Rail safety investigations & reports

Derailment of SCT Logistics freight train 2PM9 near Koolyanobbing, Western Australia on 27 October 2020

Investigation number:
RO-2020-018
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final

Download Final report
[Download  PDF: 1.6MB]
 

What happened

On 27 October 2020, train 2PM9, operated by SCT Logistics, departed Perth, Western Australia for Melbourne, Victoria. Near Koolyanobbing, Western Australia, a wheel fractured and disintegrated on the 58th vehicle on the consist, wagon ARFY2253s, resulting in a derailment. The derailed wagon and those trailing separated from the train, but no other wagons derailed. There were no injuries.

What the ATSB found

Detailed material examination identified that a transverse fatigue crack initiated in the vicinity of a spalling defect in the wheel tread prior to the incident journey. The crack propagated into the rim and flange of the wheel. On the day of the incident, a skidding event at the fatigue crack likely induced rapid brittle cracking in the wheel. This resulted in its fragmentation and subsequent derailment.

In the 12 months prior to the occurrence, ARFY2253s experienced various issues with brakes and overheated wheels, although it is not clear whether any of these issues contributed to the derailment.

The failed wheel was recently reprofiled, but the maintenance provider’s work instruction did not require non-destructive examination beyond a visual inspection to identify any remaining defects.

What has been done as a result

The operator and maintenance provider have developed a process for monitoring wagons that experience repeated issues, such as with braking. Inspection procedures for thermal cracks and overheated wheels have been refined, and non-destructive testing is being investigated for use in certain wheel inspections.

Safety message

Skids and hotspots may be repairable on wheels in otherwise good condition, however, they can induce wheel failure if cracks are present, as in this case. Diligent inspections and non-destructive testing can be useful for detecting and monitoring wheel cracks, which is particularly important as these cracks approach the wheel wear condemning limit.

Download Final report
[Download  PDF: 1.6MB]
 
 
 

The investigation

Summary

The ATSB is investigating a derailment due to a shattered wheel on freight train 2PM9 between Lake Julia and Koolyanobbing, Western Austraila, on 27 October 2020.

Freight train 2PM9 was travelling between Perth and Melbourne when it experienced a slow speed derailment. The rearmost 13 wagons derailed when a wheel disintegrated in the Lake Julia to Koolyanobbing section in Western Austraila.

Should any safety critical information be discovered at any time during the investigation, the ATSB will immediately notify operators and regulators so appropriate and timely safety action can be taken.

A final report will be published at the conclusion of the investigation.

General details
Date: 27 October 2020   Investigation status: Completed  
Time: 0843 WST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): Near Koolyanobbing   Investigation phase: Final report: Dissemination  
State: Western Australia    
Release date: 07 October 2021   Occurrence category: Serious Incident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator ARC  
Train operator Twentieth Super Pace Nominees Pty. Ltd.  
Train registration 2PM9  
Type of operation Bulk Freight  
Sector Freight  
Damage to train Substantial  
Departure point Perth, Western Australia  
Destination Melbourne, Victoria  
Last update 07 October 2021