Extinguishing Wildland Fires
Understanding how to put out a wildland fire first requires one to know the various parts of a wildland fire. These terms should be fairly easy:
Origin- The location where a fire begins
Head of the Fire- The edge of the fire moving most rapidly
Heel of the Fire- The area close to the origin, and often the slowest moving edge. Also called the rear of the fire
Finger- A sudden burst of wind or change in elevation can cause this phenomenon- a long, narrow fire extension that projects beyond the head of the fire
Pocket- An unburned area between the head of the fire and the Finger. Firefighters standing in a pocket have fire on 3 sides (that's bad news bears)
Island- A unburned area completely surrounded by fire. Similar to a pocket situation
Spot Fire- A fire that starts separately from the main fire (outside the perimeter). Often caused by fire traveling along the convection currents of the larger fire
Green- A term used to describe in area that is unburned
Black- A term used to describe an area that is already burned
We extinguish wildland fires the same way we extinguish any fire; by removing one section of the Fire Triangle.
Removing Heat- The methods of cooling fuel for wildland fires vary based on the size of the fire. Small fires may only require wildland firefighters to use a backpack pump extinguisher, which carries up to 8 gallons of water and resembles a squirt gun we all remember from childhood. If necessary, brush trucks can be brought in to provide larger quantities of water and lengths of hose for distribution. If a fire is too strong for either of these methods, aircraft will chime in to aid in suppression efforts.
Removing Fuel- Another way to extinguish a wildland fire is by removing the fuel source. Brush can be cleared away before the fire has a chance to consume it, or firefighters may choose to create a controlled burn (called backfiring). This method creates a barrier in front of the Head of the Fire by burning off the fuel source and hopefully stopping the fire's progression.
Removing Oxygen- Sometimes firefighters will try to smother a wildland fire, but usually this method is only used to put the finishing touches on a fire that has been mostly extinguished already. Compressed Air Foam Systems (CAFS) are mixed water and air with a foam concentrate that is used to absorb a fire's heat and prevent oxygen from reaching the vegetation it has been applied to.
ATTACKS
No matter the scenario, there are also two ways to define extinguishment of wildland fires: Direct Attack and Indirect Attack.
A direct attack is accomplished by extinguishing the fire at the edge or the Head of the Fire. This is usually the preferred choice on smaller fires. An indirect attack is accomplished at a safe distance because these fires are usually too big to fight head on. An example would be to fight a wildland fire from the air or using natural breaks like a road or river to create a gap in the fuel source for the fire to consume. Usually firefighters on the ground will work day and night to clear the forest floor by hand, thus removing the fuel source and making the fire's ability to spread more difficult.
FIRE SHELTER
One of the most crucial pieces of equipment a wildland firefighter can have is the fire shelter. These shelters shield a firefighter from over 90% of radiant heat created by a fire if used properly. Forest fires can travel extremely fast, especially when wind is a factor. If a firefighter is overcome by a fire he or she can deploy the shelter and lay face down inside, much like a sleeping bag pulled over your head. These shelters have saved many lives of firefighters over the years and continue to be the most important piece of equipment a wildland firefighter can carry in his or her arsenal.