The mystery locomotive fire that touched off the Lac-Mégantic rail disaster was started by a broken piston in the train's engine, sparking a series of tragic events that led to the explosive derailment in the heart of the Quebec town, according to a preliminary investigation.
Until now, the reason the engine caught fire prior to the derailment had not been known. But the results of a preliminary investigation into the burned locomotive by Montreal, Maine & Atlantic Railway suggest the engine had a broken piston, which caused the fire. The problem caused unburned fuel to seep throughout the engine, resulting in smoke and sparks aboard the locomotive.
Once the blaze was extinguished, the train broke loose after fire crews switched off the engine, which caused the air brakes holding the cars in place to eventually fail. The Transportation Safety Board said not enough hand brakes had been set on the cars, as a backup to the air brakes, and the train rolled down a hill into town, where its crude oil cargo exploded, leaving 47 dead and ravaging the downtown.
Although MM&A is not involved in the TSB investigation of the disaster, "one of the last things that we were permitted to find out about is what happened to that engine that caused a fire on the engine," MM&A chairman Ed Burkhardt said in an interview. "The turbo charger in the exhaust manifold had a lot of unburned fuel oil thrown up into it because of this problem."
While the broken piston answers key questions about how the original fire began, it raises further questions about MM&A's responsibility in the disaster. In the days following the tragedy, Mr. Burkhardt alleged that MM&A's engineer failed to apply a sufficient number of hand brakes, which are located on each car to keep the train in place if the air brakes fail.
The new details open debate about whether the engine should have been turned off immediately, when the oil seepage was detected, rather than left running. Mr. Burkhardt said company policy dictates that the train should be shut down if the engine is smoking or sparking.
"There is no issue about how the train derailed," Mr. Burkhardt said. "[But] If you have an engine with a broken piston and it's shooting unburned fuel oil out of the exhaust stack, and things like that, and heavy sparking and all that, you don't leave it running."
In addition to the alleged actions of the MM&A engineer, the decisions made by the train's dispatchers on how to handle the problem may also come under scrutiny. The lawyer representing the train's engineer said the smoke from the locomotive was discussed with other officials at MM&A.
"There was a lot of smoke while he drove the train, and he reported that on arrival – they have to do that," said Thomas Walsh, the lawyer for MM&A's engineer, Tom Harding.
Mr. Walsh said he reviewed some tapes of the conversations between Mr. Harding and the dispatchers, and the issue of shutting down the train did not come up in the tapes he heard. The fire broke out after the engineer parked the train for the night and retired to a local hotel at the end of his shift.
"There was no question of them telling him to keep the locomotive running or otherwise," Mr. Walsh said. "My understanding is that as a matter of course, they keep them [the engines] running," to keep the air brakes operational.
MM&A was not carrying enough insurance to cover the disaster, which will run into the billions of dollars once lawsuits and cleanup costs are tabulated. The railway has since filed for bankruptcy protection from its creditors.
In the days after the derailment, MM&A placed substantial blame on members of the nearby Nantes volunteer fire department for shutting off the train's locomotives once the fire was extinguished, since it affected the operations of the air brakes. However, Mr. Burkhart's position now is that the engine should have been shut off as soon as the heavy smoke was noticed, before the fire was allowed to start.
The TSB has since called on regulators to write more prescriptive rules for parking trains, including the number of hand brakes that must be set as a backup to the air brakes.
The results of the TSB investigation into the crash are not expected for several months. René Verret, a spokesman for the director of criminal and penal prosecutions in Quebec, said his office is still waiting for a report from police on their investigation.
Mr. Verret said it is possible that police could choose to make arrests on their own. But he added that in complex investigations, police usually provide a report to his office first and then determine how to proceed. "No accusations can be taken against anyone [by the Crown] until we first receive the report," Mr. Verret said. "And then we take the time to analyze it and to decide if we're going to prosecute some people and what kind of accusation we will take."
The Sûreté du Québec had previously made it clear that it was looking for evidence of criminal negligence in the tragedy.
Editor's Note: An earlier online version of this story and the original newspaper version incorrectly referred to the brakes on the train as hydraulic, rather than air brakes. This online version has been corrected to reflect that terminology.