The Transport Accident Investigation Commission has published its Final Report on the causes and circumstances of a passenger train derailment at the Britomart in Auckland in May 2018.
About 130 passengers were on the train when it derailed on approach to Britomart Station, stopping just short of a concrete wall dividing two platforms. Nobody was injured, but there was moderate damage to the train and the track.
The Commission found that a fractured section of rail in a set of points caused the leading passenger car to derail
The Acting Chief Investigator of Accidents, Martin Harper, says the rail met the required specifications, but there was a machining defect that likely reduced the rail’s resistance to fatigue and fracture.
“The defect was at the point of maximum stress, midway between sleepers, at the corner of the rail foot and was undetectable either by sight or ultrasonic testing,” said Mr Harper.
Mr Harper said the Commission had found no evidence that the manufacturing defect represented a wider quality issue.
“The rail defect that caused this incident was exceptionally unlikely. Records show there have been no failures of a similar nature in New Zealand since 1995.
And inspection of a representative sample of mainline points found no marks that would indicate a defect similar to that in the failed rail.”
Mr Harper said Commission had no need to make recommendations from this inquiry.
“KiwiRail has already improved its track inspection regime, and there is now an independent multi-agency working group to study the effect of rolling stock and resolve potential rail wear issues on the Auckland passenger network.”
The Commission inquires into accidents and incidents that have - or are likely to have - significant implications for transport safety, or when the inquiry may allow the Commission to make findings or recommendations to improve transport safety.