At about 1411 on 12 February 2014, 10 wagons of a loaded grain train en-route from Birchip to North Geelong derailed at Emu in North Central Victoria. The weather was hot with a forecast temperature of 36° C.
As a consequence of the derailment there was damage to about 210 m of track. Five wagons overturned resulting in significant damage and a loss of load. The subsequent rolling stock recovery and track repair activities closed the line for five days. Emu Loop was not reinstated as a crossing location.
What the ATSB found
The ATSB found that rail creep readings within Emu Loop had been identified by V/Line as a Priority 2 defect – requiring prioritisation for rectification – and that this rectification had not been carried out by the time the derailment had occurred. The hot conditions of the day together with a latent rail creep condition contributed to the rails within Emu Loop assuming a state of longitudinal compression.
The track-train dynamics generated by the passage of 9130, even at the relatively low speed, in combination with the compressed state of the rail, produced lateral loads that exceeded the lateral resistance of the ballast, causing misalignment. The lateral misalignment was of a sufficient magnitude to result in derailment.
Due to the high forecast temperature, train speed restrictions and special track heat patrol requirements had come into force. Speed restrictions were met and a heat patrol was planned to be conducted over the length of line where the derailment occurred. However, as the train was in possession of an authority through the section, the patrol was not conducted ahead of the train.
What's been done as a result
V/Line is undertaking a review of the current procedure for managing Priority 2 rail creep defects. This will be completed by November 2015.
This derailment highlights the need for rail infrastructure managers to monitor and address rail creep conditions and track lateral stability, particularly prior to the onset of hot weather conditions.