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Report questions buried track at unsealed crossings

Pyramid Hill derailment. Photo: ATSB

The 2013 derailment of a Pacific National train in northern Victoria raises several issues over the construction, monitoring and maintenance of buried track at unsealed level crossings, a report has found.

Pacific National train 9054 derailed at the O’Tooles Road level crossing, at Pyramid Hill, in the early hours of March 5, 2013. The train’s three locomotives remained on the track, but 19 of the first 20 wagons derailed, resulting in severe damage to wagons, a significant loss of grain load and damage to about 270 metres of track.

The train’s crew was unharmed.

A recent report from the Australian Transport Safety Bureau (ATSB) found the train derailed at a fracture in one of the rails, most likely created by a passenger service which had gone through the crossing earlier that night.

The ATSB found the fracture was a result of the rail’s heavily corroded and wasted condition, and said the poor condition of the rail had not been detected by the rail operator, V/Line, nor by V/Line’s ultrasonic testing contractor, Speno Rail Maintenance.

Examination of the track following the incident found it had been heavily corroded – over a number of years. The rail web was most severely wasted in a horizontal band approximately 20mm wide, commencing about 50mm below the top surface of the rail head, the ATSB found.

Based on established corrosion rates and local conditions, the wasting of the rail must have occurred over several years, the Bureau said.

But walking and ultrasonic inspections by V/Line and its contractor – which took place a maximum of 12 months apart and had most recently occurred 10 months prior to the derailment – had not shown the rail to be in need of replacement.

“Level crossings at unsealed roads can present difficulties for automated ultrasonic testing due to contamination of the rail head and the presence of corrosion on the underside of the rail that can disrupt return signals,” the ATSB explained.

Also contributing to the corrosion going unnoticed was the method with which the rail was installed at the unsealed crossing.

“Covering of rails, fixtures and track support with loose road material increases the potential for corrosion and more rapid track degradation,” the ATSB found. “It also limits the ability to conduct efficient and effective visual inspection.”

Moreover, the Bureau found the network standard for level crossing construction did not directly address the challenges of unsealed roads.

“The standard primarily addressed crossings at roads with paved (sealed) surfaces, other than a reference to the application of a bituminous coating to rail that would contact fill material,” the ATSB said.

“The particular challenges related to drainage, the rail and track environment and the mechanisms for inspection, were not addressed within the standard.”

After the derailment, 126 higher risk sites were inspected from a total population of about 1000 unsealed road crossings on Victoria’s regional network. A more careful, detailed assessment of the rail, sleepers and fastenings was undertaken at these locations.

Of the sites inspected, 111 had sufficient data for assessment and analysis.

Two were identified as having priority faults due to web reduced thickness, and 58% were found to have foot height loss meeting the criteria for priority attention.

Deterioration was also found in fixtures and about 25% of crossings had sleepers identified as ineffective. On the Bendigo-Swan Hill section of track, which includes Pyramid Hill, 30% of unsealed crossings were inspected, of which 21% were identified as requiring immediate remedial works – this compares to 12% across the full sample set, the ATSB said.

The Safety Bureau also found that V/Line, and Transport Safety Victoria (the regulator at the time) missed an opportunity to potentially fix these issues following an earlier derailment, at Warracknabeal two years prior.

“In response to the [Warracknabeal] incident, the frequency of ultrasonic inspection on freight lines was increased from every three years to every two years [annual inspections on passenger lines remained in place], and Speno re-emphasised with its operators the requirement to hand test if indications of corrosion were identified during automated ultrasonic testing.”

These ATSB found these changes were not sufficient, however.

“An opportunity was missed to undertake a wider review of track condition monitoring at unsealed crossings and to review the standard of construction at such crossings,” the Bureau found.

Overall, the Bureau found a trio of safety issues associated with the derailment.

One issue was classed as a contributing factor to the incident:

  • The track inspection regime did not identify the deteriorated rail condition at the O’Tooles Road level crossing. The regime placed an over-reliance on ultrasonic testing and did not include sufficient supplementary systems for monitoring the condition of buried track at unsealed level crossings.

The other two identified safety issues were defined as increasing risk in the lead-up to the incident:

  • The ultrasonic testing regime was not effective in consistently identifying corrosion and wasting of the rail web at unsealed level crossings.
  • The method of constructing crossings at unsealed roads heightened the potential for corrosion and track degradation and limited the opportunity for effective visual inspection. The network standard for crossing construction did not directly address the particular challenges of unsealed roads.

Read the full report at http://www.atsb.gov.au/

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