Ep 79 Lac Megantic Rail Disaster

Engineering News – Underwater LIDAR Prototype (1:20)

This week's engineering failure is the Lac Megantic (5:10). 10 years ago, a train traveling from Montreal (9:40) derailed in downtown Lac Megantic and changed the town forever (22:20).


Engineering News

Lac Megantic Rail Disaster

Episode Summary

Hi and welcome to Failurology; a podcast about engineering failures.  I’m your host, Nicole

And I’m Brian. And we’re both from Calgary, AB.

This week in engineering news, a lidar prototype that can acquire 3D images under water.

        Researchers at the Royal Academy of Engineering at Heriot-Watt University in the UK have developed a prototype lidar system that uses quantum detection technology to acquire 3D images while submerged underwater.

        Since the system is highly sensitive, it can be used to capture information about low light areas underwater.

        There is limited light underwater and any particles can distort the images.

        As a person who often tries to take photos on dusty construction sites, I can confirm that dust also does the same and it's really hard to get good pictures.

        But the quantum based technique, which uses single-photon detection, allows high penetration and works in low light conditions.

        Lidar, which stands for LIght Detection And Ranging, creates images by measuring how long it takes laser light to bounce of the objects in the field and return back to the receiver,

        Kind of like how bats use echo-location, except with lasers.

        The system requires thousands of detectors producing hundreds of events per second, which was challenging to retrieve and process. So researchers developed algorithms for high scattered conditions and applied them with graphics processing hardware.

        The system was submerged in a tank with a scattering agent for testing and was able to achieve successful results at three different turbidity levels.

        They are now working to make the system smaller so that it can be attached to underwater vehicles.

        If you want to read more about the study, check out the link on the web page for this episode at failurology.ca

Now on to this week’s engineering failure; the Lac Megantic Train Disaster.

        Lac Megantic is a town in Quebec Canada, located about 200 km east of Montreal, 150 km south of Quebec City and 25 km north of the Canada-US border between Quebec and Maine.

        The town was a tourist destination and produced forestry products, furniture, Masonite doors, particleboard, and architectural granite up until the rail disaster which we will get to shortly. It’s about 100 km east of Asbestos Quebec, which has been renamed Val-des-Sources; and while they did not necessarily process or manufacture goods with asbestos in Lac Megantic, the area appears to have been a hot spot for making construction materials.

        Lac Megantic has a population of between 5000-6000 people and a land area of 25 km 2. It was settled in 1884, which is the same year Calgary was incorporated as a town.

        The town is situated on Lac Megantic, or Megantic Lake, where it gets its name. Megantic is an Abenaki word namesokanjik (na-may-so-can-gic) meaning place where the fish are held, dating back to the indigenous peoples who originally inhabited the area. The lake has a surface area of 26 km 2, just a little larger than the town itself, and is located in the Appalachian Mountains, which run from Georgia in the SE US up to Quebec.

Rail Disaster

        On July 6th, 2013 (10 years ago) at 1:15am local time, an unattended 73 car Montreal, Main and Atlantic Railway (MMA) freight train, carrying Bakken Formation crude oil, rolled down a 1.2% grade hill from Nantes and derailed downtown, resulting in the explosion and fire of multiple tank cars. The initial reports describe a 1km blast radius.

        At least 30 buildings, representing half of downtown, were destroyed, and 47 people were killed. During the cleanup, due to petroleum contamination, only three of the 39 buildings left standing were allowed to remain.

        This is the fourth deadliest rail accident in Canadian history and the deadliest involving non passenger or freight trains. The other three accidents which were deadlier, were before Canada became a country in 1867.

        The Transportation Safety Board of Canada completed an investigation into the derailment. There is a link to the report in the sources section on the webpage for this episode.


        The train departed Farnham (50 km east of Montreal) at 1:55pm on July 5th and arrived in Nantes at 10:50pm, where it was to be re-crewed and continue through Maine to eventually reach its final destination of Saint John, New Brunswick.

        The train had 72 tank cars, loaded with about 6.7 million liters of crude oil, 1 box car, 5 locomotives, and 1 VB car used to house equipment.

        There was only one locomotive engineer on the train, positioned in the lead locomotive. He had reported issues during the trip which affected the train’s ability to maintain speed.

        Trains are equipped with 2 air brake systems: automatic and independent. The automatic brake system applies the brakes to each car and locomotive on the train, and is normally used during train operations to slow and stop the train. Each locomotive is equipped with an independent brake system, which only applies brakes on the locomotives. Independent brakes are not normally used during train operations, but are primarily used as a parking brake.

        When the train stopped in Nantes using the automatic brakes, the engineer applied the independent brakes to the locomotive, applied 7 hand brakes on the locomotives and box car, and shut down the 4 trailing locomotives, leaving the lead running. He then released the automatic brakes that stopped the train and did a hand brake effectiveness test with the independent locomotive brakes still in play. He called rail traffic control for the area he was in and let them know the train was parked and secure.

        We mentioned he applied 7 hand brakes. As per MMA rules, for a train with 72 cars, a minimum of 9 hand brakes should have been used. This is commonly referred to as the 10% + 2 rule.

        Then he called the rail traffic controller for the next leg of the route to let them know about the mechanical difficulties and that excessive black and white smoke was coming from the smokestack. The engineer and controller agreed to leave the train as is and deal with the engine issues in the morning.

        The engineer left the train at 11:30pm by taxi to head to a local hotel. The taxi driver noticed smoke and oil droplets from the lead locomotive were landing on his windshield. The engineer stated he called rail traffic and they agreed to leave it this way.

        At 11:40pm, 10 minutes after the engineer left, a 911 call came through about a fire on a train in Nantes. The fire department and police responded, called the rail traffic controller who failed to get in contact with an engineer, and a track foreman for the rail company met them on site.

        The firefighters said that the emergency fuel cut off switch was used to shut down the lead locomotive; removing the fuel source and putting out the fire. They also turned off the automatic brakes for this locomotive to eliminate the potential ignition source. While this was in line with railway instructions, this unknowingly disengaged some of the brakes on the train that were in place when the train was brake tested. It's also important to note that the fire department was in contact with the local rail traffic controller, not the one for the next leg. The local controller was not made aware of the mechanical issues or the decision to leave the train as is.

        The locomotive's automatic brakes were an air system, so the issue wasn’t noticed right away. But without the engine running to maintain air pressure, the brake system slowly depleted and by 1am on July 6th, the train started to roll towards Lac Megantic, 11.5 km away.

        The train reached downtown by 1:15am and derailed. The overall elevation drop from where the train started to where it derailed was about 100m, and the train got up to about 100 kph by the time it reached Lac Megantic.

        Based on the fact that the train took 9 hours to travel 200 km earlier that day, its typical speed was somewhere around 25 kph. At 100 kph I have to assume it was extremely unstable.

        The route from Nantes is not completely straight, it does have a few turns in it, but they are a relatively large radius compared to the turn in downtown Lac Megantic where the rail line comes from the NW and turns south around the lake and then west again.

        The lead locomotive itself didn’t derail and came to a stop 1300m from the derailment. It separated from the rest of the train, which then further separated into two sections. The two sections were 32 m apart both traveling east and coming to rest on an ascending grade in the eastern side of town, stopping almost 150 m apart.

        We’re going to put some photos of the derailment aftermath on the web page for this episode, or you can look them up. You think this is bad, and then you look at it and realize it's so much worse.


        We mentioned earlier that the train was carrying 6.7 million liters of crude oil. About 6 million, or 90% of that was released when the train derailed. Contaminating 31 hectares, or about 1/ 3 of a square kilometer, of land around the crash site. The crude oil made its way into the town's sanitary and sewer system, which contaminated water treatment facilities and increased risk of further damage away from the original crash site. About 100,000 liters of crude ended up in Lac Megantic.

        We talked about the Cleveland East Ohio Gas Explosion on our 9th mini failure over on our Patreon. The explosion was caused by a storage tank that broke apart and sent gas throughout that part of Cleveland. But in this case, the gas also made its way into sewer pipes in the street and caused a series of underground explosions blocks away from the initial storage tank. Luckily, this does not appear to have happened at Lac Megantic.

        The engineer who parked the train in Nantes had been qualified as a locomotive engineer since 1986, 27 years. Even though his employer changed over the years as that section of rail was bought, he remained in the territory and completed hundreds of trips between Farnham and Lac Megantic. With about 60 eastbound trips on this train in the year before the accident, and about 20 of those as a single person operator.

        The train cars underwent a brake test in Toronto on July 4th and again in Montreal on July 5th. 5 tank cars had mechanical defects and were removed from the train.


Findings as to causes and contributing factors

Other findings

There were also a number of findings that were more high level and related to overall risk associated with the rail industry.


 So there you have it, the Lac Megantic train derailment which rocked a tiny Quebec town 10 years ago.


For photos, sources and an episode summary from this week’s episode head to Failurology.ca.  If you’re enjoying what you’re hearing, please rate, review and subscribe to Failurology, so more people can find us.  If you want to chat with us, our Twitter handle is @failurology, you can email us thefailurologypodcast@gmail.com, you can connect with us on Linked In or you can message us on our Patreon page.  Check out the show notes for links to all of these. Thanks, everyone for listening.  And tune in to the next episode where we will talk about GNSS or Global Navigation Satellite Systems.

Bye everyone, talk soon!