Ottawa’s LRT system faced overcrowded trains and stations on Thursday due to ongoing wheel assembly problems, with an expert highlighting overloading as a significant factor. The city reported the detection of “spalling” on several cartridge bearing assemblies, a condition that could lead to cracks and eventual failure if left unaddressed. These assemblies, responsible for supporting the train’s weight, have experienced failures in the past, resulting in a derailment in 2021 and a prolonged shutdown in 2023.
OC Transpo’s interim general manager, Troy Charter, stated that the recent defects are distinct from previous issues. However, an expert specializing in bearing faults, Professor Patrick Dumond from the University of Ottawa, expressed skepticism about this claim. Dumond believes the current problem is linked to previous overloading issues with the bearing cartridges.
The ongoing challenges suggest that the trains exceed the capacity of the original bearing assemblies, according to Dumond. He referenced a previous incident where loose nuts in the assemblies indicated potential overloading from forces on the rail tracks. Dumond emphasized that the continuous use of trains poses a high average load that strains the current setup.
The Transportation Safety Board reported a severe bearing failure in August 2021, causing a train wheel to detach from the axle. Despite the expectation that these assemblies should last over 1.2 million kilometers, the faulty assembly had accumulated fewer than 150,000 kilometers. The TSB warned that unresolved issues continue to pose safety risks.
To address the current situation, Line 1 has adjusted its service by running a combination of single- and double-car trains while maintaining regular frequencies. Charter mentioned that trains with bearings exceeding 100,000 kilometers are being removed as a precautionary measure for assembly replacement.
Dumond emphasized the necessity of redesigning the cartridge bearing assembly system as the ultimate solution. Alstom had initially paused this redesign effort due to disagreements but resumed it in 2024. The expert stressed the importance of pressuring Alstom for a more robust design to ensure longevity.
While Alstom’s CEO, Michael Keroullé, downplayed the severity of the spalling issue, the company is collaborating with RTG and the city to restore train services promptly. Mayor Mark Sutcliffe expressed expectation that contractors would bear the associated costs but acknowledged the city’s potential financial responsibility. Rideau Transit Maintenance, responsible for LRT maintenance, declined to comment on covering the latest maintenance issues, citing contractual agreements and deferring inquiries to the city.
