Communication, signalling, and teamwork
Domain 7: Communication, signalling, and teamwork
This domain tests standard signals, radio protocol, signaler positioning, blind lifts, and coordination among operator, rigger, signaler, and supervisor. The exam rewards closed-loop communication and stop-work authority.
Core rules
- Use the standard hand signals recognized in CSA Z248 and the jurisdiction. The signaler must be competent, in clear view of the operator, and clear of the load's path. Only one signaler directs the crane at a time; anyone may give an emergency stop.
- Radio protocol: use a dedicated channel, identify the crane and the function, use plain standard terms (hoist, lower, trolley out, trolley in, slew left, slew right, stop), and require repeat-back for critical commands. If the message is unclear, stop.
- Blind lifts: pre-plan with the signaler, rigger, and operator; use relay signalers, cameras, or tag lines; agree on the path and stopping points. Never feel the load into place.
- Signaler positioning: stay out of the swing radius and under-load zone; do not stand where the operator cannot see you; use high-visibility clothing; at night use illuminated signals.
- Teamwork: hold a pre-lift meeting for critical or complex lifts; confirm roles, load weight, chart, path, and emergency plan; respect stop-work authority; address language barriers with a common signal system.
- Lost communication: stop the crane until communication is restored and confirmed.
Worked example
A load must be placed around a corner where the operator cannot see the landing zone. The crew sets two signalers: one at the corner in view of the operator, one at the landing zone. They agree on a radio channel and relay protocol: the landing signaler gives commands to the corner signaler, who repeats them to the operator; the operator repeats back before moving. When a third worker steps into the swing radius, the landing signaler gives stop, all stop, and the operator stops immediately. The lift resumes only after the area is clear and the signaler confirms.
Traps that cost marks
- Two signalers giving different commands at once.
- Signaler standing under the load or inside the swing radius.
- Using hand signals when the operator cannot see them.
- Failing to repeat back a radio command.
- Treating a stop signal from a non-signaler as invalid; anyone can stop.