The Microlok signalling program design does not meet the requirements of ARTC signalling standard SCP23 ‘Design of Microlok Interlockings’ in regard to the logging of internal bits that initiate flashing, pulsing or toggled outputs.
The voltage of signal JE02 was below the ARTC standard for the type of globe installed.
There was no RailCorp instruction that specifically referred to the need for train crew to prioritise tasks at safety critical locations or at times when workload is high.
The ARTC does not have a check list available for network controllers to assist in identifying risks associated with the verbal authorisation of train movements for an integrated yard.
Although the Australian Rail Track Corporation was not resourced to actively participate in the design or commissioning phases of the Cootamundra re-signalling project, greater involvement by the Australian Rail Track Corporation (local knowledge of site geography and layout) during these phases may have assisted the South Improvement Alliance engineers in detecting the design error.
The documentation and quality control processes used by the South Improvement Alliance for the Cootamundra re-signalling project were not sufficiently robust, in particular, the closing out of identified design issues was inadequate.
The South Improvement Alliance engineers did not effectively identify and record that the interface between CA74C and CA74D was the fouling point between the Up Main line and No.1 Platform Road and thus did not recognise that the rear of a train sitting on the Up Main line at this location would foul No.1 Platform Road. The design deficiency was caused by a long standing practice of not explicitly recording the clearance point on the Signal Arrangement Plan, Track Insulation Plan or in the Control Tables.
Where a design involves complex signalling arrangements, it may be beneficial to involve the designing engineer during the final onsite field testing phase as they have the best understanding of the interlocking principles. This places them in a strong position to identify any design omissions or deficiencies that may not have been evident during earlier phases of a project.
As the re-signalling of Cootamundra neared completion it became necessary to undertake control table and software development concurrently to meet the targeted commissioning date. Normally control table and software development is done sequentially to ensure that all the control table logic is fully reflected in the final software and associated validation/testing processes.
Where a signalling design has implicit safety requirements that need to be validated onsite, field testers should be provided with comprehensive check notes and/or clearly annotated information that ensures specific testing requirements are not omitted.
A design based on using a clearance point at the interface of CA74C and CA74D should not have been implemented until it was established that the clearance between the Up Main line and No.1 Platform Road at the interface of CA74C and CA74D tracks was adequate.
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.
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.
