This story appears in the July/August issue of Equipment & Maintenance Update, a supplement to the March 19 print edition of Transport Topics.
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By Dan Calabrese, Contributing Writer
When a motor vehicle hits an object head-on, the rapid deceleration jerks the bodies of drivers and passengers forward, putting them at risk of serious injury or worse. That is why front-seat air bags are a standard supplemental restraint to seat belts in passenger cars.
What happens when a heavy truck hits an object head-on?
“The truck usually wins,” said Bill King, sales director for Key Safety Inc., Sterling Heights, Mich.
And because of that lopsided score, air bags have hardly registered as a safety feature in the heavy truck industry. Key Safety found that out in 1998, when it developed an air bag customized for the Kenworth 800 series truck.
“It just didn’t take off in the market,” King said. “We had a minimum order quantity of 500 pieces. They were ordered and never ordered again. It’s not very often you hear of trucks hitting trees or anything like that.”
Today, only Volvo offers air bags as standard equipment on all its Class 8 heavy trucks in North America. Freightliner and Peterbilt offer air bags on a limited basis, but other heavy truck manufacturers have yet to offer air bags on any models.
“The last time I read information from [the National Highway Traffic Safety Administration], 60% of all [truck] fatalities were rollovers,” said Debbie Shust, director of heavy vehicle center marketing for Navistar’s International Truck and Engine Corp.
“We have roll stability now and some collision-avoidance technology, but the air bag is not something we’re pursuing aggressively,” she said. “It continues to be something we think about and talk about, but right now, we think there are more effective methods.”
Shust’s sentiments were echoed by spokesmen for Mack and Kenworth. Much of the industry believes that rollover protection, safer cab design and accident prevention represent a better investment of safety resources.
But that thinking puzzles Frank Bio, director of marketing for Volvo Power.
“Safety has always been a priority for us,” said Bio, who also said Volvo sees no reason to eschew air bags, even if most truck mishaps do not cause them to deploy. “In a situation where a truck runs headlong into the back of another tractor, the air bag makes a big difference.”
Volvo uses air bags manufactured by Autoliv, which, Bio said, are not significantly different from those found in passenger vehicles.
One safety engineer who believes air bags for big rigs must be tailored to the characteristics of the vehicle is Jim Chimmi, director of the Center for Advanced Product Evaluation for IMMI Corp. He said the main difference from a car concerns the angle of the steering wheel in relation to the driver. IMMI-owned Lifeguard Technologies has designed an air bag, called the 4Front, that attempts to account for the angle.
“It’s the difference in the orientation of the steering wheel, because it’s in a more horizontal plane, as opposed to a vertical plane” in a car, Chimmi said.
The 4Front also features a bolster bag designed to cushion the impact between the knee and the bolster panel.
As part of an up-coming presentation to the Society of Automotive Engineers, Chimmi cites data that suggest straight-on collisions account for a higher percentage of truck accidents than conventional industry wisdom suggests.
The most recent Large Truck Crash Causation Study, conducted by the Federal Motor Carrier Safety Administration, indicates that, in 23.1% of large truck crashes, the truck runs into the rear of another vehicle. Head-on collisions account for 4% of large truck crashes, and 9% are rollovers.
Chimmi also emphasized that trucks don’t win every collision, particularly when they involve bridges, mountainsides or similar immovable objects.
“Those are the sorts of events where they slow down the truck pretty rapidly, and those are circumstances where an air bag can provide some benefit,” he said. “We have investigated some frontal collisions like that, and the most common kind we have seen is where one tractor-trailer strikes another tractor-trailer. They may be traveling in a convoy or in bad weather, or one stops on the highway and the other doesn’t see it.”
Thus far, 4Front bags have been sold for use only on fire vehicles, but James Johnson, a Lifeguard Technologies sales director, said his group plans aggressive outreach to the freight-hauling industry.
“We’re talking with all the manufacturers,” Johnson said.
The slow acceptance of air bags among most commercial truck manufacturers mirrors the history of air bags for passenger vehicles. Based on a concept first patented in the 1950s, air bags emerged as a viable automotive technology in the 1980s. But they met with resistance from the Big Three U.S. automakers, which publicly expressed concern that air bags might cause head and neck injuries of their own, especially to children.
However, when the Chrysler Corp. began widely installing air bags in the late 1980s, and the company’s high-profile chairman, Lee Iacocca, became an outspoken air bag advocate, remaining resistance from his competitors seemed to fall away quickly.
Ironically, public advocacy groups soon would take the car manufacturers to task for failing to perform adequate testing on air bags and consequently failing to put in safeguards that they believe could have prevented many of the air bag injuries that, in fact, did occur.
Since then, innovations have made air bags safer. They include adjustable inflators, higher deployment thresholds, better sensors and tethers to prevent the inflating bag from intruding too far into the passenger’s space.
Making air bags less aggressive also was key to making them safer.
Will air bags in heavy trucks experience a similar evolution of acceptance? Some anecdotal evidence offered by Volvo indicates that users are convinced of air bags’ relevance to truck safety.
Del Schreck, owner of Schreck Trucking, Onalaska, Wis., told Volvo that its overall vehicle safety design — including the air bag — saved the life of driver Steve Wick in a November 2005 accident.
Schreck wrote to say that Wick’s vehicle hit the rear of a stationary tractor-trailer with such force that it split the trailer in two.
“When his unit came to a stop, it was virtually in pieces around him,” Schreck said. “The engine had dropped down and slid under the cab. The dash had collapsed around [Wick], and his air bag had deployed. He had to untie his shoes to slip his feet out from under the pedals. He unlocked the door, opened it and stepped from the cab with only a single small scratch on his head.”
Volvo and the other truck manufacturers have focused on front-end designs that make the engine fall between the frame rails in the event of being pushed back in a straight-on collision, as opposed to older designs in which the engine might have ended up in the driver’s or passenger’s lap.
Wick’s good fortune is the kind of result Key Safety envisioned when it developed those 500 air bags for Kenworth almost a decade ago Bill King said. However, Key Safety sees nothing in the commercial truck market today to indicate any greater acceptance of air bags than in 1998. As such, Key Safety has no plans to reintroduce air bags to trucking.
Will Lifeguard Technologies have success with its products? James Johnson is convinced the technology is both relevant and a fit.
“It prevents injuries to the chest and to the head by virtue of the shape of the bag,” Johnson said. “If you tried to use an automotive air bag and put it in a heavy truck, you would not get the same protection.”
Johnson’s challenge is to convince most of the trucking industry that air bag protection is needed at all. He will certainly not be the first to try.