Electrification plays a significant role in achieving net zero targets, and existing underground mines are required to reach deeper depths to meet the increasing demand for rare earths and metals. Traditionally, underground mining loading and hauling operations have been performed using diesel-powered load haul dump (LHD) machines and trucks. These machines are powered by internal combustion engines (ICEs) that emit exhaust gases, diesel particulate matter (DPM), and heat. Battery electric vehicles (BEVs), powered by electric engine, were introduced in underground mining in the early 2010s. Electric engines enable higher energy efficiency than ICEs and do not produce exhaust. Therefore, they have the potential to facilitate cleaner air and reduce ventilation demand, thus reducing costs.

Although BEVs have been used for more than a decade in underground mining, there is limited research on user and mine experiences or operational aspects. Simulation studies comparing BEVs and diesel machines using different loading and hauling strategies and quantifying productivity differences have not yet been extensively conducted, particularly in the context of battery swapping. This thesis investigates how employing BEVs in current underground mine loading and hauling practices affects the mining operations. The research carried two exploratory surveys, targeting underground mine personnel and mine management, to obtain their points of view on BEVs and their experiences using them in underground mining. In addition, a discrete event simulation (DES) model was developed to compare and analyse the battery swapping and fleet dimensioning of LHDs in the case study block cave mine.

The survey findings show the main motivators for underground mine management to employ BEVs within their operations were to make the working environment healthier and reduce carbon emissions. The identified hindering factors were related to high costs and lack of proven reliability. Mine personnel appreciated that the BEVs were quieter, had fewer components and fluids, and improved the air quality. However, they had concerns related to fire risk, limited battery duration, and work performance. According to the DES simulation results, speed and hauling strategy have a significant impact on productivity. BEVs with equivalent gear can achieve, on average, between 6.5% and 10.3% higher productivity than equivalent diesel machines. The queueing at the swapping station appears to remain low even with a maximum number of machines and maximum battery swapping time when there are sufficient batteries within the system. The LHDs were able to reach maximal production with minimal queueing with 2-2.5 batteries per machine. Future studies should focus on analysing operational aspects and the brought value when using BEVs in loading and hauling operations. These aspects could include quantifying the impact on ventilation using field measurements, assessing the power differences of different types of LHDs, and analysing differences between different types of loading and hauling machinery from the specification perspective.