As the body rises, the vehicle's centre of gravity moves upward fast; a fully raised tipper is at its mechanically most vulnerable moment. At this moment a small ground slope, or the load sticking to one side, can be enough to tip the vehicle over.
Typical Causes of Tipping
- Sloped or soft ground: A sideways tilt grows in effect during lifting; on soft ground, one side sinking produces the same result
- Sticking load: If wet soil or clay stays stuck to one half of the body, the centre of gravity suddenly shifts sideways
- Tractor-trailer misalignment: In a combination standing at an articulated angle, the lifting force stresses the chassis laterally
- Wind: A raised body is a wide sail surface; discharge should be postponed in strong wind
- Suspension sway: Skipping the discharge procedure on air suspension creates a shaky platform during lifting
Safe Discharge Discipline
The order of the rule is clear: the vehicle is aligned on flat, firm ground, on the same axis as the tractor; if the manufacturer's procedure requires it, the suspension is put into discharge mode; tailgate locks are opened, and lifting is done under continuous, uninterrupted observation. If the load is felt not to be flowing, the body is not lifted further — it is lowered, and the problem is solved on the ground. Rocking the vehicle forward and back to shake the body loose is the most common and most dangerous habit in the field.
Tipping-over accidents almost always end with the same sentence: "we always did it this way." Safe operation is the name of the procedure that never lets that sentence be said.