This investigation, undertaken by OTSI under a Collaboration Agreement with the ATSB, was discontinued.
What happened
On 15 January 2022, the driver of 6MB4 reported losing air on the Up Main at 452.000 km, at Bethungra, NSW. Shortly after, the driver reported that three wagons (RRAY07213S, RRQY08515T and QQCY01120F), in the centre of the consist of 33 wagons, had derailed. The wagons sustained substantial damage with major damage to the track infrastructure. The train crew were uninjured.
Discontinuation
The ATSB considered the contributing factors to the derailment were a result of a failed bearing. The reasons for that failure were unable to be conclusively determined.
Due to the nature of the failure and the proposed safety actions initiated by the operator, OTSI and the ATSB considered it was unlikely that further investigation would identify any systemic safety issues or further important safety lessons for the enhancement of transport safety.
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