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If AFFF is not available, or in the case of stubborn fires or those where there is flowing or three-dimensional fire, the applicator pipe may be used to discharge dry chemical. In order to accomplish this, it is first necessary to unscrew the brass discharge head, since the small holes do not permit the effective discharge of the powder. This is a two-person operation with one member controlling the flow from the extinguisher and holding the nozzle into the base of the applicator pipe, while the other member guides the tip of the applicator, directing the dry chemical to sweep the flame ahead of it. Just as with any other dry chemical attack, utilize as many extinguishers and applicators as possible in a coordinated flooding attack to ensure success and maximize safety.
Another type of special appliance are the piercing nozzles. These devices, of which there are numerous types and manufacturers available, may be used to apply a variety of extinguishing agents, water, or AFFF, most commonly, but some may also be utilized to distribute carbon dioxide (CO2) or halon. They can be punched through an object or surface that is obstructing access to a portion of the fire, to allow extinguishment. Some fires that can benefit from their use: grease duct fires, compactor or rubbish chute fires, fires in shipping containers, automobile trunks, as well as any other fire in an inaccessible area, including various blind spaces within structures.
The key to success in using these devices is to have a break-apart nozzle on the end of the handline where the device is to be used. This way the line can be used conventionally, knocking down fire in exposed areas, and then can quickly be connected to the piercing nozzle to extinguish the remaining fire in the voids.
Fires in buildings that give us the worst problems are typically fires in inaccessible areas, cocklofts and cellars. Cockloft fires travel rapidly, threatening to burn the roof off if not quickly controlled. Normally, the best way to extinguish a cockloft fire is to pull the ceiling beneath the fire area and apply hose streams directly onto the burning roof and ceiling supports while members on the roof cut ventilation openings. At times, however, this may take more manpower and time than is readily available. In this case, a piercing nozzle may be used to quickly get some water into the cockloft.
Since most of these nozzles use impinging jets to produce a fog pattern, the fire readily converts the discharge to steam, filling the cockloft and slowing fire travel. The big drawback to most of these nozzles is their limited discharge flows, typically less than 125 gpm. That is fine for a relatively small fire, but when a serious fire is developing in a larger void, something with more "punch" is needed. Enter the distributors and cellar pipes.
Distributors and cellar pipes were designed to apply much higher volume streams than the piercing nozzles. For example, the "Baker" cellar pipe came with either a single 1 1/8-inch solid discharge which flowed approximately 260 gpm, or two one-inch solid discharges that flowed almost 400 gpm! The "Rockwood" cellar nozzle had two impinging jet fog discharges that flow about 135 gpm each, and acted like a distributor, spinning around as it operated, so that the entire area within its reach was blanketed with the 270-gpm fog pattern. The Bresnan distributor is one of the more common types of cellar nozzles; it flows anywhere from 280 to 480 gpm in the 2 1/2-inch model, depending on the pressure supplied and the manufacturer.
Distributors and cellar pipes have strong points as well as weaknesses. The Baker cellar pipe and similar solid-tip devices require a firefighter to manually direct the stream, which may be dangerous if the integrity of the floor he must operate on is in question. The solid stream discharge, however, offers the advantage of greater reach, upwards of 50 feet, which may permit the pipe to be inserted farther away from the fire, where the floor support is still stable, and direct the stream toward the seat of the blaze.
The Bresnan and Rockwood devices involve rotating heads that require little attention once inserted and water application begun. They must be inserted very close to over the seat of the fire, however, to be effective. Their typical operating radius is only about 20 feet.
When using any type of cellar nozzle, realize that they will never fully extinguish any blaze. You are operating them blindly from the floor above. You could have inserted them into a closet or bathroom and be wasting all your water. Monitor conditions closely, operate the devices in any given position for two to three minutes, then shut it down and move it over five to 10 feet, evaluating conditions as you do. If conditions do not improve after three or four applications (10 minutes total), chances are the water is not reaching the seat of the fire. Prepare defensive positions.