At approximately 2130 on 1 September 2008, 13 wagons on freight train 1MP9, owned and operated by SCT Logistics (SCT), derailed near Mt Christie, South Australia. There were no injuries, but about 4.5 km of track was damaged.
The investigation concluded that an axle-box bearing on wagon VQCY 0824U had failed and completely seized, causing the bearing journal to separate from the axle (commonly referred to as a screwed journal). Examination of the bearings suggested that inadequate lubrication had contributed to cage failure with the subsequent misalignment of the rollers and jamming of broken cage material in the rolling surfaces causing the bearing to seize. Maintenance records showed that the bearings on wagon VQCY 0824U were new in July 2004 and the wagon underwent servicing in May 2006 and May 2007. However, it is unlikely that the axle-boxes were re-greased during servicing as required by the maintenance procedures.
SCT has implemented a number of actions aimed at reducing their risk of future derailments due to axle-box bearing failures. Those actions included immediate scheduling for regreasing, a program to remove all axle-box equipped bogies from SCT's service and a trial to install on-board monitoring for hot bearings on their freight rolling stock.
Though not contributing directly to the derailment sequence, a minor safety issue was identified in relation to documented procedures at crossing loops. ARTC has proposed relevant safety action to address the issue.
|Date:||01 September 2008||Investigation status:||Completed|
|Time:||2130 CST||Investigation level:||Complex - click for an explanation of investigation levels|
|Release date:||22 June 2010||Occurrence category:||Accident|
|Report status:||Final||Highest injury level:||None|
|Train registration||Train 1MP9|
|Type of operation||Freight Train|
|Damage to train||Substantial|