Losses can be contentious — especially when two parties believe the other is at fault. In these cases, engineering principles and third-party objectivity can reveal how and why an incident occurred and who bears responsibility.
An example of one such incident was a loss dispute I investigated involving a trucking company and a ferry operator.
A large, tractor-trailer arrived at a ferry landing where personnel assured the driver they had transported similar trucks across the river. The truck boarded the ferry and was parked in a lane that encircled the control tower located in the middle of the ferry. To disembark, vehicles pulled around the tower and off the ferry. After crossing the river, the truck was the last vehicle directed to unload. That’s when the problems began.
As a whole, the tractor-trailer was too long to make the curve around the control tower. The wheels of the cab made it onto the exit ramp but the trailer wheels — set in the rear-most position — could not align with the ramp entrance. With the truck stuck and the ferry schedule disrupted, tempers escalated. Eventually, the cab and ramp separated from the ferry bow and the ferry backed off letting the trailer fall into the river. The trailer, its cargo, and the ramp were destroyed and the trailer’s leaking fuel resulted in an environmental discharge affecting a nearby Coast Guard station. The truck driver and ferry captain, who blamed each other for the incident, fought. Both were injured.
Witness interviews revealed two actions before the trailer and ramp fell. First, the truck driver tried to reposition the rear axles forward, but could not given the loaded condition of the trailer and the slick steel ferry deck. In addition, they reported the ferry captain ordered the lines securing the ferry to the station loosened.
The engineering inspection revealed no conditions of defect in the ramp and hoists, or the tractor-trailer and, additionally, the ramp was not intended to support vehicle weight without the support of the ferry deck.
So who was at fault?
The investigation clearly showed three reasons the ferry crew and captain owned the loss.
1) They allowed a larger truck than could easily be transported onto the ferry.
2) They failed to recognize that they could have reversed the ferry position to the ramp and allowed the truck to back off the ferry rather than pull forward.
3) Their maneuvering of the ferry while the truck and ramp were supported on the deck caused a loss of support that resulted in the trailer falling into the river.
Using detailed measurements to create an incident reconstruction, I could see it was impossible for the truck to exit the ferry as directed by the employees. Had the ferry captain simply reversed the ferry position to the ramp and the crew directed the truck driver to reverse off the ferry rather than pull forward around the control tower, the entire incident would have been prevented.
John Phillips, senior consulting engineer at Warren, has more than 30 years of crane and heavy equipment experience and more than 17 years of experience in forensic engineering. A licensed professional engineer in South Carolina, North Carolina, Georgia, Louisiana and Ohio, he’s NCEES registered both as a model engineer and with The United States Council for International Engineering Practice, USCIEP. John has designed crane systems, supervised installation, tested and certified lifting equipment even serving as a project engineer for maintenance and certification of nuclear weapon lifting and handling systems. John is a certified fire and explosion investigator and fire and explosion investigator instructor by the National Association of Fire Investigators. John is a member of the American Society of Materials and American