Preliminary

Summary

Preliminary report released 12 September 2014

The occurrence

At 1355[1] on 14 May 2014, freight train 3WB3 entered the Nambucca Heads crossing loop. The route was set for a through movement via the loop because of trackside work being performed adjacent to the main line.

At 1404:20, the trailing wheel set of the leading bogie on wagon RCOF20375S derailed to the right-hand-side in the direction of travel while the train was travelling through the crossing loop at a speed of 21 km/h. The derailed wagon was located fourth from last in the 44 wagon consist.

The train continued to travel with a derailed wagon for about 1,397 m. It passed over two bridges and reached a speed of 44 km/h before wagon RCOF20375S tipped on its side (Figure 1). The train then parted between the fourth and fifth last wagons. As the wagons parted, the train brake pipe separated, allowing air to vent to atmosphere and the train brakes to apply, bringing the train to a stop in about 320 m.

The train crew notified the network controller and arrangements were made to begin investigative and restoration work. The main line was subsequently reopened at 1816 on 16 May. The crossing loop line remained closed until further repairs could be conducted.

Figure 1: Derailed wagon RCOF20375S

 RO2014007_Fig1
Source: ATSB

Context

The location

Nambucca Heads is located on the main north rail corridor between Sydney and Brisbane, about 565 track kilometres from Sydney Central Station. Nambucca Heads is a crossing location with a 1,615 m crossing loop.

Track information

The ARTC manages the railway corridor where the derailment occurred. Authorised movement of rail traffic is controlled from the ARTC’s Network Control Centre located at Broadmeadow, New South Wales.

The standard gauge[2] track at the derailment location consisted of 53 kg/m rail fastened by resilient clips to timber sleepers, spaced at about 667 mm centres. The sleepers were supported on a bed of ballast to a nominal design depth of 250 mm.

Approaching from the southern end, the track through the derailment site consisted of a series of curves between 480 m and 360 m radii on reasonably level track. The posted maximum track speed was 75 km/h although this speed would rarely be reached, due to the restriction of speed through the points.

On-site examination and preliminary analysis of track condition found no indication of any serious anomalies in the track geometry leading up to the point of derailment in the crossing loop.

Train information

Train 3WB3 was a steel products freight service operated by Pacific National between Wollongong and Brisbane. At the time of the derailment, the train consisted of two locomotives (NR94 leading and AN9 trailing) hauling 44 freight wagons. It was 817 m in length and had a trailing mass of 3,363 t.

The train was operated by two qualified drivers. They had both been assessed as fit for duty in accordance with the requirements of the National Standard for Health Assessment of Rail Safety Workers.

RCOF wagons are 15.1 m long and capable of carrying up to 80 gross tonnes at speeds of up to 80 km/h (depending on track speed limits). On the day of the derailment, wagon RCOF20375S (the wagon which derailed) was carrying 40 coils of rod, each weighing on average 1.5 t. The coils were arranged, two wide by two high, in each of the 10 bays (Figure 2). The coils were contained within the wagon, but they were not individually restrained.

On-site inspection and preliminary examination of the derailed wagons found no indication of any serious anomalies in rolling stock condition. Similarly, preliminary analysis of train data indicated that there were no anomalies in the train speed, train handling or operational performance leading up to the derailment.

However, evidence of load shifting had been observed in wagons not affected by the derailment, but carrying the same rod-in-coil product.

Figure 2: Loaded RCOF wagon on train 3WB3 carrying rod-in-coil product

 RO2014007_Fig2
Source: ATSB.

Ongoing investigation activities

The ATSB’s investigation is continuing and will focus on:

  • the integrity of the rolling stock involved
  • the possibility of load shifting en route
  • the policies and procedures relating the securing of loads
  • the integrity of the track structure


[1]    The 24 hour clock is used in this report. Local time was Australian Eastern Standard Time (EST).

[2]     The name given to gauge of  track of 1435mm