A loaded coal train derailed near the Ōtira Tunnel on Tuesday night, damaging part of the Midland Line and disrupting rail services between the West Coast and Christchurch.
According to a report by 1News, the train, which was travelling towards Christchurch, came to a stop inside the tunnel at around 10 pm after one of its wagons derailed. The cause of the incident has not yet been established.
No injuries were reported. However, KiwiRail said repair work would be required before the affected section of track could be reopened.
KiwiRail general manager of engineering and asset management Lynne Morton said teams were assessing the damage and determining the repairs needed.
"The derailment has affected a section of track, and KiwiRail teams are assessing the extent of the damage and the repairs required," Morton said, as quoted by 1News,.
"We are working to restore the line as quickly and safely as possible," 1News, has quoted.
The incident also affected TranzAlpine passenger services, with Wednesday morning's journey terminating at Arthur's Pass instead of continuing to its usual destination.
Morton said disruptions could continue over the coming days, advising passengers to expect changes to travel arrangements.
"TranzAlpine services are likely to be affected for the next few days," she said, as quoted by 1News,.
"Affected passengers will be contacted directly and offered rebooking or refund options. Replacement buses will be arranged where possible."
Investigation launched
The Transport Accident Investigation Commission (TAIC) has launched an investigation into the derailment. Investigators will examine various aspects of the train, railway infrastructure and crew operations to establish what happened.
Chief investigator of accidents Louise Cook said the initial investigation would involve collecting evidence at the scene and speaking with witnesses.
"Our investigators would typically spend two to three days on site," she said, 1News, has quoted.
"Their first priority is to gather evidence while it is available. That includes examining and mapping the train and the scene, and speaking with people who witnessed the accident or were involved,” as quoted by 1News,.
Cook said the investigation would continue beyond the initial on-site examination, although investigators were expected to affect railway operations for only a couple of days.
The return TranzAlpine service was scheduled to depart Arthur's Pass at its usual time on Wednesday afternoon.