Lockout practice that survived a real shutdown
A conveyor isolation procedure is only as good as its worst-labelled isolation point. We found four.
Before a planned transfer chute reline, we walked the isolation procedure with the site crew rather than reading it. Walking it is the only way to find the gap between the document and the plant.
What the walk found
Four isolation points on the procedure could not be located from their description. Two had been relabelled during an earlier upgrade, one was behind a cable tray added afterwards, and one referred to a starter that no longer existed. Every one of them was signed off as verified on the previous shutdown.
None of this reflects badly on the crew. It reflects the normal drift of a live plant against a document that gets updated less often than the plant does.
The correction
We re-walked and re-labelled every isolation point in the affected area, photographed each one, and attached the photographs to the procedure. A photograph is harder to misread than a description, and it fails visibly when the plant changes — someone looking at a picture of a starter that is not there will ask a question.
The reline went ahead a week later without incident. The procedure walk cost half a day. It is the cheapest half day on any shutdown we run.
