Firefighters must increase their knowledge of fire behavior to increase their awareness of how it impacts all of their tactics. The fire environment has changed, and it is time the fire service reexamined its tactics to understand not just what to do but why, said Steve Kerber at his FDIC 2012 Monday morning workshop, “Tactical Applications of Fire Dynamics.”
Kerber, a fire protection engineer with Underwriters Laboratories (UL), has been attending the Fire Department Instructors Conference since 2003 and has presented at it since 2007.
The fire service receives very little training on fire dynamics, which influences everything that happens on the fireground.
In today’s fire environment, homes are larger, with architectural features and construction components that have serious effects on fire dynamics and firefighter safety. A larger modern home may include a two-story great room with a large unobstructed floor area, supported by wood I-beams or engineered truss assemblies, which if exposed to fire will fail more quickly than solid lumber floor beams used in older legacy homes. According to a 2005 study, of the floor assembly components used in construction, 46 percent were wood I-joists, and 15 percent were wood truss assemblies.
In a UL experiment comparing the time to failure in a fire of single-pane glass windows and that of double glazed thermal windows, the older glass windows failed at 10 to 14 minutes, whereas the double-pane thermal windows failed in 4 to 5 minutes. Moreover, when viewed by a thermal imaging camera, a modern double-paned thermal window will not necessarily indicate the radiant heat present in that room, unlike older single-pane glass.
Using a video of a UL experimental fire comparing a fire in a single-story home versus one in two-story home, he discussed the implications of the timing and location of ventilation.
“The fire service knows how to vent, but not necessarily what, where, when and why to vent, Kerber said. The fire dynamics studies carried out by UL and other organizations are intended to bring science to the fireground to answer these and other questions.
For more Steve Kerber, consider Research for the Fire Service: Positive Pressure Ventilation, Mastering Ventilation to Decrease Firefighter Injuries and Deaths, and Wind-Driven Fire Research: Hazards and Tactics.