Derailment of Coal Train DS212 departing Bloomfield Colliery Loop, Thornton, New South Wales, on 11 October 2004

Executive summary

At about 1345 on Monday 11 October 2004 freight train DS212, hauling 54 fully loaded coal wagons from the Bloomfield Colliery balloon loop, derailed approximately 300 metres north of Thornton station platform. The majority of the train passed through the crossing before seven wagons derailed over 103 and 104 points at the main rail corridor junction. Three of the derailed wagons tipped over fouling the Up¹ and Down² Coal Roads as well as the Down Main Line.

Thornton is located on the main northern railway corridor between Sydney and Brisbane, 182.2 kilometres from Central Railway Station, Sydney. Thornton is on the railway section³ between Broadmeadow and Maitland, prescribed as part of the Defined Interstate Rail Network (DIRN). The railway corridor contains four standard gauge lines, an Up and Down Coal Road, and an Up and Down Main Line.

The train crew tried contacting Broadmeadow Train Control Centre but were referred to Maitland signal box. The signaller at Maitland noticed the transit lights for the points flashing, indicating that the ‘points detection’ had been lost. The signaller immediately placed all signals in that location at stop and applied blocking facilities. An approaching passenger train 747 on the Down Main Line at Beresfield was stopped by signals before the section of fouled track. The track circuiting⁴ over the Down Main Line was not affected by the derailment.

To assist the investigation an independent railway engineering organisation, Interfleet Technology Pty Ltd, was engaged to inspect the track and train to determine what factors contributed to the derailment.

Other freight train traffic had traversed the line earlier in the day without incident. The first half of train DS212 passed safely over the site before wagon NHRH 50245C derailed. This indicated that although the track-based elements were significant causal factors, it was a combination of the vehicle-based and track-based factors that led to the derailment.

The investigation concluded that the derailment occurred as a result of gauge widening at about 182.527 km due to poor rail fastener condition, in between 104A points and 104B catch points which allowed the right wheel, in direction of travel, of the third axle on the trailing bogie of wagon NHRH 50245C to drop into the four foot⁵. The adjacent right wheel on axle number three rolled the high rail⁶ outwards.

Given the lack of awareness of the poor and deteriorating condition of the high rail stability, a derailment at this location was inevitable without remedial action.

A number of safety actions have been taken, or are underway, through the New South Wales Independent Transport Safety and Reliability Regulator, Pacific National, and the Australian Rail Track Corporation. These safety actions included: the inspection of all branch line turnouts/junctions used by Hunter Valley coal traffic; the implementation of a plan to remediate infrastructure identified as deficient and/or non-compliant; and the inspection of rollingstock for asymmetric wheel profiles. Of the eleven branch line turnout/junction sites inspected, one site was found to be deficient and/or non-compliant. Pacific National found one bogie with significant asymmetric wheel wear and four bogies in the early stages of asymmetric wheel wear, all were at the end of effective service life.

The report makes a number of recommendations on pages 33 and 34 relating to: track monitoring and maintenance; reviewing the effects of asymmetric wheel wear on lateral track forces and rail safety; and reinforcement of network rules and procedures regarding the protection of trains.

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1. An Up line or train is a line or train heading towards Sydney.
2. A Down line or train is a line or train heading away from Sydney.
3. See appendix 6.1 for an area map.
4. An electric circuit that uses the rails of a railway track as conductors such that a train electrically connects them via its axles. The absence or presence of this rail-to-rail connection indicates the absence or presence of a train or item of rollingstock.
5. A colloquial term used to describe the gap between the rails (laid at standard gauge of 1435mm).
6. The high rail is the outer rail of railway track in a curve.