Safety of fall arrest systems: a numerical and experimental study

Workers in elevated positions must be protected from falling or from the ha zardous consequences of fairs. Protection from falling can include fences, guard rails, etc., or a restraint system preventing the workers from reachi ng any point from which they can fall. However, protection from falling can be impractical and in such situations a fall arrest system (FAS) must be p rovided such that the fall does not cause injury to the worker or to others . This paper surveys prior work on the analysis of FASs including the energ y balance method historically used. This method is limited to simple FASs w here only one worker may fall. A novel numerical analysis technique for pre dicting the forces occurring in each component of an FAS during a fall is t hen described. Results from the numerical analysis are compared with result s from experimental tests and with those from the energy balance method. It is shown that the numerical analysis technique predicts forces to within b etter than approximately 7 per cent, the method being conservative, whereas the errors shown by the energy balance method exceed 26 per cent. The new analysis method is also shown to be applicable to multiple falls.