Bubbles Redouble
Compressed-air foam systems, or CAFS, have resurfaced in recent years, with fire service organizations around the world showing increasing interest. This technology dates back to the early 20th century, when it was used in Europe for shipboard fire suppression. The British and U.S. militaries soon adopted it for fighting flammable-liquids fires.
Firefighters treating a home during a wildfire. Photo courtesy of Intelagard.
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Compressed-air foam is a fire suppression medium created by injecting air under pressure into a foam solution, providing a 33% longer throw for the same psi pressure. The foam essentially blankets the fuel, reducing the fuel's capacity to seek out a source of oxygen. The thick foam adheres to vertical surfaces, aiding in the rapid reduction in heat, and it shields the fuel source from radiant energy.
With the positive effects of increased firefighter safety and reduced property damage from excess water, the use of CAFS is on the upswing. In the last five years, firefighting agencies in Australia, France, Germany, the United Kingdom, Brazil, China, Singapore, Saudi Arabia and the United States have begun to use — or are in the process of testing — this technology for use as a primary fire-attack tool.
In urban interface settings where firefighters are deploying and treating a lot of homes and structures, they no longer have to lug around a 100-pound hose full of water. Compressed-air foam weighs 90% less than a charged hose, which can make a huge difference in terms of firefighter fatigue. A typical ranch-style house can be treated in as little as three minutes. Another advantage when pretreating a structure is that foam stays wetter much longer than water alone.
"Most recently, we utilized several CAF units on the 2009 Olde Stage Fire in Boulder, Colo., to augment structure protection and facilitate a large-scale burnout operation behind multiple structures," says Chris White of the Anchor Point Group. "The sheer time savings in comparison to establishing a hose lay, and the capacity of the units, assured a successful operation that saved countless homes."
CAF systems come in a variety of setups. Backpacks are great for putting out spot fires. A 5-gallon backpack will provide 350 gallons of firefighting foam at a distance of 35 feet. An ATV, which provides the ability to reach some difficult places very quickly, holds 14 gallons of water to produce 1,000 gallons of foam.
Some companies that sell CAFS are marketing units to wildland-urban interface homeowners. This could be the next-generation tool for the WUI homeowner, and it already has in Southern California. In fact, this tool may become a necessity for living in the WUI, especially for situations when people can't evacuate safely.
In looking down the road, here are some reasons why CAFS may be the next-generation WUI homeowner tool. (While the list is based on what is happening in the United States, it will likely resonate elsewhere.)
Urban interface expansion. According to a report published by the National Academy of Sciences on the implementation of National Fire Plan treatments near the WUI in the western United States, from 1970 to 2000 there was a 61% increase in WUI area and a 68% increase in total housing units.
Huge investments. The same report identified nearly $3 billion of public resources being used to target fuels-mitigation work from 2001 to 2006. Seventy-one percent of the WUI is private landownership. How long will federal dollars keep flowing for this activity?
Population explosion. More babies were born in the United States in 2007 than in any year in the nation's history. Where will these children live in 20 years? (Mom and Dad are likely hoping it's not with them, and we're hoping it's not in the interface.)
Road conditions. The American Society for Civil Engineers gave a grade of "D" to the poor road conditions in the United States, stating: "The nation is failing to maintain even the current substandard conditions, a dangerous trend that is affecting highway safety and health. Americans traveled 2.85 trillion vehicle-miles in 2002. … [Highway] mileage is mostly rural; a majority of road travel, 60%, occurred in urban areas in 2002." Can the United States bring road conditions up to par and build new ones to accommodate the rising numbers in population so people will be able to safely evacuate?
First responders. According to the U.S. Fire Administration's 2008 statistics, more than 72% of firefighters across the nation are volunteers. Many rural communities have all-volunteer fire departments, which tend to be strapped for cash and have limited equipment. Without significant financial support, will their resources be sufficient to keep both themselves and homeowners safe as the WUI expands?
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