Alert no. 430 | 12 July 2022 | Version 1

Plant access systems

What happened?

A Coal Mine Worker (CMW) was checking the emulsion tank. The CMW was making their way back down the ladder (Fixed plant access system) with three points of contact when the second step from the top failed on one side. No CMWs sustained any injuries. The investigation identified multiple fatigue fractures to all the weld joints for the step rung to the ladder side rails.

How did it happen?

• The ladder was constructed from light gauge materials.
• The ladder, step / rung material was 2mm thick.
• The ladder, side rail material was 50mm x 50mm x 5mm material.
• The overhang from the step to the ladder side rail permitted torque at the weld points.
• The ladder has a high utilisation, being used two to four times a day.
• The ladder has been in service for 10 years.
• There was no maintenance strategy in place for the ladder.

Key issues

• Although there was an inspection in place for the compound, there were no structural inspections in place for the ladder (access system).
• No visual inspections for the ladder (access system).
• No non-destructive testing (NDT) in place for the ladder (access system).

Recommendations

All Site Senior Executives should:

• ensure that all fixed plant access systems be audited:
• to identify that the access system construction is fit for purpose.
• to ensure the risk from using the access system is as low as reasonably achievable.
• to identify that a competent maintenance strategy for the access system is in place and is effective.
• refresh CMWs on:
• how to identify defects on fixed plant access systems.
• use of the defect management system within the Safety and Health Management System (SHMS)