Final Report


What happened

At about 1925 CDT[1] on 23 December 2014, GWA train 2AD1 derailed near Hugh River, Northern Territory. The derailment resulted from an axle bearing failure on wagon PTMY 6-T. The wagon, carrying distillate fuel, remained upright and there was some minor damage to the track (sleepers and rail clips). There were no injuries.

What the ATSB found

The ATSB found that the journal and bearing on wagon PTMY 6-T had seized and lost interference fit – generating high levels of frictional heating between the bearing and axle journal, and the subsequent torsional shearing failure of the axle (a ‘screwed journal’). The axle failure immediately caused the leading axle of the trailing bogie to derail.

On the balance of the available evidence, the ATSB concluded that a loss of lubrication or an internal bearing cage failure was the most likely contributor to the bearing breakdown and seizure. Evidence also suggested the breakdown developed relatively rapidly, given the absence of a positive fault detection from two bearing acoustic monitoring systems (RailBAM®) passed on the day of the occurrence.

Safety message

Bearing failures leading to derailment continue to occur within the Australian rail network. Rail operators must continue to be vigilant and ensure axle bearings, and in particular axle box type bearings, are correctly installed, maintained and monitored throughout their life.

 Train 2AD1 near Hugh River, NT

 Train 2AD1 near Hugh River, NT

Source: Genesee Wyoming Australia Pty Ltd 


  1. Central Daylight Time (ACDT), UTC +10.5 hours

The occurrence



Additional safety action

Sources and submissions