1. Jim Page, 2007 Chapter 11: Fire & Explosion Investigation MINA Handbook

2. Jim Page, 2007 Investigating Fire Mishaps

3. Jim Page, 2007

4. What Are We Looking For? The point of fire origin The source of ignition Why a small fire became big The reason for causalities Did the fire deviate from normal behavior The first step is to rule out arson!

5. Jim Page, 2007 Determine Cause –As with any investigation look past the proximate cause for the root cause. Suppose a fire starts in a club kitchen when a deep fat fryer ignites and spreads through the kitchen The cause is not just “Deep fat fryer overheated.” Was the control set too high? Did the control contacts stick? Why didn’t the high temperature cut-off fail to work?

6. Jim Page, 2007 Fire patterns? Colors? Soot?

7. Jim Page, 2007

8. Handout Discussion Additional Information on Fire

9. Jim Page, 2007 Investigating Explosions

10. Jim Page, 2007 Types of Explosions –Mechanical High pressure gas cylinder BLEVE (Boiling Liquid Expanding Vapor Explosion) –Chemical Combustion explosion –Flammable gases –Vapors of ignitable (flammable and combustible) liquids –Dusts –Low explosives –High explosives –Back draft explosions –Electrical –Nuclear

11. Jim Page, 2007 Explosion Effects –Damage – low order, high order –Blast Front – rate of pressure rise vs. maximum pressure –Shrapnel effect –Thermal effect –Seismic Effect –Seated explosions High pressure & rapid rates of rise Craters –NonSeated explosions Moderate pressures & rates of rise Diffuse fuels

12. Jim Page, 2007 Human Injury Criteria THRESHOLD SERIOUS WOUNDS.6 PSI: Glass 3.0 PSI: Glass 2.4 : Eardrum 3.5 : Eardrum 3.0 : Knockdown 10.0 : Knockdown 10.0 : 1% Lethal 25.5 : 90% Lethal

13. Jim Page, 2007 Property Damage.15 PSI: Typical window breakage 1.0 : Houses uninhabitable 2.0 : Collapse of roofs/walls 3.5 : 50% destruction of homes 6.0 : Destruction of most buildings 9.0 : Box cars demolished 30.0 : Steel towers down

14. Jim Page, 2007 Pressure (PSO) versus Distance (Quantity Distance) K50=.88 psiInhabited building distance K40= 1.18 psi IBD<250,000 pounds K30= 1.70 psi Airfield Criteria K24= 2.40 psi Public highways K18= 3.50 psi Intraline K9= 11.75 psi Barricaded intraline K1.2 5 = 716 psi Magazine (side to side)

15. Jim Page, 2007 Evidence of Explosion Wide dispersal of wreckage Metal fragmentation –Shrapnel –Surface spalling Unusual damage to heavy structures Brittle fractures in ductile materials Outward deformation Radiating fire pattern Fragment penetration force Cratering of penetration holes –Splash –Edge turnover Gas wash effect Shredded or teased fabrics Chemical residue analysis Autopsy evidence Witness testimony

16. Jim Page, 2007 Explosion Investigation Identify explosion or fire Identify type of explosion Establish origin Establish fuel type and explosion type Identify ignition source Identify damage effects –Preblast & postblast fire damage