Smoke Conditions

I came across this video for a neat looking product for fighting high rise fires from the floor below.

During the video we see how water can be applied through the device in either straight stream or via a remote controlled combination nozzle.

I have no opinion about the product positive or negative, that is not the reason for my sharing the video.  As you watch, pay careful attention to the changes in smoke conditions between straight stream and fog.

Just in case you always wondered why there is more smoke when you use the fog nozzle as opposed to putting the fire out with the straight stream.

More reach, more water, less fire, less smoke.

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9 thoughts on “Smoke Conditions”

  1. Hmm Happy I’d have to disagree about the straight stream, I don’t know of any brigades/service over here in Europe who uses a straight stream smooth bore nozzle for interior fire attack. Now I know that constrcution methods are different the States compared to Europe and therefore fire tactics are different.
    But have a look at this http://www.youtube.com/watch?v=w3tAgBb2pt0&list=FLtyXs8bJEiw-wYTz4cnx5Nw&index=63
    and this http://www.youtube.com/watch?v=M4tZIB0hTYQ&feature=related
    They are pretty good representations of 3D firefighting as we do it over here. If we used the USA tactics we would be sued for water damage as the smooth bore nozzles are only 20% efficient whereas our fog nozzles are 80% efficient, allowing us to use a lot less water. We can put out a fully involved living room fire with less than 20 gallons of water in less than 2 minutes.
    So differents ways but both seem to work if used correctly.

    1. Excellent points indeed, but the first video you linked to is a remarkably unrealistic situation of a small fire on a couch cushion.  We would handle that with a hand held extinguisher as I’m sure most would.  the second scenario in the first video and the second video show the limitations of the fog nozzle with the teams having to use short bursts to get close to the seat of the fire.  With a straight stream they can hit it briefly from the next room and advance when the fire is out.
      There is no need to shoot, advance, shoot, advance etc because the stream has the reach to do the work for you.
      Construction methods do need to be taken into account, with the majority of our residences being made of flammable materials as opposed to bricks and masonry as in the second video.
      the key is using the techniques on an occupied space.  An occupied space contains flammable items that all the short bursts to the ceiling in the world will not contain, plain and simple.
      I do admire the tactic of reversing out from the fire I have seen in europe though.  Meaning we move from the fire and lay line back to the pump as opposed to America where we advance forward from water to the fire.
      Also to take into account is population density in first alarm of the fire.  We in the US seem to keep to ourselves more than our European counterparts and only in a few metro areas are we in attatched dwellings.  I think this has alot to do with fires in the US being well into free burning stage as opposed to incipient when the first units arrive.
      Certainly a topic for more discussion!
      Thanks for reading!

    2. I guess Americans are less litigious than elsewhere in the world. It is highly unpopular to sue a fire department for damages, and also highly unlikely that such a case would stand in court.

      The high pressure nozzle is efficient at changing water to steam, but as Justin pointed out, most of our structures are made out of flammable materials with high fire loads making the chance of a TRUE structural fire (in the Francis Brannigan sense) where the immediate involvement of structural members in the fire in possible. The heat release requires a higher rate of flow.

      And right now, most fire departments are using the adjustable pattern fog nozzle but you will see most departments using a straight pattern for interior attack.

      1. I guess Americans are less litigious than elsewhere in the world.

        Wait, WHAT??  Dude, you’re in healthcare- how can you even SAY that??

  2. Okay, question from the man in the street…
    Using the HEROpipe you would have personnel working directly under the fire.  And you’re pumping a lot of water into the space.  How concerned would you be with the added weight on the floor right above you?  I’m not going to claim to know squat about building codes but all that water represents a lot of weight being added to a potentially weakened floor and I’m not sure it can flow away and down fast enough. 

    BGM

    1. Benjamin, great question i will forward to the HEROpipe folks for a definitive answer, but this is not the tool to extinguish the fire.  Using a scenario where the fire is too intense to attack from the stairwells, for whatever reason, this tool can knock down the bulk of the fire to allow the interior teams to attack.  I would be less worried in a type I building than in say a type 3 or 5 where the floors could be lightweight truss.
      These larger buildings are designed to hold a lot of weight, but it all goes back to SMART water application to effect knocking down the fire.
      The key is not applying a lot of water, but the right amount of water.  The old phrase “Big fire, big water” was never correct and needs to be stricken from our lexicon.

      1. Thanks HM.  You managed to give my curiosity enough of a nudge that I just gave myself a quick crash course in structure types and a read through the technical specs on the HEROPipe system.  Both were very interesting.  And the structure types especially are going to need a bit more reading.

        One thing that struck me is that even in the middle of it’s operating range a HEROPipe system is putting a shade more than two tons of water into the fire space in a minute.  Now granted a minute is a lot longer than it sounds to most folks but still…  Would I be correct in assuming that the standard interior attack tactics would use water at a similar flow rate?  If so is drainage a consideration in planning and executing the attack?  A brief wander through the internet turned up all sorts of information about venting heat and gasses but I found nothing about allowing a safe path for water to exit. 

        Not wanting to get hung up on the question but it’s something I’ve never really considered before.  Any water used in fighting the fire has to go somewhere and it seems like a perfect way for Murphy’s law to come into play.

        BGM

        1. Ben, keep in mind we are not pouring water into a tank, but introducing it into a free burning environment with temps over 600 F at the ceiling.  Water boils at 212 F. Most of that water is being converted to steam in the initial fire fight.  As the bulk of the fire is knocked down that interior team must move swiftly and use water in a targeted manner to knock down the seat of the fire quickly.  This will decrease the amount of heat, therefore requiring less water to extinguish remaining fire.
          It’s the same as when we pour water on a camp fire.  it seems to take an incredible amount of water to extinguish the fire and one big dump rarely works.  the first few pours will simply disappear into steam, but soon we discover more targeted application works better and the fire gets smaller.  hitting it from the side or below works best, less heated air (ventilation) and it decreases the amount of fuel burning.
          Great discussion!

          1. Guess I was underestimating the steam factor.  Even if only 75% of that initial water flashes to steam that lowers the weight to about a 1000 lbs and figuring that a FF in full bunker gear is tipping the scales in the 250-300 lb. range that’s not much more weight added than the attack team themselves.  So for an office or apartment building floor loading really shouldn’t come into play at all unless things have really gotten out of hand.  Interesting. 

            Thanks Happy.

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