(a) the mine shaft, at least once every week;

(b) the shaft guides, timbers, walls and compartments used for hoisting, at least once every month;

(c) the headframe, headframe foundation and backlegs, sheave deck, dump, bin and bin supports, at least once every year; and

(d) the shaft sump, at such frequency as is necessary to assure that the tail, guide and rubbing rope connections are clear of water and spillage.