We often discover cases from outside sources that inspire reflection and introspection on our own work history at Bluefield.
Below is a link to one such case in yet another interesting video from the NSW Regulator. The video details an incident that left two workers at Tahmoor Colliery trapped for 8 hours in a shaft friction winder, 162 metres below ground.
The stand-out points from the video that resonated with our experience were:
The winder maintenance strategy did not recognise the criticality of the listed inspections (in this case, the tensions of the balanced head rope). We often see critical inspections that are not completed which then lead to breakdowns.
The department recommended a “response plan” for when critical maintenance tasks are not completed. Many times we have seen single tasks on a PM checklist that are not completed and have a long frequency like 24 weeks, where no subsequent work order is raised to get back and do the task.
Defects and results outside of acceptable limits need to be properly communicated and actioned in a timely fashion. Acceptable limits are often disregarded and it is worse when this becomes the cultural norm.
These themes are very similar to what we found recently in an integrity audit with the management of critical maintenance tasks. For one machine in particular, there was a 18 month period where structural inspections were not completed (due to access equipment damage).
Almost all of the 4 weekly, 12W, 24W and 48W NDT reports had the same comment “not inspected / no access”. No extra notifications or work orders were raised to capture the missed inspections. After our audit wherein we identified this gap, the client corrected the situation and found a critical state crack in the structure that had consistently been missed.
All tasks that are included as part of a PM program or listed on a PM checklist should be completed as written. Sometimes there are circumstances where they cannot be completed, which is understandable, but in these situations a subsequent work order should be raised to get it done without fail.