Regulation 393The manager of a mine shall ensure that in the mine(a) each overhead line including its supports and structural parts and electrical appliances and devices belonging to or connected with the line are regularly inspected and efficiently supervised and maintained with regard to electrical and mechanical conditions; and(b) a structure, machinery, or thing is not erected or placed, under or within a horizontal distance of an overhead line without the prior approval of the Chief Inspector except as prescribed by the Energy Commission Standards.