The Blind Lift Behind the Rack
You are the signaller on a warehouse extension. The mobile crane is positioned so the driver's view of the landing area is blocked by a 6 m high steel storage rack. The landing zone is a concrete slab 4 m from a live pedestrian walkway. The agreed code is the standard hand signals. You are standing where the driver can see you, but your own view of the load's far side is obscured by the rack. A second slinger is at the landing point but has no radio and is 25 m away, out of the driver's sight. The load is a 1.8 t steel beam on a two-leg sling, and the driver has begun to boom down before you have given a signal.
1. Assess the communication arrangement and identify why this is unsafe.
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The arrangement has no reliable closed loop between the person who can see the load and the person who can see the driver:
- You can see the driver but not the far side of the load - you cannot confirm the load is clear of obstructions or people.
- The second slinger can see the load but is invisible to the driver and has no radio - their stop signal cannot reach the driver.
- The driver has already started booming down without a signal, breaking the one-signal-one-signaller discipline.
Effective signalling requires a single designated signaller (or a relay with agreed, tested comms) who has a clear view of the load, the landing point, and the driver. Here no one person has all three. Under LOLER the operation must be appropriately supervised and planned; under the site's lift plan the signaller must control all movements. The pedestrian walkway 4 m away adds a further uncontrolled hazard.
2. State the corrective actions you would take now, and how you would re-establish signalling for the rest of the lift.
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Immediate:
- Give the emergency stop hand signal and hold it until the driver acknowledges and stops all motion.
- Do not resume until the driver confirms they will take signals from you only.
Re-establish control: 3. Relocate so you have line of sight to the load, the landing point, and the driver - or reposition the crane/load so a single viewpoint exists. 4. If no single viewpoint is possible, set up a relay: issue the second slinger a radio on the same channel, agree a clear protocol (who signals, who relays, and that only one person's signals count), and test it before lifting. 5. Exclude pedestrians from the walkway with barriers and a banksman for the duration; the 4 m gap is inside the foreseeable drop zone. 6. Re-brief the driver on the lift plan, the agreed signals, and the stop signal, and confirm understanding before recommencing.
Record the changes to the lift plan and inform the appointed person/supervisor.