Rail safety investigations & reports

Signalling irregularity involving train DP41, Eagle Junction, Queensland, on 23 September 2018

Investigation number:
RO-2018-020
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

Download final report
[Download  PDF: 700KB]
 

What happened

On 23 September 2018, during planned signal maintenance work, a wayside signalling system irregularity occurred where signal EJ45 at Eagle Junction, Queensland displayed an incorrect authority to an approaching train (DP41). The authority from signal EJ45 was invalid for the positioning of the 705 points ahead. Both the driver of train DP41 and a signal electrician noticed the irregularity, and reported it to the network control officer at the Mayne Control Centre. The network control officer directed the driver of the train to remain at the Eagle Junction platform. A short time later, another train (DG44) approached and crossed over the conflicting route. The actions of the driver of DP41, network control officer, and signal electrician identifying the irregularity and stopping the train mitigated the potential for a collision to occur.

What the ATSB found

The ATSB found that, following replacement of the 705C points machine, a fault was detected. The fault resulted in a mismatch between the position of the 705 points set, and the signal indication at the station (EJ45) and the Universal Train Control System display used by the network control officer. Despite not understanding the nature of the fault, for undetermined reasons, control of the 705 points was handed back to the network control officer. As such, train DP41’s route was set for the Airport Line, although the points were directed to the Doomben Line.

The new 705C points machine had been pre-wired in accordance with the Queensland Rail master circuit diagram. However, the diagram contained an error and did not reflect the wiring configuration of the old points machine, which had been functioning correctly until replacement. This error lead to signal EJ45 displaying an incorrect authority.

Queensland Rail did not have a process in place to check the master circuit diagram with the existing configuration of the in-field equipment before using the diagram for safety critical work.

What's been done as a result

Queensland Rail have introduced a procedure requiring correlation between the in-field signalling equipment and the master circuit diagrams before being used for safety critical work.

Safety message

The incorrect wiring configuration led to the signal interlocking system safeguards being circumvented. This incident highlights how accurate and up-to-date engineering documents that correlate with in‑field equipment are fundamental to the effectiveness of an engineered interlocked signalling system to maintain train separation.

Download final report
[Download  PDF: 700KB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Safety Issue

Go to RO-2018-020-SI-01 -

No procedure to cross-check master circuit diagram

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.

Safety issue details
Issue number: RO-2018-020-SI-01
Who it affects: Rail metropolitan passenger
Status: Adequately addressed
General details
Date: 23 September 2018   Investigation status: Completed  
Time: 1543 AEST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): Eagle Junction   Investigation phase: Final report: Dissemination  
State: Queensland    
Release date: 05 June 2020   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator Queensland Rail  
Train operator Queensland Rail  
Train registration DP41  
Type of operation Passenger  
Sector Passenger - metropolitan  
Damage to train Nil  
Departure point Varsity Lakes, Queensland  
Destination Brisbane Airport, Queensland  
Last update 05 June 2020