Which situation describes a higher risk of instability during cornering for a double-deck lorry?

Which situation describes a higher risk of instability during cornering for a double-deck lorry?

• A. Top deck loaded and lower deck empty
• B. Lower deck overloaded
• C. Balanced load
• D. All decks empty

Answer: (A)

During cornering, the vehicle experiences lateral forces that try to tip it outward. How easily it tips depends on where the weight is and how high the center of gravity sits. If the top deck is loaded while the lower deck is empty, the overall center of gravity moves higher, so the same sideways force causes a larger tipping moment. With less weight low down on the lower deck, there’s less counterbalance to that tipping tendency. In a double-deck lorry, this combination—heavy load high up and little weight low down—greatly increases the risk of instability or rollover in bends. Keeping loads on the lower deck (and overall balanced) lowers the center of gravity and improves stability, so the high, top-heavy arrangement is the least stable scenario during cornering.

During cornering, the vehicle experiences lateral forces that try to tip it outward. How easily it tips depends on where the weight is and how high the center of gravity sits. If the top deck is loaded while the lower deck is empty, the overall center of gravity moves higher, so the same sideways force causes a larger tipping moment. With less weight low down on the lower deck, there’s less counterbalance to that tipping tendency. In a double-deck lorry, this combination—heavy load high up and little weight low down—greatly increases the risk of instability or rollover in bends. Keeping loads on the lower deck (and overall balanced) lowers the center of gravity and improves stability, so the high, top-heavy arrangement is the least stable scenario during cornering.