Forklift Stability on a Ramp with an Off-Centre Load
You are driving a 2.5 t counterbalance forklift with a rated capacity of 2,500 kg at 500 mm load centre. The load is a crate of machine parts, 1,800 kg, but its centre of gravity sits 750 mm from the fork face because the heavy end is at the back of the crate. You must move it from the yard to a workshop 60 m away, down a ramp with a 1-in-8 gradient, then through a roller door 2.4 m wide. The forklift's data plate says capacity is derated for load centre - at 750 mm the derated capacity is approximately 1,650 kg. The ramp surface is sealed but damp from overnight rain. A colleague says the forklift "handles 2.5 tonne easy" and to just take it slow.
1. Assess whether the load can be carried and what the load centre means for the decision.
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The load exceeds the derated capacity. At 500 mm the forklift is rated 2,500 kg, but the crate's centre of gravity is at 750 mm. The data plate derates capacity at that load centre to about 1,650 kg, and the load is 1,800 kg - 150 kg over. Load centre matters because capacity is limited by the load moment (load × distance from the front wheels). Moving the centre of gravity further out increases the moment even though the mass is unchanged, so the same forklift that lifts 2,500 kg at 500 mm cannot lift 1,800 kg at 750 mm. The correct judgement is not to carry it as loaded. Options: rotate or repack the crate so the heavy end is against the fork face (reducing load centre), split the load, or use a larger forklift. Check the new load centre against the plate before proceeding.
2. Assuming the load is repacked to a safe load centre, describe the hazards of the ramp descent and how you would manage them.
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Even within capacity, the ramp introduces hazards. On a 1-in-8 gradient the load's weight shifts forward relative to the machine, effectively increasing the load moment and reducing stability - so a load that is safe on flat ground may not be safe on the ramp. The damp sealed surface reduces traction, raising the risk of wheel slip and loss of steering or braking control. The correct technique is to travel in reverse down the ramp with the load uphill, keeping the forks low (about 100–150 mm) and tilted back. Travelling forward down a ramp with a load is a tip-over risk because the load's momentum and the gradient combine to push the machine's centre of gravity forward. Keep speed low, avoid braking sharply, and have a spotter at the roller door. If the ramp cannot be traversed safely, find an alternative route or use a different machine.