The Ramp and the Raised Load
You are asked to move a 1,400 kg machine on a pallet up a loading ramp into a curtain-sided trailer. The ramp rises 1.2 m over 6 m (about 11 degrees). Your truck is rated at 2,000 kg at 500 mm load centre on level ground. The machine is 1,100 mm deep, evenly loaded. The trailer bed is 1.3 m high. The ramp surface is steel and slightly damp from earlier rain. A colleague says 'just drive up fast so you don't lose traction, and keep the load high so it clears the trailer floor'.
1. Analyse the stability and capacity implications of this lift, including the effect of the ramp and the load centre.
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Load centre: Machine is 1,100 mm deep, evenly loaded → CoG about 550 mm from fork heel. That is already beyond the 500 mm rating point, so capacity is below 2,000 kg - the chart must be consulted, not assumed.
Ramp effect on stability:
- On a gradient, the truck's centre of gravity shifts. Travelling up the ramp with the load leading, the combined CoG moves toward the load - reducing forward stability.
- The 11° gradient effectively reduces the safe capacity further; the truck is designed for level ground unless the manufacturer permits otherwise.
- Steel, damp ramp = low friction. Driving fast to 'keep traction' is exactly wrong: speed increases the risk of wheelspin, loss of steering and a slide, and a sudden stop on the ramp throws the load forward.
Load height:
- Carrying the load high raises the combined CoG dramatically, making a tip-over far more likely on a slope. The load should be carried as low as possible, consistent with clearing the ramp surface.
Conclusion: The proposed method (fast, load high) is unsafe on every count. Capacity margin is unknown and likely reduced; the ramp and wet steel add slide and tip risk.
2. State the safe method for this task, or the grounds for refusing it.
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Safe method (if the task is to proceed):
- Check the chart for the actual load centre (≈550 mm) and confirm the derated capacity exceeds 1,400 kg. If not, do not lift - use a larger truck.
- Check the manufacturer's guidance on gradients - many counterbalance trucks are not rated for ramps of this angle; if not permitted, refuse.
- Keep the load low - just enough to clear the ramp - and mast tilted back.
- Travel slowly and steadily, no sudden acceleration, braking or steering. Use gentle, constant motion.
- Load leading when travelling up (for visibility and control), reversing down.
- Clear the ramp of people and loose material; consider gritting/drying the steel.
- Use a banksman at the trailer end.
- Stop if traction is lost - do not accelerate.
Grounds to refuse: If the chart shows capacity below the load at the actual load centre, or the manufacturer prohibits the gradient, or the ramp is not rated/secure, refuse and escalate - the colleague's method must not be followed.