
By Laura Oleniacz, North Carolina State University
North Carolina State University researchers found that four new designs for shelters to protect firefighters trapped in wildfires could increase the survival time inside the shelters compared with the current industry standard. In lab simulations of wildfire burn-overs — where a wildfire sweeps over a group of trapped firefighters or equipment — temperatures inside the shelters remained within survival limits for longer, and the shelters took longer to break open.
Researchers hope their findings from the lab, as well as from field tests conducted across North America, could spur the development of new, better shelters. In addition, they hope the findings will inform new standards for shelter design and testing.
“For the wildland firefighter, deploying a shelter is the last thing they want to do — it’s the final resort, the last line of defense,” said study co-author Roger Barker, the Burlington Distinguished Professor of Textile Technology at NC State and the director of the Textile Protection and Comfort Center (TPACC). “While there’s no such thing as ‘fire-proof,’ what we’re trying to do is to buy more time. We were able to demonstrate our shelters could increase the time to failure — time that could be critical for survival.”
One problem with the industry standard shelter is that the aluminum outer layer will melt in contact with direct flame.
“In light of the failure mechanisms of shelters that we observed during wildland fires, we thought we could develop better shelters that provide enhanced protection by incorporating an inner heat-blocking barrier and additional thermal insulation into the construction,” said the study’s lead author Joseph Roise, professor of forestry and environmental resources at NC State. “We know we can make a better shelter.”
With that goal in mind, the researchers designed two leading prototypes and two lighter versions weighing less than 5 pounds. They added insulating materials, and experimented with different seam designs to keep them from falling apart.

In the TPACC lab, researchers tested the designs against the industry standard in a test chamber called the PyroDome Turbulent Flame Fire Shelter Test System. They blasted the shelters with direct flame from propane burners for 60 seconds, and measured how long it took the temperature at the floor of the shelters to reach 302 degrees Fahrenheit, the temperature threshold for survival. They also set up cameras inside PyroDome to see when the inner layer of the shelters would break open.
All of the prototypes had improved survival metrics compared to the standard, which reached the survival limit in less than 40 seconds. Meanwhile, the temperature in one of their designs was nowhere near the survival limit temperature at 60 seconds.
“We went all over North America to find different fire conditions that would give different types of fire exposures,” Barker said. “What we found is there is so much variability in the field test, confirming how useful it was for us to have PyroDome.”

The two tests in southern California had the best burn conditions, and researchers saw one of their prototypes performed well in a burn-over. In a test in South Dakota, researchers witnessed shelter failures when grass roots caught fire to spread under the walls inside the shelter. That underscored the importance of fully clearing the area around the shelter, and even scraping down underneath them to remove all organic material.
“If you have a sample of two, you can’t make any statistical comparisons,” Roise said. “But we did see that after the test in California, one of our best-performing prototypes got the full brunt of the fire. It was totally burned on the outside, but the inside was undamaged.”

The new findings could give manufacturers and people developing these shelters a new target to shoot for in terms of both how to test them and minimal performance requirements, according to Barker.
The study, “Field and full-scale laboratory testing of prototype wildland fire shelters,” was published online in the International Journal of Wildland Fire. In addition to Barker and Roise, other authors include John Williams, a former research assistant in forestry and environmental resources at NC State, and John Morton-Aslanis, a research assistant in TPACC. The study was funded by the DHS FEMA Assistance to Firefighters Grant Program.
(All of the images are from the IJWF study)
Thanks and a tip of the hat go out to Gerald.
IF YOU CAN’T GET IN A FIRE SHELTER YOURSELF TO TEST THE TRUE OUT COME THAN DONT PUT FIREFIGHTER ON THE LINE IN DANGER THINKING THAT THIS WILL HELP MAYBE SAVE THERE LIVES. AFTER 17 FIREFIGHTER LOST THERE LIVES DUE TO A FAILURE OF THE FIRE SHELTER I THINK SOME VERY SERIOUS RESEARCH SHOULD BE DONE TO PREVENT THE FROM HAPPENING AGAIN.
Teague, your caps lock appears to be stuck. Please stop yelling.
Which firefighters are you referring to?
What 17? Are you referring to the Granite Mountain 19? I believe you are seriously confused about what materials are available that can be used for fire shelters, the material thermal capabilities, and the what materials are actually able to be used by those that have to carry them on the fireline day in and day out.
“…SOME VERY SERIOUS RESEARCH SHOULD BE DONE..” Do you live under a rock? What do you think was initiated right after the hotshots were killed? Do you have any suggestions for a better shelter, or are you here to only throw rocks? For example, aluminum foil can only withstand about 1200 degrees F before it melts, a common wildfire temperature. What do you suggest is used instead? What else is there? Very easy to disparage those that work on firefighter safety by sending an all caps, anonymous, and quite ignorant post claiming they don’t care or aren’t doing anything to better protect the firefighter. That simply is not true.
Next time you post, try not to let your ignorance shine through like it did this time. You are capable of better.
I glad I’m retired and I used my shelter plastic box for my lunch and tobacco have a safe season
Based.
Lighter and more compact is a hell of a lot more important than increased survivability.
NASA was involved with the last life cycle review of the fire shelter as was NC State.
So the issue is how long is it going to take to put the newest and best version in the hands of our firefighters?
Where are the agencies on getting this mass produced and in the field?
If it were their sons and daughters, a contract for these would have been done “yesterday.”
This is an URGENT need people; get on it!
Why are we still screwing around with “grant money” to fund research for these???
Thanks for putting in work on this.
Please, if you want to get serious lets do it with hard dollars and lets invite big brain trust to the table!!
DARPA, SPACEX, MIT, CALTECH, Etc!
Even if the final product costs $10k per, if it works, it’s a drop in the bucket when considering it’s sole purpose is to save a human life.
$10,000 per shelter, Robert – No Problem, right?
Maybe for large Fed agencies, but what small Rural and Volunteer fire departments, and even some low budget State departments.
I’m on the Board of a western US Rural, and $10K would be a budget buster, and the tax payers wouldn’t fund the costs. But we still have to fight wildfires.
Seems like some objective risk analysis is needed. How much is enough and how much is too much?
Look at the wildland fire fatality records over the past 30 years and, aside from a few large fatality, non-survivable burnover events like South Canyon and the AZ Hotshot crew, what’s really killing firefighters year in and year out?
I like your thinking. In fact, this would make a good XPrize contest. No shortage of Nobel Prize winners coming from Caltech.