A Via Rail passenger train derailed in eastern New Brunswick in April 2019 because of a weakened rail that broke beneath the train, the Transportation Safety Board of Canada concluded from its investigation.
No serious injuries resulted from the derailment in Coal Branch, about 40 kilometres northwest of Moncton, but the independent transportation watchdog is troubled because the corrosion of the track at the crossing in question went undetected in previous inspections.
In its final report on the incident, released Wednesday, the board has recommended Transport Canada change its inspection guidelines.
Dennis Church, senior investigator of the board's rail and pipeline branch, said there could be other low-traffic crossings with compromised rails.
"The possibility does exist and we're concerned there could be the consequence of another derailment," Church told Shift New Brunswick.
The last two cars of the train travelling between Montreal and Halifax derailed at the Lakeville Road crossing around noon on April 4, 2019. There were 94 passengers and 15 crew members onboard, three of whom were assessed for minor injuries on site, the report said.
Salt, sand corroded rail
The investigators determined the web of the rail at the crossing had "thinned due to corrosion," where it could no longer support a train. The web is the thin middle section of the rail that connects head and foot.
"During our laboratory analysis, it was revealed that there was salt and sand that had been transferred from a nearby highway through normal traffic conditions that had been deposited inside the crossing structure and proceeded to corrode the rail," Church said.
The report said crossings inherently retain moisture and road debris and, as such, are more susceptible to corrosion.
Church said there are no regulatory provisions under Transport Canada rules for this type of corrosion to be inspected. He said the situation is a rare occurrence since the rail is usually replaced for wear and tear reasons before serious corrosion could occur.
That may not be the case at low-traffic areas, like the Lakeville Crossing, he said.
The corrosion at the crossing also went undetected during routine inspections because it's hidden by the crossing surface, the report concluded.
The Transportation Safety Board is recommending Transport Canada amend its inspection policies or implement different technology during inspections that could detect hidden corrosion.
The report said visual and ultrasonic track inspections at the crossing did not reveal the weakened rail.
Transport Canada said in a statement to CBC News on Wednesday railway companies are responsible for the safety of rail line infrastructure and operations.
"This includes ongoing inspections, testing, and maintenance programs in accordance with regulatory requirements, as well as any particular operating and environmental conditions," said spokesperson Sau Sau Liu.
The federal department will ensure the Railway Association of Canada and its members are aware of the report's conclusions and concerns for the effect of road salt on at crossings.
The statement said: "Transport Canada will engage with the Railway Association of Canada to draw attention to this finding and the need for railways to ensure that their inspection practices are reviewed and modified, as required, to prevent similar occurrences."