The train derailed after a landslip closed the track during wet weather. File photo. Photo:
It is very likely more sensitive rain monitoring systems would have stopped a train from derailing on the Kāpiti Coast in 2021, the transport watchdog says.
On the morning of 17 August 2021, a Metlink train travelling from Waikanae to Wellington with 82 passengers and 3 crew onboard derailed between Paekākāriki and Pukerua Bay where a landslip had covered the track.
Everybody onboard disembarked safely with no injuries.
The Transport Investigation Commission launched an inquiry into the derailment, which was released this morning.
The probe identified eight safety issues and made five recommendations.
Derailing of passenger train could have been prevented - report
The safety issues found included an inability for passenger trains to send an automatic radio when an emergency brake was applied, and KiwiRail's rainfall monitoring settings not taking into account periods of moderate or heavy rainfall in a short period of time.
The recommendations included that KiwiRail review their settings of rainfall monitoring equipment and that train operators Transdev and Auckland One Rail take action to fit automatic alert systems to emergency brake activations.
KiwiRail has accepted the commission's recommendation for its live rainfall-monitoring and risk systems to provide alerts for intense moderate-to-high rainfall.
Regarding the automatic alert system changes, TAIC said in Auckland the problem had been addressed but in Wellington it was "under consideration" pending approval and funding.
The commission recommended in 2010 that an automatic alert system be installed in passenger trains when one derailed when it struck a slip on a multi-line section of track.
It was then struck by another train travelling the other way.
TAIC chief investigator of accidents Naveen Kozhuppakalam said it was the third TAIC report in just over two years that highlighted the need for KiwiRail to improve its preparation and responsiveness to severe rain events.
Kozhuppakalam said before the derailment, shortcomings in KiwiRail's slope stability assessments meant they did not know about land above the part of the Kāpiti Line where the slip occurred being at risk of landslides.
He said KiwiRail has accepted the commission's recommendation for its live rainfall-monitoring and risk systems to provide alerts for intense moderate-to-high rainfall which can cause damage to rail infrastructure.
"If KiwiRail's systems had done this ahead of the Kāpiti Line accident, it's very likely that Train Control would have been alerted and stopped trains."
The commission also found that train operator Transdev and KiwiRail had no shared plan setting out how they'd work together in the case of a derailment on the Kapiti Line.
"This created a risk that Transdev train crews and KiwiRail controllers might not always follow a safe process to evacuate passengers. KiwiRail is giving this issue the priority it deserves; it has drafted a new TARP [Triggered Action Response Plan] and anticipates its first phase will be implemented across the rail industry by December 2024."
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.