There was probably no independent check of the isolation arrangements installed on the night of 29 November. An earlier internal audit of the project also reported instances of testers in charge checking their own work.
The safety actions undertaken by the Western Program Alliance and Alliance member Metro Trains Melbourne (MTM) should reduce the risk associated with this safety issue. The safety issue is categorised as partially addressed due to ongoing safety actions.
The Alliance advised that it took immediate proactive action by disseminating an MTM bulletin outlining explicit instructions regarding the Test & Commissioning Plan (TCP) and ensuring comprehensive awareness by all Alliance staff through pre-start and toolbox briefings.
The Alliance advised commitment to implementation of updated and new procedures developed post-incident, particularly those concerning independent checks. Examples of documents developed and implemented since this incident include the Signalling Testing Commissioning Inspection Procedure and the Testing and Commissioning Compliance Inspection Form.
Safety actions taken by Alliance member Metro Trains Melbourne (MTM) contribute to addressing this safety issue on WPA projects and are likely to benefit other projects involving MTM. Actions include the updating of the MTM project assurance framework and associated procedures, and active participation in the Signalling Strategy Taskforce.
