Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SATURDAY, March 26, 1994 TAG: 9403280161
SECTION: NATIONAL/INT PAGE: A-4 EDITION: METRO
SOURCE:
DATELINE: DETROIT LENGTH: Medium
Technicians admit the mechanism of the side-impact air bag, the auto industry's latest effort to minimize crash injuries, is a little dicey. The side air bag must overcome problems of physics that don't apply in front-end collisions, where the so-called "crumple zone" is longer.
But Volvo, one of the earliest carmakers to turn safety into a selling point, is ready to install side-impact air bags as part of its passenger-restraint systems in 1995 models. Others are scrambling to offer it as an option. Some predict side bags could be as common as seat belts by 1997.
"There are several technical challenges, but not barriers that can't be overcome," said Brett Smith, researcher at the Office for the Study of Automotive Transportation in Ann Arbor, Mich.
The technological challenges are simple enough to outline.
For example, how can the air bag be deployed fast enough, with just a few inches of door frame separating a passenger from tragedy?
And what stops an air bag from inflating accidentally if the triggering event wasn't caused by an oncoming vehicle?
Precise timing and placement of the air bag are the critical considerations. Unlike front-impact air bags, which have about 40 milliseconds to sense a crash and deploy, side impact bags have about 15 to 20 milliseconds before shearing metal would reach a passenger. It takes twice as long to blink an eye, according to the American Academy of Ophthalmology.
Consumer advocates say the effort to devise side air bags comes largely from tougher federal safety rules. In 1997 these rules will require that motorists be protected from side crashes of 331/2 mph. Side-impact crashes now cause an average 8,000 fatalities and 24,000 severe injuries each year.
"It's 90 percent driven by regulation and 10 percent driven by what consumers want," said Clarence Ditlow, director of the Center for Auto Safety in Washington. Still, he said the auto industry has shown surprising progress.
"Compared to front-seat air bags, which took 20 years, we're moving with lightning speed," he said.
Air bags deploying from the door, seat, roof and head rest all are in test phases, but their potential costs remain unclear.
Front air bags cost $500 to $1,500 each, but those prices have been coming down. When Mercedes-Benz introduced a driver's side air bag in 1983, for example, it charged customers $850 for the option. Now it's standard equipment.
Volvo's side-impact air bags will be available in the driver and front passenger seats in its 1995 850-series sedans and station wagons. The Swedish automaker isn't saying how much, or even whether, the embellishment will add to the sticker price.
The Volvo air bag will be placed in the upright seat back about shoulder height. The sensing device, housed in the seat cushion, will trigger when the door panel crashes into a bar protruding about 4 inches from the seat.
The air bag, about the size of a large loaf of bread, is intended to protect a passenger's torso.
Many say the side bag technology has a long way to go.
Dozens of variables must be considered. What if a child gets in the way of a fast-deploying air bag? What if a passenger is napping against the door when an air bag mounted on the outside of a head rest deploys?
"It might be like being hit with a 100 mile-an-hour basketball," said Sherman Henson, Ford manager of safety planning.
by CNB