Rail safety investigations & reports

Derailment of SCT Logistics freight train 6MP9, near Cook, South Australia, on 6 January 2019

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

Final Report

Download final report
[Download  PDF: 820KB]

What happened

On 6 January 2019, SCT Logistics freight train 6MP9 derailed near Cook, South Australia, while travelling from Melbourne, Victoria to Perth, Western Australia. The number 36 vehicle on the consist, wagon ARFY 2198T, experienced a ruptured wheel, resulting in the derailment. No other wagons derailed in the occurrence and there were no injuries.

What the ATSB found

Thermal damage to the wheel resulted in the initiation of a fatigue crack in the flange which propagated into the plate. Cracking then continued propagating around the plate, branching out to the rim, resulting in the wheel failure and ultimate derailment of the wagon.

At the last inspection, the flange fatigue crack was likely observable but was either not detected, or was deemed acceptable under the work instruction provided. This work instruction provided guidance that was less conservative than the Australian Standard, but it was not possible to establish whether compliance with the standard would have prevented the occurrence.

What's been done as a result

SCT Logistics has worked with their primary maintenance provider to develop an improved inspection process for wheels exhibiting issues with brakes (e.g. sticking brakes), as these issues can lead to heat‑related fatigue cracks.

SCT Logistics also plans to phase out the type of wheelsets that ruptured in the occurrence, in favour of a type that is less prone to the development of fatigue cracks due to thermal issues.

Safety message

Vigilant field inspections are a useful tool for the detection and monitoring of fatigue cracks. However, they are not infallible, and should be utilised with an understanding of their limitations.

Further, selection of the appropriate materials can assist in reducing the occurrence of fatigue cracks and subsequent wheel failures.

Download final report
[Download  PDF: 820KB]

The occurrence

General details
Date: 06 January 2019   Investigation status: Completed  
Time: 0635 CDT   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): near Cook (Fisher-Thomair section)   Investigation phase: Final report: Dissemination  
State: South Australia    
Release date: 29 June 2020   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator Australian Rail Track Corp. (ARTC)  
Train operator SCT Logistics  
Train registration 6MP9  
Type of operation Bulk Freight  
Sector Freight  
Damage to train Substantial  
Departure point Melbourne, Victoria  
Destination Perth, Western Australia  
Last update 29 June 2020