In August 2020, KiwiRail applied a blanket temporary speed restriction across Auckland’s metro rail network system following discovery of accelerated wear and tear (rolling contact fatigue) of the railway lines. The speed restrictions last several months, the already lengthy train journeys took much longer than usual, and entire lines had to be shut down as KiwiRail undertook urgent works.

A report that has just been made public attributes the wear and tear to the following:

  • historic under investment in the track asset prior to 2014 up to September 2020
  • insufficient rail grinding from 2015 to 2020
  • the design of the electric trains
  • wheel rail interface
  • the existence of multiple sites where the track condition is sub-optimal in engineering factors known to accelerate the growth of rolling contact fatigue:
    • track geometry and gauge exceedances including at welds and bolted joints
    • aged timber sleepers unable to hold rail in place adequately
    • historic wheel burns/squats causing sudden dynamic loads
    • sub-optimal application of cant, mainly from uncorrected past practices
    • significant sections of the network have low track modulus (low combined stiffness of rail, sleeper, ballast, and formation), at times aggravated by poor drainage.

The report singles out a 2014 evaluation which concluded that investment of around $100 million was needed to Auckland’s metro rail network to ensure it would be fit for purpose for the proposed electric trains. This investment was not approved, and the parties instead relied on increased inspections for safety, track speed restrictions, and accepted the infrastructure would provide lower levels of service.

The report does not state who vetoed the investment proposal. KiwiRail owns the network and infrastructure, and Auckland Transport pays an annual fee to use it.

The repairs have been costed in the order of $200 million.

This debacle highlights the deadweight loss of sweating critical assets and even running certain assets to failure. This practice is likely to generate further debate in the near future, especially as the resource management system moves to legislating for outcomes, which will include infrastructure and infrastructure services.