Findings from TSB investigation R23D0108: November 2023 train collision in Montréal, Quebec

Investigations conducted by the Transportation Safety Board of Canada (TSB) are complex since an accident rarely results from a single cause. In the case of the November 2023 train collision in Montréal, several factors led to the accident. The five findings below detail the causes and contributing factors that led to this occurrence. Additionally, the TSB made two findings as to risk and 3 other findings.

Findings as to causes and contributing factors

These are conditions, acts or safety deficiencies that were found to have caused or contributed to this occurrence.

  1. After the emergency brakes were applied on train CN 376, it collided with the tail end of commuter train EXO 1212, which was stopped at Saint-Léonard-Montréal-Nord station. At the time of impact, train CN 376 was travelling at 32 mph.
  2. Before the collision, train CN 376 had entered the same block as train EXO 1212, having passed a Restricting signal (signal 1349E) limiting its speed to 15 mph until the next signal (signal 1363E).
  3. The emergency brakes on train CN 376 were applied when the train was travelling at 26 mph above the maximum allowable speed and was 514 feet from train EXO 1212, which did not leave enough time to stop train CN 376, and it struck the tail end of EXO 1212.
  4. The crew of train CN 376 likely assumed that the block governed by the Restricting signal indication (signal 1349E) was clear and expected the next signal (signal 1363E) to become permissive for their movement. Therefore, the crew increased the train’s speed to 41 mph.
  5. Due to the ambient lighting conditions at the time of the occurrence, the tail end of train EXO 1212 stopped at the Saint-Léonard–Montréal-Nord station became visible to the crew of train CN 376 only when the locomotive lights were set to full power, just over 500 feet from the other train, which was an insufficient distance to avoid the collision given the train’s speed.

Findings as to risk

These are conditions, unsafe acts or safety deficiencies that were found not to be a factor in this occurrence but could have adverse consequences in future occurrences.

  1. If train control systems rely solely on administrative defences, there will be no automatic intervention to stop trains if train crews fail to follow signals or misinterpret them, increasing the risk of accidents.
  2. If safety-critical equipment on board passenger trains becomes inoperative following an accident, implementing the necessary emergency measures could be compromised, affecting the safety of passengers and onboard personnel.

Other findings

These items could enhance safety, resolve an issue of controversy, or provide a data point for future safety studies.

  1. Following the collision, the structure of car EXO 3062 performed within its design parameters.
  2. The video and voice recording system cameras on the lead locomotive of train CN 376 had been obstructed and therefore could not capture video images from inside the cab, which limited the analysis of the crew members’ activities in the minutes leading up to the occurrence.
  3. Transport Canada’s approach to compliance verification could affect the reliability of inspection and verification results, thereby reducing the likelihood of identifying potential safety deficiencies.