Based on the quonset hut design used extensively by the US military in World War II
A few of the 13,861 homes destroyed in the Camp Fire are being rebuilt using a particular design that is much more fire resistant than a typical structure. In 2018 the northern California fire burned most of the houses in Paradise after a failure on a Pacific Gas and Electric powerline ignited the blaze that raced through the town, doing much of its damage in just a few hours.
During World War II the US military purchased and installed thousands of quonset huts, a lightweight prefabricated structure of corrugated galvanized steel with a semi-cylindrical cross-section.
The steel itself is non-combustible of course, and if the rest of the exterior building materials are also, the structure should be very resistant to ignition during a wildfire. But it is important that everything within the home ignition zone is consistent with Firewise principles.
CBS News Sunday Morning produced the video story below of how this quonset hut concept is being used in Paradise.
Most structures that burn in a wildfire are not ignited by direct flame impingement, but by burning embers that are lofted and carried downwind ahead of the fire. At Wildfire Today we first covered the role of embers in igniting structures in 2010, a concept brought into the public consciousness by Jack Cohen, a researcher at the Missoula Fire Science Lab. To reduce the chances of a home burning in a wildfire, the most bang for the buck is to concentrate on the Home Ignition Zone. The flammable material near the structure needs to be modified, reduced, or eliminated to the point where multiple burning embers landing in the zone will not propagate the fire and spread to the structure.
The video below produced by the New Jersey Forest Fire Service elaborates on this concept. It is queued up to 1:42 where the issue is addressed.
BOZEMAN — Ray Rasker, who has researched wildfire for more than a decade as the executive director of Bozeman-based nonprofit Headwaters Economics, makes a bold claim about wildfire and its human impacts.
“We don’t have a forest fire problem, we have a home ignition problem,” he said. “As soon as you come to that realization, it changes your view on wildfire.”
(UPDATE: Ray Rasker contacted us in a comment, below, to say, “The top quote [above] was something I mentioned to the reporter as something that was said by Dr. Jack Cohen, a long-time Fire Science Researcher with the U.S. Forest Service. It’s not my quote and I’m not trying to take credit for Jack’s insightful comment.”)
Often we hear about the costs of suppressing wildfires, but the cost of fire trucks, firefighters, dozers, and aircraft are only part of that cost.
Some of a community’s willingness to change growth policies, subdivision regulations, building codes, and the like can be attributed to economics. Although significant, the money spent putting out a wildfire is minor — about 9 percent — relative to fire’s total financial impact, Rasker said. “Fifty percent of the cost is borne by the community. That’s businesses that close, that’s the loss of tax revenue during the fire, that’s the cost of reconstruction — restoring your wetland, for example. Your tax base goes up in flames.”
When economic losses become severe enough, elected officials find the political cover they need to push for additional regulation. Rasker said he’s seen the dynamic at work in several communities CPAW has worked with, including Flagstaff, Arizona; Boulder, Colorado; and San Diego, California. “Now it’s not planning as a liberal agenda; now it suddenly becomes something that’s fiscally responsible.”
Such regulations can include mandating better egress roads to make subdivision evacuations safer, requiring new buildings to be constructed with fire-resistant material, and developing landscaping guidelines for homeowners. There was a time, Rasker said, when municipal fire codes mandating safety measures like sprinkler systems and marked fire exits were all but nonexistent, resulting in casualties. “In an urban environment, we’ve fixed this problem,” he said. “But when the houses are surrounded by trees on the outside of town, suddenly none of those rules apply,” Rasker said, referencing a lack of regulations and enforcement in many rural areas.
The California Department of Forestry and Fire Protection has put together a list of 35 projects around the state where they intend to reduce the wildfire risk for residents. This follows multiple large fire disasters in 2017 and 2018 that killed over 100 people and destroyed tens of thousands of homes. In many areas those not directly affected by the flames were exposed to hazardous levels of smoke for days or weeks at a time.
The State will establish incident bases in proximity to vulnerable communities and coordinate fuels treatment operations from those facilities utilizing the Incident Command System. The Governor will activate the National Guard to help complete the work.
The projects, identified and planned at the local level, are intended to reduce the public safety risk for over 200 communities. Examples of work to be done include removal of hazardous dead trees, vegetation clearing, creation of fuel breaks and community defensible spaces, and establishment of ingress and egress corridors. CAL FIRE believes these projects can be implemented immediately if their recommendations are taken to enable the work.
Recognizing that entry level employees in California are not highly compensated, and often have challenges finding affordable housing in areas where they work, the state will provide additional government housing for seasonal state employees working on forest management and fuels reduction.
In addition to large-scale fuel reduction projects near communities, CAL FIRE understands that residents have to also do their part to reduce the flammable material in their home ignition zone within 100 feet of structures, and especially immediately adjacent — within 5 feet.
Details on the projects can be found online at http://calfire.ca.gov/fire_prevention/downloads/FuelReductionProjectList.pdf. CAL FIRE expects to keep the list updated.
Above: Dr. Jack Cohen makes a presentation at the 2011 Fire Litigation Conference in San Diego. Photo by Bill Gabbert.
Dr. Jack Cohen received the first National Legacy Award given by the U.S. Forest Service, National Association of State Foresters, National Fire Protection Association, and International Association of Fire Chiefs in recognition of outstanding career-long contributions to wildfire mitigation as an alternative to suppression. Dr. Cohen helped develop the U.S. National Fire Danger Rating System and developed calculations for wildland firefighters’ safe zones; created defensible space principles, which resulted in the Firewise program; the Home Ignition Zone; and conducted research on ember ignitions and structure ignitability.
His research laid the groundwork for nearly all of today’s work on wildland urban interface risk reduction. Until his 2016 retirement, he was a research scientist at Missoula Technology and Development Center. The award was presented at the IAFC WUI Conference in Reno, Nevada.
Thanks and a tip of the hat go out to Robert. Typos or errors, report them HERE.