On Saturday 7 July 2001, at about 1900, express freight Train 842 derailed in the Otira Tunnel. The leading locomotive derailed 2 axles at a failed rail joint which had been installed as a temporary repair for a fractured rail found on Thursday 5 July.
There were no injuries.
Safety issues identified included:
• the suitability of the standards for temporary track repairs
• the frequency of inspection of temporary track repairs
• the monitoring and control of rail top wear in the Otira Tunnel
• the damp contaminated ballast condition throughout the tunnel
• the high percentage of down trains exceeding temporary speed limits
• the track standard required to meet the commercial demand of coal train loadings and the necessary minimum speed required to ascend the 1 in 33 tunnel grade