Extend LIMITED Risk to Protect SAVABLE Property.
Objective: To cause the incident commander to limit risk exposure to a reasonable, cautious and conservative level when trying to save a building that is believed, following a thorough size up, to be savable.
Limited is defined as the point, edge or line beyond which something cannot or may not proceed, confined or restricted within certain limits.
In other words, there is a limit, or a line, beyond which firefighters may not be exposed to unsafe fire conditions. If a building can be saved, the incident commander should extend limited risk and carefully employ calculated operations that must be continuously monitored to ensure the safety line is not crossed.
The key word in this discussion is "savable." Incident commander must recognize they can't always save a building. No building is worth the life of a firefighter.
If a building can be saved, a cautious and conservative operation should be employed. If conditions worsen and become unsafe during interior operations, crews must be withdrawn from the building in a timely fashion and defensive exterior operations employed. Most buildings that are lost will be rebuilt.
The reality in our business is much of our firefighting is conducted in buildings that are deemed savable. Firefighters may refer to these as "bread and butter" or "routine" firefights and may allow their situational awareness to slip. However, these types of fires do expose firefighters to risks. Mishandled or inappropriate tactics can—and have—killed firefighters. The incident commander must maintain global awareness of the fireground to ensure a safe limit is not exceeded.
Where a building is deemed savable, interior firefighting operations must be fully supported with adequate resources on scene and risk must be closely and continually assessed. Fire attack hoselines must be of proper size and number to achieve fire control. There must be adequate staffing to conduct firefighting operations. All hoselines entering a burning building or compartment must be charged and operating with the correct pressure. In some cases, it may be appropriate to use large-caliber monitor devices to quickly knock down fire before crews enter a building.
A fire that can't be controlled quickly may be approaching flashover. An uncontrolled fire will continue to eat away at the building's structural integrity, weakening it and thus increasing risk. The incident commander must consider the possibility of lightweight construction of both floor and roof and an early collapse potential for both.
Underwriters Laboratory tests determined some lightweight unprotected floor truss systems can collapse as early as 6.5 minutes after flame impingement—and without warning. This short time frame means collapse could occur as the first crews are entering the building.
Recent research by Underwriters Laboratories determined that a fire in a modern home can create a flashover in just 3 minutes and 40 seconds! This rapid flashover time for the modern home reflects today's typical contents: synthetics and plastics. Such rapid flashovers quickly reduce the survival profile of any trapped victims as well as increasing risk to firefighters.
The research also showed, in many experiments, that if a firefighter is in a room about to reach flashover, the time from onset of untenability to flashover was less than 10 seconds! This does not allow much of a survival period for the firefighter to exit a building.
Abandoned and dilapidated buildings are also a particular risk to firefighters, and experience has shown there is very little likelihood that there are any occupants in the building. Should there be any active and growing fire in such a building that can't be immediately controlled, a defensive strategy must be seriously considered at the outset.
Bottom line: No building is worth the life of a firefighter. Risk must be closely and continuously assessed during interior operations. If the fire is about to harm firefighters, go defensive.
Chief Gary Morris is a director at large on the Safety, Health and Survival Section board of directors and was the team lead for the Rules of Engagement project. He was formerly chief of the Rural Metro Fire Department in Scottsdale, Ariz.