Carl F. Thelin

OTHER GM COMMENTS   

            Here is another example of the stuff an expert from GM would say. “People prefer lap belts to lap and shoulder belts.” Of course more people preferred lap belts to lap and the lousy shoulder belts in those cars made during the early 1970s.  Sinke said that a substantial number of vehicles in the survey (limited to 1974 and 1975 models, I believe) were equipped with combined belts. Yes, but those were the kind that did not have an Emergency Locking Retractor (ELR) for the shoulder belt. They expected the user to use a separate strap for the shoulder belt. That strap was stowed in clips above the side window. A substantial number could be 11 percent to GM. At that time, before the regulations required shoulder belts with emergency-locking retractors, most cars had a lap belt only, or lap and shoulder belt without an ELR retractor. I agree that only one of nine people would bee seen using such a shoulder belt.

            Another statement by a GM expert ended like this: “(A lot of blather) ... caused GM to redesign all of its front safety belt systems to new belt geometry, possibly reducing the need for comfort features.” Is this another way of saying that the number of lawsuits similar to ours motivated the redesign? Why did GM not initiate this new belt geometry sooner? My interpretation of “new belt geometry” is that GM put the belt anchors in the right places, and reduced the tension of the shoulder belt.  

            Well, why was the tension of the shoulder belt so irritating? It was because the domestic car makers chose to continue using their buckle hardware from the lap-belt-only days. Those buckles were all metal, with fancy trim. They were large enough to be comfortably gripped. The first response of the domestic industry to the new regulations requiring a combined lap-should belt was poor. They brought this too-much-tension grief on themselves. Their shoulder belt had a simple wind-up retractor. The new one-piece lap-shoulder belt had a heavy metal latch plate to insert into the buckle. The spring in the wind-up retractor had to be strong enough to pull the strap and the heavy buckle out of the way when the user left the car and closed the door. That made the tension on the shoulder too high for comfort. GM, Ford and Chrysler could have adopted the light weight metal-plastic belt latch plates used on all European and Japanese cars. Nope. They were too infected with the NIH factor. Those big guys (they were big then) did not want to use a design NOT INVENTED HERE. Thus they added the window shade feature the retractor with the spring strong enough to put the buckle out of the way. With the window shade mechanism, the user could cancel the tension. Then, by wiggling around, they could introduce too much belt slack.

            All of the claims about the observed effectiveness in the field were predicated upon the user not misusing the system and allowing more than one inch of slack to remain in the shoulder belt. “GM was concerned that the occupants who had previously worn lap belts would not stop using them because of the shoulder belt, resulting in an overall decrease in seat belt usage.”  But - if the previous restraint usage for the front seat was lap belt only, there is research that shows that there is almost no benefit except to prevent ejection. The passenger’s head would strike the instrument panel. This would result in severe head and neck injury, even in crashes as low as delta-V of only 10 mph.

             “GM focused ...on mandatory seat belt use laws ...” As I said, the unspoken intent of the tension-reliever or the seat belt use laws was to get the seat belt usage rate high enough that NHTSA could not justify requiring air bag automatic restraint systems.

            GM used statistics gathered by friendly forces. NHTSA research concluded that the comfort feature was OK with a small amount of slack. However, NHTSA (and Consumers Union, and others) proposed that the system be tested with as much slack as could reasonably be expected – and the industry went ballistic with lobbying to defeat that part of the test.

            “The Owner’s Manual and the back side of the buckle have warnings and instructions on how to use the belt system properly.” What passenger is likely to read either?

            “Not all injuries are preventable ...” That is not the point. The point is to reduce the severity of the injuries. The window shade concept was unreasonably dangerous. It traded off efficacy for a dubious gain in usage rate, but really for a means of avoiding the mandate for air bags. That no European or Japanese vehicle used that system is a strong indication that is was more reasonable to use their techniques to make lap and torso seat belts acceptable.

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