R. Scott King, BSME, Principal Automotive / Mechanical Engineer
Several years ago, a busy turnpike service structure sustained substantial fire damage. Fire investigators suspected the fire originated within a turnpike service vehicle parked nearby. Separately, but soon thereafter, another turnpike service van sustained extensive fire damage while responding to a road-side emergency call. Mindful of the coincidence, the turnpike authority commissioned an engineering investigation of the root cause of each loss.
An evaluation of the physical evidence remaining at the structure fire revealed patterns and fire effects confirming the fire originated within the turnpike service vehicle. Containment of fire to the second vehicle was self-evident. Based on these observations, both vehicles were closely examined revealing evidence of electrical system malfunctions. Although each fire was caused by different malfunctions, both were related to aftermarket adaptations to the vehicle’s electrical systems. Further, an engineering analysis revealed that the workmanship, not the aftermarket components, was the root cause of the malfunctions. Based on these findings, the turnpike commission extended the investigation to its entire fleet of road-side emergency vehicles.
In total, approximately two dozen service vehicles were examined. Each vehicle had aftermarket electrical equipment and modifications, most of which had installation deficiencies that increased the risk of fires. A survey of historic practices relating to aftermarket equipment installation revealed that nearly all modifications were performed by a variety of vendors, with no standardization, and with limited guidance or oversight.
Remedial recommendations were made for the existing fleet and an engineering standards document was developed for future fleet vehicles to ensure commonality of components and installation workmanship.
R. Scott King, BSME, Principal Automotive / Mechanical Engineer with DJS Associates, Inc., can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.