What is the maximum distance that two-way communication facilities should be located from the mine portal?

The maximum distance for two-way communication facilities to be located from the mine portal is set at 500 feet. This distance is specified to ensure that clear and effective communication can be maintained between personnel inside the mine and those on the surface. Reliable communication is crucial for safety, especially in emergencies, allowing for quick dissemination of important information and coordination of rescue efforts if needed.

Having communication facilities within this distance helps to minimize potential delays during emergency situations, ensuring that all workers can make contact without significant physical barriers. Additionally, given the conditions often found in mining environments, such as noise and interference, the 500-foot limit is designed to enhance communication reliability, thus contributing to a safer working environment.