The Transportation Safety Board examined the complex series of events leading to last year's derailment in Lac-Mégantic that killed 47 people. The events included a faulty repair on the lead locomotive's engine, a lack of sufficient handbrakes, weak safety training for Montreal, Maine & Atlantic staff and a failure of federal oversight. Here's a timeline based on details in the 191-page report.
Engine Repair: About nine months before the accident, MM&A performed a low-cost "non-standard" repair on the engine in the train's lead locomotive. The repair used a material that wasn't strong enough for the job and eventually failed, leading to a series of other problems in the engine and an accumulation of oil in the turbocharger and exhaust manifold.
Engine Troubles: Two days before the crash in Lac-Mégantic, an engineer reported trouble with the locomotive's engine on a separate trip. Despite that concern, the locomotive was put at the head of the train bound for Nantes on July 5, 2013. Engineer Tom Harding noticed that the engine was surging, making it difficult to keep up a consistent pace. By the time he arrived in Nantes, it was spewing smoke and oil droplets – his taxi driver noticed them landing on the cab's window. Mr. Harding discussed the issue with a rail traffic controller in Bangor, Me., but both agreed to deal with the matter the next morning. The locomotive was left running.
Insufficient Brakes: Mr. Harding set just seven hand brakes – far fewer than the number that would have been required to keep the 1.4-kilometre train in place on the hill where it was parked if the main air brakes failed. TSB testing found that the minimum number of hand brakes set out by a company chart – nine – wouldn't have been enough on their own either. Instead, investigators say between 18 and 26 hand brakes on cars and locomotives would have been needed to hold the train if the air brakes failed. Other locomotives, with systems that could automatically restart in a brake failure, were also shut down. The TSB said the railway didn't give staff enough training.
The Main Track: The engineer left the train idling on the main track, rather than pulling it into the siding that ran parallel . The TSB found that this had been MM&A's standard practice for several months because it kept the siding free for storing other rail cars that weren't in use. The practice was not prohibited or questioned by government. Had the train been parked on the siding when it began rolling forward, it would have hit a derail device that should have prevented it from continuing downhill to Lac-Mégantic.
The Fire: A fire broke out on the lead locomotive about an hour after the engineer left. When firefighters extinguished the fire and shut down the locomotive, no other locomotive was started – leaving the air compressor off and the air brakes slowly leaking. The "reset safety control" system was not wired to set the entire train's brakes in the event of an engine failure, the TSB found. The pressure in the air brake pipes was roughly 95 psi at midnight that evening. About an hour after the train was shut down, it had dropped to 27 psi. The train started rolling, derailing 17 minutes later 11.6 kilometres away.
The Derailment: By the time the train reached a curve in the track in Lac-Mégantic, it was travelling at 105 km/h, more than triple the typical speed at the location, according to the train's event recorder, akin to an airplane's blackbox. The locomotives made the turn, but the tank cars had a higher centre of gravity and derailed. There was now no pressure in the air brakes . The report found that "speed was the major contributing factor in the derailment," with investigators saying the train likely derailed around the sixth tanker car. The ensuing pileup left about one-third of the tanker cars with large breaches.
The Oil: The train was carrying "highly volatile" oil from the Bakken region that straddles North Dakota, Montana, Manitoba and Saskatchewan, and the level of hazard "had not been accurately documented" by the railway, the report found. A boom in shipping such oil by rail has "significantly increased the risks," it found. The amount of oil, its low viscosity and high volatility all allowed it to spill, spread and ignite quickly, triggering fireballs and a fatal fire in the heart of the town. The TSB concluded MM&A didn't do enough to identify and manage risks on the railway and cited the company's "weak safety culture."
Transport Canada: The federal regulator knew of "significant operation changes" at MM&A, but didn't offer "adequate regulatory oversight," the report found. Transport Canada also "did not follow up" to ensure the "recurring safety deficiencies" were dealt with. "Consequently, unsafe practices persisted," the report found. Transport Canada also carried out audits of MM&A's safety management system, but the audits were limited in frequency and scope and had no followup procedure.
With a report from Josh Wingrove in Ottawa