Class A Foam Extinguishes Tire Fire
At 0356 hours on August 24, 1993, the Bell Township Fire Department was dispatched to assist with a tire fire endangering a structure in the village of Moween, Pennsylvania, The original call, some 30 minutes earlier, had been dispatched as a brush fire with the Loyalhanna Township and Saltsburg Borough departments called.
A large pile of tires and surrounding brush were burning. First-in units stretched a 2’/2-inch handline and initiated exposure protection for an occupied structure approximately 50 feet from the fire. The vinyl siding had begun to melt, and occupants were evacuated. This small village has no hydrant system, and an extended tanker shuttle was anticipated. Command called for water supply units from four neighboring departments.
Once the house was cooled, firefighters attacked the fire with the 250-gpm flow. This had little effect on the burning materials.
Bell Township arrived, and we conferred with command. Command decided to use our Class A foam system because of the current lack of continuous water supply and because the attack line was making little headway. I assumed suppression sector command and directed members to attach a 20-gpm air-aspirated foam nozzle (a 60or 95-gpm nozzle would have been preferable but was not available at the time) to one of our preconnects for foam operations. If the small nozzle proved ineffective, we would try a midrange combination fog nozzle at I 50 gpm.
Since none of us had any experience in applying Class A foam to tire fires, we decided that five gallons of foam concentrate would be used in the attempt. We set our balanced pressure proportioner at 0.3 percent rate (0.3 gallon of foam concentrate per 100 gallons of water, or one gallon of foam concentrate per 300 gallons of water) to create the finished foam. The 2‘/2-inch line was withdrawn to protect the exposure, in lieu of coating the structure with a blanket of finished foam, since several windows in the house were broken.
We began foaming the unburned tires and brush and continued pushing fire toward the center of the burning pile. In about five minutes, definite progress was evident. As the temperature was in the mid-70s and humidity was high at 80-plus percent, command ordered the operation of a PPV fan to push smoke into an uninhabited area, away from firefighters. This allowed the foamline crew and members with pike poles working the perimeter of the fire to pull tires out of the pile to operate without SCBA, reducing physical stress to a degree and improving visibility.
In about 1 5 minutes, all visible flames were extinguished, using approximately 300 gallons of water and one gallon of foam concentrate to achieve control. Overhaul was accomplished, and a representative of the state Department of Environmental Resources was summoned to determine if any runoff would jeopardize water sources; he found that the small amount of water/agent used did not create a problem.
The incident was considered to involve a hazardous material/waste under Pennsylvania Act 165, and as such, cost-recovery procedures against the owner were undertaken in conjunction with a certified hazardous-materials team, in this case the Westmoreland County Team 800, the first volunteer haz-mat team certified under the legislation. Total losses included an estimated S1,000 damage to the exposed structure and more than 82,000 in personnel, equipment and materials, and two minor injuries. The first injury was bee stings sustained when a firefighter uprooted a nest while pulling tires out of the pile; the second, a cut finger from wiping threads on a hose coupling, resulted in a reprimand for not wearing gloves.
The use of Class A finished foam on this fire yielded impressive results. Knockdown time was rapid—far better than what would have been achieved using plain water. Fire control likely would have been realized even sooner had a foam nozzle with a greater flow rate been available.
While recounting this incident is not an endorsement for using low flow rates in every application, it does suggest the effectiveness of Class A foam even for applications not originally intended. Research, experimentation, and networking will allow more fire departments to bene-fit from the knowledge and experience of others.
