Most UP Express train cars 'condemned' after thermal cracks found in brake discs: union

Most of the fleet servicing the UP Express has been removed from operation after thermal cracks were discovered in the vehicle brake discs, according to the maintenance and operators’ union and confirmed by several sources, leaving Metrolinx with only four train cars in service for the rail link connecting Pearson International Airport to downtown Toronto.

“80 per cent of the fleet grounded, it’s certainly possible that those four units are impacted,” said Gregory Vaughan, General Chairman of Teamsters Canada Rail Conference Division 660, which represents GO and UP Express train operators and maintenance staff.

Metrolinx, however, is adamant the trains – which remain in service – have passed all safety inspections.

The public transit agency first announced on Monday evening the UP Express would be down to 30-minute service on Tuesday “because of limited availability of equipment due to unexpected maintenance.”

On Friday, the Crown corporation indicated delays "due to an equipment issue" would be “until further notice.”

”Over the course of regular inspections this past weekend, our team discovered hairline cracks in the brake discs on some of our UP Express trains,” Metrolinx said in an emailed statement. “In the interest of safety, we immediately removed the affected trains from service and proactively inspected the rest of our fleet.”

Sources confirm to CTV News Toronto 14 of 18 train cars in the fleet were found to have thermal cracks in their brake discs. Two trains of two cars each remain in service, limiting operations to 30-minute intervals, and forcing a quick staff changeover to maintain schedule.

Vaughan says a health and safety meeting with Alstom—which maintains and services the trains under contract to Metrolinx, and is also the employer of the train operators and maintenance staff—was abruptly cancelled on Thursday.

The company, based in France, has not returned communications since, Vaughan told CTV News on Friday.

A formal correspondence was sent by the union, Vaughan said, “to provide documentation showing when the four units in operation were last inspected, and found to be free of the defects that led to the rest of the fleet being condemned.”

Alstom has not answered that request, he confirmed.

CTV News Toronto has reached out to Alstom for comment.

Brake discs are a form of braking system that have been in wide use in motor vehicles, trains, and aircraft for decades, since their invention in the 1890s.

Their life expectancy depends on the materials used, and are routinely serviced and replaced, said mechanical engineer Solomon Boakye-Yiadom, an assistant professor in the Lassonde School of Engineering at York University.

The UP Express began operation in 2015.

The trains taken out of service have been described by the union and sources familiar with the situation as “condemned”—terminology Baokye-Yiadom says is unusual in this mechanical engineering field from his experience.

“Does it mean it’s under repairs, or is it just written off?” the engineer said.

Repairs are underway, Metrolinx confirmed.

“We are doing everything we can to get the affected trains safely back into service as soon as possible,” the Crown corporation told CTV News Toronto.

Thermal cracks result from fatigue after the discs are repeatedly heated—sometimes to above 700 degrees Celsius—and cooled during braking. It is a major cause of braking failure, said Boakye-Yiadom, as the system takes on more load attempting to halt momentum.

“As soon as you cause a very little crack initiation in the structure, know that subsequent loadings are going to cause these cracks to expand and grow,” he said. “And that’s where it gets dangerous.”

Metrolinx says all trains, which remained in service, have passed inspection since the thermal cracks were discovered last weekend. Yet, the four UP Express train cars that remain in service have not been heading to their usual yard at night, several sources say, where they are routinely inspected.

Instead, they are being yarded at a location near Lakeshore Boulevard East and Cherry Street.

“It’s a public safety concern,” a source told CTV News Toronto.

Vaughan agrees.

“I’m going to continue to press [for answers],” said Vaughan. “Not just for the safety of my people but the travelling public.”

“This is safety, we don’t negotiate, and we don’t mess around when it comes to safety.”