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Richard Marinucci |
Water remains the choice for extinguishing structure fires.
Even though advancements and technology offer other options, such as foam and other special extinguishing agents, fire departments operate with the assumption that the appropriate amount of water will extinguish most, if not all, fires.
The basic objective is to overcome the British thermal units (Btus) being generated and ensure that the fuel is cooled enough to cease generating flammable gases. It goes back to the basic fire triangle: fuel, heat, and oxygen. Although the tetrahedron was added for the chemical chain reaction, this discussion is intended to look at simplicity.
The Value of Water
Instinctively and possibly through study and experience, firefighters have always known the value of water. Studies from Underwriters Laboratories and the National Institute of Standards and Technology confirm that the faster firefighters apply water, the better the outcome. Firefighters are taught early in recruit school that using water fire extinguishers works best when water is applied to the base of the fire. This applies as the fire grows. The amount of water must be of a volume to cool the burning material quickly enough. If the volume isn’t adequate, the fire will not go out. Hence, the source of water and the delivery capabilities of hoses and nozzles affect the outcome. By source, we mean the availability of water. If volume is limited because of pipe (main) size, system pressure, pump capacity, or tanker operations, then options are limited.
The direction from which water is applied has no impact on “pushing fire” through a structure, so the goal should be to figure out the quickest way to the fire. I think the “pushing” concept is related to the debris that gets moved when a fire stream hits objects that are not fastened down. Firefighters on the opposite side of a flowing line will certainly have materials “pushed” on them, but the actual fire is not spread in this manner. What the studies have shown is that water applied to fire cools the area and other parts of the structure. Dropping temperatures are good for everyone.
Water Delivery
With this information, departments should review tactics and strategies frequently. Through training and experience, organizations should know the quickest way they can deliver water and through what means. There may be times when a quick hit with a deck gun using tank water will significantly slow down the fire and allow time to establish a water supply and deploy lines. Organizations that have limited staffing, particularly early in the operations, should consider this tactic for some types of structure fires. Staffing limitations should dictate strategies. Do you have enough personnel to deploy lines and make a fire hydrant connection? The difference between a forward and reverse lay may also affect this. If you are required to leave someone at the hydrant to flush, connect, and open, then you are taking someone from the fireground. You need to weigh the benefits and obstacles in doing this.
One of the simplest axioms in the fire service is “big fire, big water.” For the most part, I would agree. However, this is another area where staffing plays a role. Do you know how many people it will take to deploy 250 feet of 2½-inch line to the rear of a house? Do you know the difference between stretching dry and charged hose? Obviously, moving a 2½-inch line filled with water requires a significant investment in people power. It is heavy, and terrain can make the effort even