Wildland Fire: Fireline Construction

This article is part of the Wildland Fire Learning In Depth series. It is designed for students who want to learn more about fire. Find the complete series on the Fire subject site.

Firefighters use hand tools to scrape away vegetation and reach mineral soil to build a fireline.

Fireline is a break in fuel, made by cutting, scraping, or digging. It can be done by mechanized equipment such as bulldozers, but in most parks, it is done using hand tools.

Getting Down to Mineral Soil

In building fireline, all fuels are removed and the surface is scraped to mineral soil on a strip between 6 inches and 3 feet wide, depending upon the fuel and slope. It needs to be wide enough to prevent smoldering, burning, or spotting by embers blowing or rolling across the line. If it is safe, firelines should be wider at the head of the fire than along the flanks. Firelines can also be made or enlarged by backburns, wherein fuels between the advancing fire and the line are burned out to slow or stop the fire.

Containment

Eventually the firefighters do prevail. Often a break in the weather is the factor that allows the workers to encircle and contain the fire. Once the fire is contained, the hard, dirty work of mop up goes into full swing to bring the fire under control. Each ember will be painstakingly sought and put out. The entire fire perimeter, and sometimes the entire fire area is felt with bare hands (also known as cold trailing) to be sure there is no longer any heat left to allow the fire to escape. During mop up, firefighters also begin rehabilitating firelines by raking back the soil and placing water bars to minimize erosion.

Demobilization (Demob)

Just as resources were pumped into the control effort, they are released (demobilized or demobed) as it is determined that they are no longer needed. Eventually the fire will be put into the patrol phase and the fire report completed. The firefighters will refurbish their gear and ready themselves for the next call.