What is one acceptable method of communication between a rigger and a machine operator?

Using whistle signals as a method of communication between a rigger and a machine operator is effective due to its auditory nature, which can easily be heard over the noise often present on job sites. Whistle signals can convey specific commands or alerts quickly and clearly from a distance, ensuring both parties are kept informed of conditions or needed actions during operations.

Visual signals, such as gestures or flags, can be influenced by visibility, potentially causing misunderstandings in challenging weather conditions or obstructed views. Proximity alarms serve a different purpose, mainly for safety alerts rather than direct communication. Written notes may not be practical or immediate in a dynamic environment where quick, real-time feedback is essential. Whistle signals, therefore, stand out as a reliable and prompt means of communication in rigging operations.