The Transportation Safety Board of Canada (TSB) reported on Thursday that the cause of the 2022 derailment of a Canadian National Railway Company train, just outside Huntingdon in the municipality of Godmanchester, was an incorrectly positioned switch.
The conclusion is the result of an investigation into the incident which took place just after 7 p.m. on December 11, 2022, when two head-end locomotives and six intermodal platforms left the track while travelling over a “switch point derail” linked to a radio-controlled switch system.
The train was being operated by a CSX crew in the Carr siding of the CSX Transportation Montreal Subdivision when it left the track. There were no injuries, and no cars carrying dangerous goods were involved in the incident; however, around 400 litres of diesel fuel were spilled from the locomotives. There was some damage to part of the siding and the main track at the derailment point.
A statement issued by the TSB clarifies that a “derail” switch prevents unauthorized movements or movements of unattended rolling stock from entering the main track. Once in position, the device is designed to derail any equipment that rolls over it.
The investigation determined that the locomotive engineer was distracted when he entered the code for the radio-controlled switch. As a result, the power-operated derail was not set in the correct position to allow the train to enter the main track.
The report alleges that the crew then misinterpreted visual and radio signals confirming the switch position, stating: “The train crew concluded that the auditory and visual confirmations issued by the power-assisted switch system corresponded to the required route for the train to leave the siding.”
The report notes that “Most radio-controlled, power-assisted derail switches linked to railway signals in Canada are equipped with a separate position indicator light and a reflectorized sign,” before pointing out the Carr siding was not equipped with either of these. The report also alleges the crew was unable to visually confirm the switch’s position due to the time of day and their distance from its position.
Data recorded by locomotive voice and video recorders (LVVRs) suggests the train was travelling at 22 miles per hour and accelerating before it left the track. There was no recorded effort on the part of the locomotive engineer to engage the emergency brakes. Train-initiated emergency brakes were engaged after the lead locomotive derailed.
In this case, the investigation discovered that data recorded by the lead locomotives voice and video recorders (LVVRs) did not include any voice recording from inside the cab, making it impossible to determine the verbal communications between the train crew members before the accident.
The lack of audio was related to the georeferencing system, which deactivates cab voice recording while the train is operating in the United States in compliance with U.S. regulations. The accident occurred so close to the Canada-U.S. border that the system prevented the activation of the cab’s microphones.
Patrick Sirois, a senior regional investigator with the TSB Rail/Pipeline Investigations Branch, was responsible for the investigation into the incident, which included work in the field to examine the derailment site and the wreckage, as well as interviews with witnesses.
The TSB does not assign fault or determine civil or criminal liability; the objective of the report is to advance transportation safety. As a result of the investigation, the TSB sent a letter to Transport Canada suggesting the functionality of voice and video recorders used by railway companies be verified to ensure they meet regulatory requirements.
Following the incident in 2022, CSX has confirmed to the TSB that the precise location of derail switches have been added to its Montreal Subdivision timetable, while also specifying the normal position of each one.