Safety Alert

What Happened

During scheduled maintenance on the primary jaw crusher, a maintenance crew began removing a liner plate while the crusher's hydraulic system was still pressurised. The isolation tag board showed the hydraulic system as isolated, but the physical isolation valve had not been turned. The discrepancy was identified by a second fitter who noticed the hydraulic accumulator pressure gauge still reading 200 bar. Work was stopped immediately.

Why It Matters

The hydraulic system on a jaw crusher operates at pressures that can cause fatal injuries. Had the liner plate been removed with the hydraulic system pressurised, the stored energy in the accumulator could have caused the crusher jaw to move unexpectedly, crushing the maintenance crew. The discrepancy between the tag board and the actual isolation state represents a critical failure in the LOTO verification process.

Immediate Actions Required

1. 1Stand-down for all crusher maintenance pending a full audit of isolation procedures and tag board accuracy
2. 2Mandatory try-before-you-touch verification to be implemented for all isolations — physical testing of energy state required
3. 3Tag board procedures to be reviewed — dual sign-off required for all isolations on crushers
4. 4All maintenance crews to complete LOTO refresher training with emphasis on physical verification within 48 hours
5. 5Install pressure gauges at visible locations near all hydraulic isolation points

Key Learning

A tag on a board does not make equipment safe. Only a verified, physical isolation makes equipment safe. Always try-before-you-touch: test for zero energy at the work point before commencing any maintenance. If you cannot personally verify the isolation, do not start work. Your life depends on getting this right every time.

Discussion Points for Toolbox Talk

• •How do you personally verify that equipment is isolated before starting maintenance?
• •Have you ever found a discrepancy between the tag board and the actual isolation state? What did you do?
• •What would you do if you were pressured to start work before you had verified the isolation?