Fire Behaviour Indicators

Fire Behaviour Indicators

Fire Behaviour Indicators – Firefighters can easily observe some of the B-SAHF indicators. However, fire behaviour indicators encompass a wide range of factors that firefighters may see, hear, or feel. Some factors are relatively unchanging (i.e. building construction) and others are quite dynamic, changing as the fire develops (i.e. smoke conditions and flames).

Building: Unlike the other fire behaviour factors, the building and its contents are present prior to ignition and can be examined during the preplanning process. While many common types of buildings and occupancies (such as single family dwellings) are not the focus of a formal preplan program, firefighters can examine common features and their influence on fire behaviour. This pre-fire assessment of likely fire development and spread should be compared with actual fire behaviour encountered during emergency incidents to improve skill in reading building factors.

Smoke and Air Track: Smoke conditions and the pattern of smoke and air movement are two of the most important indicators of fire behaviour. The location and appearance of smoke can provide valuable cues related to the location of the fire, its burning regime (fuel or ventilation controlled) and the stage of fire in various areas of the building. It is critical that firefighters begin their assessment of smoke and air track indicators from outside the building, but continued this process on an ongoing basis from both the interior and exterior of the structure.

Heat: While heat cannot be observed directly, observation of the effect of heat on air track (i.e., velocity of smoke discharge), the building or exposures, and sensation of changes in temperature can be significant fire behaviour indicators. It is important to remember that our personal protective equipment provides significant insulation and slows the transfer of heat and resulting sensation of changes in temperature.

Flame: Flaming combustion is often the most obvious or visible indicator observed by firefighters. However, do not get so focused on visible flames that you miss more important, but subtle building, smoke, air track, and heat indicators. Flame indicators such as location, volume, colour, etc. are important, but need to be integrated into the B-SAHF framework to provide a more complete picture www.firehouse.com (2014).

Figure 3 integrates the concept maps presented in previous articles and outlines some of the major interrelationships between the B-SHAF fire behaviour indicators.