LESSON 5 - FOREST FIRE SUPPRESSION
The act of extinguishing a fire after it has been brought under control
Mop-up begins the time the fire has been contained and initial attack is no longer required. This part of the job is dependent on moisture levels in the ground and in larger fuels on the surface. In the early part of the year ground conditions are usually wet which makes the job of mop-up easy since most or all heat sources are on the surface. The job becomes much more difficult when ground conditions become dried out and heat begins to travel below the surface in fuels that are able to burn for days, weeks, or even months. Fire managers use the Drought Code of the FWI system to indicate deep burning conditions. This will determine effort required.
There are a variety of methods to complete the job:
Looking for smoke - Smoke is an indication of a heat source. Apply water to cool the source.
Cold Trail - Use your hand to feel below the surface for heat sources. Be very cautious using this method since you are looking for heat sources that cannot be seen and you could touch burning material without being aware. Use extra caution with this method.
IR Scanners - Electronic equipment (Infared Scanners) can be used to locate heat sources below the surface from either the ground or from the air. From either vantage point, the scan should be conducted early in the morning to avoid radiant heat from warming up objects on the surface which will create heat images that we do not need to be aware of. Scanning devices will pick all sources of heat: live mammals, rocks heated by the sun or burning embers below the surface.
Armed with shovels, pulaski’s, chainsaws, backtanks and hoses, firefighters scramble the scorched earth, methodically extinguishing any signs of heat. Mop up requires discipline and time to perform the job thoroughly; if one spot of over looked heat has been left, it is possible that the fire could rekindle on the surface and continue to burn unchecked again. Smouldering embers buried deep in the thick duff can be difficult to find and extinguish, thus requiring a patient firefighter.
Steps to proper mop-up include:
This completes Lesson 5 - Forest Fire Suppression