Origin Matrix Analysis: A Systematic Methodology for Post-Fire Investigation and Analysis of Compartment Fires

Transcription

1 Select Presentation Slides From: Origin Matrix Analysis: A Systematic Methodology for Post-Fire Investigation and Analysis of Compartment Fires National Fire Protection Association Conference & Expo Las Vegas, NV June 2014 Additional Information May Be Obtained From: Cox, Andrew. Origin Matrix Analysis: A Systematic Methodology for the Assessment and Interpretation of Compartment Fire Damage. Fire and Arson Investigator, Journal of the International Association of Arson Investigators (IAAI), Volume 64, Issue 1, July and/or Andrew Cox, Special Agent Bureau of Alcohol, Tobacco, Firearms and Explosives andrew.cox@atf.gov

2 Quadrant 1 Quadrant 2 ORIGIN Quadrant 3 FIGURE 1 Hypothetical Compartment Fire 2

3 Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 2 Pre-Flashover Compartment Fire Conditions Reference: Figures , NFPA 921 Guide for Fire and Explosion Investigations, 2014 Edition.

4 Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 3 Flashover Compartment Fire Conditions Reference: Figure , NFPA 921 Guide for Fire and Explosion Investigations, 2014 Edition.

5 Quadrant 1 Quadrant 2 X Quadrant 3 FIGURE 4 Post-Flashover Compartment Fire Conditions Reference: Figure , NFPA 921 Guide for Fire and Explosion Investigations, 2014 Edition. X Added by Presenter.

6 Flames will exist at the interface between the incoming fresh air (which contains O 2 ) and the heated fuel gases that have accumulated inside the compartment. As depicted correctly, flames will exist at the interface between escaping heated fuel gases and the fresh air outside (which contains O 2 ). Reference: NFPA 921 Guide for Fire and Explosion Investigations, 2014 Edition. Color Text and Diagramming Added by Presenter. Flames will T necessarily remain attached or even proximate to the solid and liquid fuels in the compartment.

7 DAMAGE What is Damage? Changes in materials resulting from a fire incident. Why are we Interested in Damage? Gives us clues about the nature of the fire that caused them. 1. Magnitude of Damage (Severity of the Cumulative Exposure) 2. Shape of Damage (Direction of Exposure) TE: This language is slightly different than the movement and intensity terminology currently used in Section 6.4 Fire Pattern Analysis in the 2011 Edition of NFPA 921.

8 FACTORS AFFECTING MAGNITUDE OF DAMAGE 1. Exposure Duration. 2. Exposure Intensity. 3. Material Properties.

9 FACTORS AFFECTING SHAPE OF DAMAGE The principles of heat transfer and fire dynamics will influence the shape of damage. Fire flows (Convection). Line of sight (Radiation). Materials (Material Properties, Construction Features).

10 Quadrant 1 Quadrant 2 ORIGIN Quadrant 3 FIGURE 1 Hypothetical Compartment Fire

11 DAMAGE SCALE Light Heavy Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 5 Pre-Flashover Compartment Fire Conditions and Associated Cumulative Damages

12 DAMAGE SCALE Light Heavy Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 6 Flashover Compartment Fire Conditions and Associated Cumulative Damages

13 DAMAGE SCALE Light Heavy Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 7 Short Duration Post-Flashover Compartment Fire Conditions and Associated Cumulative Damages

14 DAMAGE SCALE Light Heavy Quadrant 1 Quadrant 2 Quadrant 3 FIGURE 8 Long Duration Post-Flashover Compartment Fire Conditions and Associated Cumulative Damages

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19 DAMAGE SCALE Light Heavy Quadrant 1 Quadrant 2 Quadrant 3 Regardless of where the fire starts, fires that burn well past flashover conditions are anticipated to present similar postfire damages.

20 TABLE 1 GROWTH STAGE ORIGIN LOCATION Andrew Cox, Special Agent Bureau of Alcohol, Tobacco, Firearms and Explosives Quadrant 1 Quadrant 2 Quadrant 3 Pre-Flashover Flashover Short Duration Post-Flashover Long Duration Post-Flashover

21 Complications C-Side Wall in Quadrant 2 FIGURE 9 Depiction of Fresh Air Inflow During Post- Flashover Fire Conditions. 21

22 DAMAGE SCALE Light Heavy Quadrant 1 Section 2 FIGURE C1-1 Pre-Flashover Compartment Fire Conditions and Associated Cumulative Damages For Origin in Quadrant 1.

23 DAMAGE SCALE Light Heavy Quadrant 1 Section 2 FIGURE C1-2 Flashover Compartment Fire Conditions and Associated Cumulative Damages For Origin in Quadrant 1.

24 DAMAGE SCALE Light Heavy Quadrant 1 Section 2 FIGURE C1-3 Short Duration Post-Flashover Compartment Fire Conditions and Associated Cumulative Damages For Origin in Quadrant 1.

25 DAMAGE SCALE Light Heavy Quadrant 1 Section 2 FIGURE C1-4 Long Duration Post-Flashover Compartment Fire Conditions and Associated Cumulative Damages For Origin in Quadrant 1.

26 Three Analytical Divisions ORIGIN LOCATION Quadrant 1 Section 2 Andrew Cox, Special Agent Bureau of Alcohol, Tobacco, Firearms and Explosives GROWTH STAGE Pre-Flashover Flashover Short Duration Post-Flashover Long Duration Post-Flashover

27 Two Analytical Divisions GROWTH STAGE ORIGIN LOCATION Section 1 Section 2 Andrew Cox, Special Agent Bureau of Alcohol, Tobacco, Firearms and Explosives Pre-Flashover Flashover Short Duration Post-Flashover Long Duration Post-Flashover