Every mine operator must ensure, as far as reasonably practicable, that effective means of communication are available with any employee who works alone at an isolated spot at the mine. The duty is qualified by reasonable practicability, and its Act compliance note (r 7) links it to the employer's duty in section 21 of the Act. The means must be effective at the isolated location, not merely issued.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.