Chapter 14
Upcoming SlideShare
Loading in...5

Chapter 14






Total Views
Views on SlideShare
Embed Views



1 Embed 2 2


Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

Chapter 14 Chapter 14 Presentation Transcript

  • Vehicle Fires Chapter 14 © 2009 Delmar, Cengage Learning
  • Objectives• Describe the safety precautions that must be taken before starting the investigation• Describe the fuel and electrical systems of most common vehicles• Describe the potential heat sources and fuels available in most vehicles today• Describe the potential for arson and which indicators may point to an incendiary nature of the fire © 2009 Delmar, Cengage Learning
  • Case Study• Student had no feeling below arms• Family obtained used car that could be operated by hand controls• Mother noticed burning smell when son returned from school and found that he suffered burns to his back• Investigation of vehicle found seat heater had malfunctioned, causing burns © 2009 Delmar, Cengage Learning
  • Case Study (cont’d.)Figure 14-1 Front seat Figure 14-2 The heatingdriver’s side showing element that was locatedheat damage of seat directly behind fabric on thefabric. seat’s upright. © 2009 Delmar, Cengage Learning
  • Introduction• Vehicle fires are some of the most confusing fires to work• Investigators need to do fire scene reconstruction – Work the scene from the least damage to the most damage• Passenger vehicle today is an extremely complex device• 278,000 vehicle fires occurred in 2006 © 2009 Delmar, Cengage Learning
  • Safety and Initial Examination• All precautions should be taken to protect yourself and others from injury• Materials in modern vehicles contain numerous toxic fumes that are released from burning components – Range from hydrogen cyanide to carbon monoxide – Off-gassing: refers to vapors or gases that were absorbed by fabric, carpet, and so forth during a fire and then released after the fire was extinguished © 2009 Delmar, Cengage Learning
  • Safety and Initial Examination (cont’d.)• First responder investigator should not take for granted that the initial fire crews have secured the vehicle• Airbag deployment is a huge area of concern – Bags can inflate in 1/20th of a second• Not recommended to crawl under the vehicle• Always be aware of sharp edges and broken glass – Wear protective equipment at all times © 2009 Delmar, Cengage Learning
  • Type of Vehicle and Ignitable Fuels• Basic makeup of various vehicles is the same – Framework, wheels, interior, and so forth © 2009 Delmar, Cengage Learning
  • Diesel Engines• Diesel engines operate on a compressed combustion chamber• Diesel fuel is a combustible liquid with a flash point above 100° F• Fuel is stored in a sealed tank and is pumped from a fuel pump through lines and filters• Failure of the system at any given point may be a possible point of fuel release in some vehicle fires © 2009 Delmar, Cengage Learning
  • Gasoline Engines• Gasoline is more volatile and has a lower ignition temperature – Causes concern about it being the first fuel ignited• Gasoline engines operate on flammable liquids that have a flash point of less than 100°F – Lack of maintenance or worn and loose parts can cause the fuel to be sprayed • Possible cause for the spread of the fire in the event it came into contact with an ignition source © 2009 Delmar, Cengage Learning
  • Other Liquids• Transmission fluid, windshield washer solvents, ethylene glycol, motor oil, brake fluids, and other hydraulic fluids – May ignite under extreme conditions, either contributing to or causing a fire © 2009 Delmar, Cengage Learning
  • Hot Surfaces• Manifold, catalytic converter, and exhaust pipe operate at sufficient temperatures to ignite a wide range of fuels• Leaking brake fluid is most often the first fuel ignited when it leaks onto a hot surface• Gasoline will not usually ignite when sprayed onto a hot surface – Many variables such as ventilation or humidity can influence this © 2009 Delmar, Cengage Learning
  • Electrical Systems• Most vehicles operate on a 12-volt direct current (DC) system – Secondary wiring can come into play in fires from wear and tear and misuse – Resistance heating can cause the insulation around the wire to break down or melt• Hybrids bring a whole new realm to the investigation of vehicle fires – Voltage in hybrid vehicles can reach more than 300 volts of alternating current (AC) © 2009 Delmar, Cengage Learning
  • Hybrid Vehicles• Combine an internal combustion gasoline engine with an electric, battery-powered motor• Contain a high-voltage NI-MH battery pack• In a series hybrid, the gasoline engine will automatically stop and start• In a parallel system, the electric motor runs in conjunction with the gasoline engine• If the vehicle is partially or more submerged, do not touch any high-voltage components © 2009 Delmar, Cengage Learning
  • Other Forms of Heat• Vehicle’s heater, fans, and wires attached need to be looked at• Properly operating catalytic converter, located on the underside of the vehicle, can reach temperatures of more than 700° F• Turbo chargers create tremendous amounts of heat and may be a source of ignition• Smoking-related incidents can be difficult to find © 2009 Delmar, Cengage Learning
  • How Did the Vehicle Burn and Why?• If the vehicle was kept in clean and running condition and there is a fire, it may have been arson – For the purpose of insurance fraud• Scene first needs to be photographed from all sides• Photos of the area from the vehicle looking outward need to be taken – Particularly important when a stolen vehicle is found © 2009 Delmar, Cengage Learning
  • What Does the Exterior of the Vehicle Tell You?• Extent of damage may show direction of fire travel• Burn marks or demarcation lines may show path of travel• Patterns left behind will show the direction from where the fire began• Fire burns typically up and out – V pattern as in structure fire © 2009 Delmar, Cengage Learning
  • What Does the Exterior of the Vehicle Tell You? (cont’d.)• VIN contains information about the vehicle, such as year, make, model, engine, and paint color• One interesting facet to look at is the vehicle’s glass – Fire will cause long cracks on the front windshield• Look at the tires remaining on the vehicle – May show direction of flame © 2009 Delmar, Cengage Learning
  • Inside the Vehicle• Look at the glove box• Did the owner leave the keys in the vehicle?• Most of the interior of the vehicle is combustible – Composed of plastics or fabric• Hood will show burn patterns from the heat and flame impingement if the fire was in the engine compartment © 2009 Delmar, Cengage Learning
  • Motor Homes• Motor home contains components of a vehicle combined with the combustibles and heat source of a structure• Motor homes are unusual and must be investigated with care – May contain liquid propane gas for heat and fuel for the cooking equipment – May have a built-in generator that may use a flammable or combustible liquid © 2009 Delmar, Cengage Learning
  • Boats• Not much different from a vehicle or a motor home• Gasoline can collect in lowest part of hull• Unique situations in boat fires – Possibility that the boat sank• With inboard motors, you should look into the engine compartment• Area where the boat was moored should be closely examined © 2009 Delmar, Cengage Learning
  • Summary• Work the fires from the exterior to the interior and from the least damaged to most damaged• Scene needs to be documented and photographed on all sides• Investigator needs to sift debris to find evidence that will aid in using a scientific methodology• Both motor homes and boats have the same characteristics as other motorized vehicles © 2009 Delmar, Cengage Learning