The Big Fire
DEPARTMENTS
Gene P. Carlson’s Volunteers Corner
Most fire departments find themselves confronting two A types of fires: the fire in a dwelling or small commercial building, and the larger fire that can occur in several different types of occupancies. But many departments are making the mistake of using the same procedures for both.
With modern apparatus, it’s common to mount an aggressive initial attack from the stored water supply of the first pumper to arrive at the scene. This has been made possible by larger water tanks and the preconnected, 1¾inch attack line’s ability to deliver a larger flow.
Because this method of attack has been successful on some residential and smaller fires, some fire departments have been lulled into adopting it as a standard operating procedure for all fires. They often forget to augment the tank with a constant water supply, or they routinely use the tank for larger fires where it doesn’t provide an adequate and positive attack.
Large structure fires merit separate procedures appropriate to them. After all, one or two large fires each year account for the major portion of a department’s fire loss figures. Operations should make full use of the large pumps now being purchased. Engines with pump capacities of 1,250, 1,500, and 1,750 gpm are becoming common, yet few departments are prepared to use this pump capacity efficiently. The apparatus should do what it was designed to do—pump at near capacity, not just supply two or three small-caliber preconnects.
First judgments
The first step toward this efficiency is size-up, to determine whether the situation is one that requires large-fire tactics. First-arriving officers must be trained to judge avenues of fire spread and areas of possible involvement. And they must be able to make a quick, correct decision on whether to move into large-fire operations with more than a preconnected water supply. This is based on conditions that can be seen from the outside—such as fire on more than one floor, fire in a large area with life exposures above, fire showing on more than one side of a building, or fire adjacent to a building with a heavy life load, such as a nursing home or hospital.
If large-fire operations are appropriate, officers must have available SOPs that outline methods of water supply, use of hose loads, the 2‘/2-inch handline and master stream attack possibilities, and use of tactical support. These procedures must take into account the size of the building, the potential fire area, and the fire’s location. The SOPs must be laid out to include positioning of apparatus and line placement that will cut off the fire spread, confine the fire to the smallest possible area, maintain exposure protection, and, eventually, extinguish the fire.
Water supply at large fires is critical, but too often it’s overlooked in the initial set-up because tactics designed for smaller fires are employed. A single, 2½or 3-inch hydrant supply line or a long, unsupported, large-diameter hose line isn’t going to be adequate for the large fire. If a forward lay is used, then multiple, supported small supply lines; a short, large-diameter hose line; or a long, supported, large-diameter hose line is necessary. If a reverse lay is used, the pump must be connected to the larger “steamer” connection of the hydrant, if such a connection is present. If possible, an auxiliary suction line should also be used.
With weaker water systems, supplementary pump supply operations may be necessary. Often, when low pressure or smaller mains exist in the system, the reverse lay will provide the best delivery capability because it puts the pump close to the source, and that will lessen the friction loss.
A large fire requires a fast, knockout punch. This means attack lines with high-volume delivery; 2‘/2-inch attack lines must be stretched. Master streams may be needed for a defensive attack if no interior firefighting is taking place. Or they may be needed momentarily for quick knockdown to support the mounting of an offensive attack. Hose lines need to be placed to minimize the fire spread, protect interior and exterior exposures, and aid in fire extinguishment. Remember to use that large pump to its capacity. If necessary, use other apparatus to lay lines and connect those lines to the pumper, which should be efficiently close to the fire scene.
Lack of personnel can severely limit use of the pump’s capacity. You need an early call for assistance or mutual aid.
Lack of personnel may be a severe limitation to total use of the pump’s capacity. This will necessitate an early call for assistance or mutual aid to provide enough firefighters to handle all the hose lines the pumper can supply.
Additional support
All large fires require extended tactical support. Request personnel and truck company response early, before the building is lost. Ventilation, salvage, and rescue frequently are necessary concurrent with stream development. An incident command system should be initiated. Logistics to provide food, fuel, additional air supplies, and other resources must be established. In cases of extreme temperatures or other weather conditions, a method of personnel rotation will also be required.
All in all, there’s much to be considered at the large-fire scene. Early mistakes in fire attack—the use of smallfire tactics—let the situation deteriorate. Train officers to recognize large-fire potential, develop ample water supplies, and attack with an adequately sized hose line.
Stop the big fire in its tracks!
