A railway repair machine ran off the tracks and was badly damaged after rails were removed, causing the blindsided driver to plough through 16m of ballast.
The Transport Accident Investigation Commission (Taic) said rules and procedures failed to prevent a derailment in Auckland’s Purewa tunnel because critical staff wereoverloaded, unsupported, and unaware of the missing track.
Key staff who knew about the missing track hadn’t properly communicated about it, Taic’s final report said.
Train controllers and the worksite’s Rail Protection Officer were both unaware that the track was missing, which then led to the “preventable” 2023 accident.
Taic’s report investigated how three linked tamper machines derailed inside the Purewa tunnel just after midnight on October 9, 2023.
The specialised railway maintenance machine used to maintain and repair the railway track had been authorised to pass through the tunnel, but rails and sleepers inside had been removed.
Neither the train control nor the Rail Protection Officer for the worksite, nor any of the four train crew members, knew about the gap.
The driver of the lead machine saw the missing rails but couldn’t stop in time, the report said.
The machine then ran off the end of the track and ploughed through 16m of ballast before it stopped.
None of the crew or any track workers were injured, but the machine was badly damaged.
Taic acting chief investigator of accidents, Louise Cook, said the accident was preventable.
“There were no engineering protections in place — nothing automatic to stop a train or to warn that rails weren’t in place.
“Engineering controls are more reliable than rules and procedures that govern human behaviour.
“We’ve recommended KiwiRail require such protections wherever tracks are impassable - like in the Purewa Tunnel that night, where the track had been removed for repairs.”
Cook told NZME that staff in critical safety positions were overworked and unsupported at the time of the incident.
“As a result, the safety oversight suffers because they’re burdened, and they become basically too busy to look after their safety.
“Authorisation for the rail movement relied on people applying rules and procedures.
“But those failed because safety-critical staff were overworked, and the people who knew the track was gone were unavailable and hadn’t communicated crucial information.”
Cook said they want KiwiRail to require engineering protections as part of its network.
“The engineering protections, such as physical stop barriers, help remove the reliance solely on human behaviour.”
She said the second recommendation Taic gave to KiwiRail is for an improvement on how it authorises the movement of rail vehicles within work sites.
The last recommendation is to ensure that there are safe workloads and effective support for safety-critical project staff.
Concrete sleepers stacked on tunnel 19 up main line. Photo / TAIC
Overworked staff
The Commission found that high workloads, lack of support for key staff, and perceived time pressures with project requirements likely led to oversights and errors contributing to the incident.
Cook said the tamper machines ran off in an area within the Auckland rail network rebuild project.
