Post Collision Vehicle Fires Causes and Room for Improvement

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Post Collision Vehicle FiresCauses and Room for
Improvement

• Markus EgelhaafF. Alexander Berg DEKRA Accident
  Research

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Agenda

• Introduction
• General Statistics
• Accident Analysis
• Starting Points for Fire Protection
• Summary and Outlook

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Introduction

• No Action-Movie without Vehicle Explosion

this presentation will give an overview about
the real live fire occurrence.
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Introduction

• Findings from GDV, BASt and NHTSA studies

• About 60,000 vehicle fires each year in Germany
• About 6 of them are accident caused
• Less than 1 of all accidents result in a fire
• The fire share among fatal accidents is above 3.5

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Introduction

• Basis of the DEKRA pilot-study

• Legal expert opinions including a reconstruc-tion
  and pictures
• Access to about 25,000 opinions each year
• Cooperation with more than 1,800 DEKRA experts

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General Statistics

• Analysis of 79 post-collision vehicle fires

Severe deformations of all vehicles
Involvement of areas relevant for ignition like
fuel system or electric components
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General Statistics

• Accident location

urban areas 12outside urban areas 88
n 79
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General Statistics

• Maximum permissible speed

Speed-limit and driven speed 80km/h or above in
more than 70 of all cases
n 77
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General Statistics

• Environmental conditions

Curve 43 Straight 36 Junction 16
Intersection 2,5Hilltop 2,5
n 79
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Accident Analysis

• Method of evaluation

• Analysis of the experts opinion
• Analysis of the pictures of the vehicle and the
  scene
• Additional information from the police reports
• Comparison of a pre- and the post-crash vehicle

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Accident Analysis

• Kinds of accidents

• Primarily one (33) or two (47) involved
  vehicles
• The most frequent opponents are cars (37),
  trucks (23) and trees (30)
• In most cases a frontal collision

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Accident Analysis

• Significant constellations

• Single car accident against a tree
• Frontal collision car against car or truck
• Truck against the rear end of a car
• Frontal collision motorcycle against truck

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Accident Analysis

• Single car accident against a tree

• Complete energy conversion vehicle sided
• Deep impacts
• Load of critical components
• Endangerment of wedging

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Accident Analysis

• Frontal collision car against car or truck

• High energy potential by relative movement
• Big differences in mass and height in car to
  truck collisions
• Risk of fire spread in case of wedging

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Accident Analysis

• Truck against the rear end of a car

• Squashing of the car between road and truck
• Big differences in mass and height
• Early load of the fuel tank
• High risk of fire spread

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Accident Analysis

• Frontal collision motorcycle against truck

• Extreme differences in mass
• Unprotected fuel tank of the motorcycle in the
  height of hot engine components of the truck

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Accident Analysis

• Ignition scenario

• thermal ignition
• mechanic ignition
• electric ignition
• Fire spread

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40
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26
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Starting Points for Fire Protection

• Protection against short circuit

• Non-fused wires as short as possible
• Automatic battery cut off in case of a collision
• Fuse box outside the deformation area

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Starting Points for Fire Protection

• Substitution of combustible fluids

• Fuel gt no alternative
• Engine- and gear-oil gt no alternative
• Power-steering oil gt electric power-steering
• Window cleaning agent gt water down

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Starting Points for Fire Protection

• Fuel system

• Tank mounting outside the deformation area
• Tank integrated fuel pump with valve function
• Fuel emergency cutout in the engine compartment
• Large distance between fuel- and exhaust-system

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Starting Points for Fire Protection

• Light metal

• Predominantly aluminum and magnesium
• Burn with very high temperatures
• No aqueous extinguishing agents usable

Source VW
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Summary and Outlook

• Post collision vehicle fires are a rare event
  with a high risk for the occupants
• Primarily severe accidents with high energy
  potentials
• Thermal ignition most frequently
• No explosions

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Thank you very much, Dankeschön