2 years on, a fix to the LRT's derailment issue remains far off

The first clue something was wrong was theburning smell.

Ona sunny Sundayafternoon 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 theissue 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."

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But why didthe bearing fail in the first place? Two years on after a four-week provincial public inquiry,several TSB inquiries, and numerousconsultancy contracts we still don't know for sure.

What we do know is that bearings have causedproblems 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 Alstomstill have notexplicitly outlined the root cause. ButRichard 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.

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As for the forces that are apparently too strong for the parts to withstand, the city says it has just begun implementing solutions tolongstanding issues around the track's tightest curves.

Those issuesincludeconsistent contact between the wheel and a guard meant to prevent derailments, as well asa lack of lubrication ontop 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

Nopassengers wereon 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 stationto the maintenance garage, but TSB investigatorsconcludedthat 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."

Inspectionsuncovered similarly problematiccartridges in roughly a quarter of the fleet's vehicles. Afterward, Alstom decided to look for thisbearing "play," or looseness,after every 7,500 kilometres of service.

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"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 maintenanceexperienced an even more unsettling failure.

Video footageshowed the train scraping against the platform as it departed from Tremblay station, spraying stones.

The operator failed tonotice.

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In fact, he said he did notrealize the train had derailed and then travelled another400 metres until he disembarked.

The train and the track suffered extensive damage. Twelve passengers wereon board.

This time, the root cause was obvious:Alstommaintenance 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 thissecond derailmentwhich 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 issueda 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.

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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,Rene Amilcartook 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."Iwill work very, very hard with my team. And we'll find solutions for the customers for sure."

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A day later, transit commission heard that Alstomplanned 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 didafter "two years of constant dysfunction" and after the city paid$2.1 billion for the line.

"[This comes] now, after two derailments," they 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.

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"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 resumedwith fewer trains on the track and replacement bus service in operation.

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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 CBCconfirmed the city knew about the system's unreliability even before it took the reinsfrom RTG.

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"We can all agree things are not going well," Manconi wrote in an e-mail.

May 10, 2022

While the August derailment occurred because ofthe wheel hub assembly, the parties involved have often disagreed over its root cause.

A preliminary report from Alstomindicated the "actual design of the track" wasgenerating 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 speedsand modifying wheel profileswere 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 buildwas a factor in the derailment.

June 13, 2022

The provincelaunchedan inquiry that saw dozens testify over four weeks, laid barebehind-the-scenes decision-making and raised fresh concerns.

Its findings included thatintense political pressure led to trains beingrushed into service.

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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 wascaught early when a train operator reported an unusual vibration.

That promptedRTGto announce that Rideau Transit Maintenance would replace the axle wheel hubs in the front and rear on all LRT vehicles after 175,000 kilometres.

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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

Thecity and RTG reached an out-of-court settlementover the contract to maintain the system.

A joint statement said it resolved disputes and reset a testy relationship.

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Terms of the settlement are still being kept secret, but it involved the citymaking a payment in the millions of dollars.

Feb.15, 2023

The TSB'slast report on the August 2021 derailmentsaid 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 carrymore people at unusually high speeds.

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Holder responded by saying OC Transpo would not be running trains if there werea "shadow of a doubt" they weresafe.

"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 respondingto 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'sfinal decision will be, but assured councillors train service would not be impacted.

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The trainmaker began tests with vehicles outfitted with scientific instruments and vibration sensors.

What is a restraining rail and what does it look like?

1 year ago

Duration 0:40

Ottawa officials and LRT stakeholders are looking into concerns with the train system's restraining rails. These rails have been doing something experts agree they should not: consistently rubbing against wheels.

July 17, 2023

A routine inspection finds the bearing issue behindthe current LRT shutdown.

Excess grease alerted officials to the problem, which didn't exist eight days earlier whenthe trainwas lastinspected.

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 assemblieswill be replaced about every six months at the60,000-kilometre mark.

"With a newly designed axle we will no longer have the problems that we've been experiencingso far," Mayor Mark Sutcliffe told reporters."The issues that have caused disruptions in service will no longer happen."

In the meantime, service is slatedto partially resume Tuesday, whileriders waitfor a full return to serviceestimated for Aug. 14.