A record of the welds carried out at the 8.351 km point at Tottenham on the 30 January 2009 was not documented in accordance with the requirements of Civil Engineering Circular 3/87.
The section of track where train 6MB2 derailed, was previously utilised as the Tottenham standard gauge passing loop. It was not stress tested after slewing and welding when it was converted to mainline operation on 28 July 2008, 5 months before the derailment.
Regular monitoring and accurate measurement of rail creep was not carried out at the east end of the curve where train 6MB2 derailed in accordance with Civil Engineering Circular 3/87 - 70.2 and 70.3. Creep monuments were not installed on the east end of the curve following the work to convert the passing loop track to mainline operation in July 2008.
Punch marks were not made on the rail and documented with references to monuments at the 9 km mark following the realignment of track west of the Ashley Street rail bridge. This omission precluded the detection of rail creep that may have been present during the October 2008 maintenance inspection.
The ARTC Code of Practice at the time of the derailment did not categorise bolthole cracks as defects requiring action unless they exceeded 20 mm in length.
Examination of wagon RCPF31882C revealed a crack on the tread of a wheel on the second axle of the leading bogie. While not contributing to this derailment, if the crack were to develop to such an extent that the wheel tread completely fractured, the risk of derailment would increase significantly.
The trailing bogie of wagon RCPF31882C was found to have loose and broken wedge wear plates. It could not be verified whether the wedge wear plates had broken free before or during the derailment sequence. However, if the condition had existed prior to the derailment, it is likely that body roll induced while traversing a series of track irregularities could result in undamped harmonic oscillations.
The ARTC Code of Practice does not clearly address the possibility that a series of track irregularities, even minor ones which do not exceed intervention limits, could cause an undesirable harmonic response in some rail vehicles.
Manual systems of train management, such as Special Proceed Authority working, are used when interlocked/engineered systems are not available. However, manual systems are subject to human error and increase the risk of safeworking irregularities/incidents when compared to interlocked/engineered systems of safeworking.
There was no record to indicate that a worn section of rail, inserted into the track on 25 July 2007, was tested as being suitable for reuse as prescribed in the WestNet Rail Standard Gauge Mainline Code of Practice. The lack of construction and maintenance documentation compromises the ability to maintain railway infrastructure safely and places greater importance on adhering to mandated test procedures.
