At about 0730 (CDT) on 31 March 2015, intermodal freight train 2MP9 passed No. 1 signal at the southern end of the Mile End crossing loop (South Australia). The signal was displaying a ‘Calling on/Low speed’ indication. The train proceeded at low speed, but subsequently collided with the rear end of intermodal freight train 2MP1, which was stationary on the main line. The collision resulted in moderate track damage and the derailment of three wagons at the rear of train 2MP1. There were no injuries to train crews.
The ATSB determined that the signalling and communications systems were operating correctly and as designed. The investigation found that the driver of train 2MP9, on receiving a ‘Calling on/Low speed’ signal indication, proceeded at the prescribed speed of less than 25 km/h, but was unable to stop the train. The driver was aware that the operational rules stipulate that ‘block ahead may be occupied or obstructed’, but did not expect that train 2MP1 was stationary on the track so close ahead. As he approached train 2MP1, some stumpy vegetation and a low fence initially obscured his view of the empty flat wagons at the rear of the train. When the driver finally saw the rear of train 2MP1, he immediately made an emergency brake application, but was unable to stop the train before it collided with 2MP1.
The ATSB noted that the pathing of a train by a network control officer (NCO) onto a line occupied by a preceding train, when an alternate route is available and not obstructed, presents an elevated level of risk. Similarly, well thought out and clear communications between an NCO and crew of an approaching train, as to the proximity of a train occupying the track ahead, can significantly enhance situational awareness and reduce operational risk.
The Australian Rail Track Corporation (ARTC) and SCT Logistics have implemented a range of proactive strategies for enhancing the safe operation of train movements when entering an occupied section of track under a ‘Proceed restricted authority’ (PRA). This includes the use of all available infrastructure to reduce risk, encouraging communications between train drivers and NCOs where clarification of operational conditions is necessary, and a review of the National Train Communications System (NTCS) for the Adelaide area.
Train drivers should carefully consider their obligations when accepting a ‘Calling on/Low speed’ signal indication in relation to sighting constraints, train speed and occupation of the track ahead. In circumstances where sighting constraints may exist, drivers should consider requesting further information from the NCO before moving through the track ahead.
NCOs should carefully consider the pathing of trains under their control, and the communication of information that may mitigate collision risk when dispatching trains.