Powerline, environmental and site-specific hazards
Electricity is unforgiving. Treat all lines as live unless the network operator confirms de-energisation and isolation in writing. Maintain the legislated safe approach distances for the voltage, remembering that distances apply to any part of the crane, load or rigging, and that the load can swing closer. Where you cannot maintain distance, use a permit, an observer, tiger stripes or barriers, and consider de-energising. Beware of induced voltages, arcing across gaps and step potential if contact occurs.
Environmental hazards include wind, heat, cold, lightning, rain, poor visibility, dust and noise. Wind acts on the load's sail area and on the boom; know the manufacturer's wind limit and stop when gusts exceed it. Ground can soften after rain. Site-specific hazards include other cranes, overhead structures, traffic, pedestrians, excavations, confined spaces, hazardous materials and simultaneous operations.
Traps: measuring distance to the nearest line only, ignoring sag and swing, relying on rubber tyres for insulation, and continuing a lift as wind rises.
Rule of thumb: if in doubt, stop and de-energise. Worked example: a lift must pass within 4 m of an 11 kV line where the required distance is greater. Controls are to have the line de-energised and isolated, or to relocate the crane so the load and boom cannot encroach, with a dedicated spotter and barriers as backup.