Powerline, Exclusion Zone and Environmental Hazards
Electricity is unforgiving
Approach distances to overhead powerlines are specified by regulators and network operators, and they vary with voltage. The safe approach distance applies to the crane, the boom, the load and the rigging, in all positions including slew and boom movement. If you cannot maintain the distance, the line must be de-energised and isolated, or the work planned with the network operator. The trap is assuming rubber tyres or a fibreglass boom provides insulation; they do not. Another trap is measuring only the crane body and ignoring the load or taglines.
Exclusion zones
Establish a ground-level exclusion zone beneath and around the lift path, sized to the load and the consequence of failure. Barricade and sign it. No one enters without authorisation. For powerlines, the zone extends to the safe approach distance plus the load swing.
Environmental hazards
Wind is the most common environmental limit. Manufacturers specify maximum wind speeds for operation and for erecting or stowing the boom. Wind acts on the load's sail area, not just its mass, so a light but bulky load can be uncontrollable. Other hazards include heat, poor visibility, lightning, flooding and unstable ground after rain. Stop work when limits are exceeded.
Worked example
If the safe approach distance for the line voltage is 6 m and the load can swing 2 m, keep the crane and load at least 8 m from the line, or have the line isolated.