Transcript Vehicle Fire Investigation - Idaho Chapter of the International
Vehicle Fire Investigation
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Introduction
This presentation will address the trials and tribulations of vehicle fire investigation The presenter is Steve Mackaig from Fire Cause Analysis located in California. Don’t hold that against him.
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How’s the National Vehicle Fire Loss Picture?
Approximately 285,000 vehicle fires occur per year, 75% of vehicle fires are motor vehicles.
Vehicle fires result in 330 deaths, 1400 injuries and 692 million in Damage 83 PERCENT ARE CLASSIFIED AS ACCIDENTIAL 3
Our Topics for Discussion and Debate
Vehicle fire investigation popularity How is the vehicle fire cause determined?
The field formula of vehicle fire cause Understanding vehicle systems Indicators of vehicle system failure Methodology of a physical fire cause examination Subrogation Vehicle arson 4
Suggested Reading
Investigation of Motor Vehicle Fires, Lee S. Cole Kirk’s Fire Investigation, John Dehaan NFPA 921, 2011 edition 5
Who Enjoys Vehicle Fire Investigation?
It appears to be the least popular form of fire cause investigation WHY?
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Who is Initially Determining the
Cause of Most Vehicle Fires?
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Private Fire Investigators
Different scope of responsibility Uses same process of fire cause determination but long after extinguishment Limited power to pursue arson Suspected arsonist may also be client of insurance company More time and resources for accidental fire causes 10
Determining Fire Cause You Can Choose:
The wheel of fire origin or Flip a coin or You can use burn patterns and fire behavior indicators in an organized, safe and scientific approach.
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Landmark Cases such as Daubert have Challenged Fire Experts Methodology
What is the most internationally excepted Guideline text in Fire Investigation?
National Fire Protection Association 921 Guide For Fire and Explosion Investigations 2011 Edition Chapter 25 Motor Vehicles
Use a Fire Determination Process that is Considered a Systematic
Approach
The Scientific Method is considered a reliable contemporary Systematic Approach
Scientific Method
Recognize The Need ( fire occurs) Define The Problem ( requires fire cause Investigation) Collect Data ( facts and indictors) Analyze Data ( inductive reasoning) Develop an Hypothesis ( cause opinion) Test Hypothesis ( what didn’t cause the fire ) Select Final Hypothesis ( Fire Cause Opinion) 15
Burning Modern Vehicles Are Influenced by
Composites Unlimited air supply and wind influence Preheated components Fuel and oil sources under pressure Large amount of plastics and rubber 16
The Basic Rule of Thumb in identifying the Area of Origin is:
The area of origin is identified as the area of most severe damage and the lowest level of severe damage.
Accidental fires tend to start and develop slowly while arson fires are associated to rapid fire start and spread.
What is it about modern vehicles that can potentially screw up this basic theory?
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Burn patterns and physical indicators on the vehicle provides the clues of fire cause & origin.
Unfortunately, the amount of fire damage is proportional to the amount of indicators or clues that remain after the fire.
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Factors that effect your indicators
Fire fighting activities Salvage activities Towing activities Condition of night time Wet surfaces Standing water, foam or snow 20
Once You Have Identified The Area of Fire Origin
Identify all potential ignition sources Identify all potential fuel sources Systematically rule out unrelated fire causes Challenge your own opinion 21
Additional Information that can be valuable in determining the fire cause:
Events prior to the fire Vehicle history and use Mechanical and recall data research 22
Formula For Fire Cause
FUEL HEAT EVENT 23
The First Step
Fire typically originates in the area of most severe damage Burn patterns on the body reveal direction of fire travel, fire exposure and liquid patterns Heat naturally rises and flammable liquids flow to the lower areas.
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Work towards area greatest damage comparing surfaces and the various levels of damage.
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Consider the probabilities
Where do you think the most common place for a accidental fire to occur is?
Where do you think arson is the most common?
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Document your investigation as you proceed
Compare the 5 compartments between each other Compare damage within each compartment Photograph before and after debris removal Recommend using photo procedure that parallels inspection 27
Methods of Documentation
Digital Camera Video sketching 28
Systematically rule out unrelated fire causes
Potentials include fuel, lubrication, electrical, friction, heat exposure, smoking materials, open flame sources 29
Potential follow up issues
Manufactures defects Recent repairs Fluid analysis Component analysis Dealer survey, mechanic inquiry & parts department resources Exemplar vehicle 30
Let’s examine the 3 elements of fire cause
First is fuel sources Gasoline Diesel fuel Propane Power steering fluid Transmission oil Gear oil Anti freeze Air conditioning refrigerant Wet cell batteries 31
Heat ignition sources
Engine surface heat Exhaust system-pipes, manifolds & mufflers Friction-brake pads, bearings & tires Electrical system-resistance heating, dead short & energized ground Smoking materials Intentional fire setting 32
Events
Was vehicle operating System failure potential after parking Pre-fire activities and indicators Pre-fire conditions such as weather, road grade, towing, turning accessory use 33
Fire behaviors
Fuel system failure is typically rapid flame onset Lubricating oil on the exhaust system create lots of white smoke while the vehicle is moving, but no flaming combustion why?
Electrical fires typically develop from a slow, smoldering state 34
Vehicle Component Analysis
To accurately evaluate accidental fire causes requires a basic understanding of vehicle systems It has been my experience that arson determined fires are typically countered with accidental causes so prepare by learning accidental causes.
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Carburetors
Common in vehicles up to 1975 Typically in 2 or 4 barrel configuration 2 to 6 pounds of fuel pressure FAILURE POTENTIAL Gasket & seal leakage, improper adjustment Backfires 36
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Fuel Injection
Fuel is injected into each cylinder by use of a mechanical pump, air pump or electric signal Because of normal system pressure, leakage is typically in the form of a spray at 30-40 pounds per square inch.
Immediate fire, black smoke, rapid spread 38
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Fuel injection failure potential
Leakage at the rubber seals Leakage where fuel distribution rail connects to injectors Leakage at Schrader valve Leakage at fuel hose connections Fuel hose side wall System pressure spike Plastic failure from heat, pressure and vibration 40
Indicators of fuel system failures
Severe fire damage in the area of origin Area of origin houses fuel system components with leakage potential Origin surfaces are burned cleaned and brightly discolored Liquid stains and evidence of fuel wash Fire start described as immediate Fire described as explosion Fire occurs during start up Engine operation is disrupted as fire is discovered 41
Lubrication system
This includes systems that lubricate the engine, transmission and power steering.
Oil ignites from exposure to exhaust system surface heat FAILURE POTENTIAL Leaks at gaskets, seals and hoses.
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Indicators of oil leakage related fire
Area around the origin burned clean with adjacent areas oil stained Reported white smoke prior to flame discovery Initially reported as fire under vehicle along with dripping liquid Fire discovered once vehicle stops moving or up to approximately 10 minutes after parking 56
Areas with leakage potential
Engine-front and rear seals, valve covers, oil filter, oil pan, intake manifold & distributor seal.
Power steering- hoses, crimp connections, fluid reservoir Transmission-rear seal, vent tube and dip stick tube 57
Electrical system
Most types of system failure protected with fuses, relays, fusible links.
These devises can activate from a short circuit or fire caused heat exposure.
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Types of failure
Dead short- electrical energy to ground Resistance heating-electrical resistance during current flow at weak connection or damaged wire Ground fault-ground system becomes energized or ungrounded from poor connection.
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