Theories of August 2021 train derailment emerge at LRT inquiry

The technical testimony at the Ottawa light rail public inquiry is sometimes overshadowed by the appearance of star witnesses. But over the past three weeks, it's sparked theories of how Confederation Line's track design may have contributed to the first of two derailments that summer.

City rail manager had warned of derailment a year earlier, with concerns that mirror Alstom's

The testimony of a number of high-profile players at the ongoing LRT inquiry has made for some dramatic moments, from the revelation it was the city's former transportation manager who asked for the trial testing to be made easier to the fact Mayor Jim Watson forgot to tell inquiry lawyers he was getting daily updates on the project — which other council members didn't get.

But those star witnesses sometimes overshadow other testimony, especially that of a more technical nature. After all, one of the key aims of the inquiry is to shed light on what caused the two derailments of Alstom Citadis Spirit trains in 2021.

We know now that the second one, in September of that year, was due to human error and —  in the words of a Transportation Safety Board of Canada (TSB) report — "incomplete maintenance." 

Indeed, the way Rideau Transit Group's (RTG) maintenance arm and its subcontractor Alstom have performed is one of the key issues of this inquiry. 

But what caused the  August 2021 derailment? The wheel broke off the axle due to a bearing issue, but we still don't know what loosened the bolt inside the bearing in the first place. 

A red and white light rail train on the tracks with the Ottawa skyline in the background.
The final week of hearings for the Ottawa light rail public inquiry starts Monday. (Sean Kilpatrick/The Canadian Press)

Alstom has a theory.

The France-based company, along with axle manufacturer Texelis, produced a preliminary report in early May. Its central assertion is that the stress on the components came from excessive pressure from going around sharp curves on the Confederation Line.

And not only is there the stress of the train components, but there's also "corrugation" on the rail: tiny wave-like ridges that had to be removed by grinding. (How often, and how well, this grinding is done — or should be done — is a matter of some discussion at the inquiry.)

The report contends that the "actual as-built track is not in line with the design as stated" in the specifications Alstom agreed to with the LRT builders.

The axle of an LRT train on Ottawa's Confederation Line came dislodged from the rail on Aug. 8, 2021, prompting an investigation by the Transportation Safety Board of Canada. (Alexander Behne/CBC)

The rail was flatter than expected, according to the train maker.

The inquiry has heard from executives of both Alstom and OLRT Constructors — that's Rideau Transit Group's construction arm — that the gauge, or distance between the parallel rails, was too narrow. During the testing phase, OLRT Constructors widened the rails.

Lowell Goudge, Alstom's lead engineer and safety certifier for the Citadis Spirit trains, testified on June 21 that while the company was able to operate the vehicles safely, it still had "concerns."

The profile of the track is also not matched to the profile of the wheel, the report contends. 

"It's a combination of the track, the wheel rail interface, the operating profile," he said. Goudge, who signed off on Alstom's preliminary investigation, conceded that the company cannot make definite cause-and-effect findings from all its observations.

"The only conclusion we could really draw absolutely was that we were taking excessive loads in the curves," he testified. And that unexpected pressure was causing components to wear out prematurely, which led to the August 2021 derailment.

Limited testing window for LRT may have caused officials to miss problems, inquiry hears

3 months ago
Duration 1:37
Lowell Goudge, who was the train system engineer for the Confederation Line, says the testing schedule seemed ‘compressed,’ which may have caused officials to miss problems that would have been seen if the testing had run for longer.

Rideau Transit Group does not agree with Alstom's preliminary conclusions, however.

"RTG has commissioned an independent root cause analysis that will review the Alstom findings and evidence as well as information provided by all other relevant parties," according to a statement from Helen Bobat, the spokesperson for RTG and its parent companies, SNC-Lavalin, ACS Infrastructure, and Ellis Don.

City rail manager concerned about track, derailments

The track itself has been a subject of discussion in local rail circles for years.

A CBC access to information request for communications concerning the cracked wheel issue in the summer of 2020 revealed that one of the city's own rail managers had raised concerns about a possible derailment a full year before the two in 2021.

On July 13, 2020, Russ Hoas — a rail systems manager, particularly for the Trillium Line — wrote to rail operations director Duane Duquette about his concerns over the wheel cracks. Hoas was "strongly suggesting" that the fleet be pulled until the problem was addressed.

(The TSB said in December 2020 that a protruding jack screw may have caused the cracks, but the final report has yet to be released.)

"Bad track just adds a higher degree of possible derailment, while in revenue service," Hoas wrote.

He went on: "Poor design coupled with a lack of proper geometry testing in 2017 and 2019 (pre-service) as was pointed out then, would have provided evidence of track structure abnormalities. Not forgetting that the wheel/rail interface is a key component to cause of derailments. Trains screeching around curves on [the Confederation Line] is an indication of improper running surface on a lack of balance speed through curves."

OC Transpo's director of transit operations Troy Charter. (Jean Delisle/CBC)

Hoas was one of the five city-appointed evaluators, along with rail director Michael Morgan, who failed SNC-Lavalin in their technical submission for the Trillium Line expansion. SNC-Lavalin still won the $1.67-billion contract.

According to his LinkedIn profile, Hoas worked for Bombardier for 15 years before joining the city in 2015.

Troy Charter, the city's director of transit services and rail operations, wrote to Duquette that he wanted to meet with Hoas to tap into his knowledge but also to "make it clear that at no time was public safety jeopardized."

He also wrote that he was "disappointed" that Hoas believed the city "would ever consider running a service while putting customers at risk."

The city did not allow CBC to interview Hoas. As well, the first response sent after CBC's access to information request did not include the email from Hoas or the response from Charter.

Both only materialized after CBC requested a second search for records.

LRT constructors' own consultant had concerns

And Friday morning's testimony by consultant Derek Wynne — overshadowed by the mayor's virtual appearance at the inquiry that afternoon — conveyed even more concerns about the track.

Wynne is a senior vice-president at the U.K.-based SEMP, which was the systems engineering and assurance firm hired by OLRT Consultants from 2017 until just after the LRT launched in the fall of 2019.

He testified that even by 2018, it was clear that safety analysis was being thought of as something to check at the end, rather than something that should have been in place from the start.

The commission saw a few pages of a PowerPoint presentation called "OLRT-C Rail Wear Hazard" from January 2019 that Wynne said was never presented because the track assessment "caused a great deal of consternation." 

The presentation concluded that based on the design of the wheel interface, there was "significant potential for rail defect hazards to develop" that could lead to "premature failure of the rail component."

Wynne said that at the request of OLRT Constructor executives, he came up with a "more softly worded report" that called for more restrictions and maintenance on the system, as opposed to "significant changes" to the track.

"Both options are valid — either fix it before revenue service or maintain it extensively during in-service life," he said, adding that the issues were "very known" prior to the LRT being in public service.

The U.K. consultant, who testified he had nothing to do with Alstom, appeared to agree with a number of the train company's assessments of what may have led to the bearing failure that caused the August 2019 derailment.

The safety certificate that he finally signed off on near the end of the project included caveats about how the track was to be maintained, but it was unclear to Wynne when he returned to Ottawa — two years after the LRT was open — if all the restrictions he had placed were being followed.

On Monday, city manager Steve Kanellakos is set to testify, followed by the independent certifier, Monica Sechiari of Altus Group.