Expert Attributes Line 1 Wheel Issue to Overloading

Ottawa’s light rail transit (LRT) system faces significant challenges due to ongoing wheel assembly issues. Recent events have resulted in overcrowded trains and stations, exacerbating the city’s transportation difficulties. An expert analysis identifies overloading as a contributing factor, disputing the city’s claims regarding the nature of the wheel problems.

Overloading and Wheel Issues: An Expert Opinion

On Wednesday, OC Transpo reported “spalling,” a metal flaking issue observed in several cartridge bearing assemblies. If left untreated, spalling can lead to severe cracks and potential failures, as warned by the city. These bearing assemblies are critical in supporting the weight of the trains and have a troubled history. For instance, a 2021 derailment and a lengthy shutdown in 2023 arose from related bearing failures.

History of Failures in the LRT System

The most recent defects have been categorized as “separate” by Troy Charter, OC Transpo’s interim general manager. However, Patrick Dumond, a University of Ottawa professor specializing in bearing diagnostics, challenges this assertion. He believes the new issues are indeed related to previous ones, as both stem from overloading of the bearing cartridges.

• The 2021 derailment was linked to a catastrophic bearing failure.
• Assemblies that failed had less than 150,000 kilometers of use, despite an expected lifespan exceeding 1.2 million kilometers.
• The Transportation Safety Board (TSB) has flagged ongoing risks associated with these issues.

Impact on Train Operations

Dumond highlighted design flaws in the assembly, indicating that both bearing wear and the average load on the trains exceed safety thresholds. Following the discovery of overused bearings, OC Transpo is removing train cars that have surpassed 100,000 kilometers as a precautionary measure. This action has led to a decrease in available train cars, significantly affecting morning commuters on Line 1.

Adjustments in Train Services

Starting Wednesday evening, Line 1 began operating with a mix of single- and double-car trains. OC Transpo aims to maintain service frequency while managing the reduction in operational car numbers. Dumond emphasizes that replacing problematic parts is only a temporary solution.

The Need for a System Redesign

According to Dumond, the ultimate resolution lies in redesigning the cartridge bearing assembly system. This redesign was temporarily halted but is set to resume in 2024 due to prior disagreements involving Alstom, the train manufacturer. Dumond insists that the city must pressure Alstom to create a more robust assembly capable of withstanding expected wear.

Contractual Obligations and Financial Accountability

Mayor Mark Sutcliffe expressed concerns over the financial implications for the city, emphasizing that contractors, who are compensated for providing train services, should be accountable for these recurring issues. The Rideau Transit Group, responsible for LRT maintenance, has been noncommittal about potential costs related to the latest maintenance problems, referring to existing contractual agreements with the city.

As Ottawa’s transit system grapples with these wheel assembly issues, the emphasis remains on finding long-term solutions to improve service reliability and safety for commuters.