Analysing Battery Swapping of Battery Electric Load Haul Dump (LHD) Machines in Block Cave Mining Using Discrete Event Simulation (DES)

Diesel-powered load haul dump machines have been the backbone of underground mining loading and hauling operations for over six decades. However, as mines get deeper, and regulations become more rigorous, the adoption of battery electric vehicles (BEVs) has the potential to enhance energy efficiency and provide a healthier environment for miners. Electric engines have a significantly higher energy efficiency and produce no exhaust gases or diesel particulate matter. The use of BEVs in underground operations introduces additional factors to consider, such as battery swapping and the required number of batteries, swapping, and charging stations. This study conducted a discrete event simulation using Arena simulation software with a focus on queueing and its relationship to different numbers of machines, batteries, and swapping times in an underground block cave mine. The results suggest that when there are six, eight, or 12 LHDs and four swapping and charging stations with an unlimited number of batteries, the queueing time to swap the batteries remains minimal. In scenarios with eight LHDs and a limited number of batteries, depending on the battery swapping time, 2–2.5 batteries per machine are required to achieve maximum production with minimal queueing. However, when there are too few batteries, queueing becomes significant. Moreover, when the number of working groups (machines going for a battery swap around the same time) is less than the ratio between the battery operational time and the swapping time, the queueing remains low.