In Part 1 of our three-part series, we addressed a few of the many developments affecting today's fireground environment, including: changes in firefighting gear and equipment, the effects of building techniques and materials, and the regulatory standards and guidelines that specifically deal with interior fire attack. Part 1 also outlined the first five steps of our action plan, including: apparatus placement (and the importance of worst-case planning), the first-arriving radio report, what to look for when conducting a 360-degree size-up evaluation, the need to assemble the proper tools for interior operations and the critical importance of proper fireground staffing.
Steps 6 through 10 detail suggested courses of action for the attack crew and those support personnel on the fireground who are assisting in the initial attack operation. In Part 2, we will focus on the next two steps in our action plan to create a safer, more effective interior fire attack. Step 6 concerns the selection and advancement of hoseline, while Step 7 involves the evaluation of interior conditions (i.e., risk assessment, and what efforts can be made to minimize the potential of risk).
STEP 6: HOSELINE SELECTION/ADVANCEMENT
Hoseline Selection: As a general rule of thumb, "GPMs > BTUs," meaning that a flow of water that provides a sufficient number of gallons per minute can usually overpower a fire (as represented here by its British Thermal Units). However, we must be careful as we approach our choice of hoseline. The selection of the correct attack line is a decision that can prove less than forgiving, if figured carelessly. Let's face it--as firefighters we are creatures of habit. We have a general tendency to repeat past actions that have previously worked out successfully--even though those actions may actually have been rooted in mistakes.
As it pertains to hoseline selection, the choice of the conventional 1.75-inch cross lay--usually made because of its easy deployment--can and has led to tragedy on the fireground. The fact is simple: If the GPMs you take with you during your initial attack don't absolutely overwhelm the BTUs exhibited by the fire you might face, you're destined for failure and could suffer potentially serious injury. The old saying "Big fire, big water" has been repeated by many fire-service experts across the country. Unfortunately, far too many of us continue to resort to our prior efforts, which may have been less-than-safety-conscious in nature. And then when we factor in the rising threat of rapid thermal insult due to the increasing use of synthetic fuels (such as gasoline in its solid state) and the prevalence of "tight" construction zones that are overbuilt, we are facing a greater chance for trouble than ever before.
So what's the solution? How do we select the right hose for the task at hand? First, we must take the information we gathered during Step 3 (Size-up) and use it to answer the following questions:
1. What is the overall size of the structure?
2. What type of occupancy are we dealing with? (If it's a commercial occupancy, we need the "big water" provided by 2 to 2.5-inch hose. If it's a residence where one to two rooms are involved, a 1.75-inch hose should suffice. If the affected residential area consists of more than two rooms, we need the same type of delivery required in commercial occupancies--a 2 to 2.5-inch hose.)
3. How does the building construction itself contribute to the spread of fire? (Wood frame construction leads to a rapid fire spread, while tilt-wall construction promotes a limited spread of fire, but a concentrated build-up of heat.)
4. What is the actual fuel load of the occupancy? What are the common combustibles or other fuels that may support or enhance rapid fire spread? If the fire is located in a commercial or industrial occupancy, are there combustible liquids and/or pressurized vessels stored in the building?)