FIRE FACTS: Containment lines
Firelines are constructed around a fire to "contain" the fire and serve as the point where fire crews will do all they can to stop the progress of the fire. Firelines are "containment" lines.
On the fires here in Louisiana, these lines are mostly constructed with dozers and "tractor-plows." Dozers generally have wider blades than tractor-plows and make wider fire/containment lines that are often easier for wildland "brush trucks" to drive down. This is important because the brush trucks are the Wildland engines capable of transporting hundreds of gallons of water almost anywhere along remote fire, or containment lines.
The tractor-plows are generally designed to be able to maneuver more quickly in forested areas to plow the line by breaking through the surface fuels and mix them with sandy soils common in many coastal southern areas, like this part of southern Louisiana. As the tractor-plow and/or dozer constructs the line, crews then use it to hold the line.
Not all sections of a fire/containment line need to be constructed. Firefighters will use existing roads and trails, and natural fire breaks such as rock outcrops (in some geographic areas), and even streams and rivers that are relatively free of riverbed brush. In areas that are difficult to get into by mechanized equipment, hand crews will be used to "cut" handline. And, on some wildfires in mountainous areas, it may be too hazardous to even put hand crews. In those cases, a section of fireline may end up being held by fire retardant dropped to connect that section with adjacent hand or dozer line.
The primary objective of the "containment" line is simply, to not let the fire go beyond that point. In a future post, we will talk more about how wildland firefighters actually "hold" a fire or containment line once segments of the line are completed.