Operation and Signal Communication
Operation and Signal Communication
This domain tests control under real conditions: who may direct the operator, how signals are given, and what to do when communication fails. Boom-truck operators must respond to a designated signal person but must stop for anyone’s emergency stop signal. The exam favors conservative decisions over saving a few minutes.
Core rules
- Use one designated signal person. The operator takes signals only from that person, except that anyone may give a stop signal.
- Hand signals should follow ASME B30.5 and OSHA standard signals. If radio communication is used, agree on the channel, test it, and have a backup method.
- If the signal is unclear, the operator stops. Do not guess or continue on momentum.
- Keep the load under control: no sudden starts or stops, no side pulls, no dragging, no free-swinging. Use tag lines and slow speeds near people or structures.
- Never lift personnel unless the platform, attachment, and procedures meet the applicable standard and employer plan.
Worked example
An operator is placing a 9,000 lb load behind a wall and loses sight of the load. The signal person is visible but the radio fails. The operator should stop, lower the load to a safe supported position if possible, and re-establish communication-not continue by watching the signal person’s arm movements through a gap. The signal person may be directing boom motion while the load is drifting toward an unseen obstruction; stop-and-reconfirm is the only safe control.
Traps
Taking signals from a rigger who is not designated; continuing after a radio dropout; treating a stop signal as a courtesy only; and swinging over people because the load is light.