If the Operator and Signal Person cannot see each other, what is an alternative method for communication?

When the Operator and Signal Person are unable to see each other, using radios as a method of communication is considered the most effective alternative. Radios allow for clear, direct communication over distances and obstacles that may prevent visual contact. This method facilitates timely decision-making and ensures that instructions or warnings can be transmitted promptly, minimizing the chances of accidents or misunderstandings during operations.

Other methods, such as hand signals or whistles, rely on visual and auditory cues, which are ineffective when the two parties cannot see or hear each other clearly. Physical touch is not a practical communication method in this context, particularly in situations where operators and signal persons may be separated by a considerable distance or various hazards. Therefore, using radios is preferred for its reliability and efficiency in maintaining safe operations.