Forklift Stability and the Stability Triangle Flashcards

How does raising a load to a greater height affect forklift stability?

Answer: It reduces stability by raising the combined centre of gravity and increasing tip-over risk

Raising a load elevates the combined centre of gravity, making the forklift more susceptible to tipping in all directions, which is why loads must be lowered to the travel position before moving.

What effect does cornering at excessive speed have on a forklift's lateral stability?

Answer: It increases dynamic forces, shifting the combined centre of gravity outward and increasing tip-over risk

Cornering at excessive speed generates centrifugal forces that shift the combined centre of gravity outward toward the edge of the stability triangle, significantly increasing the risk of lateral tip-over.

How does operating on an uneven or sloped surface affect forklift stability?

Answer: It shifts the effective stability triangle and can cause tipping even with a correctly loaded forklift

Uneven or sloped surfaces tilt the entire forklift, shifting the effective position of the combined centre of gravity relative to the stability triangle and increasing the risk of tip-over.

What effect does under-inflation of forklift tyres have on stability?

Answer: It can cause uneven load bearing, reducing stability and causing premature tyre failure

Under-inflated tyres cause uneven load bearing across the tyre surface, which reduces the effective support base, increases rolling resistance, and can compromise the forklift's stability triangle.

When carrying an asymmetric or off-centre load, what stability risk is increased?

Answer: Lateral (sideways) tip-over risk, as the combined centre of gravity shifts to one side

An off-centre load shifts the combined centre of gravity to one side of the forklift, moving it closer to the edge of the stability triangle and increasing the risk of lateral tip-over.

Which condition MOST significantly reduces the stability of a forklift travelling with a raised load?

Answer: Travelling over a small raised edge such as a door threshold

Travelling over a raised edge or bump with a load at height causes a sudden jolt that can dramatically shift the combined centre of gravity, greatly increasing the risk of tip-over when compared to smooth, flat surfaces.

Why does adding an attachment (such as a side-shifter or extension) to a forklift reduce its rated capacity?

Answer: The weight and extended load centre of the attachment moves the combined centre of gravity forward, reducing stability and capacity

An attachment adds weight and extends the effective load centre distance, moving the combined centre of gravity further forward toward the fulcrum, which reduces the load the forklift can safely carry.