Signals, Communication, and Personnel Coordination
What this domain tests
This domain tests crew communication: designated signal persons, standard hand signals, radio discipline, stop authority, and line-of-sight rules.
Core rules
- Designate one signal person and agree on hand signals or radio channels before the lift or dig.
- The operator stops immediately on an unclear signal or a stop signal from anyone. Stop authority is not limited to the signal person.
- Maintain line of sight. If the signal person cannot see the load or the operator, movement stops until communication is restored.
- Hold a pre-job brief covering roles, exclusion zone, travel path, set-down location, and emergency stop.
- Acknowledge and repeat critical signals; use a spotter for blind lifts and backing.
Worked example
During a pole lift the signal person steps behind the truck and loses sight of the load. The operator should stop the movement and wait for restored communication. Guessing the next move, or continuing because “it was almost set,” is the wrong answer and a common exam trap.
Traps
Acting on hand signals from an untrained bystander; using a cell phone instead of the agreed radio; failing to brief the crew on the stop signal; and assuming the spotter can see when the boom blocks the view.
Key points
- Designate one signal person and agree on signals before work.
- Anyone may give a stop signal; the operator must obey.
- Stop when line of sight is lost.
- Brief roles, exclusion zone, and emergency stop before the lift.
- Repeat and acknowledge critical signals.