Atsb transport Safety Report

Locations where trains have higher incidence of overrun

Many of these records of events contained evidence of poor track adhesion due to wet weather or track contamination. For the period January 2010 to January 2013, investigation records for IMU and SMU class trains found the event causes were ‘Human Contributed’ (59%), ‘Low Adhesion’ (33%) and ‘Rolling stock Contributed’ (8%).

For the month of January 2013, immediately before the collision at Cleveland, there were 25 investigated occurrences where low adhesion was cited as the event cause. There were 19 occurrences where ‘human contributed’ was listed as the cause and five of these had observed that wet track was a contributing factor.

These investigations were conducted by supervisory or investigation staff who would interview the train driver and occasionally the guard and other involved persons. In most instances the investigator was a TMIO who interviewed the train driver. For the majority of these investigations the TMIO would only provide advice to the driver on how to adjust and improve their driving and braking technique to reduce the likelihood of train slides when stopping at station platforms and signals. A review of the TMIO notes and findings found where the track was contaminated with leaves and moisture, the TMIO did not offer an explanation or provide training to the driver on why contamination to the rails may have adversely affected the driver’s ability to slow or stop the train while braking under these conditions.

Where drivers were unable to stop their train before overrunning the platform by less than six car lengths, approval was sought from the network controller to set back onto the platform to allow passengers to board and alight. Where a train was set back onto the platform a Special Proceed Authority (SW10) was issued to the driver to complete the move. Where SW10’s were issued, delay times to the service were recorded, usually ranging between 1 and 6 minutes. Occasionally, where a train had exceeded the platform stopping point by more than six car length’s the network controller would recommend the train driver continue to the next station.

Figure : All passenger train overruns at station platforms (alphabetical order) March 2010 to January 2013

An assessment of overrun data was made to discover if particular train types had a higher incidence of slide occurrences when stopping at railway stations and whether individual locations showed a higher number of occurrences (Figure ) for trains that were predominantly fitted with disc or tread brakes. The overrun occurrences involving the IMU160 and SMU260 classes were compared with the other train classes in the Queensland Rail Citytrain fleet for the period 8 March 2010 to 12 February 2013.

The findings exclude station locations where there were less than three train overrun occurrences and trains where the class type was not identified.

Figure : Incidence of passenger train overruns by station location

The assessment included a review of aerial photographs showing vegetation growing along the railway corridor on the approaches to each of the station platforms to discover if leaf fall may have contributed to overrun occurrences.

Typically, the top 10 locations where trains had overrun station platforms were found to have vegetation growing next to, or overhanging the railway corridor, and were within the train braking zones on the approach to these stations. Figure shows the topography either side of railway stations recording the greatest number of overruns for the period.

Figure : Railway station locations recording a high incidence of train overruns where trackside vegetation on the approaches was identified.

The results showed the IMU160 and SMU260 class trains had higher incidence of station overruns at Lindum, Ormeau, Coopers Plains, Canon Hill and Wacol. Most locations included overruns by the other classes of trains except Canon Hill and Wacol where the IMU160 and SMU260 classes were solely represented. The remaining 23 station locations that recorded a lower number of overrun events with other classes included 13 stations that did not have the IMU160 and SMU260 class represented. Where there were three or more overrun occurrences recorded at these railway stations for this period, 163 involved the IMU160 and SMU260 class and 101 were by the other train classes.