Stronger rain monitoring could have prevented train derailment – report

The train derailed after a landslide closed the track in wet weather. File photo.
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It is highly likely that more sensitive rain monitoring systems would have prevented a train derailment on the Kāpiti coast in 2021, the transport watchdog says.

On the morning of August 17, 2021, a Metlink train traveling from Waikanae to Wellington with 82 passengers and 3 crew on board derailed between Paekākāriki and Pukerua Bay, where a landslide had covered the track.

Everyone on board disembarked safely and without injuries.

The Transport Investigation Commission has launched an investigation into the derailment, which was released this morning.

The study identified eight safety issues and made five recommendations.

The safety issues found included the inability of passenger trains to control an automatic radio when an emergency brake was applied, and KiwiRail’s rain monitoring settings that did not take into account periods of moderate or heavy rainfall over a short period.

The recommendations include that KiwiRail should review the settings of its rain monitoring equipment and that train operators Transdev and Auckland One Rail should take action to fit automatic warning systems with emergency brake activations.

KiwiRail has accepted the committee’s recommendation for its live rainfall monitoring and risk systems to provide warnings for intense moderate to high rainfall.

Regarding the changes to the automatic alert system, TAIC said the issue had been addressed in Auckland but was “under consideration” in Wellington pending approval and funding.

The committee recommended in 2010 that an automatic warning system be installed in passenger trains when they derailed due to a slip on a multi-lane track section.

He was then hit by another train heading in the opposite direction.

TAIC chief accident investigator Naveen Kozhuppakalam said this was the third TAIC report in just over two years to highlight the need for KiwiRail to improve its preparedness and response to serious rain events.

Kozhuppakalam said before the derailment, deficiencies in KiwiRail’s slope stability assessments meant they were unaware that land above the part of the Kāpiti Line where the slip occurred was at risk of landslides.

He said KiwiRail has accepted the committee’s recommendation for its live rain monitoring and risk systems to provide warnings of intense moderate to high rainfall that could cause damage to rail infrastructure.

“If KiwiRail’s systems had done this before the accident on the Kāpiti Line, there is a good chance that Train Control would have been alerted and brought the trains to a halt.”

The committee also found that train operator Transdev and KiwiRail did not have a joint plan setting out how they would work together in the event of a derailment on the Kapiti Line.

“This created a risk that Transdev train crews and KiwiRail inspectors would not always follow a safe process to evacuate passengers. KiwiRail is giving this issue the priority it deserves; it has drawn up a new TARP (Triggered Action Response Plan) and anticipates its first phase. will be implemented across the rail sector by December 2024.”

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