A new investigation report from the Transportation Safety Board of Canada (TSB) has concluded that a missed signal led to a collision between two Canadian Pacific Railway (CP) trains, injuring a conductor, nearly a year ago.

The accident occurred at 5:16 a.m. last Aug. 21 in north Toronto, according to the report, which was published on Aug 1. An eastbound CP freight train consisting of two locomotives and 24 loaded cars was travelling through the North Toronto Subdivision at that time and was crossing over from the north track to the south track; meanwhile, a westbound train with two locomotives was moving along the north track and hit the tail end of the eastbound train at the crossover.

Aside from the westbound conductor’s injury, the collision resulted in damage to four cars on the eastbound train, a spill of about 2,500 litres of diesel fuel from the fuel tank of the westbound train’s lead locomotive and several small fires.

The subsequent TSB investigation found that the westbound train had passed a signal that required the crew to stop before the next signal, but had failed to slow down. Because the westbound crew was distracted by train operation, reviewing a timetable and looking for a reported trespasser, the train could not stop in time before the crossover.

“Although both crew members carried a sleep debt and the [westbound] train was being operated during a period of low circadian rhythm, it could not be determined whether fatigue affected the crew members’ performance relating to signal recognition,” the report read.

The TSB noted that the lack of locomotive voice and video recorders on the westbound train had made it difficult for investigators to determine how the crew had interacted with each other at the time of the accident. “Without audio or visual recordings,” wrote the TSB, “it could not be determined with certainty whether the dynamics and interaction between the crew members, including potential distractions, contributed to the crew’s signal-recognition errors.

“If locomotive in-cab voice and video recorders are not installed on lead locomotives, there is a risk that valuable information that can lead to the identification and elimination of safety deficiencies will continue to be unavailable.”

The report also concluded that train-control systems must rely on physical defences as well as administrative defences to operate trains safely; otherwise, “signal-recognition errors may not be adequately mitigated, increasing the risk of train collisions and derailments.”

Re-familiarization with their designated territories is also necessary for employees who return to work after long absences, the TSB added.