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Preliminary

Summary

The information contained in this Preliminary report is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the ongoing investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB's understanding of the accident as outlined in this Preliminary report. As such, no analysis or findings are included in this report.

The occurrence

At 2026[1] on 8 November 2014, train 735, a scheduled intermodal freight service conducted by TasRail as a driver only operation[2], departed from Burnie, bound for Rogerville (south of Brighton) in Tasmania. At 0300 on 9 November, there was a scheduled change of drivers at Conara Junction, with the new driver to take the train through to Rogerville.

Conara Junction is approximately 140 km from Rogerville by rail. Most of the journey is over rolling tablelands with gentle grades. The last 40 km of the journey includes the 13 km descent through Colebrook, with most of the descent having a posted track speed of 35 km/h due to the steep grades and tight radius curves.

Figure 1: Location map – Tasmania

RO-2014-020_Fig1

Source: NatMap Railways of Australia

The passage of the train from Conara Junction to Rhyndaston Tunnel at the top of the grade, was uneventful. At 0512, the driver of train 735 called Train Control to report that the train was clear of the Rhyndaston tunnel and commenced descending the grade under dynamic braking[3].

At 0516 the train crossed the level crossing at Mud Walls Rd at 30 km/h. The train’s data logger showed that shortly thereafter, the speed had dropped to 20 km/h and the driver disengaged the dynamic brake. As the train gathered speed, the driver then reapplied the dynamic brake, followed by the train [air] brake. The train continued to gather speed, reaching 64 km/h as it approached the curve located at the 65 km post. As the train negotiated the curve, the driver placed the train brake into emergency. At the exit of the curve both locomotives left the track and rolled onto their sides into the cess drain (Figure 2). All but the last seven of the train’s wagons derailed and most lost their cargo/freight containers.

Figure 2: Locomotive TR10 at the derailment site

 Figure 2: Locomotive TR10 at the derailment site

Source: ATSB

Events post-derailment

The TR class locomotives include a feature that automatically notifies train control if the driver makes an emergency brake application. Having received an alert that TR10’s emergency brake had been applied, the train controller attempted to call the driver of 735. The driver attempted to respond to the train controller’s call but was unable to locate the radio microphone in the overturned locomotive cab. The driver subsequently located a mobile phone and contacted the train controller to report the emergency. The driver was coherent but had sustained minor injuries.

The driver located the dangerous goods details for the train and exited the locomotive cab through an emergency exit[4]. The train controller commenced notifying emergency services and TasRail first responders, while the driver checked the train to ascertain the damage and the state of the various dangerous goods being carried as freight.

After it became evident that some dangerous goods liquids had been spilt, the Tasmania Fire Service was notified and dispatched to manage the spill.

Context

Location

The derailment occurred approximately 1 km north of Colebrook – about 40 km north of Hobart, near the 65 km post on the South Line in Tasmania. The South Line through this area runs in a north-south direction, forming a main arterial link between Launceston and Hobart.

Train and train crew information

Train 735 was a regular intermodal freight service that operated between Burnie and Brighton. The train consist comprised two locomotives at the head of the train (TR10 leading and TR07 trailing) followed by 16 loaded container wagons. The train had an overall length of 274.4 m and a gross mass of 1041 t.

Locomotives TR10 and TR07 were each equipped with data loggers and forward facing video cameras. The data logger and camera systems are used for recording train information such as date/time, speed, brake pipe pressure, throttle position, distance travelled and external imagery. Data from the recorders and video imagery were used by the ATSB in examining the sequence of events leading up to the derailment.

The driver at the time of the derailment had about 5 years train driving experience. The driver held the required qualifications to operate the train and had been assessed as competent to drive the route. Examination of the driver’s health assessment records confirmed that they met the required National Standard for Health of Rail Safety Workers.

Following the derailment the driver was tested for drugs and alcohol and returned zero readings.

Figure 3: Derailed Wagons on the right hand side of the track and wagons behind stacked on the track.

Figure 3: Derailed Wagons  

Source: ATSB

Examination of rolling stock

Examination of the derailed wagons and locomotives indicated that none of the derailed rolling stock had travelled far in a derailed state. The locomotive and the first six wagons had been cast to the right of the track and the next three wagons were stacked up on and about the track. Some containers from the train had separated from their wagons and were cast to the right of the track. The last seven wagons of the consist had not derailed and had retained their loads.

Initial on-site inspection of the rolling stock found no obvious defects or mechanical deficiencies that could have been considered contributory to the derailment.

Track Information

The Tasmanian South Line substantially comprised a bidirectional single track with crossing loops strategically located throughout its length.

The track through the derailment site was narrow gauge (1,067 mm) and consisted of 47 kg/m rail, fixed to concrete sleepers with resilient fastenings[5]. The track had been re-layed with new concrete sleepers about 1 year earlier.

The track leading into the derailment site was a set of reverse curves with a short tangent between the curves. The second curve was a left hand compound curve with a tight radius of 190 m, tightening further into a curve of 110 m radius. The grade of the track leading into the derailment site was downgrade about 2.4% (1 in 41) in the direction of travel. The posted track speed through this area was 35 km/h.

Examination of track post-derailment

Examination of the track identified a number of marks on the head of the right hand rail, consistent with wheels moving abruptly across, and running along the rail head. Clusters of sleepers had been damaged and pushed into bunches (Figure 4) adjacent to where the locomotives came to rest.

In the middle of the derailment site was a short transom-top bridge. The western side wing walls of both bridge abutments had impact damage, and apart from damage to the ends of a few bridge transoms, the track over the bridge appeared to be undisturbed.

Undamaged sections of track were measured for gauge, cant and curve radius. There was no evidence of track spread, and gauge widening was considered unlikely to have been a factor in the derailment. There was no evidence of any broken or fractured rail. The track structure surrounding the derailment site appeared to be well maintained and in good condition.

Figure 4: Sleepers pushed into bunches adjacent to locomotive TR10

 Figure 4: Sleepers pushed into bunches adjacent to locomotive TR10

Source: ATSB

Summary of initial investigation outcomes

The preliminary evidence available suggests that train 735 entered a 35 km/h speed rated curve, located at the 65 km post, at a speed of about 64 km/h. The train was unable to safely negotiate the curve at this speed. The leading wagons lost their containers to the right, one of which impacted the bridge abutments, before the locomotives and leading wagons overturned, rolling over the right hand rail. The remainder of the train was brought to an abrupt stop; causing further wagons to derail and some containers to be cast to the left of the track.

Ongoing investigation activities

The ATSB investigation is continuing and areas of focus will include:

  • The methods adopted for handling trains through the Colebrook area
  • Train braking performance
  • Factors affecting driver actions and performance
  • Effectiveness of driver training and accreditation processes
  • The track alignment and inspection requirements.


[1]     The 24-hour clock is used in this report and is referenced from Australian Eastern Daylight Time (EDT).

[2]     Driver only operation means there is only one person in the cab of the locomotive who is responsible for the operation of the train.

[3]    Use of the locomotive’s traction motors to effect braking. The traction motors become generators and the power generated is dissipated as heat through fan cooled resistor grids in the locomotive.

[4]     The windscreens of the TR class are designed to be removed as an emergency exit.

[5]     A fastening that provides a degree of elasticity between the sleeper and rail with the aim of avoiding the loosening of the fastening due to vibration, as well as enhancing the ability of the fastening system to resist longitudinal creep forces and buckling forces associated with continuously welded rail (CWR).

 
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