Some aspects of the reliability of drilling equipment

Conclusions1.Existing criteria for estimating the reliability of mining equipment (time to breakdown, coefficient of operational readiness, etc.) based on the time factor cannot be used to estimate the operational reliability of drill rigs without involving the borehole length, because the latter influences their operational conditions.2.The reliability of drill rigs must be estimated by means of indices functionally related to the borehole length (the probability of occurrence of reject boreholes and of correctible and uncorrectible breakdowns, and the probable length of breakdown-free drilling). In some cases it is possible to elucidate the physical nature of a breakdown and to determine the suitability of the equipment for particular conditions.