Electronic stability control is becoming a popular safety option on heavy commercial trucks after several years of success on passenger cars and SUVs. This year, ESC will be offered on some models of construction trucks as well.
It doesn’t take much to roll over a highway tractor, and concrete mixers are especially at risk due to their high center of gravity and dynamic loads. Surprisingly, few rollovers occur. “It is not a prevalent problem, however, the consequences can be severe,” says Robert Garbini, executive director of the National Ready Mixed Concrete Association.
|Rock ’n’ Roll. ESC slows vehicles down to avoid dangerous tipping.|
Mack Trucks Inc. is the first maker to offer ESC on a mixer chassis. Available now, the $1,500 safety feature “could easily go standard” in the future, says Senior Vice President Kevin M. Flaherty. Mix trucks typically cost up to $200,000.
ESC systems could be a handy training tool. Following the curve of a highway off-ramp too fast with a load of ready-mix spinning in the back is plenty to send a transit mixer into a tailspin, potentially killing the driver and others nearby. In many cases, drivers don’t sense danger until it is too late.
Safety officials from Mack and Bendix Commercial Vehicle Systems made the point clear last month in the parking lot of the Las Vegas Motor Speedway, where they demonstrated a prototype ESC on a mixer. The drum was filled with water and sand, while special outriggers kept the vehicle upright.
Charlie Ross, a test driver for ESC-maker Bendix, took the mixer around a curve at 26 mph and came back around for a double-lane change. Both times, the truck tipped. With ESC turned on, sensors mounted on the chassis and wheels triggered the truck’s ABS brakes and slowed it down enough to escape tipping.
Even though the new stability devices can’t stop every crash, they will “lessen the circumstances,” Ross says.