Final Report


What happened

At 1159 on 24 November 2014, freight service 4190 passed Signal 66.8 while it was displaying a stop aspect and without an authority[1]. Signal 66.8 is located in the section between Wyee and Warnervale on the NSW central coast. The SPAD represented a breach of the Network Rules and Procedures involving the use of Absolute Signal Blocking (ASB) that had been granted as part of worksite protection arrangements for a workgroup conducting electrical maintenance tasks at Warnervale. The Protection Officer for the workgroup was granted ASB shortly after there was a change in the Network Control Officers (NCO) at Morisset, from where the signals protecting the section were controlled. Although assurances were given to the PO that the section was clear, two trains were still travelling between the protecting signals and the worksite at the time ASB was implemented. The first train passed the worksite shortly afterwards without incident. The second, travelling some eight minutes behind, came to a stand approximately 1,300 metres before the worksite after the driver reacted to a signal returning to stop in front of the train. The signal had returned to stop because of electrical testing being conducted as part of the maintenance tasks. Its return to stop also (fortuitously) prevented the train from entering the worksite and potentially injuring the workgroup members.

There were no reported injuries or infrastructure damage as a result of the incident.

What the ATSB found

The ATSB found that when the NCOs changed over at Morisset, there was a breakdown in the handover process. This breakdown resulted in ASB being granted to the PO at Warnervale without the exact location of trains being established, signals V8 and V6 being set back to stop and blocking facilities applied in accordance with Network Rule NWT 308. At the time of this incident Sydney Trains was trialling a modified ASB methodology to address previously identified safety issues, however this trial had not been extended to Morisset. If it had been, the progress in granting ASB would have been documented and would have assisted the NCOs during the handover process.

What's been done as a result

Sydney Trains advised that it has expanded its trial of the ‘Coded Authorisation Process for Absolute Signal Blocking’ to include signal box locations on the Main North Line between Gosford and Broadmeadow. It further advised that, upon completion of the trial, the Network Rule and Procedure for Absolute Signal Blocking will be rewritten to improve its readability and application.

Safety message

This incident illustrates the criticality of minimising interruptions and distractions that may affect the process for the granting or authorisation of work on track authorities, particularly Absolute Signal Blocking. Similarly, it reinforces the importance of information and situational awareness exchange between personnel during the handover process for the control of dynamic rail network operations.



  1. Signal passed at stop without authority is also referred to as ‘Signal Passed at Danger’ or ‘SPAD’.

The occurrence


Safety analysis


Safety issues and actions

Sources and submissions