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The ART of Reading Smoke

Developed by: Dave Dodson

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Why “Read” Smoke?To determine To determine ““HOW MUCHHOW MUCH” fire” fire

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Why “Read” Smoke? To help find the To help find the LOCATIONLOCATION

of the fireof the fire

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Why “Read” Smoke?To help predict To help predict COLLAPSECOLLAPSE

potentialpotential

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Why “Read” Smoke?To help To help PRIORITIZEPRIORITIZE Strategies Strategies

& Tactics& Tactics

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Why “Read” Smoke? To To PROTECTPROTECT Firefighters from aFirefighters from a

““HOSTILE FIRE HOSTILE FIRE EVENT”EVENT”

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The “ADVANCED” BasicsConcept #1: Smoke Concept #1: Smoke

is Fuelis Fuel

Particulates Particulates Aerosols Aerosols

Gases Gases

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The “ADVANCED” Basics

Concept #2: Fuels have Concept #2: Fuels have changed: Mass and Make-changed: Mass and Make-up!up!

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The “ADVANCED” Basics

Concept #3: Smoke has trigger Concept #3: Smoke has trigger points:points:•Flash Point Flash Point •Fire PointFire Point•Ignition TemperatureIgnition Temperature

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The “ADVANCED” Basics

How does How does “flammable range”“flammable range” factor factor in?in?

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Flammable Range & the Three Fires

Too Lean . . .Too Lean . . .

Too Rich . . .Too Rich . . .

Just Right . . .Just Right . . .

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The “ADVANCED” Basics

Need to be able to determine...Need to be able to determine...

• What stage is the fire in…What stage is the fire in…

• Is the “box” absorbing heat? Is the “box” absorbing heat? Laminar Laminar vs. Turbulent smoke flowvs. Turbulent smoke flow

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“ HOSTILE ” Fire Events

• FlashoverFlashover• BackdraftBackdraft• Smoke ExplosionSmoke Explosion• Rapid Fire SpreadRapid Fire Spread

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FLASHOVERWARNING SIGNS:WARNING SIGNS:Turbulent SmokeTurbulent Smoke““Rollover”Rollover”Auto Ignition outsideAuto Ignition outsideSmoke –Cloud Ignition is likely after Smoke –Cloud Ignition is likely after

flashoverflashover

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BACKDRAFTRemember – Backdraft is triggered by O2 Remember – Backdraft is triggered by O2

being introduced to a pressurized being introduced to a pressurized “box”“box”

Yellowish-grey smokeYellowish-grey smoke WhistlingWhistling Bowing windowsBowing windows ““Sealed” containersSealed” containers

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SMOKE EXPLOSIONRemember – A Smoke Explosion is a spark Remember – A Smoke Explosion is a spark

or flame applied to a mixture below its or flame applied to a mixture below its ignition temperatureignition temperature

Trapped gases in upper areasTrapped gases in upper areas Growing fireGrowing fire Increasing smoke densityIncreasing smoke density Air intake overtaking smoke exitingAir intake overtaking smoke exiting

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RAPID FIRE SPREADUsually “Container” InfluencedUsually “Container” InfluencedFuel for fire spread is smoke driven vs. Fuel for fire spread is smoke driven vs.

contents surface flamingcontents surface flaming Look for fast-moving smoke in high Look for fast-moving smoke in high

pressure zones (stairs and hallways)pressure zones (stairs and hallways)

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“ Reading Smoke”

• Observations are Observations are typically made typically made from outside - from outside - inside inside observations hide observations hide the “real” picture.the “real” picture.

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“ Reading Smoke”• Nothing is absolute Nothing is absolute • Visible FIRE is easy to read - look past it Visible FIRE is easy to read - look past it

for the real storyfor the real story• Compare vent openingsCompare vent openings

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The ART of Reading Smoke

A A 4-STEP PROCESS4-STEP PROCESS to help to help predict fire behavior and hostile predict fire behavior and hostile

eventsevents

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Step 1: Evaluate Key

Factors• VolumeVolume • Velocity Velocity

(Pressure)(Pressure)• DensityDensity• ColorColor

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VOLUMEAlways relative Always relative

to the “Box”to the “Box”Tells “how Tells “how

much” fuel has much” fuel has off-gassedoff-gassed

Sets the StageSets the Stage

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VELOCITY (Pressure)How fast is the How fast is the

smoke leaving?smoke leaving?Can indicate Can indicate

volume or heatvolume or heatHelps find the Helps find the

location of the location of the actual fireactual fire

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DENSITYMost Important Most Important

FactorFactorQuality of Quality of

BurningBurningContinuity of FuelContinuity of FuelLikelihood of an Likelihood of an

eventevent““Degree” of the Degree” of the

EventEvent

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COLOR Rarely tells Rarely tells

“material burning”“material burning” Stage of HeatingStage of Heating Location of FireLocation of Fire Amount of FlamingAmount of Flaming ““Brown” SmokeBrown” Smoke ““Black Fire”Black Fire”

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“BLACK FIRE”“Black Fire” is the

term we give to High Volume, High Velocity, Extremely Dense, Black Smoke.

It is the sure sign of impending flashover – VENT & COOL are your only choices.

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Step 2: Weigh Factors

• Container (most Container (most important factor)important factor)

• Thermal BalanceThermal Balance• WeatherWeather• Firefighting Firefighting

effortsefforts

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Step 3: Judge the Rate of Change

How fast are SMOKE conditions How fast are SMOKE conditions getting better or worse?getting better or worse?

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Step 4: Predict the EVENTConsider that:Consider that:

• One hostile event can - One hostile event can - and and usually willusually will - lead to another - lead to another event.event.

• Communicate your observations.Communicate your observations.• Warning Signs are not always Warning Signs are not always

visual – use your KNOWLEDGE visual – use your KNOWLEDGE and EXPERIENCE.and EXPERIENCE.

TRUST YOUR INSTINCTS…TRUST YOUR INSTINCTS…

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Some other “Tricks”When you open a door or window - When you open a door or window -

watch what the smoke does – and watch what the smoke does – and what the fresh air does!what the fresh air does!

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Some other “Tricks”A 5-second change in any key factor A 5-second change in any key factor

means an event has taken place – means an event has taken place – the key is to define what event has the key is to define what event has taken place and to forecast what taken place and to forecast what will likely happen next. will likely happen next.

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THE ART OF READING SMOKE

Some ExamplesSome Examples

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Special THANKS to:

Mike Scott, Battalion Chief, Kent (WA) FireDavid Ross, Chief of Safety, Toronto Fire

ServicesPeter McBride, Shift Safety Chief, Ottawa

Fire

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Be Safe – Make it Safe