Section 2(1)(m) in The Coal Mines Regulations, 2017
(m)"competent person" in relation to any work or any machinery, plant or equipment means a person who has attained the age of twenty years and who has been duly appointed in writing by the manager as a person competent to supervise or perform that work, or to supervise the operation of that machinery, plant or equipment, and who is responsible for the duties assigned to him, and includes a shot firer;