OC Transpo is cautioning riders of the Confederation Line that an end-to-end trip between Blair and Tunney's Pasture stations will take an extra four to five minutes as the investigation into an axle hub failure continues.

Twenty vehicles were pulled for inspections last week after a wheel hub on one train failed for a reason that has yet to be determined. Rideau Transit Maintenance (RTM) says this failure is different from the axle bearing problem that led to a derailment in August 2021.

All trains with more than 175,000 kilometres of service were pulled for inspection and are to have their axle hubs replaced. In a memo Saturday, OC Transpo general manager Renée Amilcar said there were 22 vehicles, or 11 double-car trains, in operation as of Saturday. The line runs with up to 15 double-car trains during peak periods on weekdays.

However, the Rideau Transit Group and Alstom—the manufacturer of the train cars—have asked OC Transpo to reduce speeds along certain sections of the track while the investigation into the cause of the axle hub failure continues.

"Due to lower speeds, customers will see a small change in travel times; end-to-end service will be an extra four to five minutes," Amilcar wrote.

OC Transpo says its typical end-to-end time is less than 25 minutes.

The Transportation Safety Board is also investigating. The TSB was informed last week when the axle hub failure on one vehicle was discovered. Earlier this week, RTM CEO Mario Guerra said he suspects equipment fatigue may have been the cause.

"I think once we start doing non-destructive testing on the hub that failed, as well as all of the hubs we're taking off, then we'll be able to tell whether this was one event or if it's something that's permeated throughout," he told reporters Tuesday.

The axle hub failure was reported just before part of the LRT's overhead power line was damaged in Sunday's thunderstorm, cutting service to part of the line for several days. Full service was restored Friday afternoon.


Amilcar's memo Saturday did not mention an unspecified technical issue that is also causing delays.

OC Transpo said just before 10:30 a.m. Saturday that service at Cyrville and St. Laurent stations was only available on the eastbound platforms. Customers were asked to change trains at St. Laurent.

The issue was resolved just after 12:40 p.m., but the nature of the issue has yet to be disclosed.