Seat Defect History
Rear impact dangers have been the focus of scientists for many years. The initial tests and inquiries surrounded whiplash injuries in low speed accidents.
Early tests showed that it was important to have adequate seat back height and seat back strength to protect a vehicle's occupants during all rear impacts. Earlier seat design lacked height to prevent whiplash and strength to prevent rearward seat collapse. Some vehicles today still lack these provisions.
"Seat-back strength should be increased and that higher seat backs or head restraints should be used.. It is well within the range of early possibility to provide survivability in 60mph rear-end impacts." - Detroit auto manufacturer engineer 1966 |
FMVSS (Federal Motor Vehicle Safety Standards) 207 - "the seating system will not separate from its attachment when subjected to a 20G loading, without an occupant"
FMVSS 207 S.4.2 General performance requirements. When tested in accordance with S5., each occupant seat, other than a side-facing seat or a passenger seat on a bus, shall withstand the following forces, in newtons. (a) In any position to which it can be adjusted—20 times the mass of the seat in kilograms multiplied by 9.8 applied in a forward longitudinal direction; (b) In any position to which it can be adjusted—20 times the mass of the seat in kilograms multiplied by 9.8 applied in a rearward longitudinal direction; (c) For a seat belt assembly attached to the seat—the force specified in paragraph (a), if it is a forward facing seat, or paragraph (b), if it is a rearward facing seat, in each case applied simultaneously with the forces imposed on the seat by the seat belt assembly when it is loaded in accordance with S4.2 of § 571.210; and (d) In its rearmost position—a force that produces a 373 newton meters moment about the seating reference point for each designated seating position that the seat provides, applied to the upper cross-member of the seat back or the upper seat back, in a rearward longitudinal direction for forward-facing seats and in a forward longitudinal direction for rearward-facing seats. |
To show just how insufficient FMVSS 207 is, an engineer built a seat out of cardboard that passed the test. Since car seats are made stronger than cardboard, there was no need to spend any money to reinforce current seats on the market.
In 1980, the NHTSA Administrator wrote the leaders of the major US auto manufacturers addressing seat back performances in rear crash tests and the agencies concerns:
"The crash tests of our New Car Assessment Program have revealed a number of seat track and seat back failures. The automakers should review their designs to insure that seats do not fail catastrophically" |
Rear impact seat test results have greatly improved due to new seatbelt designs which have the seatbelts attached to the seats, not the frame of the car. This does a much better job of keeping the occupant in the seat. Manufacturers who have designed such seat belt systems include Mercedes, BMW, GM, Chrysler and Audi.