IPAF Ground Conditions and Stability — Questions and Answers
Question 1: Before positioning a MEWP, what must be assessed about the ground conditions?
- Only whether the ground is dry
- The load-bearing capacity, levelness, presence of voids or underground services, and surface condition (Correct answer)
- Whether the ground matches the colour scheme of the MEWP
- Only whether the ground is concrete or tarmac
Correct answer: The load-bearing capacity, levelness, presence of voids or underground services, and surface condition
A thorough assessment of ground conditions must cover load-bearing capacity (can it support the machine's total weight?), levelness (is it within the machine's gradient limits?), presence of underground services (drains, cables, voids), and surface condition (soft, wet, loose, or unstable ground).
Question 2: What is the primary risk of operating a MEWP on ground that is not level?
- The paint may get scratched
- The machine may overturn due to the shifted centre of gravity (Correct answer)
- The battery will drain faster
- The controls will operate in reverse
Correct answer: The machine may overturn due to the shifted centre of gravity
Operating on unlevel ground shifts the machine's centre of gravity, significantly increasing the risk of overturning — the most dangerous type of MEWP incident. Most MEWPs have a maximum operating gradient of 3-5 degrees, and exceeding this can be fatal.
Question 3: What precaution must be taken when positioning a MEWP near an excavation or trench?
- Park as close as possible for easier access to the trench
- Maintain a safe distance equal to at least the depth of the excavation from the edge, to prevent collapse (Correct answer)
- Position the outriggers over the edge of the excavation
- No special precautions are needed if the MEWP is on tracks
Correct answer: Maintain a safe distance equal to at least the depth of the excavation from the edge, to prevent collapse
A MEWP must be positioned at a safe distance from excavation edges — generally at least equal to the depth of the excavation. The weight of the MEWP can cause the excavation sides to collapse, potentially overturning the machine into the trench.
Question 4: Why are spreader plates used under MEWP outriggers?
- To make the MEWP look more professional
- To distribute the point load over a larger area, preventing the outrigger from sinking into soft ground (Correct answer)
- To raise the height of the MEWP
- To prevent scratching the floor surface
Correct answer: To distribute the point load over a larger area, preventing the outrigger from sinking into soft ground
Spreader plates distribute the concentrated point load from the outrigger foot over a much larger surface area. Without them, the outrigger can sink into soft ground, causing the machine to tilt and potentially overturn, especially when the platform is elevated with a load.
Question 5: A MEWP is to be used on a suspended floor (such as a car park deck). What additional assessment is required?
- No additional assessment — all floors can support MEWPs
- The structural load capacity of the floor must be confirmed by a competent person before the MEWP is positioned (Correct answer)
- Only the colour of the floor markings needs checking
- The MEWP hire company will assess this automatically
Correct answer: The structural load capacity of the floor must be confirmed by a competent person before the MEWP is positioned
Before placing a MEWP on a suspended floor, the structural load-bearing capacity must be assessed by a competent structural engineer. The combined weight of the MEWP, operator, materials, and dynamic loads during operation must not exceed the floor's design load.
Question 6: What is the danger of positioning a MEWP over an underground service such as a drain or utility cover?
- The service cover may be too slippery
- The cover or ground above the service may collapse under the concentrated weight of the MEWP or outrigger (Correct answer)
- The underground service may cause electromagnetic interference
- There is no danger as services are designed to bear heavy loads
Correct answer: The cover or ground above the service may collapse under the concentrated weight of the MEWP or outrigger
Drain covers, utility access chambers, and the ground above shallow services may not be designed to bear the concentrated point loads from MEWP wheels or outriggers. They can collapse, causing the machine to suddenly drop and potentially overturn.
IPAF Ground Conditions and Stability
Before positioning a MEWP, what must be assessed about the ground conditions?