Maintenance strategy optimization for load haul dumpers operating at an underground mine

Abstract : The mining sector is one of the biggest economy drivers in South Africa. Most of mining companies are experiencing high operational cost and production pressure. Research suggests that 30% to 60% of total operational cost is accounted for by ore handling mobile machines. The literature reviewed suggest that little is done relating to understanding aspects influencing reliability and maintenance cost of LHD (Load Haul Dumper) fleet in South African hard rock underground mines. This study attempts to determine data centric factors influencing reliability and maintenance cost of LHD fleet in one of South African underground mine. The main objective is to analyze the LHD fleet data relative to best practice to determine categorization. The research study uses multiple data collection methods to answer study research questions and also gain the knowledge of the subject at hand. Data collection focuses on operational values comprising of maintenance and financial values for LHD fleet operating at the expansion project being executed at the South African hard rock underground mine. Data centric identification of improvement to optimize maintenance strategy of LHD fleet is outlined. The study used real case data of LHD fleet utilized at the South African underground hard rock mine. The study outcome suggest that the expansion project LHD fleet is operating with subsystems which are in the middle of the wear out stage. The expansion project maintenance team does not use condition based maintenance strategy, this strategy can be used to predict possible failures and can assist the maintenance department to proactively prevent breakdowns from occurring. There is a correlation between four subsystems forming part of the top twenty percentile subsystems which caused eighty percentile failures and the associated cost. Tyres are found to be the component which accounted for the highest maintenance spend, the researcher suggest that although tyres are managed by the maintenance department, the expenditure thereof does not necessarily mean that poor maintenance is conducted, however, replacement is required due to the expected wear and tear. To achieve the effective development of the underground mine, the expansion project maintenance team must consider the implementation of risk based inspection which assists in planning, selecting cost effective and condition based maintenance execution and techniques. The implementation of LHD fleet refurbishment program must also be given priority, subsystems which forms part of top twenty percentile for both failures and cost must be given priority one.M.Phil. (Engineering Management