The Transportation Safety Board of Canada (TSB) released its final investigation report on Wednesday into the Canadian National (CN) train derailment of Canadian National freight train A47151-05 near Squamish, British Columbia, on August 5, 2005.
The report sites a number of contributing factors, including, "safety deficiencies in the Canadian railway transportation system", CN's operation of long trains in the Squamish Subdivision "without adequate consideration of the value of retaining and using local knowledge and experience in the operation of long distributed power trains", and "lack of training and proper supervision" of railway personnel.
Long trains are marshalled (assembled) using a variety of strategies to ensure that tension, weight, and other characteristics are appropriately distributed and maintained along the length of the train. This long train was a Distributed Power (DP) train, meaning the power component consisted of lead locomotives at the head, and remote-control locomotives in the middle of the train. Effective marshalling and power distribution can mitigate the risk associated with longer trains and challenging terrain.
The lead locomotive (the locomotive from which the crew operates) did not have on-board instrumentation to provide crew members detailed information about the status of the remote locomotives. The second locomotive did have appropriate technology on-board, but of course that doesn't help when the crew is in a different locomotive. The previous crew, which operated the train out of North Vancouver, received Distributed Power trouble alarms, but for some reason did not advise the Squamish crew of those alarms. If the previous crew had access to more detailed information about the status of the remote engines (which the second engine could have provided) they may have responded differently, but even without that additional information they should have been alerted to a potential problem with the remote engines. In any event, the Squamish crew that was operating the train at the time of the incident was unaware of the alarms.
Nevertheless, the train's behaviour led the Squamish locomotive engineer to test, then conclude, that the mid-train remote engines were effectively non-functional. From that point the train should have been operated under the more restrictive requirements for conventional trains. As the report states, "A 6700-foot DP train would have no difficulty ascending the grade between Cheakamus and Mons. A conventional train was restricted by bulletin and could not achieve such a train length and still comply with the instructions" (emphasis my own).
When the terrain is flat and the track is straight, having lead locomotives do all the work isn't necessarily a problem. However on this stretch of rail - with sharp corners and differences in elevation - a combination of "pull" from the front and "push" from the middle are necessary to help cars follow the track around corners, rather than through them. With only the lead locomotives pulling from the front, northbound Canadian National freight train A47151-05 stringlined the curve at the accident site (at right), meaning that some of the cars climbed the rail on the inside of the curve because the train was being pulled straight like a string.
Background
After it acquired the former BC Rail system (including the line on which the accident occurred) in 2004, CN moved to improve efficiency by running fewer, but longer trains. Longer trains with remote locomotives are operationally more complex, so CN devised a work process that involved contacting one or more of four road foremen should problems with remote locomotives be encountered while a train was en route. The Transportation Safety Board report describes as these road foremen as,"long service, experienced supervisors responsible for providing training and technical advice on train handling and engine service problems to locomotive engineers". However, the report goes on to describe that, "all four people in the road foreman positions left BCR shortly after the CN acquisition". There is now a single road foreman position in place. The report does not indicate whether the crew operating the train at the time of the accident notified either CN operators or the road foreman once they realized that the remote engines were not loading.
Bad Judgement Loves Company Too
It's obvious that relevant expertise was lost after CN took over BCR, and if that expertise had been brought into the developing situation the derailment and the devastating environmental damage it caused could have been averted. So that covers 1). training and, 2). retaining and using local knowledge. But what about the deficiencies inherent in the "Canadian railway transportation system" identified by the report?
The report states, "it is not the function of the (Transportation Safety) Board to assign fault or determine civil or criminal liability". However, in respect to "safety deficiencies in the Canadian railway transportation system", one might conclude that the risks associated with running long distributed power trains through challenging terrain in the Squamish Subdivision were not adequately assessed.
The Railway Safety Act states, "When a risk assessment is carried out by a company before a major operational change, there is no requirement for the company to provide the risk assessment to Transport Canada (TC)". However, section 1.8 of the report indicates:
No formal risk assessment was performed before CN's decision to operate DP trains, although TC agreed that operating one train per day made the overall system safer as it would minimize the possibility of conflict with the passenger service between Lillooet and Darcy.
Since BCR had operated DP trains in the past according to train handling instructions approved by the former provincial regulator, the British Columbia Safety Authority, CN decided that no formal risk assessment was required when it resumed running DP trains over the territory.
While BCR had operated DP trains in the past, it had discontinued the practice prior to the acquisition by CN. A lay reading of the report suggests that considering CN's failure to retain experts familiar with the challenges of running long, complex trains through the Squamish subdivision, either CN or Transport Canada should have recognized the need for a risk assessment.
A risk assessment might have identified training deficiencies that result in poor situational assessments, and the need to make crews aware of an escalation pathway they should use to seek guidance from an expert when dangerous conditions - such as the failure of remote locomotives - occur. One might guess that an experienced road foreman would have advised this train to simply stop where it was, rather than continuing on its way with only lead engines engaged.
To share your thoughts with Right Up Your Alley: Kamloops readers, click on "Comments" (below).
Recent Comments