Rollover reminders keep coming

Aug. 1, 2011
TANK truck rollovers remain an all-too-frequent occurrence. We get regular reminders that this is a problem that must be taken seriously by every facet

TANK truck rollovers remain an all-too-frequent occurrence. We get regular reminders that this is a problem that must be taken seriously by every facet of the tank truck industry.

The latest reminder came earlier this month from the National Transportation Safety Board (NTSB). The agency, which is a part of the Department of Transportation, issued a highway accident report detailing an October 2009 rollover involving a propane transport in Indianapolis, Indiana.

Here is how the report described the incident: Carrying more than 9,000 gallons of LP-gas, the rig was exiting I-69 southbound to proceed south on I-465. While negotiating the right lane on the connection ramp, which consisted of two southbound lanes, the rig began to encroach upon the left lane, which was occupied by a passenger car.

The truck driver responded to the car's presence in the left lane by oversteering clockwise, causing the tanker rig to veer to the right and travel onto the paved right shoulder. Moments later, the truck driver steered counterclockwise to redirect and return the rig from the right shoulder to the right lane.

The truck driver's excessive, rapid, evasive steering maneuver triggered a sequence of events that caused the tank trailer to roll over, decouple from the tractor, penetrate a steel W-beam guard rail, and collide with a bridge footing and concrete pier column supporting the southbound I-465 overpass.

This collision entirely displaced the outside bridge pier column from its footing and resulted in a breach at the front of the cargo tank that allowed propane to escape, form a vapor cloud, and ignite. The tractor came to a rest on its right side south of the I-465 overpasses, and the decoupled tank trailer landed on its left side near the bridge footing supporting the southbound I-465 overpass.

Both the truck driver and the passenger car driver sustained serious injuries in the accident and post-accident fire. In addition, three occupants of other vehicles on I-465 incurred minor injuries from the post-accident fire.

Outside factors seem to have played little or no contributing role in the event. It was an overcast fall day around 10:30 am. The temperature was about 58°F, and the pavement was dry. In addition, the NTSB investigation turned up no mechanical issues with the truck.

NTSB's investigation was extensive and thorough. Everything in that investigation points to driver error, plain and simple. Truck driver error stands out at the primary contributor in a majority of tank truck rollovers, according to the Battelle study commissioned by DOT several years ago.

Driver training is where the rollover-prevention focus needs to remain for the tank truck industry, and the rest of trucking. The Battelle study showed that a well-trained, alert truck driver is the first line of defense against tank truck rollovers.

Unfortunately, NTSB seems to work in a world where technology solutions are the magic fix to human error. That is the rabbit trail NTSB follows in so many of its investigations.

One of the many recommendations in the wake of the Indianapolis rollover called for a federal mandate to retrofit vehicle stability devices on tank trailers with a gross vehicle weight rating greater than 10,000 pounds. However, NTSB offers no absolute proof that a vehicle stability system would have prevented the event.

NTSB also called for a far-reaching review of accident data on DOT-specification cargo tanks to identify design weaknesses and eliminate all crash risks. We already have ample proof that MC330 and MC331 pressure vessels are some of the most thoroughly engineered and tested cargo tanks on the road. They simply are not intended to be driven off a highway overpass.

Somewhat surprisingly, NTSB's investigators called for the Pipeline and Hazardous Materials Safety Administration (PHMSA) and the Federal Motor Carrier Safety Administration to develop and disseminate guidance that will assist hazardous materials carriers in implementing comprehensive cargo tank motor vehicle rollover prevention training programs. On it's face, it seems logical.

It is a somewhat stunning recommendation in light of the fact that PHMSA and FMCSA already offer rollover prevention training that includes an excellent video developed jointly with National Tank Truck Carriers.

There is no magic technology bullet or federal initiative that will eliminate cargo tank rollovers. Prevention must start and end out on the highways where the rubber meets the road. It means constant oversight by fleet managers and constant training for drivers to keep them alert to the rollover threat at all times.

About the Author

Charles Wilson

Charles E. Wilson has spent 20 years covering the tank truck, tank container, and storage terminal industries throughout North, South, and Central America. He has been editor of Bulk Transporter since 1989. Prior to that, Wilson was managing editor of Bulk Transporter and Refrigerated Transporter and associate editor of Trailer/Body Builders. Before joining the three publications in Houston TX, he wrote for various food industry trade publications in other parts of the country. Wilson has a bachelor's degree in journalism from the University of Kansas and served three years in the U.S. Army.