Acoustic Emission Testing for Fibreglass Booms: Why It Matters

Acoustic emission testing is a vital part of the ongoing maintenance and safety assurance for elevating work platforms (EWPs) fitted with fibreglass or fibreglass reinforced plastic (FRP) booms. In the construction, maintenance, and arboriculture industries, these specialised EWPs are often used for work around electrical hazards due to the insulating properties of fibreglass materials. However, the structural integrity of these components requires regular verification to ensure worker safety.

The Science Behind Acoustic Emission Testing

Acoustic emission testing detects microscopic defects that may be invisible to the naked eye. This non-destructive testing method works by detecting stress waves produced when a material undergoes deformation or damage. When fibreglass materials develop cracks or delamination, they release energy in the form of sound waves. Specialised sensors capture these emissions, which are then analysed to determine the location and severity of potential defects.

Regulatory Requirements in New Zealand

A competent person or organisation must conduct acoustic emission testing on all EWPs with fibreglass booms at least every 24 months. This requirement is stipulated in AS 4748: Acoustic Emission Testing of Fibreglass Insulated Booms on Elevating Work Platforms. For operators and owners of these specialised machines, compliance with this standard is not merely a suggestion, it’s a legal obligation.

The Business Case for Regular Testing

While some may view acoustic emission testing as just another compliance cost, the business case for this testing is compelling. Consider the potential financial impact of an EWP failure: worker injury or fatality, property damage, business interruption, regulatory fines, increased insurance premiums, and reputational damage. The relatively modest cost of testing every two years pales in comparison to these risks.

Early Detection Prevents Catastrophic Failures

The value of acoustic emission testing lies in its ability to detect problems before they become catastrophic failures. Fibreglass components can develop internal defects that aren’t visible during routine visual inspections. These defects might include:

• Delamination between layers of fibreglass
• Microscopic stress cracks
• Water ingress and subsequent degradation
• Impact damage that affects structural integrity but leaves the surface intact

By identifying these issues early, repairs or replacements can be scheduled during planned maintenance periods rather than experiencing unexpected downtime when a component fails during operation.

Testing Process and Documentation

The acoustic emission testing process involves applying controlled stress to the fibreglass boom while monitoring for emissions that indicate defects. This process must be performed by technicians with specialised training and equipment. Following the test, a certificate of compliance should be displayed near the ground controls or platform entrance of the EWP.

The owner must retain test reports to:

• Provide documentation when requested by WorkSafe inspectors or equipment users
• Establish a history of the boom’s condition to track deterioration patterns over time
• Demonstrate due diligence in maintaining safe equipment

When Additional Testing Is Required

While the standard testing interval is 24 months, some situations necessitate more frequent testing. If an EWP has been involved in an accident or subjected to misuse that could potentially compromise the fibreglass boom’s integrity, a new acoustic emission test should be conducted regardless of when the last test was performed. This ensures that any damage is identified promptly, and the equipment remains safe for use.

Consequences of Non-Compliance

If a fibreglass boom fails an acoustic emission test, the EWP must be immediately removed from service. It cannot be used again until the boom is either replaced or repaired, and subsequently passes retesting. Operating an EWP with a failed boom not only places workers at risk but also exposes the business to significant liability and potential regulatory penalties.

Improving Business Efficiency Through Compliance

Far from being just a regulatory hurdle, acoustic emission testing contributes to business efficiency by:

• Reducing unexpected downtime through planned maintenance
• Extending equipment lifespan by identifying issues before they cause major damage
• Providing documentation that may be required for insurance purposes
• Building client confidence in your commitment to safety
• Protecting your workforce and enhancing your safety culture.

Processes should be reinforced as part of your EWP training.

Conclusion

Acoustic emission testing represents a critical investment in workplace safety and business continuity for organisations that operate EWPs with fibreglass booms. By understanding and embracing the importance of this testing, businesses not only comply with regulatory requirements but also protect their workers, their reputation, and their bottom line. In the high-risk environments where these specialised EWPs operate, particularly around electrical infrastructure, this testing is not just about ticking a compliance box, it’s about ensuring everyone goes home safely at the end of each workday.