Compressed Air Foam System - History

History

The idea that water is not a perfect tool for fire extinguishment has been long noted, as by W. E. Clark (1991), "The process of extinguishing fire by water is cumbersome and generally costly … the cost of installing water mains large enough for required flow, the installation and maintenance of fire hydrants, and the acquisition and maintenance of fire department pumpers, fire hose, and nozzles, make water a fairly expensive extinguishing agent … the use of water is hardly the ideal way to extinguish fire … there must be a better method waiting to be discovered." (p. 75)

Liebson (1996) adds, "Water is an inefficient extinguishing agent. It requires the use of large quantities at costs both financial and physical. These costs are imposed on the firefighter and the community." (p. 5)

The use of foam additives to water for extinguishment dates back to an English patent in 1877 for a method to produce chemical foam (Liebson, 1991, p. xi). The Royal Navy experimented with agents foamed by means of compressed air in the 1930s (Darley, 1994) and the United States Navy was using compressed air foam systems (CAFS) in the 1940s for flammable liquid fires. By the 1960s do-it-yourself car washes were using CAFS with low pressure and small-diameter hoses and nozzles, which flowed about 4 US gallons (15 L) per minute of solution and 4 cubic feet (0.11 m3) per minute of compressed air, with a nozzle reach of about 40 feet (12 m) (Rochna and Schlobohm, 1992).

In the mid 1970s Mark Cummins, while working for the Texas Forest Service, developed a water expansion system known as the Texas Snow Job. Mr. Cummins invented the CAFS and was issued the US Patent 4318443 in 1982. This pioneering Class A CAFS used dish-washing detergents or a pine soap derivative, which was readily available as waste from local paper manufacturing industries, as a foaming agent mixed as 8 to 9 parts agent to 91 to 92 parts water, flowing up to 30 US gal (110 L) per minute. The duration was limited by the use of compressed air cylinders rather than compressors (The US and foreign patent issued to Mark Cummins also included all types of air compressors and inert gas generators). By the mid-1980s, research by the United States Bureau of Land Management in co-operation with Mark Cummins, led to modern design features of rotary air compressors, centrifugal pumps, and direct-injection foam-proportioning systems (Fornell, 1991; IFSTA, 1966). CAFS received national attention in 1988 during the Yellowstone Park wildfires when the four-story Old Faithful Lodge was successfully protected by blanketing it with compressed air foam (Darley, 1994).

In the spring of 1994, a compressed air foam demonstration vehicle manufactured by W.S. Darley & Co., was driven from coast to coast in North America by Troy Carothers. The purpose was to spread the word about CAFS and display this relatively new technology to United States and Canadian firefighting services. Many years earlier Darley Co. teamed up with Cummins on the WEPS (water expansion pumping system) demonstration vehicle. The 1994 Darley demo vehicle was operated by Troy Carothers who was involved with the initial design and assembly of the Darley AutoCAFS product. Carothers is now the Darley AutoCAFS Manager and oversees all aspects of CAFS development for Darley Co. This demonstration vehicle concept has continued annually since 1994.