Safe lifting operations and load control
This domain tests whether you can take a load from ground to set-down without shock loading, overloading, or losing control. The exam favours sequence and judgement over speed.
Rules
- Verify the load: weight from drawings or manifest, centre of gravity, lift points, and whether anything is loose, trapped, or embedded. Never lift a load you cannot weigh.
- Check the chart at the radius that will exist at the pick and at set-down, measured from the slew centre to the load's centre of gravity - not to the hook.
- One motion at a time on hoist, trolley, and slew; bring the load to rest before reversing direction.
- Pre-tension and check the rigging, then lift a few centimetres and hold to confirm balance, brake, and rigging before the main lift.
- Tag lines on long or high-sail loads; no side pulls, no dragging, no lifting over personnel; nobody under the load or inside the swing radius.
- Watch jib deflection: under load the jib drops and the real radius grows beyond the no-load radius.
- Stop at the manufacturer's wind limit, and earlier for large sail-area loads.
Worked example
Chart at 30 m shows 4.2 t; at 32 m, 3.6 t. The load is 3.9 t at a no-load radius of 30 m. Deflection under load adds roughly 1–2 m of radius, so plan on the 32 m figure: 3.6 t < 3.9 t, so re-plan - shorten the radius or reduce the load. Quoting the 30 m figure is the classic failure.
Traps
Radius to hook instead of centre of gravity; gross capacity without deducting hook block and rigging; snatching a slack rope; assuming the slew brake holds a swinging load.