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Investigations

Helping transport become safer is the central focus of every Commission inquiry. Here you can find details of every investigation we have opened, inquiry reports, and links to recommendations made.

RO-2025-107

TranzAlpine train - two locomotives and several carriages in a rural setting with snow-capped mountains in the background

The TranzAlpine service, photographed in 2016. Credit NZ Steam

TranzAlpine locomotive, fuel leak, near Arthur’s Pass, 5 August 2025

Status

Current

Occurrence Date

5 Aug 2025

Jurisdiction

The Commission is investigating an incident involving the TranzAlpine service on 5 August 2025. The reported circumstances were that the train was travelling towards Christchurch. At Arthur’s Pass station after passing through Otira tunnel, the locomotive engineer reported diesel leaking onto the running board of the lead locomotive DXC5379.