Fall arrest characteristics of a scissor lift

Problem

Census of Fatal Occupational Injuries (CFOI) data indicate 306 aerial lift fatalities between 1992-2003. Seventy-eight of these fatalities specifically involved scissor lifts. Members of standards committees have requested that NIOSH conduct research to determine the effects of safety-control practices related to using fall-protection systems for scissor lifts.

Method

This research examined the structural and dynamic stability of a scissor lift subjected to fall arrest forces. This was accomplished by conducting drop tests from a scissor lift. Anchorage locations evaluated included manufacturer-supplied anchorage points on the scissor lift platform as well as mid-rail and top-rail locations.

Results

Preliminary drop tests determined that a 2400 lb maximum arrest force (MAF) could be generated by dropping 169 lb through a fall height of 36” using Nystron® rope as a lanyard. The scissor lift maintained structural and dynamic stability for all drop tests when fully extended and on an incline.

Discussion

Anchoring a fall arrest system to either the mid-rail or top-rail is not a recommended practice by the scissor lift manufacturer. Anchor points are provided on the platform floor of the scissor lift for this purpose. However, our results demonstrate that the mid-rail and top-rail absorb substantial energy from an arrested fall and may have potential as appropriate anchorage points.

Impact to Industry

Employers and workers should consider implementing fall arrest systems when using scissor lifts as part of their overall risk mitigation plan for fall injury prevention.