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Management of rail stress
Date issue released
Safety Issue Description

A variety of techniques to indicate and record rail stress at specific locations are available, however, Aurizon had not used any of these techniques in some locations with elevated risk of rail stress, such as tangent track on steep grades. As a result, Aurizon could not readily determine the presence or absence of compressive rail stress at these locations.

Issue number
RO-2018-005-SI-02
Transport Function
Rail: Infrastructure
Issue Owner
Aurizon
Mode of Transport
Rail
Issue Status Justification

The ATSB acknowledges that Aurizon has taken (or is proposing to take) safety action to improve their knowledge of rail stress throughout its network. Although this proactive safety action does not specifically address all aspects of the safety issue, the ATSB believes the risk of derailments will be reduced by this safety action, together with the other action in relation to the other safety issue with its hazard location register (RO-2018-005-SI-01).

Proactive action
Action number
RO-2018-005-NSA-002
Organisation
Aurizon
Action date
Action Status
Closed
Action description

During the investigation, Aurizon advised that it was implementing the following actions:

  • Review and align Civil Engineering Procedure 44 - Measurement of Rail Stress Free Temperature and the Track Stability Manual (AZN NA MAN 12 6170 005) to define the maximum permitted time between completing track disturbing works and performing a rail stress test, and action to be taken should those test results fall outside acceptable limits.
  • Review the management of rail stress on completion of ballast removal works.

In June 2019, Aurizon also advised that:

  • Aurizon currently maintains and controls a register of known stress free temperatures of sites located within the Central Queensland Coal Network. Aurizon has committed to a program of work to ensure that the register progressively covers a greater percentage of the network, enabling more effective asset management in the extreme weather periods.
  • The stress free temperature register highlights areas of high risk or concern for all seasons, but especially leading up to and throughout the hot weather period when track buckling is at a higher risk of developing into incidents.