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Permalink Reply by 144Truck on January 14, 2009 at 7:48am

I guess I read too much into the initial question... No, we do not always use deck or elevated streams at high volume or pressure. In fact, in the earlier scenario, the Truck flowed rather low amounts of water toward the end of the job to wash down a soffit area of the "A" side, and to apply water to a portion of the roof area of what was the haevily involved portion of the structure.

These latter stage applications were of such low volume and pressure that interior operations continued.

As far as water supply is concerned, we are fortunate that at least two pumper/tankers (2000gal. tanks) respond in addition to several 1000 gallon trucks so that gives us about 8000 gallons of tank water. Obviously, in hydranted areas this is a moot point for us as the hydrants are quite good. With that said, we have sufficient water to do a quick knockdown, assess, and decide whether to operate defensive or offensive based on all of the standard considerations.

As far as switching from offensive to defensive and back to offensive, or transitional, as mentioned by Chief Waller, this depends on the assessment of Command, Operations and Safety. We have often transitioned betwen modes or used acombination of them.

144Truck

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Permalink Reply by Salty Jake on January 14, 2009 at 11:35pm

Jenny,
I think your last few paragraph sum up your issue at hand. I'm refering to the lack of water comment. If your intentions of "gating down" your pressure in an effort to save water, the deck gun, monitor or ladder pipe is the wrong tool. If you are only looking to operate at 100gpm you would be better served using a handline. I wouldn't hesitae to dump your 500 - 750 gallons of water on a large fire using a mounted device with a smooth bore nozzle, GO BIG, GO EARLY, or go home. At this point of the game; by the time you set up your water supply, and get the right amount of tankers to provide the adaquet fire flow needed to extinguish this large fire, your now catching the the down side of your time-tempature curve; the building is lost.

My thoughts on switching from a defensive mode back to offensive: DON'T! In most cases the building takes on a massive insult to the structural componets not only by fire, but the tens of thousands gallons of water that your pouring onto what ever it is that your buring. I cringe every time my department shuts down a defensive operation only to send in FF to mop up and search for and dig out hot spots. Yeah! We completly extinguished a fire in a building that will be torn down in a week. Not an accomplishment that I'm willing to sacrifice a life for.

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Permalink Reply by Ben Waller on January 14, 2009 at 11:45pm

A Transitional (Defensive to Offensive) attack is a recognized attack mode, and my department uses it when it's appropriate. A minute or two of deck pipe operation doesn't put "tens of thousands of gallons of water" into the structure. A 750 GPM stream for one to two minutes is 1,500 gallons or less.

If there is a heavily involved garage, open downstairs area, etc. we use a shot from the deck pipe to knock down the body of the fire. We then evaluate the structure and if we deem it safe, we transition to an interior attack to hit fire that's not accessible from the outside.

I'm all about staying avoiding lost causes, but starting a master stream doesn't mean you necessarily can't shut it down for hours.

Ben

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Permalink Reply by Salty Jake on January 15, 2009 at 10:11am

Ben,

You are absolutly right, a quick knock down using an appliance is just that; a quick knock down, please don't confuse the two; it is not a defensive move! Call it what you will, I call it a blitz; knocking down a large body of fire in an effort to buy time so we can make entry. My post has to deal with pouring water onto a fire for extended periods of time, that my friend equals the tens of thousands of gallons that i was refering too. The last defensive fire that we, (I) participated in, I witnessed a large desk get blow through a second story wall from 1 1/4" smooth bore ladder pipe, direct hit. Prior to that happening the stream was directed into the attic and second story windows, that is one hell of an insult to building and materials, don't put yourself or your folks in a situation where you think an offensive mode is a good idea after extended periods of dumping water onto an already lost building.

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Permalink Reply by Ben Waller on January 15, 2009 at 12:06pm

Jake,

I haven't confused the two, but there have been posts in this thread and the related one that triggered Jenny's questions that assume that a) all master stream use is for continuous defensive attack and that b) all master stream use will put thousands of gallons into the building and drive the fire into uninvolved areas.

With that said, Transitional attacks do start Defensive, then move to Offensive, by definition. If you attack from the exterior, no matter if it's for two minutes or two days, it's defensive. The initial Defensive part of a Transitional attack is still Defensive.

I agree completely that buildings that have been hammered with master streams for an extended period of time should stay Defensive due to the collapse probability.

Ben

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