on videos.

With pulsing method, we flow 0,22gallons each time, and have only 10% on the floor so 0,022 gallons of "water damager": turn out gear stay dry, we don't suffer heat stress (so less heart attack) and so on.

What I can say is that this way of doing is very very good and very easy to learn. But, at "contrario" is very very very hard to explain with text of only video. But really, you must see that.

If you want to stay with the idea that fog create steam and burn everybody, OK. But we use that without burn. So in this case, we are not talking about the same: I don't want to be burned, and I'm not. So my conclusion is that you certainly know how to use a solid bore, but you don't really know how (and why) use a fog pattern. So it's very hard to build a correct opinion.

 

I'm now living in Brasil. It's far from USA, but I think we must show you.If you can do something for that, feel free to contact me, eg by using the contact form on www.tantad.com

Best regards to you all, and sorry for my poor english

Pierre-Louis

Permalink Reply by Adam Miceli on February 2, 2011 at 8:59pm

"use fog not solid stream. Why? In order to cool something, water has to increase in temp then evaporate. That's physics. In order to do that, water must have a large contact with heat. The more the contact is, the better is the transformation of water so the better is the cooling effect. The problem is that this transformation of state (from liquid to gas) create steam which will burn you."

 

I guess I'm not convinced of the bold statement above. Doesn't the cooling take place when the heated material transfers heat to the cooler water? In the process the water temp rises to 212 F and evaporates. In fact, if you are correct, wouldn't we just use steam spray to extinguish fires. The point being is that the evaporation is a side affect and not a benefit of the cooling process. The reason more contact is better is that it allows more heat transfer. The contact of already heated or smaller particles only succeeds in reducing the cooling power of the water. This is somewhat different in 3D tactics where you need the smaller particles to stay aloft to absorb heat, vs. the larger heavier droplets that fall to rapidly to absorb and the superheated gases. 

 

So, while I'm not a 3D convert or user, I can understand the value from purely theoretical standpoint and why it works for so many, but alas, I cannot see using fog on the actual burning material. Theres's a great article on nozzle/hose selection in this months FE magazine that gets into so specific data supporting the use of solid streams in direct fire attack.

 

As for those who asked about steamed vs. fire/smoke fatalities? I doubt we'd know without a specific study or autopsy. One need only be in a steamed container to understand how the situation can only be far worse for any unprotected victims. Our PPE allows us to withstand far hotter dry heat than wet, our skin also can withstand dry better than wet heat. 

Permalink Reply by Jim Miller on February 2, 2011 at 9:13pm

10-4, let's remember some things; water absorbs heat and THEN turns to steam. All things must be in a gaseous state before it can burn and for a solid to turn to a vapor it must pyrolize (be heated and produce gases). to stop this triangle or tetrahedron shaped reaction with the use of water then it must be applied on the seat of the fire to take the heat away (absorbing heat). So as for the smoke, yes steam (vaporized water) may cool the smoke or atmosphere after it has been converted because it absorbed heat from the fuel and is now aloft!! The question is in the event the smoke may be hot enough to make you think flashover is imminent, which is the best answer??
1. Does the water that penetrates the super heated atmosphere and connects with surfaces in the room that are driving the heat release rates in the room to increase by re-radiating heat do more good here by lowering the temperature?

OR

2. Do you need the steam in the atmosphere?

Personally I believe in cooling the heat producers (fire and heat producing surfaces)

Adam Miceli said:

"use fog not solid stream. Why? In order to cool something, water has to increase in temp then evaporate. That's physics. In order to do that, water must have a large contact with heat. The more the contact is, the better is the transformation of water so the better is the cooling effect. The problem is that this transformation of state (from liquid to gas) create steam which will burn you."

 

I guess I'm not convinced of the bold statement above. Doesn't the cooling take place when the heated material transfers heat to the cooler water? In the process the water temp rises to 212 F and evaporates. In fact, if you are correct, wouldn't we just use steam spray to extinguish fires. The point being is that the evaporation is a side affect and not a benefit of the cooling process. The reason more contact is better is that it allows more heat transfer. The contact of already heated or smaller particles only succeeds in reducing the cooling power of the water. This is somewhat different in 3D tactics where you need the smaller particles to stay aloft to absorb heat, vs. the larger heavier droplets that fall to rapidly to absorb and the superheated gases. 

 

So, while I'm not a 3D convert or user, I can understand the value from purely theoretical standpoint and why it works for so many, but alas, I cannot see using fog on the actual burning material. Theres's a great article on nozzle/hose selection in this months FE magazine that gets into so specific data supporting the use of solid streams in direct fire attack.

 

As for those who asked about steamed vs. fire/smoke fatalities? I doubt we'd know without a specific study or autopsy. One need only be in a steamed container to understand how the situation can only be far worse for any unprotected victims. Our PPE allows us to withstand far hotter dry heat than wet, our skin also can withstand dry better than wet heat. 

Permalink Reply by John Ceriello on February 2, 2011 at 9:38pm

So what you are saying is you would rather deal with uncontrolled fire gases than steam, my thoughts on that is that they need to be re-examined. I know of a number of firefighters who have died because we did not get water on the fire, yet I know of none that have been killed by steam, civilians included. If any one knows of any then have I would like to hear about it. Yet the fear of steam production is on the foremost on firefighters minds, their focus needs to look at uncontrolled fire gases that is a larger danger. By the way I've spoken to steam engineers and they tell me that steam can not be hotter than 212 F, steam at 212 F will burn you much more than water at 212 F however our gear can handle that for a period of time. 

Adam Miceli said:

"use fog not solid stream. Why? In order to cool something, water has to increase in temp then evaporate. That's physics. In order to do that, water must have a large contact with heat. The more the contact is, the better is the transformation of water so the better is the cooling effect. The problem is that this transformation of state (from liquid to gas) create steam which will burn you."

 

I guess I'm not convinced of the bold statement above. Doesn't the cooling take place when the heated material transfers heat to the cooler water? In the process the water temp rises to 212 F and evaporates. In fact, if you are correct, wouldn't we just use steam spray to extinguish fires. The point being is that the evaporation is a side affect and not a benefit of the cooling process. The reason more contact is better is that it allows more heat transfer. The contact of already heated or smaller particles only succeeds in reducing the cooling power of the water. This is somewhat different in 3D tactics where you need the smaller particles to stay aloft to absorb heat, vs. the larger heavier droplets that fall to rapidly to absorb and the superheated gases. 

 

So, while I'm not a 3D convert or user, I can understand the value from purely theoretical standpoint and why it works for so many, but alas, I cannot see using fog on the actual burning material. Theres's a great article on nozzle/hose selection in this months FE magazine that gets into so specific data supporting the use of solid streams in direct fire attack.

 

As for those who asked about steamed vs. fire/smoke fatalities? I doubt we'd know without a specific study or autopsy. One need only be in a steamed container to understand how the situation can only be far worse for any unprotected victims. Our PPE allows us to withstand far hotter dry heat than wet, our skin also can withstand dry better than wet heat. 

Permalink Reply by John Ceriello on February 2, 2011 at 9:40pm

The tests for PPE don't test for wet vs. dry heat, where did you get that info from, I'd like to see it.

Adam Miceli said:

"use fog not solid stream. Why? In order to cool something, water has to increase in temp then evaporate. That's physics. In order to do that, water must have a large contact with heat. The more the contact is, the better is the transformation of water so the better is the cooling effect. The problem is that this transformation of state (from liquid to gas) create steam which will burn you."

 

I guess I'm not convinced of the bold statement above. Doesn't the cooling take place when the heated material transfers heat to the cooler water? In the process the water temp rises to 212 F and evaporates. In fact, if you are correct, wouldn't we just use steam spray to extinguish fires. The point being is that the evaporation is a side affect and not a benefit of the cooling process. The reason more contact is better is that it allows more heat transfer. The contact of already heated or smaller particles only succeeds in reducing the cooling power of the water. This is somewhat different in 3D tactics where you need the smaller particles to stay aloft to absorb heat, vs. the larger heavier droplets that fall to rapidly to absorb and the superheated gases. 

 

So, while I'm not a 3D convert or user, I can understand the value from purely theoretical standpoint and why it works for so many, but alas, I cannot see using fog on the actual burning material. Theres's a great article on nozzle/hose selection in this months FE magazine that gets into so specific data supporting the use of solid streams in direct fire attack.

 

As for those who asked about steamed vs. fire/smoke fatalities? I doubt we'd know without a specific study or autopsy. One need only be in a steamed container to understand how the situation can only be far worse for any unprotected victims. Our PPE allows us to withstand far hotter dry heat than wet, our skin also can withstand dry better than wet heat. 

Permalink Reply by Adam Miceli on February 3, 2011 at 8:13am

John Ceriello said:
"So what you are saying is you would rather deal with uncontrolled fire gases than steam, my thoughts on that is that they need to be re-examined."

Sorry that was not what I was getting at. I have no issue with using the stream to cool the overhead where it's necessary. As I think Ray was getting at with this thread in the first place, we tend to not spray water into smoke unless that smoke is what we consider dangerously heated, "black fire" or otherwise indicates pre-flashover conditions. Do we take too much heat at times and possibly risk more than we should? Probably there's some truth to this. For the most part our way (my FD) of controlling fire gases is through proper ventilation, more often than not in the form of unassisted horizontal  ventilation and vertical vent when the fire is in the top space of the structure. 

John Ceriello said: "By the way I've spoken to steam engineers and they tell me that steam can not be hotter than 212 F, steam at 212 F will burn you much more than water at 212 F however our gear can handle that for a period of time."

So at 213 F water ceases to exist in any form? The steam has completely transformed? I'm not arguing, merely hadn't heard this before. This would seem to support the use of direct attack with a solid stream as any steam produced as the burning material cools would never rise to the ceiling where the temp was greater than 212 F, but merely disappear? So we'd have the cooling affect, fire extinguishment and little to no disruption of the fire gases above, except to remove the heat from below? Sounds great, but I think we already knew this...

John Ceriello said: "The tests for PPE don't test for wet vs. dry heat, where did you get that info from, I'd like to see it."

Not sure of any specific testing of PPE, but it doesn't take long to learn this in the field. Wet gear allows steam contact. The water is a great conductor of heat as opposed to the dry gear. Here's a simple test: Start a fire in a burn room and sit there and let it grow, when it starts to become hot, hit the room with a fog stream and suddenly you'll feel far great discomfort through your PPE. Another interesting source is the reason you can sit in a dry sauna at much higher temps than a wet one. While the PPE design minimizes steam/vapor pass through, it's hardly perfect. Even in the "old days" of neoprene barriers our own sweat would steam us, hence the need for vapor barriers that allow moisture to wick away, but not allow them to pass in the other direction.

Permalink Reply by John Ceriello on February 3, 2011 at 2:16pm

When you speak of using ventilation helping to control fire gases, is that with a line in place or when the line is not in place? Do you think ventilation on its own can control fire gases or wil itl increase the heat release rate,and  the fire will travel in all directions, some out the window and some to other openings wherever they are., including the rest of the structure.

Water and steam can be the same temp. 212 F the stream will burn you quicker because it contains more energy. Nothing disappears. What will drive you out of the hallway, hot fire gases or steam? Again I'm not really concerned about what happens in a burn container, I'm concerned with what happens in the field where firefighters are getting killed by uncontrolled gases, not steam. The origin of not opening up on smoke goes back to pre mask days and who wrote the early firefighting books pre 60's. It does not apply to today yet many would still say "don't open up on smoke", I believe they would be wrong to say that. If you ever get a chance to learn what they do in 3D attack(which my dept. does not use) you can see clearly what the intent is. Wet gear is always bad compared to dry gear. It's conduction that the burn injury occur, it won't matter if its radiant heat or steam.

Adam Miceli said:

John Ceriello said:
"So what you are saying is you would rather deal with uncontrolled fire gases than steam, my thoughts on that is that they need to be re-examined."

Sorry that was not what I was getting at. I have no issue with using the stream to cool the overhead where it's necessary. As I think Ray was getting at with this thread in the first place, we tend to not spray water into smoke unless that smoke is what we consider dangerously heated, "black fire" or otherwise indicates pre-flashover conditions. Do we take too much heat at times and possibly risk more than we should? Probably there's some truth to this. For the most part our way (my FD) of controlling fire gases is through proper ventilation, more often than not in the form of unassisted horizontal  ventilation and vertical vent when the fire is in the top space of the structure. 

John Ceriello said: "By the way I've spoken to steam engineers and they tell me that steam can not be hotter than 212 F, steam at 212 F will burn you much more than water at 212 F however our gear can handle that for a period of time."

So at 213 F water ceases to exist in any form? The steam has completely transformed? I'm not arguing, merely hadn't heard this before. This would seem to support the use of direct attack with a solid stream as any steam produced as the burning material cools would never rise to the ceiling where the temp was greater than 212 F, but merely disappear? So we'd have the cooling affect, fire extinguishment and little to no disruption of the fire gases above, except to remove the heat from below? Sounds great, but I think we already knew this...

John Ceriello said: "The tests for PPE don't test for wet vs. dry heat, where did you get that info from, I'd like to see it."

Not sure of any specific testing of PPE, but it doesn't take long to learn this in the field. Wet gear allows steam contact. The water is a great conductor of heat as opposed to the dry gear. Here's a simple test: Start a fire in a burn room and sit there and let it grow, when it starts to become hot, hit the room with a fog stream and suddenly you'll feel far great discomfort through your PPE. Another interesting source is the reason you can sit in a dry sauna at much higher temps than a wet one. While the PPE design minimizes steam/vapor pass through, it's hardly perfect. Even in the "old days" of neoprene barriers our own sweat would steam us, hence the need for vapor barriers that allow moisture to wick away, but not allow them to pass in the other direction.

Permalink Reply by Pierre-Louis LAMBALLAIS on February 3, 2011 at 2:29pm

Hi,

 

I must admit that the replies are very interesting  and start to explain your point of view.

 

First you MUST undestand my fire service courses, I took many years ago, were giving me the SAME info that the one you write. I was WRONG! And... sorry if it seems unpolite, but you are wrong. It's not an opinion, that's physics and chimical fact. Nothing more and we have validation of that everyday. So let's go (it's hard to me to deal with Farenheit, gallons and so on, but I'll try to translate).

 

Water. We use water for two reasons. First it's a non-carbon product. Combustion is a chimical reaction between carbon and O2. As water don't have carbon, O2 can't react with it to produce combustion (notice we speak about mineral water as carbon chimics is name organic chemistry). Secondly water has a very special feature: it's avaible in the three states of mother nature (solid=ice, liquid=water and gas=steam) at the atmospheric pressure.

Water start to change state at about 40°F. Surprising? No. The water after you clean clothes, evaporate, and the atmosphere is not at 212°F. What is the process? in fact we say that heat (energy) is like a kick: you can kick someone, he can kick you, but you can "possess" a kick. This mean everthing is moving. When you put water on something, water will rise in temp and for that, it will absord heat.

But, rising the temp of water don't need a lot of "energy". The old unit "calory" was made with that: the calory is the energy neede for one "gramme" of water to increase temps of one degree Celsius.

But, what is marvellous with water is that, when the water change of state, and turn from liquidi to gas, it "suck" 537 times more that when rising only in temp without changing state. You don't have "heat absorbtion" then "turn to steam". This is the state change (so in fact the steam production) which absord heat.

After being tansformed in steam, the "water" will still increasing in temp.The steam engineers of John are just laughing at him. We can have steam at a higher temp than 212°F and we know that the expansion is depending on the temp.

In terme of volume, one liter of water will produce 1700 liters of steam at 100°C (so one gallon of water will produce 1700 gallons of steam at 212°F). But at 400°C so about 752°F, the same volume of water will expand about 3000 times. Remember the "pushing effect" you suffer from,  when you put water on the fire. A kind of heavy, hot and wet effect. This is the steam effect due to this important expansion.

The main problem with that, is that you can't avoid steam production because this is the way water absord heat.

This can be a good thing to read:

http://www.engineeringtoolbox.com/saturated-steam-properties-d_101....

and also that: http://en.wikipedia.org/wiki/Steam

I suggest John to send the link to the "engineers"  :)

 

Now, deal with smoke. Why does it smoke? Why does a fire produce smoke. The answer is "because it's under ventilated" so in order to avoir smoke production, we must ventilate. Funny. That's wrong. The flame, in a fire is a diffusion flame, meaning there is a molecular movement moving the carbon along the flame. The diffusion flame we have in our fire, is not a "solid"" flame: it's a hollow one. The chemical reaction take place only at the surrounding. The diffusion flame take O2 from the surrounding. In order to see how we can produce heavy black smoke with a little candle, see that:

http://www.dailymotion.com/video/xezq3b_why-does-a-flame-produce-sm...

http://www.dailymotion.com/video/xdb8f2_why-does-it-smoke-y-4-the-a...

First video demonstate the lack of oxygen can't explain the smoke production. The second video gives the answer.

If you are able to use a very thin tube and put it inside the flame of a candle, you'll see white smoke exiting rom the tube: inside the flame, there are pyrolyse gazes.

 

Also, just remember the US definition of IDHL. We can read in our book that IDHL situation start when the flame touch the ceiling and that's right. This explain why, sometimes, by using PPV you produce more smoke than without PPV: as you blow you increase the fire so there are more flames touching the ceilling. In this case there is a game-balande between increasing production ond being ablr to extract the smoke.

Now, back to Jim question:

1. Does the water that penetrates the super heated atmosphere and connects with surfaces in the room that are driving the heat release rates in the room to increase by re-radiating heat do more good here by lowering the temperature?

OR

2. Do you need the steam in the atmosphere?

Personally I believe in cooling the heat producers (fire and heat producing surfaces)

 

Of course, if I can put water on the fire, I put water on it. But take docs from NIOSH and oher organisation about acccidents. Keokuk (3 LODDs). Were they facing the fire? No. Blaina (Wales 2 LODDs); were they facing the fire? No. Neuilly, Paris Fire Brigade, (5 LODDs). Were they facing the fire? No. Black sunday? The fire was floor 3 they were floor 4. Winipeg? Montreal? and all other? You will see that ALL accident happen when people are NOT dealing with the fire. They are searching (in many cases for people who are not there) or are advincing without cooling the gaz.

THE problem is not extinction. The problem is the distance from outside to the seat of the fire. When you see the fire, you can use a bucket of water if you want, it' doesn't matter. But, before facing the fire you have to cross a danger zone as the fire protect itself with smoke.

Really, take a few second and watch carefully these three videos:

http://www.dailymotion.com/video/x38tg8_progression_tech

http://www.dailymotion.com/video/x393be_attaque-pulsing-penciling_news

http://www.dailymotion.com/video/x3935a_attaque-combinee_news

The first is progression. TAKE CARE, this is ONLY for searching the fire and going to it. In this case, we have to cross the smoke-zone. So we must avoid ignition of smoke. We CAN'T deal with the seat of the fire, if we can't reach it.

The second show an attack, when you can see the seat of the fire, but the room is not well ventilated. We must use a small amount of water, carefully, in order ot prevent over steam production. We protect ourself with fog pattern then use small "blocks" of water to the fire. It's a kind of direct attack, blended with a protection operation. We call that "'pulsing-penciling". It really show the problem and the solution; two kinds of fuel: a gazeous one, and a solid one. So two patterns: a fog to cover a great volume, and don't touch the surface, and a narrow pattern, to penetrate the radiation surrounding the fire, and "splashing" water on it, stopping combustion and pyrolyse.

The third video show attack in a well ventilated room: in this case, the fire increase quickly and we must deal with it rapidly. But if it increase, this is because of air intake. So we will take the air intake as our advantage; we will flow at hig flow rate Z, O, or T (combination attack, a US method). It will over produce steam which will push out O2 and kill the fire.

 

As you ca see, we don't have ONE method, but a real tool box. And each tool as a specific use. We can't cool gazes with solid bore: the contact surface is bad, the water will strike the wall and ceiling, over producing steam which will push soke down. But, we can't kill the fire with a small fog pattern as the water will evaporate before striking the solid fuel.

I repeat: two fuels, two tools. Nothing more.

 

We are opening an international fire school in Brasil. It would be very nice to show you. You'll see a strange, but marvellous way of dealling with fire, with no stress, no over production steam.

 

Notice also I've read a few days ago an article on this web site, about the new "ecological" houses. In Belgium, and north of Europe, we deal with that kind of house for more than 20 years. Windows that you can't break, roof with about half a meter of isolation element and so on. I know these houses as some friends of mine are organising an annual meeting of architecs in Belgium,, building such houses. I don't like to be a bird of bad luck, but if you don't change quickly your way of doing, you will face problem and increase quickly the LODDs number. These house are coming, and with the rising price of fuel, we can't stop this kind of construction. We have to adpat our way of doing. Quickly.

A few years ago, coming back from the Belgium exibit about "passive houses", I told a friend "As a firefighter, I was in this exibition, as if I was a rabbit, visting a hunting and arms exibition, just a few days before the opening of the hunting season. It was very strange, and not very comfortable".

 

Best regards to you all, thank a lot for the "dialogue" and again and again, excuse my poor english.

Pierre-Louis

Permalink Reply by Pierre-Louis LAMBALLAIS on February 3, 2011 at 3:02pm

As for those who asked about steamed vs. fire/smoke fatalities? I doubt we'd know without a specific study or autopsy. One need only be in a steamed container to understand how the situation can only be far worse for any unprotected victims. Our PPE allows us to withstand far hotter dry heat than wet, our skin also can withstand dry better than wet heat. 

 

Studies about heat stress and impact of humidity are numerrous, but not always for human. EG you can find many studies about death of chicks in industrial farms. When heat rise (summer) the rate of death increase? But when the heat is wet, the rate of death increase much more.

You can also read a very interesting report about xtrem heat condition here:

http://pubs.drdc.gc.ca/PDFS/unc65/p527951.pdf

Its' a doc about heat stress for Leopard tank's canadian crew, in the area of Kandahar in Afganistan.

 

Best regards

Pierre-Louis

Permalink Reply by Adam Miceli on February 3, 2011 at 3:54pm

John Ceriello said:

When you speak of using ventilation helping to control fire gases, is that with a line in place or when the line is not in place? Do you think ventilation on its own can control fire gases or wil itl increase the heat release rate,and  the fire will travel in all directions, some out the window and some to other openings wherever they are., including the rest of the structure.

Water and steam can be the same temp. 212 F the stream will burn you quicker because it contains more energy. Nothing disappears. What will drive you out of the hallway, hot fire gases or steam? Again I'm not really concerned about what happens in a burn container, I'm concerned with what happens in the field where firefighters are getting killed by uncontrolled gases, not steam. The origin of not opening up on smoke goes back to pre mask days and who wrote the early firefighting books pre 60's. It does not apply to today yet many would still say "don't open up on smoke", I believe they would be wrong to say that. If you ever get a chance to learn what they do in 3D attack(which my dept. does not use) you can see clearly what the intent is. Wet gear is always bad compared to dry gear. It's conduction that the burn injury occur, it won't matter if its radiant heat or steam.

I don't think we're as far off the same mark as it may seem. Our use of ventilation to control fire gases, fire and smoke is generally in concert with the fire attack crew. A coordination of the advance with the vent is key. Of course there are times when ventilation is done regardless of the lines position (venting for life), albeit rarely in our case. In any case, the easier we make it for the hot fire gases ans smoke to reach the sky, via window or vertical h***, the better. This relieves pressure, heat and allows for a safer and more rapid advance to the seat of the fire. 

I too have no interest in training burn container fires, in my posts I use container in place of "room". And like you I do feel that the old "never put water on smoke" is not longer valid. The reason being is the change in fire load. Now we have a far more flammable mixture in the smoke with so much of our fire load made up of petroleum based products. We now know we must cool the smoke and fire gases to safely be under them. This obviously doesn't mean indiscriminately shooting water into smoke, but using our hat racks to determine how much, when, where and why we spray water. I too have some interest in the 3D tactics as they relate to cooling the overhead, but I'm skeptical to give up my solid or straight stream for actual extinuishment. And of course the smoothbore doesn't seem to lend itself well to "penciling".

I'm still lost where you noted that a steam engineer stated steam does not exist above 212F? If we can have both water and steam at 212 F, what happens at 213F? 

Permalink Reply by John Ceriello on February 3, 2011 at 4:12pm

What I've been told is that steam is not hotter than 212 F, it's still there it's just not hotter that 212 F. The Europeans disagree with that. 

Adam Miceli said:

John Ceriello said:

When you speak of using ventilation helping to control fire gases, is that with a line in place or when the line is not in place? Do you think ventilation on its own can control fire gases or wil itl increase the heat release rate,and  the fire will travel in all directions, some out the window and some to other openings wherever they are., including the rest of the structure.

Water and steam can be the same temp. 212 F the stream will burn you quicker because it contains more energy. Nothing disappears. What will drive you out of the hallway, hot fire gases or steam? Again I'm not really concerned about what happens in a burn container, I'm concerned with what happens in the field where firefighters are getting killed by uncontrolled gases, not steam. The origin of not opening up on smoke goes back to pre mask days and who wrote the early firefighting books pre 60's. It does not apply to today yet many would still say "don't open up on smoke", I believe they would be wrong to say that. If you ever get a chance to learn what they do in 3D attack(which my dept. does not use) you can see clearly what the intent is. Wet gear is always bad compared to dry gear. It's conduction that the burn injury occur, it won't matter if its radiant heat or steam.

I don't think we're as far off the same mark as it may seem. Our use of ventilation to control fire gases, fire and smoke is generally in concert with the fire attack crew. A coordination of the advance with the vent is key. Of course there are times when ventilation is done regardless of the lines position (venting for life), albeit rarely in our case. In any case, the easier we make it for the hot fire gases ans smoke to reach the sky, via window or vertical h***, the better. This relieves pressure, heat and allows for a safer and more rapid advance to the seat of the fire. 

I too have no interest in training burn container fires, in my posts I use container in place of "room". And like you I do feel that the old "never put water on smoke" is not longer valid. The reason being is the change in fire load. Now we have a far more flammable mixture in the smoke with so much of our fire load made up of petroleum based products. We now know we must cool the smoke and fire gases to safely be under them. This obviously doesn't mean indiscriminately shooting water into smoke, but using our hat racks to determine how much, when, where and why we spray water. I too have some interest in the 3D tactics as they relate to cooling the overhead, but I'm skeptical to give up my solid or straight stream for actual extinuishment. And of course the smoothbore doesn't seem to lend itself well to "penciling".

I'm still lost where you noted that a steam engineer stated steam does not exist above 212F? If we can have both water and steam at 212 F, what happens at 213F? 

Permalink Reply by Adam Miceli on February 3, 2011 at 4:17pm

Pierre-Louis, we are dealing with changing architecture, green homes and energy efficient buildings. We're making them be sprinklered. While far from complete across the U.S. almost every major building code book now requires sprinklers in nearly every new occupancy. There are many states fighting the adoption of these codes for fear of the increase in cost to build, but even slowly, they will come around. 

 

As for your "new" methods of "dealing with fire, with no stress, no over production steam" I must ask how this effects unaccounted for civilians? Or are you merely using penciling/pulsing as a means to safely reach the seat of the fire and not changing the other tasks involved in a typical fireground operation?

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