Estimation of remaining strength of steel wire rope by electromagnetic testing

Two methods to estimate remaining strength of steel wire ropes on site by electromagnetic testing data are described. One is for winding ropes of inclined shafts in a coal mine; the remaining rope strength (F sub R ) is given by F sub R = F sub 0 B exp --m , where F sub 0 is the initial strength, B is the background noise level on a recording chart and m is a constant which depends on the shaft. The other is for parallel wire strand ropes which are used as tension members of a suspension roofing; the remaining rope strength can be computed using the cross sectional area loss which is estimated from the electromagnetic testing records.