Rail safety investigations & reports

Defective axle bearing leading to fire on passenger train SN68 Yerrinbool, New South Wales, on 13 October 2020

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


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This investigation was conducted under the Transport Safety Investigation Act 2003 (Commonwealth) by the Office of Transport Safety Investigations (NSW) on behalf of the ATSB in accordance with the Collaboration Agreement. Released in accordance with section 25 of the Transport Safety Investigation Act 2003.

What happened

On 13 October 2020, TrainLink passenger service SN68, was operating from Moss Vale to Campbelltown, New South Wales with approximately 20 passengers on board.

The train driver stopped the train at Yerrinbool Station after being alerted to a small fire at the rear of the train. The fire was identified as coming from the vicinity of an axle bearing on the rear wheelset of the train. The passengers were evacuated onto the platform and the driver attempted to extinguish the fire using an on-board fire extinguisher.

The fire was subsequently extinguished by Fire and Rescue NSW. As a result of the fire, parts of the axle box were heat affected and sustained significant damage to the speed sensor and rubber suspension components. There were no reported injuries.

What the ATSB found

The investigation determined that the fire was the result of a collapsed axle bearing on wheel 8 on the trailing bogie on car 2811, the end of the train. The axle bearing failed when the axle end cap bolts loosened and one fractured which caused the collapse of the bearing and frictional heat to be generated. The resulting fire was fuelled by grease, oil and rubber suspension components in the immediate vicinity of the axle box.

It is likely that during the last overhaul of bogie NJA31, the locking plate tabs retaining the axle end cap bolts were not fitted correctly against the sides of the bolts. The axle bearing installation process was not sufficient to ensure the tabs on the locking plate were installed correctly during a refurbishment three months before the incident.

A wayside monitoring system at Burradoo on the Down Main line detected an elevated temperature on one bearing, but the temperature recorded was below the threshold for an alarm to be sent to network control.

What has been done as a result

Following the occurrence Sydney Trains, which is the maintenance provider for NSW Trains, initiated an inspection of similar axle boxes in the fleet and undertook an audit of the contracted maintainer’s practices.

Sydney Trains have advised the following actions have taken place to prevent a recurrence:

  • Improvements have been made to the contracted maintainer’s quality assurance processes to ensure that bolts and locking tabs are correctly installed.
  • An improved process was implemented to review and retain the contracted maintainer’s certificate of completion checklists.

Safety message

Bearing failures continue to occur within the Australian rail network. This occurrence emphasises the significance of having adequate bearing installation processes and ensuring that axle bearings are correctly maintained and monitored throughout their operational life.

Download Final Report
[Download  PDF: 1.52MB]

The Occurrence


Safety analysis


Safety issues and actions

Sources and submissions

About the ATSB


The ATSB is investigating an incident which occurred on a NSW Trains passenger service at Yerrinbool, New South Wales, on 13 October 2020.

At 1805, the driver on SN68 advised a fire had occurred on the trailing bogie of locomotive TE2811 at Yerrinbool platform on the Up Main. A wheel bearing assembly on bogie NJA31 had failed. The fire brigade attended and the fire was extinguished. There were no reported injuries to staff or members of the public. There was minor damage to the bogie and nil damage to track infrastructure.

This investigation is being led by the NSW Office of Transport Safety Investigations (OTSI). OTSI conducts rail investigations in NSW on behalf of the ATSB under the Transport Safety Investigation Act 2003. Investigators have commenced collecting evidence from involved parties.

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: 13 October 2020   Investigation status: Completed  
Time: 18:05 AEDT   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): Yerrinbool   Investigation phase: Final report: Dissemination  
State: New South Wales    
Release date: 20 January 2022   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator Australian Rail Track Corporation (ARTC)  
Train operator NSW Trainlink  
Train registration SN68  
Type of operation Passenger  
Sector Passenger - metropolitan  
Damage to train Minor  
Departure point Moss Vale, New South Wales  
Destination Campbelltown, New South Wales  
Last update 20 January 2022