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Fire DynamicsEvidence Based Fire Tactics Tradition Versus Science Tactics were based on tradition "We've done it that way for years!" The fire service: 150 years unchanged by progress Tactics, science, and fire behavior were passed down We accepted that what we were told was based on fact We believed what we knew was true Tactics/Strategy were not based on science or evidence Tradition versus Science Science has given us evidence Underwriter's Laboratory (UL) Firefighter Safety REsearch Institute (FSRI) National Institute of Standards and Technology (NIST) We now know that what we believed wasn't accurate Legacy fire development Modern fire development Can't "push" fire with correctly applied streams What does it mean? We have to change the way we think, operate Tradition versus Science Terminology Fire dynamics- How a fire starts, develops, spreads Fire behavior- how a fire reacts to its environment Heat release rate- fires in buildings give off heat faster Pressure - Fires create high pressure, which moves low pressure Flow path- the space through which fire, snoke, heat, gas travel, from high to low pressure Neutral plane- the boundary between the heat smoke/ gasses and cooler air Ventilation limited fire- Fire in which the heat release rate or growth is controlled by the amount of air available to the fire. Tradition versus Science Stages of fire development Ingition Growth Fully development Decay Flashover- Transition phase between growth and fully developed 100 seconds to untenibility after ventilation occurs Backdraft- a deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products and incomplete combustion Tradition versus Science Legacy fire development: fuel limited Tradition versus Science Modern fire development Ventilation limited Tradition versus Science Ventilation We were taught to vent early, vent often. We experienced a lifting of POC, perceived cooling due to influx of cooler air Based on experience, not evidence Tradition versus Science Ventilation- intentional Forcible entry/exit Tactical Ventilation Vertical/horizontal Opening void spaces Ventilation - unintentional Window failure Building failure others? Tradition versus Science FSRI Ventilation findings 1. The fire gets bigger if you provide a ventilation opening 2. Ventilation must be coordinated with fire attack Ventilation only equals cooling when water has been applied to the fire 3. Fire attack crew entrance is a ventilation opening 4. If the fire has "self-vented: out of a window, apply water from the outside Tradition versus Science Keeping our cool Heat release is limited when conditions are vent limited Control doors/ openings Do not break windows, start tactical ventilation until water is on the fire, or is going ot be on the fire- Beware the flow path Control entry point openings- less air equals less heat Ventilate after water is applied to the fire Tradition versus Science Fire attack - attacking from the burned side Not long ago, it was unheard of to attack from the burned side "You'll push fire into uninvolved areas," they said. Fast water slows the progress of fire A properly applied stream from outside will not "push" fire Transitional attack- action of opportunity Flow water into a window at a steep angle with a straight stream Keep the nozzle still Quickly moving a nozzle will entrain air. The air moving past the stream can push smoke, steam, fire where you don't want it Tradition versus Science We still fight fire from the inside If possible, cool from outside, then move in Cooling theories Gas- slowly move the steam in an inverted "u" from upper wall, to ceiling, to opposite wall, to cool gas and surfaces This doesn't disrupt the neutral place, thermal balance Extinguishment- Sweep the stream across the base of the fire S, Z and O patterns have fallen out of favor if air entrainment is concern Tradition versus Science Search- Oriented Left or right handed search pattern, typically from a doorway One person maintains the search team orientation Visual, verbal, "touch" Search - vent/ enter/ isolate/ search Create an opening- enter from a window typically Enter the room Isolate the room by closing the door Search, and exit the room the way you came in Walk the walls- search the middle of the rooms Tradition versus Science Matzen's Big Idea- It's all VEIS Relative to entry point- front door/ window/etc. Isolate yourself from the flow path/POC Close the door to the room you are in Close the door to the fire room Close the door you came through One member maintains Orientation From the window From inside the door of the room you are searching Wall #1 is the wall containing the opening through which you came 2, 3, 4 follow a clockwise pattern Tradition versus Science Matzen's big idea, cont. If you locate a victim, consider taking them out a window or door that doens't expose them to POC (maintain your isolation) Tradition versus Science Resources for further study- The Evolving Fireground, Research-Based Tactics, Gray/Norwood, Fire Engineering Books SBSK (Stop Believing, Start Knowing), Facebook and Instagram 25 to Survive, Reducting Residential Injury and LODD, Shaw/Mitchell, Jr. UL Firefighter Research Institute- www.ulfirefightersafety.org