The tank cars involved in the Feb. 14 CN train derailment about 80 kilometres south of Timmins met the recently upgraded standards for new tank cars carrying crude and other flammable liquids, the Transportation Safety Board said in its preliminary findings.
But the cars — called Class 111 — still "performed similarly" to those involved in the devastating derailment and explosion in Lac-Megantic two years ago, which predated the changes, the board said.
In both cases, the board said, the tank cars ruptured and released crude oil, which fed the flames.
The agency said this month's incident, which affected passenger rail service between Toronto and Winnipeg, "demonstrates the inadequacy" of the new standards.
"We've pointed for years at the vulnerability of the Class 111 tank car and the board has called for tougher standards for some time," said Rob Johnston, TSB manager for the central region.
The new standards, implemented in January 2014, were meant as an "initial step" in improving the safety of the cars in the wake of the Lac-Megantic tragedy, he said.
"This was supposed to be the better car and it was important for us to really get a handle and understand how they performed under those circumstances," he said.
"There's more that needs to be done," he said. "Ideally, you want to see a more robust tank car to transport this product.
The agency is urging Transport Canada to quickly introduce enhanced protection standards to reduce the risk of spills when these tanks are involved in accidents.
TSB investigators looking into this month's incident found 29 cars derailed in a remote area, and at least 19 were breached, spilling crude. Seven cars caught fire, but the oil fed the flames, which eventually ignited 14 more cars, the board said.
The board estimates more than a million litres of product were released into the ground or atmosphere. It took six days to extinguish all the fires, it said.
A preliminary assessment found the train was travelling at roughly 60 kilometres per hour at the time, due to a speed restriction imposed because of the frigid -31 C temperature.
In comparison, the train that careened into the town of Lac-Megantic and levelled its downtown, killing 47 people, was travelling at roughly 105 kilometres per hour, the board said.
Johnston said speed — and how it affects the tank cars — is part of what investigators will examine during their probe.
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