Abstract
Deviations in drill holes during underground mining substantially impact operating efficiency and safety. An examination of six stopes at Thompson Mine revealed systematic deviations of roughly 1 m (3 ft) from the designated drill hole configuration. Excessive deviations may result in imprecise ore body targeting, elevated operational expenses, and possible safety risks. A correlation was identified between the percentage of holes deviating beyond the average and the mucking rate, indicating that to sustain an average of 544 tonnes (600 tons) per day, less than 21% of holes should surpass the average deviation. It is also essential that drill speeds average 9.14 m (30 ft) per hour, particularly for novice operators, to reduce hole deviation. Regulated drilling rates improve precision, resulting in more efficient and economical operations. Decreased drilling rates mitigate the likelihood of misalignment and structural complications. Efficient management of drill hole variations necessitates sophisticated drilling tools, meticulous planning, and ongoing monitoring to guarantee adherence to the designated drill trajectory. Mining operations can achieve improved resource recovery, decrease waste, and enhance production by limiting deviations. Mitigating drill hole deviations is crucial for enhancing underground mining projects' economic and environmental results, allowing for a degree of tolerance for systematic deviations. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s44346-025-00007-2.