A critical investigation into missing persons in underground mines and related tracking technology

Abstract

Even though mining has always been at the heart of the economy, it is also regarded as one of the most hazardous industries. Miners and any other persons who work underground can, not only be fatally injured during mining accidents, but also from being trapped underground. This study shows that there is a significant number of fatalities caused by miners going missing underground. These miners are deceased due to being trapped underground for an extended period of time without any help. These fatalities are often incorrectly reported, attributing the fatalities to the initial event. This study shows that the miners can survive the initial event, but become trapped in unknown, life threatening locations. Several accidents that led to miners going missing were investigated. It was found that the lack of positioning information regarding the missing miners causes search-and-rescue operations to either fail or last longer. This study shows that the miners who were deceased from being trapped/lost underground could have been saved by such a system that can urgently provide their locations. A slow implementation of these systems in mines could suggest a failure to learn by the industry; in realising the need and value of these systems. The aim of this study was to firstly emphasize the need and value of these systems in underground mines. Secondly, to make the industry aware of the availability of different systems in the market. Lastly, to define and recommend a suitable and fit for purpose system. The identified systems are mainly classified into Through-the-Wire (TTW), Through-the-Air (TTA) and Through-the-Earth (TTE) systems according to their signal transmission techniques and frequency spectrum. TTW systems transmit signals through cable connections. The TTW systems are used as phones or network infrastructure. TTA systems enable the exchange of signals wirelessly in the air as a medium of signal transmission. TTE systems propagate seismic or electromagnetic signals through rock. The functions, capabilities and limitations of these systems were investigated. Furthermore, devices used for similar purposes in related industries with the potential to be adopted in the mining industry were studied. Several factors that can affect the suitability and applicability of these systems in underground mining environments were investigated. With a wide variety of systems commercially available, there was a need to determine the most suitable and fit for purpose system. This was done by, firstly developing user requirements that resemble an ideal system. Secondly, the underground areas in which miners are expected to work and travel were identified. Lastly, from the investigated accidents, scenarios in which miners can go missing were derived. These parameters were used to evaluate the suitability of the systems. Therefore, the most suitable and fit for purpose system can thus be selected based on the evaluation outcomes. Even though all these systems worked well, it was found that no single system could satisfy all the user requirements, no single system was suitable in all the underground areas and no single system was suitable for all the going missing scenarios. This necessitated the need to assess the possibility of integrating different systems to improve suitability and effectiveness. It was recommended that mining operations identify further scenarios in which persons can go missing, especially those that are more relevant to their underground areas. The user requirements and underground areas should be considered and used for selecting a suitable system. The mining industry needs to learn and realise the need and value of these systems to save lives.