reading smoke developed by dave dodson, battalion chief (ret.), colorado
TRANSCRIPT
Reading Smoke Reading Smoke
Developed by Dave Dodson, Battalion Chief (ret.), Colorado
Preparing to use this Preparing to use this program: program:
View the “Reading Smoke” video on View the “Reading Smoke” video on DVD #1 prior to delivering this programDVD #1 prior to delivering this program
Review Reading Smoke Lesson PlanReview Reading Smoke Lesson Plan
Prepare by finding raw fireground Prepare by finding raw fireground footage to use in order to practice footage to use in order to practice “Reading Smoke” (See slide “Practice “Reading Smoke” (See slide “Practice Examples” for usable websites)Examples” for usable websites)
The Reading Smoke The Reading Smoke ProcessProcess
Reading Smoke can help you answer 3 Reading Smoke can help you answer 3 questions:questions:
1.1. Where, specifically, is the fire?Where, specifically, is the fire?
2.2. How big or intense is the fire?How big or intense is the fire?
3.3. How fast is the event changing? (rate and How fast is the event changing? (rate and severity of fire spread)severity of fire spread)
Basic Process – the Basic Process – the ScienceScience
3 concepts:3 concepts:
1.1. Smoke is Smoke is FUELFUEL
2.2. The fuels have The fuels have changed – changed – more more continuity and continuity and explosiveness than explosiveness than previously taughtpreviously taught
3.3. The smoke has trigger The smoke has trigger points: right points: right temperature and right temperature and right mixturemixture
Consider this…Consider this…
Gas Self-Ignition Temperature
Flammable Range
Acrolein 450°F 3-31%
Benzene 928°F 1-8%
Hydrogen Cyanide 1000°F 5-40%
Carbon Monoxide 1123°F 12-74%
The following gases create “ladder fuels” within smoke (remember, there are particulates and aerosols also).
The Basic Process (cont.)The Basic Process (cont.)
Process Rules:Process Rules:
1.1. Nothing is absoluteNothing is absolute
2.2. Compare ventilation Compare ventilation openings openings (restricted or (restricted or unrestricted, smoke or unrestricted, smoke or no smoke)no smoke)
3.3. Start measuring rate of Start measuring rate of change change (seconds or (seconds or minutes)minutes)
The 3 Steps for “Reading Smoke”
1.1. Inventory & compare Inventory & compare
smoke attributes: smoke attributes:
volume, velocity, volume, velocity,
density, and colordensity, and color
2.2. Factor in influences Factor in influences
that change the that change the
meaning of VVDCmeaning of VVDC
3.3. Answer the Answer the
questionsquestions
STEP 1: Inventory and compare the key attributes
Volume Velocity
(Pressure) Density Color
VOLUME
Gives an impression Establishes relativity
to the “box” Remember: a small
volume of smoke from a very large box is significant
Volume is a source of pressure (velocity)
VELOCITY (Pressure)
How fast is the smoke leaving?
Turbulent or Laminar?
Is laminar heat or volume pushed?
Compare velocity from like-sized openings to find fire location
Density Most Important
Factor Tells you the Tells you the
futurefuture Continuity of FuelContinuity of Fuel Likelihood of an Likelihood of an
EventEvent ““Degree” of the Degree” of the
EventEvent
Color Tells Stage of Heating Should compliment
velocity to find location of fire
“Brown” Smoke is usually unfinished wood being heated
Remember, smoke color can be filtered over distance or through resistance
STEP 2: Factor in Influences
Container Container (defines (defines the significance of the significance of VVDC)VVDC)
WeatherWeather
STEP 3: Answer the Questions
Where’s the fire?Where’s the fire? How big or intense How big or intense
is the fire?is the fire? How fast is it How fast is it
changing? changing? (rate (rate and severity)and severity)
Always Remember:Always Remember:
Velocity trumps Velocity trumps colorcolor
ANYANY thick, fast thick, fast moving smoke is moving smoke is ignitableignitable
Zero visibility Zero visibility makes you a makes you a slave to your slave to your environmentenvironment
Single Most Important Point:
Turbulent smoke Turbulent smoke is is ready to flash – ready to flash – and indicates that and indicates that floor temperatures floor temperatures are past human life are past human life thresholds (zero thresholds (zero rescue profile!)rescue profile!)
Manage it – but Manage it – but reduce your risk-reduce your risk-taking!taking!
Practice Practice ExamplesExamples
Use raw fireground footage from your Use raw fireground footage from your department, or from the internet:department, or from the internet: www.youtube.com (search on (search on
house fires or flashover)house fires or flashover) www.community.firevideo.net www.firefighterclosecalls.com www.fire.nist.gov
Be Safe – Be Safe – Make it Safe !Make it Safe !
For more information on Reading Smoke
contact Dave Dodson at [email protected]