Forklift Stability Basics

Forklifts are precisely designed for stability. Left unaltered, they are safe and effective workhorses, but some forklift accessories and attachments can significantly affect their stability. An understanding of forklift stability basics can help you avoid inadvertently turning your forklift into a potential hazard.

The Stability Triangle

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Although the physics is complicated, every forklift is designed around a stability triangle. The corners of the triangle represent the 3 point suspension system and a point somewhere in the center of the triangle represents its center of gravity. The forklift’s capacity limitations and safe operation procedures all stem from these points of reference.

As long as the center of gravity remains within the triangle, the lift truck will not tip over. Factors that affect the vehicle’s center of gravity include:

  • The weight of the load on the forks
  • Positioning of the load
  • The weight of ballast (“counterbalance”) at the rear of the forklift
  • The surface of the floor (most forklifts are designed for level surfaces only)
  • Turning
  • The height of the load
Wire lift truck stability training tool

Wire lift truck stability training tool

Most forklift operators are trained to remain within the safe operating limits of the forklift, but sometimes become so accustomed to following standard procedures, they aren’t prepared when an alteration to the forklift causes its center of gravity to shift. Obvious examples of this are fork extensions and boom attachments, but there are other hidden dangers as well. For example, some forklift owners purchase cheaper, lighter forklift replacement batteries without realizing that their lighter weight shifts the lift truck’s center of gravity. Purchasing a taller or heavier mast will also change the center of gravity.

Forklift Stability Training

magnetic stability training model

Magnetic forklift training model

A quick and effective way to learn about the importance of forklift stability is to see or cause a forklift to tip over; but, it is not advisable. A better way to give practical instruction in forklift stability is with forklift training materials.  Two particularly instructive materials available at are the magnetic stability training model and the wire lift truck. Using these tools, a forklift safety instructor can give practical demonstrations of the consequences of taking forklift stability lightly.

While forklift accidents caused by unstable loads are rare in comparison to other forklift accidents, tip-overs account for 25 percent of forklift fatalities and serious injuries. These incidences are due to unstable loads and are far more common than they should be. If an investment of less than $200 and a couple of hours training can save lives, isn’t that an investment worth making? We think so, and that’s why we offer an extensive range of forklift training materials.

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