By Eve Byron
Missoulian, Mont.
MISSOULA, Mont. — Most Montanans are familiar with the “what” portion of the 1949 Mann Gulch tragedy — 13 men who lost the uphill race with a deadly wall of flames. But since the 1960s, scientists at the Missoula Fire Sciences Laboratory are better understanding the “why” of the situation and how to keep it from happening again.
Many parts of firefighting are intuitive. Fire burns faster uphill. Fires need fuel, a spark, and oxygen. Wind pushes fire.
But to the scientists and engineers at the lab, which is tucked into a nondescript building near the Missoula International Airport, those properties are just the start of their research, and their discoveries are making firefighting safer.
Bret Butler, a mechanical engineer, notes that the 10 standard firefighter orders and 18 “watch out” situations were devised in the 1960s and haven’t changed much. They include the basics like posting lookouts, giving clear instructions and identifying escape routes and safety zones. But when he asked firefighters to define a safety zone, he got mixed responses.
“How big should it be? That was left to personal experience,” Butler said. “I did a survey, and the size of the safety zone varied by three orders of magnitude. But when they saw the pictures of the fire, their sizes (for safety zones) increased greatly. That indicates to me that we fire people have a hard time envisioning what fire looks like and its impact on us.”
So the scientists at the lab play with fire, testing and recording its characteristics for “boots on the ground” situations.
On a recent afternoon, Mark Finney, a research forester, noted that scientists began looking into the mechanics of wildfires in Region 1 after the 1910 fires.
“Eventually there was a fair amount of momentum to invest in fire research,” Finney recalled. “Experimental research is at the heart of science; you can’t address the unknowns without experiments. You have to play with them and experiment with them in different ways than ever imagined in the 1960s, when the lab opened.”
He stood in front of a 6-foot table with the bottom closest to him lower than the top. Inserted in it were pieces of cardboard with uniform teeth like combs standing up. Finney had selected some that were relatively thin and about an inch tall as he noted that even the simplest questions about wildland fires are unanswered.
“How do fires spread? What is the physical process?” Finney asks. “That’s still largely unknown. But it doesn’t mean we can’t test the processes. It’s like agreeing on the ingredients for a recipe, but if you don’t know the amounts of the ingredients and the instructions, you’ll get something different every time.”
The different types of cardboard tines represent different fuel types, like fine grasses or maybe pine needles or sagebrush. Finney sprinkled “excelsior,” which is shredded wood formerly used in Easter baskets, at the base of the table and lights it on fire. He called it an ignition line.
“This isn’t intended to emulate what happens in the wildland fires since fuel in the field is heterogeneous; in the field, it varies from centimeter to centimeter,” Finney added. “But it helps us study how heat is transferred from what’s burning to the next fuel element that ignites.”
He lighted the excelsior, and as the flames started to lick up the tabletop, Finney pointed to the troughs in between the tips of the flames. While eyes may be drawn to the dancing tips, activity in the troughs is what makes the fire spread.
“The trough is where the cold air comes down, and that’s what’s pushing the fire. The top of the flame isn’t what’s igniting; it’s the lower part of the flames,” Finney said. “A lot of this hasn’t made its way into training and predictive models, but in the not-so-distant future — maybe a few years — we’ll work this into prediction and training curriculums. We can explain to firefighting personnel how to interpret this in the field. What does this mean, and how does it translate to different decisions they make for safety purposes?”
He noted that flame behavior on the larger 12-by-20-foot “sand burner” behind him also is relevant to Mann Gulch because they’re using propane and other liquid fuels to experiment with the effects of slope on fire spread and flame behavior.
“Those poor guys in Mann Gulch ran up the mountain from down below. Flames will stick to the slope and run very rapidly uphill,” Finney said. “We test cautionary behaviors. Don’t work upslope of fires. That was Mann Gulch, steep slope and fine fuels. It’s interesting that everybody knows fire spreads up slope faster but we still can’t fully explain it.”
In his office, Butler pulled out a 1993 paper by Richard Rothermel called “Mann Gulch Fire: A Race that Couldn’t Be Won” and opens it to page 5. A distance and time graph showed the estimated positions of the Mann Gulch crew and the fire, plotting the movements of both.
“It’s simple. People go slower uphill and fires go faster,” Butler said, shaking his head as he recalls the 14 firefighters who died in 1994 in Colorado trying to outrun a fire burning on a slope below them and pushed around by the wind. “I don’t know why we can’t learn that lesson.”
What they did learn is the need to predict and understand local winds at the ground level. That led to the creation of the WindNinja, a mobile phone app to help fire managers predict what winds will do while out in the field.
Matt Jolly, an ecologist with the Fire Science Lab, said they’re also getting ready to roll out across the country the first revision in 40 years for fire danger ratings. The ratings are based on a wide mix of conditions, including humidity, rainfall, sunshine, cloud cover, wind speed and direction, and fuel moistures, among other items.
“We went through the entire fire danger rating system and determined where we have better science,” Jolly said. “It both simplifies the system and makes it fully automated. The old system required daily observations at weather stations across the country, a relic of when weather observations were made manually.”
Jolly said the nearby regional Northern Rockies Coordination Center, which is the interagency focal point for mobilization of wildland fire resources, already is using the new system.
“We just presented it to the smokejumpers next door last month, and they’re excited about it,” Jolly added. “Just because it’s cool and wet here doesn’t mean it’s the same when they fly into Idaho.
“Both the firefighters and the public are the reason I come to work each day. I want to ensure we’re providing the best possible information so we can keep people safe.”
As Jolly, Butler and Finney reflect on the conditions facing the Mann Gulch firefighters, and the knowledge that’s available now that wasn’t then, they hope that the tools they’re providing will prevent another firefighter’s death. But they all know that despite their best efforts at the fire science lab, firefighting always will be a dangerous profession.
“I do know that the information we can give them today versus the information they had then, is significantly better and they would have had a better idea of the conditions where they were about to jump into,” Jolly said. “What we also have done a better job with since Mann Gulch is empowering firefighters to express their concerns about a decision, and having discussions on how they will mitigate those factors to keep their crews safe. That’s a cultural shift that’s evolving.
“The big thing is in this lab and all over the country we are committed to learning as much as we can about fire, then taking that last step, which is how do we keep people safer, and the community safer. Because science for science’s sake is valuable, but when you can translate that into something people use day to day, hour to hour to keep communities safer and people safer — that’s the reason we’re here.”
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©2019 Missoulian, Mont.