Another in a series from Deputy Fire Chief Coffman..In prioritizing our operations, we talk about the protection of exposures. This can mean both interior as well as exterior exposures.
Cluster homes are showing up in new communities all over the county. These are home of various sizes but some are quite large. The homes are built with very similar floor plans, extremely close to one another and often have windows facing each other on the B and D sides of the homes.
Assume you are a later arriving engine company and units are already working on the inside of the building of fire origin. Fire is out of two windows on the B side facing the next door home. Discuss all the possibilities for fire extension and what tactics you might have to employ if given the assignment to protect the exposures.
Cluster homes are showing up in new communities all over the county. These are home of various sizes but some are quite large. The homes are built with very similar floor plans, extremely close to one another and often have windows facing each other on the B and D sides of the homes.
Assume you are a later arriving engine company and units are already working on the inside of the building of fire origin. Fire is out of two windows on the B side facing the next door home. Discuss all the possibilities for fire extension and what tactics you might have to employ if given the assignment to protect the exposures.
Take the time with members of your shift to discuss the above.. C'mon you have ten minutes to spare.
1 comment:
Well, since no one else has chimed in on this one, let me take a stab.
My first consideration coming in is what is the water supply situation. Is it sufficient for our worst case scenario or should we take steps to ensure our own water supply.
Next, what are the conditions present upon our arrival? What stage is the fire in? What are the exterior conditions? Where are my exposures and what are the exposure priorities? Do I need to consider sacrificial properties that will allow me to make a good/realistic stop?
The exposures will be threatened by radiant heat and direct flame. Windows are transparent, so fire coming from windows can transfer through opposing windows on other exposures. It will be important to get a line in the exposures, remove curtains and window dressings. As well, we would have to ensure we have water cascading directly on the exterior of the exposures. Do not consider water curtains. This is old school and has been proven not to be effective, since water curtains are also transparent and will allow radiant heat to pass through.
When considering positioning, place your engine in a good defensive position that will allow access to multiple properties, will keep you outside of collapse zones, and will keep your apparatus out of the path of radiant heat. Position to allow for the use of your deck gun and/or monitor. Setting these devices up with a master fog when close to the target exposure will allow you to flow large amounts of water on the exterior surface without causing exterior damage to siding/shingles or taking the risk of knocking the building down. If you are a distance away, solid tip nozzles can be effective at providing adequate reach and large water droplets to cool and protect exposures. Be cautious, as the solid tip may threaten structural stability depending on if it is a finished structure or one under construction.
Valuable information can come from effective smoke reading. Look at the direction of the smoke to determine its travel path. This will help you prioritize your potential exposures. Look at the smoke coming from the origin structure. What is the progress or lack of progress of the interior crews? Are you seeing something they are not, and should you report this information to Command?
In managing exposure protection, we are not only considering the immediate exposures around the original fire structure, we must consider radiant heat traveling distant from the fire origin. Sometimes this can be surprisingly remote from the original fire area, like a block or two away. Also, are flying embers under control, and if not, where are they going and do you need additional resources to ensure they remain in check. These large single family dwellings will put off tremendous amounts of heat, especially as the fires fully develop. Embers and radiant heat may be significant.
Construction wise, these structures will likely be lightweight wood construction. Expect rapid fire spread and rapid structural deterioration. A variety of veneers will be found. The most important type to consider is the vinyl siding, which is going to melt quickly on exposure properties threatened by radiant heat and direct flame. Melting siding can lead to flame spread and can easily spread fire before lines are in place. Get a quick knock with a sweeping stream motion on the exterior if this is the case.
As trees are torn down to make room for these MacMansions, it has become common place for arsonists, protesters, and vandals to act out, whether in protest of the housing expansion, the attack on the environment, or a general opportunity to get a charge out of starting these fires. Fires occurring in subdivisions where homes are not occupied will create a delay in noticing and reporting the fire. As well, structures in the open shell stage will have great potential for spreading fire from one structure to the next. Consider these circumstances as you create your plan of attack. Weigh your risk and benefits carefully. What do you hope to gain and is it worth the safety of your personnel? During these circumstances, you will likely have to determine where your line will be drawn and which properties will be sacrificed in order to create a realistic stop line. Factor in resources available, those needed, those on their way, and forecast how long it will take to have resources in place on the fire ground and where the fire will be at that point. Will you be ahead of the game or behind? Establish and work within collapse zones when the time comes. These structures will begin to fall down early.
Finally, continually size up and re-evaluate. Do not waste time changing strategy if it will make a positive difference.
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