Load Handling, Rigging, and Attachment Use
What the exam tests
This domain tests whether you can plan a lift, calculate sling tension, verify capacity, and safely change or use attachments on excavators and loaders.
Core rules and concepts
- Capacity comes from the OEM load chart and falls as radius and height increase. A bucket or thumb is not a rated lifting point unless the OEM approves lifting and publishes a chart. Never exceed capacity, and include the weight of rigging and bucket in the load.
- Rigging: know the WLL of every sling, shackle and hook, and use hooks with working latches. Inspect for cuts, broken wires, stretching, burns and worn pins; destroy damaged gear rather than using it.
- Sling angle: tension per leg equals (load divided by number of legs) divided by sin of the angle from horizontal. The multiplier is about 1.15 at 60 degrees, 1.41 at 45 degrees, and 2.0 at 30 degrees.
- Centre of gravity: attach so the load hangs level, use tag lines to control rotation, and keep everyone outside the swing and drop zone.
- Signals: one designated signaler, agreed hand signals or radio, and a stop signal that anyone may give.
- Attachments: lower to the ground, relieve pressure, fit the OEM lock pin or engage the quick-coupler safety, confirm the visual indicator, and test with a light lift before full operation.
Worked example
A 4,000 kg load is lifted on a two-leg bridle at 45 degrees from horizontal. Reasoning: each leg carries 2,000 kg vertically, but the tension is 2,000 divided by sin 45 degrees, which is 2,828 kg. Select slings rated at least 2,828 kg WLL in that configuration, add shackle and hook weight, then compare the total against the machine capacity at that radius.
Traps that cost marks
- Measuring the sling angle from vertical rather than horizontal.
- Assuming legs of unequal length share load equally.
- Shock loading a chain by jerking the load off the ground.
- Lifting with a quick-coupler that is not fully engaged.
- Using a damaged sling because it is only one lift.