Queensland Rail did not have a procedure in place to cross-check a master circuit diagram with the existing configuration of the in-field equipment before using the diagram for safety critical work. This removed an opportunity to detect any error in master circuit diagrams.
The ATSB is satisfied that the action taken by Queensland Rail will ensure that any errors with a master circuit diagram will be identified prior to the installation of new equipment.
Safety action taken: Following the incident, the team lead electrician proposed a new procedure to check the in-field equipment wiring with the master circuit diagram during the planning process, before work commences. Queensland Rail subsequently introduced a new procedure, MD-18-366 GSS Part 13D Correlation of Signalling Records, to correlate the wiring as early as possible before installation.
Part 2.2 notes:
The prime causes for poor correlation between records and the physical wiring and equipment on site are:
• Inadequate record control when the original works were installed;
• Site equipment or wiring that has been altered without the corresponding source records being updated;
• Multiple schemes at the same location that have been installed in a different order to that for which they were designed;
• Works installed but never commissioned.
