DASH-MOUNTED airbags protect drivers from injury in frontal crashes; however, more than half of driver fatalities in heavy trucks occur in rollover accidents. At the Great American Trucking Show in Dallas, Freightliner Trucks introduced a new tubular side airbag to cushion the driver's head during crashes that cause a tractor to roll over.
In a rollover crash, the driver usually moves up and sideways as the vehicle rolls. A seatbelt offers little protection to prevent the driver's head from striking the left interior side of the truck. To prevent head injuries, Freightliner's new tubular airbag inflates a 2.3-ft long balloon that provides 0.42 cubic ft of cushioning that extends diagonally from the upper rear corner of the door area to the lower front corner near the edge of the dashboard. The airbag is positioned at head level so that a driver's head contacts the bag instead of the streetside window or interior surfaces above the window. The airbag is triggered by a sensor that measures angular acceleration and vehicle roll rate to deploy the system as a rollover incident begins.
Freightliner's tubular airbag differs from the side airbags used in automobiles, because it is designed to counter a completely different set of circumstances. Automobile systems deploy in side-impact crashes. The tubular side airbag deploys to prevent injuries that result from the force and motion of a rolling truck rather than from the exterior force of a second vehicle.
The side airbag works in concert with other injury prevention devices. In a crash, a seatbelt tensioner pulls the driver down from the vehicle roof and away from the steering wheel by tightening the seatbelt and lowering the air suspension driver's seat. At the same time, a front airbag deploys from the steering wheel hub. The entire system is designed to pull the driver away from potentially dangerous surfaces while cushioning the head from side or frontal impact. Seatbelt use is essential for system effectiveness.
The new safety device will become available in Century S/T conventional tractors and Argosy cabovers in mid-2001.
For more information, visit www.freightlinertrucks.com.