At 0743 on 25 April 2001, the Countrylink XPT daylight service ST3 (train 8622) left Sydney bound for Melbourne. The train consisted of a lead power car followed by seven passenger cars designated from 'A' through to 'G' and a trailing power car. On board the train was a crew of five- the driver, a passenger service supervisor and three passenger attendants- and 127 passengers.
The run from Sydney south was routine. No problems were reported at the driver changeover in Junee at approximately 1354. At 1528 the train arrived in Albury where the passenger service supervisor and three passenger service attendants changed over. The train departed from Albury Station at 1532, approximately 30 minutes late, with 98 passengers on board.
After leaving Albury Station, the driver accelerated to 80 km/h and maintained that speed until approaching the Melbourne end of the Wodonga coal sidings, where he reduced the train speed to slightly below the 40 km/h posted speed. Shortly after this, the train passed the Hovell Street level crossing in Wodonga and continued to round the tight right-hand curve in the main line before the High Street level crossing. The train's speed was approximately 25 km/h. As the train entered this section of curve, the driver applied some power to maintain the train's speed through the curve.
At approximately 1538 at 301.1086 km, the inner wheel on the lead axle of the lead bogie (NHA 198B) of car 'E' (XF 2214) dropped from the low rail of the curve. At 301.105 km the inner wheel dropped completely from the low rail into the track fourfoot. The train travelled approximately 2.75 m further until the outer wheel on the same axle climbed over the high rail and onto the ballast shoulder on the outside of the curve. At 301.0911 km the trailing wheel-set of the bogie also derailed with the outer wheel climbing over the high rail and the inner wheel simultaneously dropping into the four-foot. The bogie, now completely derailed, travelled in this condition for approximately 950 m until the train was brought to a stop by the driver. The driver had stopped the train in response to a passenger emergency alarm which had been initiated by the passengers in car E.
The derailment occurred on the sharpest curve on the main line between Sydney and Melbourne. The alignment at this point in the main line was originally dictated by the presence of a crossing diamond where the broad gauge branch line to Bandiana had crossed the standard gauge main line. The alignment of the curve had not been changed since the closure of the branch line and the removal of the diamond in 1997.
Assessment of the track at the derailment site revealed a number of factors which contributed to the derailment, the most significant of which was the condition of the high rail fasteners which resulted in gauge widening of up to 49 mm at the point of derailment.
The derailment was unusual in some ways as there had been other freight and passenger train traffic on the line earlier in the day without incident. In addition, the derailment involved only one bogie in the middle of the train with bogies in the same train passing safely over the site before and after bogie NHA 198B had derailed. This indicates, that while the track-based elements were the primary causal factors, it was the combination of the vehicle-based and track-based factors that caused the derailment.
Inspection of the bogie which derailed revealed some factors which contributed to the derailment including a thin flange on the number-1 wheel and the poor condition of the bogie's side bearer yaw friction pads.
|Date:||25 April 2001||Investigation status:||Completed|
|Release date:||16 December 2002|
|Report status:||Final||Occurrence category:||Accident|
|Highest injury level:||None|