Bottom Line
New technology in rollover, jackknife prevention

by Bill Siuru

According to the U.S. Department of Transportation, 23 percent of all large truck accidents result from out-of-control catastrophes like trailers swinging sideways onto public roads, rigs rolling over or jackknifing. The National Highway Traffic Safety Administration reports 60 percent of truck occupant fatalities involve a rollover.

Rollover protection
Freightliner recently introduced its Tubular Side Airbag System on its Century Class S/T and Argosy models. This is the first application of the world’s first rollover protection system designed specifically for the commercial truck developed by IMMI (Indiana Mills and Manufacturing Inc.), a leading manufacturer of commercial vehicle safety restraints. During a rollover accident, the driver’s head and body often are propelled upwards and sideways. Even seat-belted drivers can be injured as their head strikes surfaces on the left side of the truck. To alleviate these kinds of injuries, the Tubular Side Airbag System inflates a 2.3-foot long airbag that extends from the A-post to upper B-post. The system incorporates an integrated sensor that monitors the truck’s angular or roll acceleration and deploys the airbag as rollover begins to occur. The airbag is positioned at head level, so as the truck rolls over, the driver’s head contacts the side airbag rather than the side window or surfaces above it. Unlike automobile side airbags designed to protect the driver or passengers during a side impact, the Tubular Side Airbag is designed specifically for truck rollover accidents where the danger is from the forces and motion inside the rolling truck.

The Tubular Side Airbag System works in conjunction with Freightliner’s Seat Pretensioner Activation for Crash Survival Enhancement (SPACE) system introduced in 1995. During a rollover or major frontal impact, SPACE pulls the driver away from the roof and steering wheel by automatically lowering the driver’s air suspension seat and tensioning the seat belt. Freightliner also offers a Driver Front Airbag in the steering wheel that cushions the driver’s head and body from impact with the steering wheel, steering column and other forward surfaces. Together, the Tubular Side Airbag, SPACE system and Driver Front Airbag attempt to create a zone of protection for the driver. However, wearing a seat belt remains the fundamental way to prevent injury during any vehicle accident.

Accident Control and Anti-Jackknife System 
Safe Transportation Systems (STS) in Bellingham, WA, has developed its Accident Control and Anti-Jackknife System to prevent loss of control and jackknifing of tractor-trailer rigs. The system is a rather simple, why-didn’t-I-think-of-that solution consisting of a high tensile steel mechanical limiter attached to the underside of the trailer and inserted between the forks of the fifth wheel. The system mechanically limits the amount of trailer rotation relative to the tractor without reducing full braking and steering capabilities. With the STS system installed, passing or obstacle avoidance ability is still fully available, but now greatly reduced is the possibility of losing control, rollover or jackknifing. With a click of an illuminated dash-mounted switch in the cab, the driver lowers the steel engaging bar. The system is engaged during all normal driving conditions, but can be turned off in less than a second when needed to allow sharp turns on urban streets or when parking.

The STS system was tested successfully at NHTSA’s Transportation Research Center in East Liberty, OH. It withstood more than 100 hard impacts, some at speeds of up to 60 miles per hour. The first units are being installed on trucks operated by

Northwest Tank Lines Inc., a hazardous waste hauler. The system, which can be retrofitted easily onto existing trailers or installed at the factory on new trailers, will be available through Truck Trailer Manufacturers and Trailer Dealer Networks’ installation facilities from Alaska to Florida. It can be used on tractor-trailers with and without anti-lock braking (ABS).

Bill Siuru is an automotive journalist from San Diego, CA.