How to Contain a Wildfire
By Aidan Grundy-Reiner, SB Staffer & Wildland Firefighter
J.P. calling in a helicopter bucket drop on the active edge of the Grouse Fire in the Klamath NF. Helicopters are used to drop water to slow fire growth where hose cannot reach as in the case of remote fires like this one. They are guided in by radio traffic by someone on the ground.
Fighting a wildfire is a very different beast from putting out a building that has gone up in flames. We rarely have water or hoses and when we do it never seems to be enough. Our trucks usually only get us part of the way there, after that we go by helicopter or on foot. We rarely get to put out a fire and return home to our beds that night - 14 days in the field is the norm. And perhaps most tragically: we have no fireman’s pole to dramatically slide down at our station.
Unlike in structure firefighting, the goal is rarely to extinguish the fire but rather to contain it and allow it to burn itself out safely - putting out a 100,000 acre fire with water simply would not be possible. The tactics used to fight wildfires are surprisingly simple, and most fires fought using a “full-suppression” model (the norm in highly flammable California) follow a progression of sorts through several different phases.
1st Phase: Initial Attack (IA)
This begins as soon as a fire is reported, spotted by fire lookouts, spotting planes, etc. This is similar to urban structure firefighting in that time is of the essence - the fire has started and is growing, and the faster we can get to it the easier it will be to stop it. Depending on where a fire is though, the resources dispatched to it vary. In reasonably accessible areas, engines or handcrews like the one I’m on roll out to the incident. In more remote wilderness areas they may deploy smokejumpers (basically firefighting paratroopers) or heli-rappellers (crews that rappel from helicopters hovering above the ground). Once resources are on scene the real work begins.
T.D. cutting open a burning heavy log to provide access for a helicopter bucket drop on the Henry Fire in the Stanislaus NF Carson-Iceberg Wilderness. This log was close to the line and needed to be cooled down so as not to threaten the line.
The goal is almost always to box the fire in by constructing “fireline” around it - a fuel break line through the forest that it cannot burn across, typically consisting of a 10-foot wide saw swathe through the brush (but leaving live trees) and a 2-foot wide scraped trench down to mineral soil. On a 20-person crew like mine, everyone has a role in line construction. 3-4 saw teams, each consisting of a sawyer with a chainsaw and a “swamper” who removes cut material, work together to lead the way with the saw cut. Following behind them is the rest of the crew in the “scrape” or “dig” with a variety of tools. The first 2-3 people wield hybrid axe/hoes called Pulaskis, intended to break up the soil, cut up roots and small plants, and pull out rocks. Following behind them are several people with a variety of heavy-duty hoe-like tools all intended to remove the top layer of leaf litter and soil. At the back of the line the last person comes through with a “monkeypaw”, a short handled rake that pulls any last bits of leaf litter or wood scraps off the line, leaving a clean barrier to the fire’s spread.
Fire burns behind a log coated in airplane-dropped fire retardant on the Grouse Fire in the Klamath NF. The retardant slows fire growth and intensity so a fireline can be constructed around it safely.
This line construction usually begins at the “heel” of the fire, the safest, least active part, and then works around the flanks of the fire with the ultimate goal of eventually catching the “head”, the most active part, and closing the box around it. During an IA we are cutting “direct line” or “hot line” - line as close to the fire as we can safely cut, in the heat and smoke. If air support is available helicopters or planes may assist by strategically dropping water or fire retardant to keep fire intensity down. It is among the hardest work in fire.
2nd Phase: Extended Attack
There are times when the IA phase does not succeed. Weather conditions, extreme fire behavior, and other factors sometimes make it impossible to successfully contain a fire during the IA, forcing us to shift tactics to an Extended Attack. This is the kind of fire you see on the news - large campaign fires that go on for weeks or months and require extensive resources.
Nighttime controlled burning operations on the Cronan Fire (River Complex) in the Klamath NF. Cooler night air, higher humidity, and downslope winds all serve to make burning at night safer and easier to control. Burning sections of fuel off strategically deprives the fire of fuel and stops its spread.
The end goal is the same: get line around all active portions of the fire, but often “indirect line” is used as opposed to the direct line common on an IA. Indirect line is constructed at a geographically advantageous spot, often a road or a ridge, and is frequently constructed using bulldozers and other machinery. This sort of line leaves hazardous unburned fuel between us and the fire and often requires burning operations to secure - we light fires strategically to close the gap between us and the fire and keep the fire intensity low and manageable.
Phase 3: Mop-Up
At some point days, weeks, or months later, once there is line around the fire, it is declared contained and mop-up begins. This usually means patrolling the line and putting out all heat sources first 10 feet, then 50 feet, and eventually 100 or more feet interior from the line.
Morning light shines through the smoke over the fireline around the Grouse Fire in the Klamath NF. The line in this section held, separating the unburned “green” on the left from the burned “black” on the right. The fireline we constructed can be seen under the hose in the center of the frame.
When water is available this stage is much easier - without it we “dry mop” essentially burying any hot material to deprive it of oxygen. As you might expect, this stage can take a very, very long time on huge fires with miles and miles of line.
Phase 4: Patrol
This applies more to small fires. Once a fire is mopped up and we are pretty sure it is out it spends some time on “patrol status”, where someone will visit it and check on it regularly to make sure it is fully out.
Phase 5: Out (+Rehab)
Once a fire has been patrolled sufficiently it is declared officially “out”. The whole process, from IA to out, might take a week for a small, ¼ acre fire or might take six months for a large campaign fire - it might not be out until the rain comes in the fall. Fires have been known to reignite the following year even, all it takes is one ember smoldering in a heavy log deep under the snow to start something back up. After suppression efforts are over, rehab also gets underway. Erosion control measures are put in place on dozer lines and hand lines, all equipment is removed, and in wilderness areas additional effort is put in to reduce the visual impact of our work.
Helicopter loads being picked up and dropped off on the Henry Fire in the Stanislaus NF Carson-Iceberg Wilderness. This fire was far enough into the wilderness that all personnel and equipment came and went via helicopter.
Every fire is obviously different. The plan made at the beginning is almost never the one executed in the end, but this does roughly describe how we do it. For far more in-depth information, the National Wildfire Coordinating Group (NWCG) provides numerous free learning and training resources through their website, and is just one of many such resources available to help understand all that goes into battling the giant fires that have become our norm.
Jed Clark says...
well written article. I am going to save this.
thanksOn September 12, 2021