Rampant safety-system tampering on mine sites prompts regulatory action

The NSW Resources Regulator has urged mine operators to strengthen controls around explosion-protected diesel engine systems after a series of incidents revealed widespread tampering, bypassing, overriding and component failures.

Investigations by the regulator into multiple loader and transport-vehicle incidents found shutdown systems overridden or left in unreliable condition. In several cases, exhaust temperature sensors and strangler valves were bypassed to keep machines running despite blocked scrubbers, loose wiring or repeated shutdowns.

Failures were also identified where components had not been deliberately bypassed but were unable to operate as designed, including frozen strangler valves and fuel shut-off cylinders stuck in the run position. These conditions left equipment unable to shut down when demanded by safety circuits.

Against this backdrop, the regulator recently released a safety bulletin, calling for strengthened engineering and procedural controls. Operators are advised to ensure systems cannot be modified without authorisation, and to update mechanical engineering control plans where risk reviews identify gaps. The bulletin also encourages sites to confirm that only trained and competent personnel are permitted to work on explosion-protected diesel systems.

To manage situations where system interference is unavoidable, such as battery charging or commissioning, the regulator recommends considering formal bridging and forcing registers or permit systems. It also urges operators to review reliability trends across their fleets to maintain equipment in a compliant, explosion-protected state.

Mine workers are also expected to follow site protocols, report reliability concerns early and carry out tasks in ways that preserve safety-critical functions.