Executive summary
On Wednesday 24 March 2004, at about 0149, USQ 7663, the 27th wagon on southbound express freight Train 237, derailed while negotiating a left-hand curve between Puketutu and Kopaki on the North Island Main Trunk. The wagon ran derailed for about 750 m until it struck the spreader bar on the north-end facing points at Kopaki, derailing the following 4 wagons and parting the train between the 29th and 30th wagons. The condition of the trailing bogie of wagon USQ 7663 was a significant contributing factor to the derailment.
Safety issues included:
• the fractured friction wedge springs
• the identification and correction of displaced bearing adaptors
• the assembly procedures for fitting wear liners to bolster wedge pockets
• the identification of individual bogie components.
Two safety recommendations were made to the Chief Executive of Toll NZ Consolidated Limited to address these issues.
Related Recommendations
Develop a documented procedure for fitting the wear liners to the bolster wear pocket.