|
Key points:
|
Rail infrastructure including 4,350 sleepers were damaged when the wheelset of a wagon of a fully loaded coal train derailed near Moss Vale due to fatigue cracking, a new transport safety investigation report says.
The coal train TM94, consisting of three locomotives and 45 wagons, had departed Tahmoor Colliery for Port Kembla in the early hours of 28 June 2019. As the train approached the Suttor Road level crossing the 14th wagon’s L1 axle bearing journal separated from the rest of the axle, resulting in the wagon’s R2 wheel derailing. As there was no loss of brake pressure the train continued, with the train crew initially unaware that a derailment had occurred.
As the front of the train passed through the Suttor Road crossing at 12:42 am, a rail enthusiast who was filming the train saw sparks and heard a loud noise coming from the wheelset and contacted the Network Control Centre South at Junee. At 12:44 am, the Junee area controller requested the train crew to stop and check the train. The train came to a stop minutes later, about 2.6 kilometres past the point of derailment, by which point approximately 4,350 concrete sleepers and the concrete pad at the Suttor Road crossing had been damaged.
A transport safety investigation into the incident conducted on behalf of the ATSB by the New South Wales Office of Transport Safety Investigations (OTSI) found that the derailment was due to a through-axle fracture at the start of a radius transition, about 250 mm from the end of the axle.
The report notes that although no clear initiation point for the fatigue crack was visible, a discoloured area, extending 16 mm into the cross section, was the likely the initiation point and that cracking was likely present at the time of two separate wheelset maintenance activities in January and November 2016 and would have been detected had non-destructive testing been carried out on the wheelset.
There was no evidence to suggest that the actions of the train crew contributed to the derailment.
“This investigation highlights the need for rolling stock operators and maintainers to ensure that axle maintenance and inspection procedures include non-destructive testing of known defect areas are as part of their regular maintenance program,” said OTSI CEO and Chief Investigator Mick Quinn.
“Records of these inspections also need to be kept within their asset management system for the life of the asset.”
To ensure that no axles pose an immediate risk of failure, the operator has completed a program in-situ of non-destructive testing of axles, including ultrasonic testing of all 7E5S axles.
The operator has also issued a Rolling Stock Notice to their wheel set overhaul contractors reinforcing the requirement to inspect and test the fillet radius for all axles where bearing removal is mandated.
Read the report: Derailment of loaded Pacific National coal service TM94, near Moss Vale, New South Wales, on 28 June 2019