Container Stuffing at Kwai Chung: Load Centre Exceeded on a Wet Ramp
At a Kwai Chung yard a 2.5 t counterbalance forklift is stuffing a 40 ft container standing on a trailer. The tractor unit has been detached, the trailer is not chocked and the twist locks are not engaged. The truck carries a side-shift attachment, and its data plate gives 2,200 kg at a 500 mm load centre with that attachment fitted. The load is one pallet of bagged cement, shown as 1,850 kg on the delivery note, but the bags have slumped so the centre of gravity now sits roughly 700 mm from the heel of the forks. Access is a steel yard ramp at about 1 in 8, wet from rain, with bent side kerbs and a loose toe plate. The banksman who normally guides the driver has gone for lunch. The yard supervisor says: "It's only one pallet - just get it in before the rain gets heavier."
1. Using the load chart logic and the physical conditions on site, decide whether this lift should go ahead. Show your reasoning, including any calculation.
Read the worked answer
Do not proceed. The pallet fails on at least three independent grounds, and any one of them is enough to stop the job.
1. Capacity at the actual load centre. The plate rating of 2,200 kg applies at a 500 mm load centre with the side-shift fitted. Capacity falls roughly in inverse proportion to load centre:
- 2,200 kg × (500 / 700) ≈ 1,570 kg
- Actual load: 1,850 kg - about 280 kg over, before gradient or dynamic effects.
Treat that figure as a sanity check only; the manufacturer's chart for the attachment governs, and it must be consulted, not estimated from the delivery note.
2. Gradient. 1 in 8 is about 12.5%, steeper than most counterbalance trucks are rated for when laden. On a slope, the load's effective load centre moves further forward and the forward stability margin falls.
3. Load integrity. Slumped bags mean the centre of gravity moves during travel. A shift of a few hundred millimetres on a ramp produces a dynamic overturning moment the truck cannot resist.
4. The container. Detached tractor, no chocks, open twist locks - any contact pushes the container and the trailer.
The correct answer is not more counterweight or a faster run. Break the bags down into two stable pallets, each within the derated capacity at its true load centre, and confirm a machine and attachment combination the chart actually supports.
2. List, in the order they must be completed, the controls required before any pallet is lifted again.
Read the worked answer
Order matters because several controls depend on others being in place first.
- Stop and secure the scene. Park the truck, forks flat on the ground, key out, and keep others clear of the ramp and the container doors.
- Make the container immobile. Either couple the tractor unit or fit chocks to the trailer wheels and engage the twist locks, or transfer the container to a purpose-built stand. A container that can move is not a load destination.
- Repair or replace the ramp. Kerbs and toe plate are part of the ramp's function, not decoration - a loose toe plate catches a wheel and a missing kerb allows a wheel to run off the edge. Until it is sound, no laden travel.
- Re-plan the load. Re-palletise into stable units, weigh or confirm the true mass, measure the load centre, and read the chart for that machine with that attachment.
- Assign a banksman who is briefed on the route, the signals, and the exclusion zone, and who stays in the driver's view. The driver's mirror coverage up a ramp with a high load is not sufficient alone.
- Brief the travel plan: laden travel with the load uphill, forks pointing uphill, load kept low and mast tilted back, no turning on the ramp, no raising or lowering on the move.
- Check the machine: tyre condition and pressure, brakes, mast and hoses, and confirm nothing has been altered since the last inspection.
Only when all seven are closed does the first lift start.
3. Halfway up the ramp the pallet's bottom board cracks and the bags begin to shift. What is the correct immediate action, and why is continuing to the top the wrong choice?
Read the worked answer
Immediate action:
- Stop forward travel smoothly - brake progressively, do not stamp on the pedal, because a sudden stop throws the load forward.
- Lower the forks steadily until the pallet is resting on the ramp deck, keeping the mast tilted back. Do not raise, do not tilt forward, do not turn.
- Apply the park brake, neutralise the controls, and keep the area clear while you assess.
- Call the banksman. If the load can be stabilised on the deck, do so; if the bags are running, keep people away and let the load settle rather than trying to catch it by hand.
- Restack on level ground with a sound pallet, then re-plan the lift from the beginning.
Why not continue to the top: you would be carrying a known-unstable load, at height, up a slope, for the remaining distance - every metre adds time in which a further bag shift can occur. At the top you must stop, turn and lower, and each of those manoeuvres applies a lateral or forward load the truck is least able to resist on a gradient. Reaching the top converts a contained problem into an uncontrolled one at the worst possible moment.
The decision point was earlier: a damaged or overloaded pallet should never have been taken onto the ramp.