Just a few weeks into the 2018 fire season, any hopes that an ongoing drought and a winter of weak snowfall wouldn’t wreak havoc are already toast. Fires are already popping up across Colorado, New Mexico, and west into Oregon and California.
This year’s season got off to a roaring start more than a month ago in Durango, Colorado, where the 416 Fire has burned more than 50,000 acres in the San Juan National Forest. The burn started in a populated area and grew to cover huge swaths of ground in just a few days, but crews managed to contain the blaze and prevent the loss of any structures or life.
And as the fire season picks up momentum, it’s worth an examination of the techniques and tools firefighters use to fight back the flames.
The 416 Fire started on June 1, early in the Colorado fire season, which turned out to be somewhat helpful. There are only so many firefighters, engines, planes and helicopters to go around, and federal agencies must allocate them based on current and emerging threats to life and property. For a time, the Durango fire was the highest priority wildfire in the United States, and that means the crews fighting it got everything they needed. Including the VLAT.
When it comes to controlling a fire, aircraft are one of the most important tools in the arsenal. Whether it’s helicopters dropping a few hundred gallons of water on a single burning tree or enormous aircraft dropping tens of thousands of gallons of flame-suppressing chemicals at once, aircraft can change the tide of the fight. The rarest resource of all is the VLAT, or Very Large Air Tanker. Oftentimes these are repurposed DC-10’s with 11,600-gallon capacities, five times as much as a Large Air Tanker. And they put on quite a show, as this video shot by Durango Fire & Rescue (where I was a volunteer firefighter for five years) makes clear:
“They’ll use it to buy time strategically,” explains Deputy Chief Randy Black of Durango Fire & Rescue. “They don’t want to put crews in steep terrain at night. They’ll bring one in and paint the line, and that can take care of it for the evening. That was the last aircraft to come in, then sometime the next afternoon they started working that line.”
The red chemical mixture, or slurry, this aircraft dumps isn’t actually meant to extinguish the flames. “It’s to push the fire out of the trees and down to the ground,” says Black. “They’ll get it down to the ground, then do a burn off from the line up to the fire and control it. Create the line they want on their terms.”
The line is all important in battling wildfires, where the main tactic is cutting the flames off from the fuel they need to keep going. This part of the process looks like high-precision, high-speed landscaping. Twenty-man hand crews will use chainsaws, shovels, and a specialized tool called a Pulaski to remove leaves, pine needles, and other sorts of fuel from a stretch of ground to create a barrier around the fire. If the fire is creeping along the ground, an 18-inch wide stretch of line just might be enough to stop it.
Sometimes, the best way to fight fire is, yes, with fire. A controlled burn can eat up the fuel the main fire needs to advance. By creating an area of “black”, or burned out ground, firefighters can control where the fire goes.
“You have actual line, then the black, leading up to the fire that’s burning. Then you can mop up and make sure it’s cold in the black area. You’ll have a strong, reinforced line and you’re good,” says Chief Black. “Slurry bombers are working on slowing the fire and trying to control it to the point where it would be a line.”
Each unit relies on the other to work. A plane dropping slurry can’t do much without crews on the ground reinforcing the drop, and those crews can’t do anything if the fire is torching— jumping from tree to tree high above the ground. The logistics are daunting, especially when aircraft are involved: It can take hours for a DC-10 to return to base, refuel, refill with slurry, and then get back to the fire. In Durango, the plane needs to go back to Colorado Springs, which takes at least a two-and-a-half hour turnaround time. An aerial attack team must coordinate all of the assets at hand to best fight the fire. VLATs, helicopters, heavy tankers, single engine air tankers, ground crews—all to steer and manage the fire as best they can.
“That’s the science coming out of the command team, the fire behavior analysts, and meteorologists,” says Black. “Here’s what the weather is, tactically do this, then do this at this time. They have all this fuel modeling software and engineers—it’s not two 1970s Forest Service dudes sitting up in a tower there hoping this works. It’s a calculated scientific process.”
And when fire season roars in, you just hope it’s enough.
More Great WIRED Stories
- PHOTO ESSAY: These flowers are actually fireworks
- Did Satoshi Nakamoto write this book excerpt?
- How Tesla is building cars in its parking lot
- The new arms race threatening to explode in space
- How technology helped me cheat dyslexia
- Hungry for even more deep-dives on your next favorite topic? Sign up for the Backchannel newsletter