Memorandum - NHTSA

WC Retention Overload Test 67.13)
IV-22
Deploy the outer barrier with the lift 89 mm (3.5”) above the ground. Apply 7,117 N (1,600 1k s.)
and attain the load within 1 minute. If a rectangular outer barrier, the Ioad is to be distributed
[area = 25 mm (1”) high by the width of the barrier face)] and centered 63 mm (2.5”) above thc
platform surface. If the WC retention device is other than a conventional outer barrier design,
apply the 7,117 N (1600 lbs.) directly to the WC test device (which would be pushed up agaimt
the retention bamer. The WC retention device must maintain 7,117 N (1,600 lbs.) for 2 minulles
without cracks, separations, fractures or breakage.
For hrther details, the agency has placed in Docket No. NHTSA-98-45 11) an analysis entitled,
“Wheelchair Retention Device Impact test Analvsis, June 6, 1996,” Also, the same docket sec an
analysis entitled, “Determination of Center of Gravitv of Cross-Bar Frame Powered Wheelcha irs.
June 6, 1996.”
It is believed that very few, if any, lifts currently on the market would meet NHTSA’s dynamic,
WC retention test in the loaded condition. Therefore ,it is believed all personal and commerc la1
lifts would certify using the 7,117 N (1,600 lbs.) static overload test. Although all lifts curren ly
manufactured have an outer barrier [at least 76 mm (3”) hi&], it is believed that they are of
insufficient height to prevent WC climbing. VRTC found that 127-152 mm (5-6”) high barricr
would be needed compared to the 76 mm (3”) barrier used on lifts today to prevent the
wheelchair from climbing over the barrier given the test speed involved. Therefore, some
consumer cost may be incurred to make the outer barriers 51 mm- 76 mm (2”-3”)higher. Thc