Fire Investigations: The Basics. Anthony Cole, P.E., CFPS, CFEI

Transcription

1 Fire Investigations: The Basics Anthony Cole, P.E., CFPS, CFEI

2 Presentation Outline What is a fire investigation? Fire chemistry and dynamics Causes of fires Investigative procedures Conclusions and questions

3 What is a Fire Investigation A complex endeavor involving skill, technology, knowledge, and science. A compilation of factual data as well as analysis of those facts truthfully and objectively. using a systematic approach and methodology

4 What is a Fire Investigation Origin Cause Responsibility Protect Property The TRUE purpose of a investigation is to save lives by preventing reoccurrence

5 Fire Chemistry and Dynamics The Fire Triangle Enough OXYGEN to sustain combustion Enough HEAT to raise the material to its ignition temperature Some sort of FUEL or combustible material This chemical, exothermic reaction is called FIRE

6 Fire Chemistry and Dynamics Flash Point: The lowest temperature at which vapors are given off at a sufficient rate to form an ignitable mixture at the surface but NOT sustain combustion. Fire Point: The lowest temperature at which vapors are given off at a sufficient rate to form an ignitable mixture at the surface but WILL sustain combustion.

7 Fire Chemistry and Dynamics Vapor Pressure: The pressure of the vapor exerted by a volatile liquid on the atmosphere above its surface. This is a characteristic of all liquids and is a direct indicator of the ability of the liquid to evaporate. Boiling Point: The temperature at which vapor pressure is equal or exceeds atmospheric pressure.

8 Fire Chemistry and Dynamics Autoignition Temperature: the lowest temperature at which a combustible material ignites in air without a spark or flame.

9 Fire Chemistry and Dynamics 1. Incipient 2. Growth 3. Fully developed 4. Decay/burnout RELEASE RATE TIME

10 Fire Chemistry and Dynamics Exponential T-Squared Triangular Q = Q o exp ( t - t o ) / τ Q t = α ( - ) t o Q = β ( t - t o ) 2 Qp EXPONENTIAL T- SQUARED TRIANGULAR Qo to to to

11 Fire Chemistry and Dynamics Fires in the open: k lf = 1 Fires along walls: k lf = 2 Fires in corners: k lf = 4

12 Fire Chemistry and Dynamics Flashover: A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature simultaneously and fire spreads rapidly throughout a space. The result of a flashover is full room involvement.

13 Fire Chemistry and Dynamics - Fire Yellow Orange Red White Green Blue Ordinary combustible (class A) Later stage class A Flammable/combustible liquids Metals Cooper and nitrates Alcohol and natural gas with proper mixture of air

14 Fire Chemistry and Dynamics Smoke Hay Benzene Sulphur Sulfuric/hydrochloric acid Chlorine gas Wood Hydrocarbons White White to gray Yellow to brownish yellow Yellow to brownish yellow Greenish yellow Gray to brown Black

15 Fire Chemistry and Dynamics

16 Fire Chemistry and Dynamics

17 Fire Chemistry and Dynamics

18 Fire Chemistry and Dynamics

19 Fire Chemistry and Dynamics

20 Fire Chemistry and Dynamics

21 Fire Chemistry and Dynamics

22 Fire Chemistry and Dynamics

23 Causes of Fires - Industrial

24 Causes of Fires - Apartments

25 Causes of Fires Single Family

26 Investigative Procedures

27 Investigative Procedures Systematic approach Recognize the need Define the problem Collect data Analyze the data Develop a hypothesis Test the hypothesis AVOID Presumption of cause

28 Investigative Procedures Recognizing the need Preparing for the investigation Conducting the investigation Collecting and preserving evidence Analyzing the incident Conclusions Issuance of a report

29 Investigative Procedures Recognizing the need Fleeing persons or vehicles: On foot height, weight, clothing, or distinguishing characteristics. Car make, model, year, color, license plates, or any notable information. Forced delays: Blocked street or access False alarms in the area response Timed/coordinated

30 Investigative Procedures Recognizing the need Windows or door - Opened Broken Forced Burglar tools? Closed but not locked locked (bolt and chain)

31 Investigative Procedures Recognizing the need Watch persons at the scene Listen to what observers are saying Look for unusual items Be alert to spectators who offer help

32 Investigative Procedures Preparing for the Investigation Organize the investigation team (experts) Organizing resources Documentation

33 Investigative Procedures Conducting the Investigation Photos Video Evidence Third party testing Documentation FIND THE FACTS!!

34 Tools of the Trade

35 Tools of the Trade

36 Tools of the Trade

37 Investigative Procedures - Conclusion State the facts! Present report clearly

38 Conclusion All fires should be investigated Look for FACTS Call the experts Be open-minded

39 Resources NFPA 921 Guide for Fire and Explosion Investigations Kirks Fire Investigation Kennedy s Fire and Arson Investigation Beveridge s Forensics Investigation of Explosions Noon s Engineering Analysis of Fires and Explosions Phillips/Mcfadden Investigating the Fireground

40 Thanks!!