Ground Conditions and Stability Flashcards

After heavy rainfall, what additional ground condition checks should be carried out before using a MEWP?

Answer: Check for waterlogged or softened ground, reduced load-bearing capacity, and potential for the machine to sink or slide

Heavy rain can significantly reduce the load-bearing capacity of soil, create hidden soft spots, and cause previously firm ground to become unstable. A fresh assessment must be made, paying particular attention to areas where water has pooled or where soil may have become saturated.

What is the maximum gradient (slope) that most scissor lift MEWPs can safely operate on?

Answer: Typically 3 to 5 degrees as specified by the manufacturer

Most scissor lift MEWPs have a maximum safe operating gradient of 3 to 5 degrees, as specified by the manufacturer. Operating on steeper slopes can cause the machine to overturn. The exact limit varies by model and must be checked in the operator's manual.

What role does a ground conditions assessment play in the MEWP risk assessment process?

Answer: It is a fundamental part of the risk assessment that must be completed before any MEWP is positioned

A ground conditions assessment is a mandatory and fundamental component of the overall MEWP risk assessment. It must be completed before positioning any MEWP, regardless of type. The assessment should consider ground type, loading capacity, services, slopes, and environmental factors.

A MEWP needs to be operated on a newly laid tarmac surface. What is the concern?

Answer: New tarmac may be soft and unable to support the concentrated loads from wheels or outriggers, causing sinking

Freshly laid tarmac may not have fully cured and can be soft, especially in warm weather. The concentrated point loads from MEWP wheels or outriggers can sink into the soft surface, causing the machine to tilt and potentially overturn. The surface must be fully cured before use.

When operating a MEWP on a slope within its rated gradient, what additional precaution should be observed?

Answer: The machine should be positioned so that any boom movement operates uphill where possible, and travel should be up and down the slope, not across it

Even within the rated gradient, the machine should be oriented to minimise overturning risk. Travel should be directly up or down the slope (not across it, which creates a side-tipping hazard), and boom movements should be directed uphill where possible to maintain stability.

What is the purpose of checking for underground services before positioning a MEWP?

Answer: To ensure that the combined weight of the MEWP does not collapse underground voids, chambers, or shallow services beneath the setup position

Underground services such as drains, culverts, service chambers, and shallow utility runs can create voids or weakened ground. The concentrated weight of a MEWP (which can exceed several tonnes) can collapse these features, causing the machine to suddenly drop and potentially overturn.