Skip to main content

An engineer checks the engine of a Montreal Maine and Atlantic locomotive outside the offices of MMA railway in the town of Farnham, Que., on July 11, 2013.Graham Hughes/The Canadian Press

Transportation safety officials have told Ottawa to rewrite train safety rules in the wake of the tragedy at Lac-Mégantic, Que., suggesting that Canada's current regulations are too vague and open to interpretation by railway workers that can lead to disaster.

In a pair of letters sent to Transport Canada, the federal body that oversees the rail industry, the Transportation Safety Board said more detailed rules must be created to govern the number of brakes that must be set when parking freight trains, and whether those trains can be left unattended when carrying dangerous cargo.

The letters come in the wake of the deadly accident involving a freight train operated by Montreal, Maine & Atlantic Railway loaded with crude oil. The train, which had been parked for the night, caught fire and rolled down a hill into Lac-Mégantic, where its cargo exploded, killing 47 people and demolishing more than 40 buildings. In the letters, investigators said the number of handbrakes activated on the train was "insufficient" to stop the train from careening down the hill.

When a train is stopped, a handbrake can be activated individually on each car to hold it in place. Estimates on the number of handbrakes required to immobilize the 72-car train vary from nine to 30, but MM&A's assessment is that only five handbrakes were activated by the operator the night of the derailment, MM&A chairman Ed Burkhardt has said.

The TSB said the rules governing the setting of brakes need to be more prescriptive, so that the decision on how many brakes to set isn't left up the interpretation of a rail operator, which could lead to miscalculations or human error. "The rule currently states that a sufficient number of brakes needs to be set; that's the problem with the rule," TSB manager Ed Belkaloul said during a news conference in Lac-Mégantic Friday.

In a report issued by the TSB in 2011, investigators warned that a similar runaway train incident in Sept-Îles, Que., was also caused by ineffective handbrakes. On Friday, Mr. Belkaloul said that the similarity between the accidents in Lac-Mégantic and Sept-Îles moved the federal investigators to issue the urgent warnings.

The TSB letter also called on Transport Canada to "review all railway operating procedures to ensure that trains carrying dangerous goods are not left unattended on a main track."

The call for new regulations comes as both the TSB and Transport Canada are conducting separate investigations of the crash site. Officials are collecting samples of oil from the rail cars to determine the exact composition of the crude inside. Sources close to the investigation say investigators are puzzled as to why the train erupted so quickly, causing several large explosions almost immediately after the crash.

The train cars were carrying the standard placards denoting their cargo was crude oil, which is considered flammable, but not necessarily explosive. Officials are probing whether the crude may have contained other substances that would have made it more volatile, since it is unusual for crude to explode so quickly after impact. However, the investigation is being slowed somewhat by large amounts of contamination around the site and in the air.

Police and fire crews have spoken of large pools of greenish benzene in the area. Two petroleum experts told The Globe and Mail it is unlikely the substance is benzene, which is clear in colour, but is likely large pools of crude, which could contain a host of potentially flammable chemicals including benzene. The existence of these pools, and the vapour around the site, have forced crews to work slowly to unsure further explosions don't occur.

Although explosions involving crude are rare, there are circumstances where a large fire outside rail cars can cause the liquid inside to boil and vaporize, increasing the pressure inside and forcing them to burst once the steel walls are weakened. It is unusual for these types of explosions to happen so quickly after a derailment as in the Lac-Mégantic accident, though it is not impossible. "Usually it takes a little bit of time before it happens," said Jean-Paul Lacoursiere, associate professor of chemical engineering at the University of Sherbrooke. If the composition of the crude oil inside is more volatile – containing agents that are more susceptible to explode – it could speed the process.

The accident has forced railways to review their operations. Canadian Pacific issued an internal bulletin last week announcing changes to its procedures to comply with a "pending order" on rail safety from Transport Canada. The bulletin, obtained by The Globe, lists four specific changes the company expected Transport Canada to introduce, including a prohibition against parking dangerous goods on a main track and a requirement for all rail companies to use handbrakes on trains that are left unsupervised for more than an hour.

A spokeswoman from Transport Minister Lisa Raitt's office said Friday that the department has been directed to review the TSB recommendations "on an expedited basis."