The crew of a Via Rail passenger train that derailed last year in Burlington, Ont., killing the three locomotive engineers, likely misread the light signals that ordered them to slow down for a track crossover, the accident investigation has concluded.
The Transportation Safety Board of Canada says however that, because of the lack of video or audio recorders, it will never know for sure why the train was going at more than four times its authorized speed while switching tracks.
"The absence of any attempt to slow the train indicates that the VIA 92 crew members expected to proceed at track speed," says the accident report, which was released Tuesday morning.
TSB chairwoman Wendy Tadros said the accident reinforced the board's past recommendations that trains be equipped with onboard video recorders and automated ways to stop trains, as already exist in the U.S. and Europe.
Similar misreading of freight and passenger train signals happen monthly, she told reporters at a briefing.
"About once a month, somewhere in Canada, there's a disconnect between what the signals display and the actions the crew takes. That's the risk and we need to drive the risk down," Ms. Tadros said.
In a statement, CN said it was working on a fail-safe automated train controls.
Positive Train Control (PTC) "is a technologically complex system that as of yet has not been proven in any large scale industry implementation … further deployment of PTC beyond the existing mandated rollout should not be pursued until we can fully validate the reliability and operability of the system," CN cautioned.
The transporter also said it was in discussion with its trade unions to find a way to implement video cameras in cabs.
The TSB report says that, at the time of the accident, on the afternoon of Feb. 26, 2012, the crew was experienced and rested and the locomotive, cars and tracks were in good condition at the time, as VIA Rail train No. 92 carried 70 passengers from Niagara Falls.
The Toronto-bound train had travelled less than two kilometres from Aldershot station when it changed tracks by entering a remotely controlled crossover switch.
The train was normally routed eastward on track 2, the middle of three parallel tracks. However, on that Sunday afternoon, a work crew had been dispatched to repair a hot-box detector on track 2. As a result, the rail traffic controller decided to route the train around the work crew by getting it to switch from track 2 to track 3.
The crew misperceived at least one of three light signals warning them to slow down for a track crossover.
The two engineers and one trainee at the controls in the locomotive cab had more than 80 years of combined experience, Rob Johnston, the TSB manager for Central region and headquarters, told reporters.
"It is much more likely that the signals were seen but misperceived."
Mr. Johnston said the crew might have been "strongly influenced by the expectation that they would continue on track 2, as they did, 99 per cent of the time."
The presence of the work crew ahead might also have distracted the locomotive engineers, he said.
"We will never know for certain" because of the lack of voice or video recorders, Mr. Johnston said.
The TSB has raised concerns for nearly a decade about the lack of voice recorders on Canadian trains. There are data recorders on the train but, unlike the case for airplanes, no voice recorder.
"If we don't fix it, this will happen again," Mr. Johnston said.
The track switches were lined to route the train from track 2 to track 3, at an authorized speed of 15 mph. The train however entered the crossover at about 67 mph, over four times the authorized speed limit.
The train and all five coach cars derailed. The locomotive engine at the front rolled on its side and slammed into a building next to the track.
In addition to 45 people who were injured, the derailment killed Patrick Robinson, 40, of Cornwall, and Ken Simmonds, 56, and Peter Snarr, 52, both of Toronto.
Mr. Simmonds and Mr. Snarr had over 30 years of experience. Mr. Robinson was a trainee but had previously conducted freight trains for Ottawa Central Railway, a subsidiary of Canadian National Railway.
Toxicology tests showed that one crew member, the locomotive engineer in charge, had alcohol in his urine. The TSB concluded that the alcohol had been consumed more than 12 hours before the accident and was not a factor.
Already, the TSB has issued two rail safety advisories. One asked Transport Canada to review operating procedures when higher-speed passenger trains were routed through slower speed crossovers.
The other advisory raised concerns about the sturdiness of the locomotive cab. In the Burlington derailment, the front nose of the locomotive cab collapsed and was seriously damaged, instantly killing the three men.