The first clue something was wrong was the burning smell.
On a sunny Sunday afternoon exactly two years ago, a technician identified burn marks on a brake disc on one of two cars on a Confederation Line LRT train.
After the issue was seen to, the train was given the all clear and sent on its way — without anyone ever checking the other car.
That mistake proved costly.
The train made it just 90 metres out of the station before a wheel was severed and the vehicle derailed. The Transportation Safety Board (TSB) would later describe the cause as a "previously undetected catastrophic roller bearing failure."
But why did the bearing fail in the first place? Two years on — after a four-week provincial public inquiry, several TSB inquiries, and numerous consultancy contracts — we still don't know for sure.
What we do know is that bearings have caused problems time and again, including the latest Confederation Line shutdown, now 21 days and counting.
The latest response
OC Transpo, line builder Rideau Transit Group (RTG) and train manufacturer Alstom still have not explicitly outlined the root cause. But Richard Holder, the city's director of engineering services, said on Friday "several factors" are involved.
Progressive wear is causing fatigue in the axle shaft, bearing and hub assembly — parts that connect the wheels to the train body — and that, he said, will be solved by a more resilient and durable hub.
As for the forces that are apparently too strong for the parts to withstand, the city says it has just begun implementing solutions to longstanding issues around the track's tightest curves.
Those issues include consistent contact between the wheel and a guard meant to prevent derailments, as well as a lack of lubrication on top of the rails.
Straightening them is not on the table.
"If we had a lot of engineers designing the light rail system, we would make it straight. But we had to build a system in Ottawa. We had to connect a lot of infrastructure together," he said. "It's not a case that we need to eliminate those curves, and it's not the situation that we could have avoided those curves."
Here's a timeline of how we got to this point.
Aug. 8, 2021
No passengers were on board the Alstom Citadis Spirit train when it lost a wheel and came off the track. It derailed while on its way from Tunney's Pasture station to the maintenance garage, but TSB investigators concluded that the cartridge — which encloses and protects the bearing — failed hours earlier and several stations away.
Officials halted service across the Confederation Line for five days to check every vehicle.
"We're not going to try to do things quickly," Troy Charter, the city's director of transit operations, told CBC at the time. "We're going to make sure we do it safely and reliably."
Inspections uncovered similarly problematic cartridges in roughly a quarter of the fleet's vehicles. Afterward, Alstom decided to look for this bearing "play," or looseness, after every 7,500 kilometres of service.
"Something's really quite wrong if after the event you detected one [problem], but then during the inspection you detect another eight," said Ian Naish, a former rail inspector with the TSB.
"Would I be concerned? Yes, I would."
Sept. 19, 2021
The next month, one of the trains identified as needing additional maintenance experienced an even more unsettling failure.
Video footage showed the train scraping against the platform as it departed from Tremblay station, spraying stones.
The operator failed to notice.
In fact, he said he did not realize the train had derailed — and then travelled another 400 metres — until he disembarked.
The train and the track suffered extensive damage. Twelve passengers were on board.
This time, the root cause was obvious: Alstom maintenance staff did not tighten the bolts on a gearbox or tell the incoming shift workers that the work still needed to be done.
No one was injured, but this second derailment — which took place on a bridge over a busy roadway — shook public confidence in the system and set off a political firestorm.
Sept. 24, 2021
The city issued a second "notice of default" to RTG — the consortium of SNC-Lavalin, ACS Infrastructure and Ellis Don that built the train system — asking court to confirm it hasn't lived up to its obligations.
It's a step that could have allowed the city to end it's 30-year maintenance contract early.
Oct. 19, 2021
A month into the system-wide shutdown, Renée Amilcar took the helm of Ottawa's transit system from retiring general manager John Manconi.
"Technical problems will be resolved by technical solutions, and I'm very good on that," she told CBC. "I will work very, very hard with my team. And we'll find solutions for the customers for sure."
A day later, transit commission heard that Alstom planned to "uplift competencies of the leadership and supervision teams" and "regain a professional and productive work environment" by bringing in new staff.
Then-transit commissioner Catherine McKenney questioned the timing, coming as it did after "two years of constant dysfunction" and after the city paid $2.1 billion for the line.
"[This comes] now, after two derailments," she said. "The second one [of which] could have been catastrophic."
Nov. 10, 2021
As the wait to restart service stretched from days to weeks, some councillors rallied for transparency. City leadership responded to their demands for emergency meetings with offers to discuss questions in private.
But a motion for a judicial inquiry failed at council.
"I come from the school of where there's smoke there's fire. Just the talk of a judicial inquiry obviously has people concerned," said then-councillor Carol Anne Meehan.
"There are people who don't want us asking questions."
Nov. 12, 2021
After 54 days, the LRT resumed with fewer trains on the track and replacement bus service in operation.
Councillors had already decided to provide riders with free service for all of December, at a cost of $7.2 million.
Nov. 17, 2021
Documents obtained by CBC confirmed the city knew about the system's unreliability even before it took the reins from RTG.
"We can all agree things are not going well," Manconi wrote in an e-mail.
May 10, 2022
While the August derailment occurred because of the wheel hub assembly, the parties involved have often disagreed over its root cause.
A preliminary report from Alstom indicated the "actual design of the track" was generating excessive force that created "fretting under the bearing of the axle" — contact damage created by microscopic movements.
The report made several suggestions.
Greasing the tracks, lowering speeds and modifying wheel profiles were suggested as immediate responses. In the long term, Alstom proposed grinding down the track and changing the axle design.
RTG disagreed that the track's design and build was a factor in the derailment.
June 13, 2022
The province launched an inquiry that saw dozens testify over four weeks, laid bare behind-the-scenes decision-making and raised fresh concerns.
Its findings included that intense political pressure led to trains being rushed into service.
The 664-page final report, released in November, outlined problems that contributed to the derailments, from a heavier train design that pushed the limits of LRT technology to an adversarial relationship between the city and RTG.
July 23, 2022
A bearing issue that could have potentially led to another derailment was caught early when a train operator reported an unusual vibration.
That prompted RTG to announce that Rideau Transit Maintenance would replace the axle wheel hubs in the front and rear on all LRT vehicles after 175,000 kilometres.
The assembly that failed had nearly 150,000 kilometres on it, but the TSB said it should have lasted for 1.2 million.
Jan. 27, 2023
The city and RTG reached an out-of-court settlement over the contract to maintain the system.
A joint statement said it resolved disputes and reset a testy relationship.
Terms of the settlement are still being kept secret, but it involved the city making a payment in the millions of dollars.
Feb. 15, 2023
The TSB's last report on the August 2021 derailment said the bearing issues "continue to pose a risk to safety" and were likely prompted by the unique train design ordered by the city.
The Citadis Spirit has the same cartridge assembly as other Alstom trains but was built to carry more people at unusually high speeds.
Holder responded by saying OC Transpo would not be running trains if there were a "shadow of a doubt" they were safe.
"We will not be making any changes to the operations," he said at the time. "What we will continue to do is continue to work with RTG and as much as possible get the root cause analysis finished."
April 28, 2023
City staff updated the light rail subcommittee on how they were responding to the results of the public inquiry, including potentially changing the restraining rails and redesigning the axle bearing assembly.
Holder said it was too early to say what Alstom's final decision will be, but assured councillors train service would not be impacted.
The trainmaker began tests with vehicles outfitted with scientific instruments and vibration sensors.
July 17, 2023
A routine inspection finds the bearing issue behind the current LRT shutdown.
Excess grease alerted officials to the problem, which didn't exist eight days earlier when the train was last inspected.
One week later, a complete redesign of the axle hub assembly is officially announced and hailed as a permanent solution to these ongoing problems. But until they can be designed, tested and installed, the front and rear assemblies will be replaced about every six months — at the 60,000-kilometre mark.
"With a newly designed axle we will no longer have the problems that we've been experiencing so far," Mayor Mark Sutcliffe told reporters."The issues that have caused disruptions in service will no longer happen."
In the meantime, service is slated to partially resume Tuesday, while riders wait for a full return to service estimated for Aug. 14.
https://news.google.com/rss/articles/CBMiUWh0dHBzOi8vd3d3LmNiYy5jYS9uZXdzL2NhbmFkYS9vdHRhd2EvbHJ0LWRlcmFpbG1lbnQtMi15ZWFyLWFubml2ZXJzYXJ5LTEuNjkyODI4MtIBAA?oc=5
2023-08-08 08:00:00Z
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