The ATSB is highlighting the importance of the early detection and treatment of defects of rail infrastructure, especially those that could cause a rail facture and lead to derailment.
The ATSB’s investigation into the derailment of freight train 1501S, near Dry Creek in South Australia on 28 July 2017, found a vertical split head defect had developed through the centre line of the lower leg rail in the curve approaching Dry Creek South.
The ATSB determined the defect had developed undetected from impurities in the rail during its manufacture. When a preceding train travelled over the defect, it caused a break in the rail that was not obvious – visually – to the crew of the following train 1501S. When 1501S travelled over the break, a 2-metre section of rail fragmented derailing its last three wagons.
Acting ATSB Executive Director Transport Safety, Patrick Hornby said the defect in the rail failed to be detected, despite the previous month’s ultrasonic track inspection.
No follow-up action was triggered by the testing provider as required by the track owner creating a missed opportunity for the detection and possible treatment of a defect
“ATSB investigators found that ultrasonic testing indicated the presence of an anomaly, however these results were attributed to the rail’s poor surface condition and not a potential rail defect,” Mr Hornby said.
“No follow-up action was triggered by the testing provider as required by the track owner, creating a missed opportunity for the detection and possible treatment of the defect.”
Following the incident, the testing provider reviewed its operational and reporting procedures and the rail owner confirmed the effectiveness of its code of practice for ultrasonic rail testing.
“This incident highlights the importance of maintenance providers reporting testing anomalies, to highlight operational risk and to initiate further action,” Mr Hornby said.Last update 16 November 2018