Slewing mobile crane operation and load handling
Safe operation
Smooth, controlled operation is the mark of a competent operator. Plan the lift: know the load, the path, the destination, the signals and the emergency stop. Keep the load as low as practical, avoid sudden starts and stops, and never drag or side-load the load. Slew slowly and use taglines to control the load. Keep personnel out from under the load and out of the crush zone between the load and fixed objects.
Monitor the LMI/RCL, wind, ground and load stability continuously. If the load shifts, the crane alarms, or wind rises, stop and reassess. Never leave the controls with a load suspended; if you must leave, lower the load first. Pick-and-carry must follow the manufacturer's chart and limits.
Traps in exam questions
- Side-loading the boom or dragging a load.
- Slew too fast, causing the load to swing out.
- Leaving a suspended load unattended.
- Continuing when the LMI alarms or wind increases.
- Using people as counterweights or allowing them under the load.
Worked example
Rule of thumb: if a load starts to swing, stop slewing and let it settle; do not chase it with the boom. Lower it if you can, then resume slowly with a tagline.
Exam tip
If an option says 'continue carefully', check whether the hazard is one that requires a stop.