Rail safety investigations & reports

Derailment of loaded Pacific National coal service TM94, near Moss Vale, New South Wales, on 28 June 2019

Investigation number:
RO-2019-013
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

Download final report
[Download  PDF: 1.88MB]
 

What happened

In the early hours of 28 June 2019, a fully loaded coal train TM94, travelling in New South Wales from Tahmoor colliery to Port Kembla, derailed one wheelset near Moss Vale. The train crew, initially unaware of the derailment, were notified by train control to stop and inspect the train. A member of the public, who had witnessed a problem with the train, had phoned train control to alert them of an issue. Once the train was stopped, a train crew member discovered that one wheelset on the trailing bogie of the 14th wagon had derailed. The derailed wheelset had travelled approximately 2.6 km past the point of derailment at 150.067 km. This caused damage to the track infrastructure, including approximately 4,350 concrete sleepers.

What the ATSB found

The ATSB investigation found that the derailment was caused by a through-axle failure, on a 7E5S-type axle. The axle failure occurred at the start of a radius transition, approximately 250 mm from the left-hand end of the axle. The fracture of the axle in the No. 1 wheelset led the No. 2 wheelset on the same bogie to derail.

A metallurgical analysis conducted after the derailment found that the axle had corrosion pitting on the axle surface adjacent to the likely fracture initiation point. The fracture surface featured a discoloured area of corrosion, which extended 16 mm into the axle cross section. This was evidence of a crack which existed prior to the final complete brittle failure of the remaining axle section.

An examination of maintenance records found that non-destructive testing had not been carried out on this wheelset during the last two maintenance activities in January and November 2016. Testing, if conducted, would likely have detected the initiation of the axle crack, which probably existed at that time.

What's been done as a result

As a result of this derailment, Pacific National commenced and completed a program of non-destructive testing of axles, in-situ, to ensure that no axles pose an immediate risk of failure. This included all 7E5S axles and involved ultrasonic testing.

A Rolling Stock Notice was also issued, to reinforce to Pacific National’s wheel set overhaul contractors of the requirement to inspect and test the fillet radius for all axles where bearing removal is mandated.

Safety message

Rolling stock operators and maintainers should ensure that axle maintenance and inspection procedures include non-destructive testing of known defect areas as part of the regular maintenance program. Records of these inspections should be kept for the life of the asset within their asset management system.

Download final report
[Download  PDF: 1.88MB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Safety Issues

Go to RO-2019-013-SI-01 - Go to RO-2019-013-SI-02 -

Axle testing

Axle testing on wheelset number 7E5S 831444 was not carried out during the two most recent wheelset maintenance events in January 2016 and November 2016. It is likely the axle crack existed at the time of these maintenance activities.

Safety issue details
Issue number: RO-2019-013-SI-01
Who it affects: All owners and maintainers of rolling stock
Status: Closed – Adequately addressed

Maintenance records

Inspection records for the December 2010 wheelset maintenance activity and wheel change on wheelset number 7E5S 831444 were not available. It is a requirement specified in Pacific National's Wagon Maintenance Manual that records be retained for a period of 12 years.

Safety issue details
Issue number: RO-2019-013-SI-02
Who it affects: All owners and maintainers of rolling stock
Status: Closed – Adequately addressed
General details
Date: 28 June 2019   Investigation status: Completed  
Time: 0040 AEST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): Moss Vale   Investigation phase: Final report: Dissemination  
State: New South Wales    
Release date: 24 November 2020   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator Australian Rail Track Corporation (ARTC)  
Train operator Pacific National  
Train registration TM94  
Type of operation Freight - coal  
Sector Freight  
Damage to train Substantial  
Departure point Tahmoor, New South Wales  
Destination Port Kembla, New South Wales  
Last update 30 November 2020