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What happened

On 26 November 2012, train 9104 was en route from Rankin Dam, near Coober Pedy, South Australia, to Pelican Point at Outer Harbor, SA, when it exceeded the limit of its movement authority at Tarcoola, SA.

The crew of train 9104 had been issued with an authority (TA 84) to travel from Northgate to Tarcoola, occupy the Branch Line and wait for train 1PA8 to pass and an opposing train 6WP2 to cross. Following the departure of 1PA8 from Tarcoola, the crew of the opposing train 6WP2 at Ferguson were issued with an authority to travel to Tarcoola, once 1PA8 had cleared into Ferguson. After the arrival of 1PA8 at Ferguson, 6WP2 departed for Tarcoola as authorised.

At about this time, the crew of train 9104 were issued a further authority (TA 94) to travel from Tarcoola to Ferguson. That authority was conditional upon first fulfilling the instructions contained in their current authority (TA 84; cross 6WP2 at Tarcoola) that had been issued some 2 hours earlier. On receipt of TA 94, the crew set the route and immediately departed Tarcoola towards Ferguson. When clear of the yard limit, the crew reported the departure to the Australian Rail Track Corporation Network Control Officer. The Network Control Officer, realising that there was a conflicting movement on the section (train 6WP2), directed both drivers to stop their trains. The trains came to a stand about 13.5 km apart.

What the ATSB found

The ATSB found that the crew of train 9104 departed Tarcoola yard before completing the cross with train 6WP2 and contrary to the instructions contained in the current train authority TA84. The ATSB concluded that crew error, miscommunication and some procedural weaknesses within the Train Order Working system had contributed to the incident. In addition, the driver of train 9104 was likely experiencing some level of fatigue impairment, probably due to reduced restorative sleep during a recent illness.

The investigation also found that the ARTC train communication system had not been working as designed. As a result, the crew of train 9104 missed a prompt as to the status of local train movements such as train 6WP2 approaching Tarcoola from Ferguson.

What's been done as a result

The ARTC has restored the broadcast feature of the voice communications system at Tarcoola. In addition, the ARTC has installed Centralised Train Control with colour light signalling between Port Augusta (Spencer Junction) and Tarcoola. Final commissioning of the signalling system occurred in June 2014, replacing Train Order Working as the primary safeworking system in that area.

The ARTC has also implemented a trial to address procedural weaknesses within the Train Order Working system. The Office of the National Rail Safety Regulator (ONRSR) is liaising with the ARTC in relation to concluding this matter.

Safety message

Each member of a train crew must ensure they use effective communication strategies to confirm their shared understanding of an authority and compliance with its requirements.

Train crew and rolling stock operators must implement adequate strategies to safeguard against fatigue impairment.

Network managers must ensure that communication protocols and verification procedures used in conjunction with a conditional proceed authority include controls sufficient to mitigate the risks associated with human performance.

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The occurrence


Safety analysis


Safety issues and actions

Sources and submissions


Safety issues

RO-2012-011-SI-01 - RO-2012-011-SI-02 - RO-2012-011-SI-03 -  

The management of fatigue impairment

SBR’s fatigue-management processes were ineffective in identifying the fatigue impairment experienced by the driver leading up to, and at the time of the occurrence.

Safety issue details
Issue number:RO-2012-011-SI-01
Who it affects:Rail operators and rail safety workers
Status:Adequately addressed


Communication of ‘safety critical information’

The ARTC communication protocols did not provide the NCO adequate guidance with respect to standardised phraseology to ensure messages are clear and unambiguous.

Safety issue details
Issue number:RO-2012-011-SI-02
Who it affects:Rail operators and rail safety workers
Status:Adequately addressed


The management of conditional proceed authorities

The procedures in the ARTC CoP for the use and verification of a conditional proceed authority were ineffective in mitigating the risk to the effectiveness of that authority arising from human error.

Safety issue details
Issue number:RO-2012-011-SI-03
Who it affects:Rail operators and rail safety workers
Status:Adequately addressed

General details
Date: 26 November 2012 Investigation status: Completed 
Time: 2148 CDT  
Location   (show map):Tarcoola Investigation type: Occurrence Investigation 
State: South Australia Occurrence type: Safe Working Irregularity/Breach 
Release date: 22 June 2015  
Report status: Final Occurrence category: Incident 
 Highest injury level: None 
Train details
Train registration: 9104S 
Type of operation: Freight train 
Sector: Freight 
Damage to train: Nil 
Departure point:Rankin Dam
Destination:Pelican Point
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Last update 14 November 2018