Communication Breakdown During a Blind Lift
You are the dogger on a site where a 12 t steel beam is being lifted over a 6 m high wall into a trench. The crane operator cannot see the landing zone; you are on the far side of the wall and can see both the load and the landing area, but the operator can only see a second rigger on the near side. Radio contact has been intermittent; the operator has been relying on hand signals relayed by the near-side rigger, who cannot see the landing zone. The beam is 0.5 m from the trench edge and drifting. The operator is asking for a signal to lower.
1. Identify the communication failure and state the safe course of action before any further movement.
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The failure is a broken signal chain: the person giving signals to the operator cannot see the landing zone, and the person who can see it is not in direct communication. Relayed hand signals through a blind intermediary are not a safe control for a load near an edge. The operator is being asked to act on information that is at best second-hand and at worst stale.
The safe course is to stop. Signal 'stop' by whatever means is reliable, and do not authorise lowering until a single, competent signaler with a clear view of both the load and the landing zone is in direct, confirmed communication with the operator. Options: move the near-side rigger to a position where they can see the landing zone; establish a dedicated radio channel with a radio check and a clear 'say again' protocol; or use a recognised relay with an agreed, unambiguous code and a confirmed acknowledgement for every command. Until one of these is in place, the load stays put. The dogger's authority to stop the lift is not negotiable.
2. Describe the signalling protocol you would set up, including how you would handle the intermittent radio.
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Agree a single signaler, and confirm by name and position that the operator knows who is giving commands. Use a dedicated channel; do a radio check before the lift and again at the start of each phase. Adopt a closed-loop protocol: the signaler gives a command, the operator repeats it back, and the signaler confirms before the action starts. Use plain, standard commands - hoist, lower, slew left/right, stop - and reserve 'stop' as an unconditional command that needs no acknowledgement before the operator acts. If radio drops, the default is stop, not continue. Have a backup: a whistle or air horn for emergency stop, and a pre-agreed hand-signal fallback if the operator has line of sight to the signaler. Never allow two people to signal at once. Brief the whole team on the protocol before the lift resumes, and keep the exclusion zone clear so signals are not obscured.