By Jane Jerrard
Published Thursday, March 1, 2012
| From the March 2012 Issue of FireRescue
A two-year research study is underway, investigating the capabilities and limitations of compressed-air foam systems (CAFS) for interior structural firefighting. The study is funded by a $940,571 AFG grant, and led by California Polytechnic State University (Cal Poly) in San Luis Obispo. Technical support is provided by the National Institute of Standards and Technology (NIST) and the Fire Protection Research Foundation (FPRF).
Although CAFS is a common tool in wildland firefighting, opinions and limited data vary on how effective it is when used on structure fires typically located in the wildland/urban interface (WUI). “While CAFS is not a new concept, especially for fighting wildland fires, we need to know why it wouldn’t work in structural firefighting,” explains Capt. Homer Robertson, apparatus and fleet manager for the City of Fort Worth Fire Department. “We don’t have good, comprehensive research on its effects in these situations. I’ve had people come up to me and tell me [anecdotes] about how CAFS doesn’t work—but a structure fire at two in the morning is a terrible way to test its effectiveness.”
A Panel of Experts
Robertson sits on the advisory panel that provides ongoing guidance to the Cal Poly research team. The nine-member panel and other experts met in December 2011 to determine how to maximize the CAFS study, says Casey Grant of the FPRF. “We worked on providing refined input for the scientists. We want to make the most of the time and money available for this research.” Note: A report on that meeting can be downloaded from www.nfpa.org under the “Reports and Proceedings” tab.
Another panel member, Steve Lohr, is the division chief for Montgomery County (Md.) Fire and Rescue Service. His department, which hosted the meeting, has made “a huge investment in CAFS,” including an entire frontline pumper fleet. “In our industry, we’re facing challenges that continue to push the limits of our available resources,” he points out. “One of those challenges is faster-developing fires. Any technology that will bring more [resources] to that fire in reduced time, with greater security, is better for the service.”
Wanted: Scientific Data
Dr. Thomas Korman, P.E., associate professor for the Fire Protection Engineering program at Cal Poly, is the lead researcher for the study. He explains, “We’re trying to get some scientific data on the use of CAFS. There’s been a lot of testing done that’s not necessarily scientific.” Anecdotal information implies that CAFS uses less water, and will improve knockdown time, among other benefits. “We want to measure [CAFS vs. water] so that fire departments can make a decision about what to use,” Korman explains.
Previous tests of CAFS on structure fires have been limited or subjective, according to Korman. “If you do tests that are too small, you’ll get fantastic results. What we want to do is design a repeatable test where we run different fuel loads,” he says.
The current study on CAFS will involve examining effects, such as potential hose kinking; rate of flashback; effect on thermal imagers when looking for victims; slip hazards; and the rate of heat absorption vs. water, heat release and knockdown times.
Rumors & Misconceptions
The fire service includes a substantial anti-CAFS faction when it comes to structural fires. Lohr explains, “There are some fundamental misunderstandings about the technical [workings of CAFS], one of which is that we are pumping air onto the fire. This is not true. Foam solution has a demonstrative impact on fire; when you add high-energy air to that solution, it makes bigger bubbles, increasing the effectiveness of the solution.” The current research is necessary to prove precisely how much that effectiveness is increased or altered.
Robertson admits that there’s tremendous resistance in departments to adopting CAFS for structure fires. He attributes some of this to a cultural resistance to change. “We’re taught in the academy that water is in our DNA, and it’s what we use to put out fires. Water was good enough for Ben Franklin, and it’s good enough for us,” he says.
The AFG grant calls for the report to be released in July 2013. Korman stresses, “Our conclusions won’t be recommendations. Our report will primarily be an explanation of the tests and how they were run, in case someone wants to reproduce them, such as [a Canadian counterpart]. Then departments can use the information to make informed decisions regarding CAFS.”
Robertson adds that industry groups and media are certain to disseminate the results and add their own recommendations based on the data. “You’ll see members of the project technical panel at association meetings and conferences, giving presentations on the data,” he predicts.
The Ultimate Goal
The goal of this research, ultimately, is to get information that will help fire departments improve how they fight structure fires, while keeping personnel safe. “We want to make firefighters’ work more efficient and safer,” Robertson says. “Using CAFS would make the lines lighter and more mobile.” This, of course, would reduce physical stress, which is one of the contributing factors to cardiovascular events.
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