News release

Today, the Transportation Safety Board of Canada (TSB) released its investigation report (R24C0012) into a 2024 main-track derailment near Brooks, Alberta (AB). 

On February 5, 2024, a Canadian Pacific Railway (CPKC) freight train was proceeding westward on the Brooks Subdivision when a train-initiated emergency brake application occurred. Upon inspection, it was determined that the trailing head-end locomotive had derailed as well as the first 17 intermodal rail cars. There were no injuries reported, and no dangerous goods were released.

The investigation determined that the train had to be stopped in Ontario the day before due to smoke emanating from one of the trailing head-end locomotive’s traction motors. In consultation with the supervisor mechanical (locomotive) (SML), the locomotive engineer cut out the affected traction motors and their associated speed sensor. The locomotive engineer was instructed to monitor the issue and the train continued on its trip. However, when recording the traction motor issue neither the locomotive engineer nor the SML made mention of the speed sensors in their respective fault logs. The next day, after several crew changes, the axle seized with the resulting damage to the wheel set causing a track failure and the subsequent derailment. 

The investigation also found that cutting out the speed sensor removed an important line of defence to protect against locked axle conditions. However, neither the locomotive engineer nor the SML fully understood the implications of this action. In this case, the SML was still completing his training modules and had not yet received training on the mechanical aspects of locomotives, which covers essential information for troubleshooting. Without this specific technical knowledge, he was unaware of the potential consequences of cutting out speed sensors.

Additionally, in 2014–2015, CPKC eliminated the central locomotive specialist position, which required in-depth knowledge of all major locomotive systems and many years of hands-on troubleshooting and repair experience. When the position was eliminated, SMLs assumed many of the responsibilities, however, their role is broader. When specialist duties are transferred to a position occupied by an individual that is not specialized in those duties, unless technical training, mentoring, and operational experience are provided to bridge the gaps between the two positions, there is an increased risk that these duties will not be performed to meet safe railway operations.

Following the occurrence, CPKC issued a bulletin to all locomotive facilities explaining the critical role of traction motor speed sensors. The bulletin further indicated that traction motor speed sensors can only be disabled in specific cases. CPKC also implemented a Mechanical Locomotive Support desk, a dedicated five-person team of operations support coordinators, which has taken over the locomotive troubleshooting responsibilities from SMLs.

See the investigation page for more information.