The design of all mine cage suspension
equipment, is in accordance with NCB codes & rules unless specified otherwise.
Generally, equipment will have a minimum static factor of safety of 10 in relation
to the maximum SWL, except where the load is bourn by a threaded component, in
which case the minimum static factor of safety shall be 15:1.
Due to the cyclical loading of the gear, the principal design
consideration is fatigue, and components must demonstrate infinite fatigue life
(with reserve) under the most severe dynamic loading conditions.
In the past, photo-elastic analysis was employed to determine
the magnitude of stress concentrations; today however, this existing data is combined
with FEA analysis to assist in the design of new equipment.