2008/01
Track misalignment causes derailment
29 January 2008
An ATSB investigation has found that a number of factors combined to cause the derailment of a freight train at Yerong Creek in southern NSW on 4 January 2006, any one of which may not have resulted in a derailment in its own right.
The Australian Transport Safety Bureau investigation into the derailment concluded that a track misalignment occurred as a result of localised stresses in the rail that had built up until the track moved as the train passed over it.
The track at this location, the main rail corridor between Melbourne and Sydney, has rails that have been welded into one continuous length, in accordance with modern international practice.
The investigation found that the track had not reacted evenly to the forces upon it, and that this had led to a fault in the track, in the form of excessive localised stress in the area of the misalignment.
The investigation found that such localised stresses are very rare, and difficult to detect, even with the best modern technology.
The ATSB acknowledges that both the ARTC and the NSW rail regulator have procedures in place to reduce as much as possible the risk of track stresses building up to the point of track instability.
The ATSB has issued a safety advisory notice to all track maintainers in Australia to highlight this limitation of present technology when managing continuous welded rail.
Copies of the report can be downloaded from the ATSB's internet site at www.atsb.gov.au or obtained from the ATSB by telephoning (02) 6274 7687 or 1800 020 616.
| 
