Jan. 21, 2026: O-Train Line 1 Cartridge Bearing Assembly Spalling and Service Impacts

To	Mayor and Members of Council
From	Troy Charter, Interim General Manager, Transit Services Department
Subject	O-Train Line 1 Cartridge Bearing Assembly Spalling and Service Impacts
Date	January 21, 2026

The purpose of this memo is to inform the Mayor and Members of Council that beginning this evening, O-Train Line 1 will operate with a mixture of single and double-car trains while maintaining its current frequency. This measure is the result of a new issue that has been identified involving the Cartridge Bearing Assemblies (CBA) on O-Train Line 1 vehicles, which require additional maintenance to prioritize the safety of the fleet.

Our top priority is always the safety of transit customers and employees. Out of an abundance of caution, OC Transpo has asked RTG to replace CBAs on trains with mileage higher than 100,000 kilometres. As the CBAs are replaced, trains will be returned to service.

Line 1 service

Due to this new maintenance requirement, the number of trains available for service will be reduced, and therefore Line 1 service will be operating with a mixture of single and double-car trains, while maintaining its current frequency. Customers will see this change begin in the evening of Wednesday, January 21, and this modified service will continue until the spalling issue has been adequately addressed.

For customers this means that:

• Line 1 hours of operation and frequency will remain the same.
• Because single-car trains will be deployed, customers may experience crowding on trains and platforms at times during the morning and afternoon peak periods.
• The Transit Operations Control Centre (TOCC) will monitor the system in real-time and make adjustments where possible.
• Lines 2 and 4 trains are not affected by this issue, and service will continue as normal.

Spalling issue

As part of their ongoing investigation and analysis of the previously identified axle bearing assembly issue, Rideau Transit Group (RTG) notified OC Transpo that spalling was detected on several CBAs. Spalling is caused when flakes break off the metal surface inside the axle bearing, creating pits that grow over time. If not addressed, this can lead to cracks and can result in bearing failure.

This is a separate issue from the axle bearing assembly issue previously identified, and RTG has begun a root cause analysis in relation to it. OC Transpo, together with its independent safety consultant, Transportation Resource Associates (TRA), have been in discussions with RTG to ensure the ongoing safety of customers and staff. While RTG has maintained that the system is safe to operate, critical information remains to be provided by RTG.

As a result, and after a careful review and close collaboration with TRA, the City has provided a Safety Order to RTG requiring that any vehicle with CBAs with 100,000 kilometres or more of mileage be removed from service, and the CBA units replaced. OC Transpo is taking this step from an abundance of caution so that customers and employees can be assured that the train fleet is safe.

OC Transpo is closely monitoring the mileage on CBAs, and anticipates that as replacements occur, more vehicles may become available for service.

OC Transpo is prioritizing safety, while completing the necessary due diligence to ensure RTG and its subcontractors are accountable and working to restore reliable capacity on Line 1. These steps include:

• Working with RTG to establish timelines for increasing fleet availability
• Ongoing, careful monitoring and planning of fleet availability and CBA mileage
• Continue to work closely with our independent safety consultant, TRA
• Holding RTG to the requirements of the Project Agreement (PA) and the Safety Management System (SMS)

OC Transpo recognizes that this situation is disruptive to customers and will provide updates on all of its communication channels including octranspo.com, text messages, social media and public service announcements. OC Transpo staff will also be at key stations to support customers. A media availability will be hosted later today and will be available to watch on the City’s YouTube channel.

If you have any questions, please contact Sabrina Pasian at [Personal information redacted] or me at [Personal information redacted].

Original signed by
Troy Charter

cc:Senior Leadership Team
Transit Services Departmental Leadership Team
Chief Communications Officer, Public Information and Media Relations