Cargo Loading, Weight Distribution and Load Securement
What the exam tests
This domain tests axle and gross mass limits, load placement, centre of gravity and securement. The examiner wants to see that you understand why a load is unsafe, not just that straps were used.
Core rules
- Know the gross vehicle mass, gross combination mass, axle-group limits and tyre ratings. Overloading any one axle is a violation even if the total mass is legal.
- Place heavy items low and centred between the axles. Too much load behind the rear axle unloads the steering axle and reduces steering grip; too far forward can overload the steer axle.
- Secure every load against forward, rearward and lateral movement. Use rated chains, straps or binders, and know each component's working load limit (WLL).
- The aggregate WLL of the tiedowns must meet the required ratio for the load mass; the number of straps alone is not the test.
- Use direct contact or blocking to prevent shifting. Check the load again after the first few kilometres and during the trip.
- Cover loads that can blow off or spill. A tarpaulin is not a substitute for proper tiedowns.
Worked example
A 20-tonne load is placed so that most of its mass sits behind the trailer axle group. Reasoning: the trailer axle group may exceed its limit while the steer axle becomes light, causing poor steering and reduced drive traction. The load must be repositioned forward or redistributed so each axle is within its rating. Recheck axle loads and re-tension the securement after moving it.
Traps
- Counting straps instead of checking their rated WLL.
- Assuming a legal gross mass means every axle is legal.
- Using damaged or unmarked straps.
- Failing to recheck the load after the first part of the journey.