Newsletter Articles

Lateral and Longitudinal Instability

Fork lift trucks are extensively used throughout industry. However, they are a major contributory factor in many workplace accidents.

Although fork lift tip overs are not as frequent as they once were there are still several accidents each year as a result of a truck tipping either forwards (longitudinally) or sideways (laterally).

The Provision and Use of Work Equipment Regulations 1998 places certain responsibilities on employers to ensure that supervisors and managers of work equipment (fork lift trucks falls into the category of work equipment) must be trained including the methods of using the equipment, any risks and precautions to be taken.

Some of the risks of operating lift trucks include longitudinal and lateral instability. 

The type of actions that could lead to longitudinal instability include:

• Exceeding the trucks lifting capacity
• Undercutting (the forks not fully inserted in to the load)
• Extended load centre
• Harsh braking / harsh reverse acceleration
• Live loads (eg liquids, jumbo bags etc)
• Tilting a load forward at height
• Incorrect use of hydraulic controls
• Incorrect travel on an incline

Examples of the causes of lateral instability include:

• Turning or driving across an incline
• Live loads
• Uneven surfaces
• Load off centre
• Badly worn or under inflated tyres
• Turning at speed
• Turning with an elevated load

These lists are not exhaustive.

To lessen the chance of a fork lift tip over should any of these actions be observed in the workplace then they should be stopped immediately.

Basic fork lift training delivered to operators should cover instability as it is part of the course syllabus issued by the accrediting bodies so they are fully aware of the actions that could potentially make a truck tip.