1. #1
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    Default Dangers of WATER-FOG tactics article!!

    I read, with great interest, the article by Knapp, Pillsworth and White that appeared in the February 2003 edition of Fire Engineering magazine (USA). The article described how a series of tests suggested that the use of fog nozzles, during interior firefighting operations, can create dangerous air movements inside spaces being occupied by firefighters.

    However, the author’s research efforts were clearly spoiled by an obvious error – they based their approach from the outset on a distinct attempt to discredit combination nozzles, and fog patterns, failing to offer an unbiased review of their conclusions. It is certain that the figures derived in the tests could be used equally to demonstrate the advantages of fog patterns when compared to those offered by smooth-bore nozzles.

    Their research appeared innovative but failed to reference previous research in this area.

    I would CHALLENGE the authors of this article to come online here and now to debate with me the pros and cons of using water-fog tactics and put this issue to bed, once and for all! Are you out there??!!

    http://www.firetactics.com/FIRE-ENGINEERING-2-2003.htm

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    Certainly hurts their credibility to set out with a biased goal in mind. I have always felt, though, that fog patterns should be used judiciously. You just can't storm into every fire and do tasks A, B, and C just the way you did them on your last structure fire. You must observe conditions and see what is prudent given the circumstances as you know them. This may dictate choice of nozzle pattern, size of line, number of attack crews, ventilation, blah blah blah. You can't make blanket statements about what you're going to do.

    That said, you can't make blanket statements about what you will NOT do, either, so we should not EXclude fog patterns any more than we should INclude them.

    It's a tool in the toolbox. Use it where it's appropriate, and ditch it where it's not.
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    Unhappy

    Oh boy, here we go again!

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    The testing of equipment and the results shown are almost always flawed. With only two exceptions nozzle testing is so unscientific that it is now just a waist of our time to listen to the results.

    Only two times have I seen testing for nozzles that was relevent and could be reproduced. David Fornell in his book Fire Stream Management Handbook does multiple tests to compare Nozzle reaction, reach, footprint etc. The other time was the various tests that Kirk Allen preforms with the vindicator, including the FDNY tests, comparing it to both sb and fog nozzles.

    We need to do testing relevent to putting out fires. Perhaps I haven't seen it or I've forgotten it but where is the data with identical fires one put out with the 3d fog and another put out with a sb or straight stream fog nozzle? I want to see numbers, temp, time till dark down / extinguishment, total gpm. Please pretend you are in college and need to preform an experiment, or work for UL.

    Myself, I know that a fog will move air, more then a sb or straight stream. What relevence is that on an actual fire. Not an opinion. What happens when you attack a well ventilated fire with the fog. Experience has cooked me more then once so I don't do it. I've found that many guys that don't like fogs have had a bad experience once or twice. And because of that I'm not going to experiment on a real fire scene.

    Please some one show me data for an actual structure on fire. Show me data on what nozzle or technique works best on a bedroom fire, post flashover, that is extending down the hallway. Until I see something scientific I'm going to use a SB or completly devastate the fire with our vindicator.

    Unfortunatly the safer claim only works if someone is hurt so don't tell me that a technique is safer unless you have a fire where guys have been hurt and duplicate it using a diff tech and the guys didn't get hurt. The faster the fire is put out the better / safer the scene. so please show me some data.

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    Yeah Paul, I knew you'd be chiming in on that article. While I was glad to read it and it's conclusions, I also felt it had failed to fully research the matter.

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    Exclamation Illinois Chiming in again!

    Originally posted by ADSNWNFD

    Myself, I know that a fog will move air, more then a sb or straight stream. What relevence is that on an actual fire. Not an opinion. What happens when you attack a well ventilated fire with the fog. Experience has cooked me more then once so I don't do it. I've found that many guys that don't like fogs have had a bad experience once or twice. And because of that I'm not going to experiment on a real fire scene.

    Please some one show me data for an actual structure on fire. Show me data on what nozzle or technique works best on a bedroom fire, post flashover, that is extending down the hallway. Until I see something scientific I'm going to use a SB or completly devastate the fire with our vindicator.
    Bravo. My friend from DuPage his hit the nail on the head, but here's the rub: I want to see the kind of testing he advocates, but by different groups. Show us the SAME fires, at the SAME temp, in the SAME conditions. But, more importantly, send in the group with the 3D fog EXPERTLY TRAINED IN ITS APPLICATION. Reset the fires, duplicate the conditions, and send in the group with the smoothbores EXPERTLY TRAININED IN ITS APPLICATION. Throw a funky wrinkle in it and give the vindicator fans a shot. Give us all the data ADSNWNFD proposes: knockdown time, gpm used, temp reactions, steam production, patterns, etc.

    As was shown by the Knapp, Pillsworth and White article, groups trying to prove a point will skew results to their preconceived notions (please note that I am a fan of smoothbores). Having said that, I have seen the same massaging of data regarding fog nozzles from the groups that promote fog usage.

    I suppose the only reason we don't have definitive testing and data is that, in addition to the cost, the only ones doing the testing are those trying to sell a product.
    Omnis Cedo Domus

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    Hey Lou - thanx for picking up on my point - the research and article was interesting but it did fail to offer any relevant conclusions as their research failed to cover all aspects.

    Mallet - participation is optional but don't look at this as ANOTHER smooth .v. fog debates! There are broader issues that have been raised by the article in question and I feel it is important to recognise that many firefighters may be wrongly influenced by its content. Some may even be throwing their combos out as we speak!

    ADSNWFLD - Hey bro....we have had some battles on the forums eh! But you do raise some very relevant points that deserve answers -

    1. David Fornell's book is excellent and offers some most interesting advice when comparing straight .v. smooth .v. fog etc. Unfortunately, and I have spoken personally with David on this, his book contains no reference to 3D fog tactics and neither was he aware of them at publication.

    2. Kirk Allen also offers excellent advice and his reports demonstrating the performance capabilities of VINDICATOR are full of interesting information. Again, the FDNY research report you refer to only compared a 15/16 smooth-bore against Vindicators - no fog patterns.

    3. As I have said before, the Austin Fire Department (Texas) evaluated 3D water-fog applications during 146 live burns in 2001 where over 500 firefighters compared the effects against smooth-bores. They confirmed that, whilst not suitable to all situations, 3D tactics most certainly proved effective and firefighters would receive training in the use of 3D water-fog as an option.

    4. It is difficult to achieve true comparisons in aquired structures as each fire burns differently with varying amounts of fuel-load and ventilation profiles. However, the US Navy did complete extensive practical and scientifically monitored tests, comparing smooth .v. 3D fog against classA loads onboard a test ship. They showed over and again that 3D fog tactics were able to out-perform smooth-bore nozzles. I have the reports in hard-copy but they are pretty extensive.

    5. You talk of a bedroom fire that is post flashover and extending down the hallway - Hey, its time for a high-flow tool. But why use a smooth-bore when you are better equipped with the versatility of a combination nozzle for changing conditions. I have been in fire-fights where I have changed from 3D to direct back to 3D back to direct applications within the space of 15 seconds.

    6. You state 'Unfortunatly the safer claim only works if someone is hurt so don't tell me that a technique is safer unless you have a fire where guys have been hurt and duplicate it using a diff tech and the guys didn't get hurt. The faster the fire is put out the better / safer the scene. so please show me some data' Well that's a MAJOR point. Data? I can only say that guys have been badly burned and even killed in situations where 3D tactics 'might' have saved them. In Europe and other countries that use £D water-fog tactics they are cutting flashover deaths amongst firefighters drastically - is that good data? I mean zero losses for 20 years or more!

    Again - don't ever believe that 3D fog is the answer to everything - its a tool....an option....not a replacement for tried and tested methods.

  8. #8
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    In relation to 3D applications of water-fog the ventilation profile is irrelavent - either vented or non-vented compartments....the only point here is that well vented compartments may cause the fire spread to overcome the flow capability of a particular hoseline/nozzle in use....whatever the application is!

    US Navy strategy is written in NSTM 555 s 555-5.3 which recommends the 3D approach to control growing/steady state fires where the space can still be entered but the seat of the fire cannot be attacked immediately.

    Post WW2 'fog attack' (indirect attack) is still a viable tactic for fires in sealed compartments demonstrating under-ventilated conditions.

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    Random thoughts after a read of the article:

    Good that people do tests. Numbers help reach decisions, but like everything else they don't tell the whole story.

    Minor editing issue, but I've always seen fog patterns described as 30 degree (a/k/a Narrow a/k/a Attack) and 60 degree (a/k/a Wide). Not the 30 and 45 mentioned in the article. I believe that was just an editing issue though.

    "Given all the facts presented above, why is anyone STILL using a fog stream inside a fire building? Some of the reasons are experiences with one-room fires and, even more so, the misinterpretation of the indirect method of attack as developed and presented by Lloyed Layman..."

    'Cause fog is particulary effective in knocking down one room, vented fires and most of us see primarily one room fires or fires that can be treated as a series of one room fires?

    That's why they make combination nozzles, you can use the straight stream when appropriate, you can go to fog when appropriate.

    I also take extreme exception to the idea that someone would use a fog pattern into a room for 20 seconds, introducing more air than it could hold or vent.

    First, on a technical level they don't seem to particulary take into consideration steam formation in addition to air movement.

    "In 20 seconds, you would've introduced about 2,000 cfm, thereby more than doubling the volume of air that room is capable of holding."

    Again, first editing issues

    If you're moving 6,000 cfm and you go for 20 seconds, you don't introduce 2,000 cfm. You introduce 2,000 Cubic Feet, the "per minute" part gets dropped.

    Each gallon of water converted to steam will generate 227 cu. ft. of steam. 5 gallons of water converted will fill the room with steam, if it's not properly vented. That's more like 5 to maybe 10 seconds at the outside depending on how efficient the water is being converted. After that time, you won't see fire anyway, so proper nozzlemanship on a fog attack, you shut down.

    I can't conceive of being in an direct fog attack inside a building for more than a few seconds -- well under ten. That's a training issue, not a tactics issue. If you're keeping the nozzle open after you lose sight of the fire, either you're using the wrong tactic or you weren't trained to use that tactic it right.

    Direct and Indirect Fog Attacks are two different beasts. Just like 3-D tactics shouldn't be confused with either of the above. Yet at the end of the article, they tried to draw a direct connection between direct fog attacks & Layman's work.

    3-D (Paul correct me...) is concerned with cooling overhead areas while advancing towards the seat of the fire. It's a tactic to safely approach the seat, then you can use a different tactic to kill the fire.

    Direct Fog Attack is based on having a well ventilated fire you can push. You use steam and air movement to push the heated gases out a vent hole. If you use in a poor vented area, problems can happen. If you're really good (sarcasm) you can push it all around the building. When appropriate, it is highly effective.

    Indirect Fog Attack is based on having a poorly vented room you introduce limited amounts of fog into in order to smother the fire in it's own steam. It's applied from outside the fire compartment -- open a door, hit it high quickly, close door, let it stew a minute (count), re-open & re-assess. It's not a tactic we need too often, but can work if you know what you're doing.

    "Would you conduct an interior fire attack by simultaneously advancing a nozzle team and a smoke ejector team into the fire building? Of course this sounds ridiculous..."



    Watch your hyperbole in articles. Advancing a nozzle team and a smoke ejector team simultaneously? Sure sounds like (drum roll please) Positive Pressure Ventilation.

    Only difference being the fan is left at the entry door, but the air flow is following the attack team if they're headed towards where the fire is vented.

    Hmmmm, maybe that's one reason I generally lump Fog & PPV into the same tactical family....

    Now, would someone hand me that CAFS smoothbore so we can go put out some real fire?

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    GREAT post Dal

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    Exclamation Bump!

    Thought maybe this thread should go to the front one more time.
    Last edited by KLMR23; 03-05-2003 at 10:59 PM.
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    I am interested in hearing there facts and figures...
    Last edited by sconfire; 03-05-2003 at 11:03 PM.
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    Default Re: Bump!

    Originally posted by KLMR23
    Thought maybe this thread should go to the front one more time.
    Thanks!! BTW - where are the authors of the article - dont they visit these forums??!!

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    Default Test Data

    As in ALL research...He who pays the bills..gets the answer desired.

    Sad but true.

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    Don, you speak the truth.......

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