Crane operation and load movement
Domain 5: Crane operation and load movement
This domain tests smooth control, load path planning, wind and visibility decisions, multiple-crane and power-line awareness, and emergency response. The exam looks for the safe decision, not just the control lever.
Core rules
- Before the lift: confirm load weight, radius, chart capacity, rigging, signaler, radio channel, path, exclusion zone, and weather. Calculate gross load including hook block, slings, and below-hook devices.
- Keep the hoist rope vertical. No side pulls, dragging, or using the crane to pull a load sideways. Side loading can collapse the jib or damage the rope.
- Maintain drum wraps: keep at least two full wraps on the drum, or the manual's minimum. Do not rely on the limit switch to stop normal operation.
- Smooth operation: accelerate and decelerate gradually; avoid shock loading; allow a long jib to coast to a stop; use tag lines to control rotation.
- Wind and sail area: monitor the jib anemometer; stop at the manufacturer's limit; reduce sail area or wait. For out-of-service wind, follow the manual's storm procedure, for example slewing to the specified position and releasing the slewing brake if required.
- Multiple cranes and power lines: use zoning or anti-collision systems, a dedicated signaler, and the jurisdiction's limit of approach. If communication is lost, stop.
- Emergencies: loss of power, brake failure, or a stuck load: secure the area, lower the load if possible, and follow the emergency plan. Do not improvise a bypass.
Worked example
A 2,000 kg panel with 10 m2 sail area is to be placed at 45 m radius. The chart for the current jib and two-fall configuration gives 2,600 kg at 45 m. Gross load = 2,000 + 150 kg rigging + 120 kg hook block = 2,270 kg, so the chart is satisfied. However, the wind is 13 m/s and the manufacturer limits that panel to 8 m2 above 12 m/s. Reasoning: the load chart is not the only limit; the load-specific wind limit also applies. The lift waits or the panel is reduced.
Traps that cost marks
- Using jib length as radius, or measuring radius to the hook instead of the load centre.
- Forgetting hook-block and rigging mass.
- Shock loading with rapid slewing or hoisting.
- Side-pulling a load just a little.
- Continuing after losing radio contact with the signaler.