There is no doubt vehicles are getting more complicated. As we make lighter, more fuel efficient vehicles, one aspect that can be overlooked is the potential of these changes to increase the risk of a vehicle fire and complicate the determination of the fire’s origin and cause. More and more plastics and exotic materials are making their way into vehicles, potentially accelerating fires that result in full involvement. Turbocharged engines are becoming more dominant in an effort to balance small-engine fuel economy with the feel of big-engine power. Turbochargers become an additional hot surface for possible ignition of other fluids, and can become a source of fuel due to oil leaking past its bearing seals and feeding the engine. Contrary to popular perception, sales of clean diesel engine passenger cars are also on the rise. These are generally paired with a turbocharger, and can lead to the rare but possible condition of diesel engine runaway, in which the engine speed continues to increase until eventual failure due to an external fuel source.
On the commercial side, the proliferation of Diesel Particulate Filter (DPF) technology on vans or heavy equipment, as emission controls get tightened, may play an important role in fire investigations, particularly in Midwestern states that comprise the majority of corn and soybean harvesting, for example. Finally, the continued increase in vehicles with hybrid or electric powertrains on the road may highlight the effects of higher voltage systems and the potential of battery-related fires.
When it comes to the examination of vehicle fires, the combination of a mechanical engineering background and fire investigation training offers several advantages. When traditional fire origin indicators (such as fire patterns and effects) become less reliable (as in a fully involved vehicle), intimate knowledge of vehicle’s systems can provide a unique perspective to help establish not just the area of origin, but also identify the cause of the fire. In addition, knowing what to expect from a vehicle while it is operating is invaluable to interpreting a witness’ narrative and matching the story to the available evidence. While the need for a dedicated Origin & Cause (O&C) fire expert may be critical on a building fire, for example, a vehicle fire offers a platform in which the mechanical engineer/fire investigator may be more suited to offer comprehensive investigation results in a reduced timeframe, providing better value to the interested parties.
Crane Engineering has experts that provide O&C investigations of fires on passenger and commercial vehicles, farming, forestry and construction equipment, and stationary engines, among others.