Issues that caused LRT derailment still 'pose a risk to safety': TSB report

The problems that caused an August 2021 derailment and a component failure in July 2022 on Ottawa's light rail system "continue to pose a risk to safety until the issues are resolved," the Transportation Safety Board says.

In a letter to city officials dated Feb. 3, 2023, Vincenzo De Angelis, the board's director of rail investigations, says the failure of the cartridge assemblies that caused the derailment is likely due to the actual design of the Alstom Citadis Spirit vehicle — a design the city requested.

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Ottawa was the first city to ever use the Citadis Spirit, a winterized version of the French train-maker's Citadis model, which has worked reliably in other parts of the world, according to the the Transportation Safety Board (TSB).

But the Citadis Spirit built for the Confederation Line "has had numerous reliability issues and experienced two serious main-track derailments since it commenced operations," the safety inspector wrote.

That's despite the fact Ottawa's trains are equipped with the same cartridge assembly as other Citadis trains.

Instead, the TSB believes it's the specific design requested by the city that is part of the problem. Ottawa ordered up a train that would transport more people, at higher speeds, than is usual for light rail vehicles.

During last year's LRT public inquiry,  Alstom executives testified the trains the city ordered did not exist yet — it was a prototype — and were pushing the limits of what a light rail vehicle could do. Alstom even designed a new undercarriage, or bogie, for Ottawa's system that was similar to those used for the New York subway system.

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The TSB found that the motor used in Ottawa's light rail vehicles produces more torque and accelerates more quickly than the original Citadis, and frequent stops and starts could lead to quicker wear and tear of a number of components.

"The City of Ottawa may wish to ensure that all parties involved in the OLRT undertaking work together to resolve design, operational, and maintenance risks to safety as they emerge," wrote De Angelis of the TSB.

He repeated the TSB's request that the city and Rideau Transit Group install on-board monitoring systems "to protect the travelling public." 

The TSB can only recommend that the city make changes to its rail operations.

"The safety of transit customers is paramount," the city's transit general manager Renée Amilcar wrote in a memo to council members Wednesday afternoon.

She stated the city has already undertaken a number of measures to "ensure that the trains and system are safe," including:

• Daily inspections of all light rail vehicles before service launch by Rideau Transit Maintenance (RTM).
• Reducing the speed of trains at several locations along the track.
• Replacing "all leading and trailing bogie axles" after 175,000 kilometres of service, and inspecting bearing assemblies every 7,500 kilometres. The TSB says an axle assembly should last 1.2 million kilometres.
• All other axles are inspected every 3,750 kilometres when they have travelled more than 175,000 kilometres.

Amilcar also wrote "RTG has installed vibration monitoring equipment on some trains and plans to expand the installation on additional vehicles in the coming months."

Root cause of earlier problems still unknown

Although the TSB report shines some light on some of the potential problems with the LRT vehicles, a fuller root cause analysis of what caused the August 2021 derailment — and what could have caused another one in July 2022 — is not complete.

The inquiry heard from a number of witnesses that there could be a misalignment of the train wheels to the Confederation Line track that may have caused the first of two derailments last year. Inquiry commissioner Justice William Hourigan called it a "critical safety issue" and said a long-term fix is needed, even if it means ripping up the track.

On Aug. 8, 2021, an eastbound train derailed near Tunney's Pasture after a wheel was severed from the axle. A subsequent inspection of the fleet found another destroyed cartridge assembly and 17 loose ones.

Last July, after a driver reported unusual vibration on the train, an inspection found the cartridge assembly was 10 times looser than it should have been, and the axle hub was so damaged "catastrophic failure was likely to occur if it had remained in service."

The TSB found some of the components showed oxidation and heat discolouration, and grease samples suggested the parts had been subjected to "a higher-than-average heat event."

"The observed damage was widely spread throughout the cartridge assemblies," De Angelis wrote in his letter.