A hydraulic fluid leak that caused a 12-hour shutdown on the Bloor-Danforth TTC subway line in May was caused by equipment failure and not sabotage, two independent reviews found.
Questions about the shutdown arose because the subway system saw two serious hydraulic leaks each month in the first four months of 2024, while the normal rate is about one a year.
The TTC hired Hatch, a group of rail industry experts, and the American Public Transit Association to study the problem and create a report.
The findings pointed to equipment failures as the cause of the frequent hydraulic leaks.
The report said the leaks occurred on the TTC’s “work car” fleet. Unlike standard subway cars that carry the public, the TTC’s 75 work cars are used for various tasks when the system is shut down to passengers at night. One specializes in tunnel leak repair, two are for tunnel washing and four are for dealing with snow.
The most serious of the leaks, in terms of disruption to the system, occurred on May 13. It developed as a kind of perfect storm, forcing a shutdown of a central part of the Bloor-Danforth line just at the beginning of morning rush hour.
In the end, the subway was shut down between St. George and Woodbine stations for 13 hours as crews worked to manually clean up 200 litres of hydraulic fluid.
Hatch's report said TTC crews found a leak in RT56, a vacuum car, in the early hours of May 13. The car was then moved to Lower Bay station, which exists for historical reasons and isn't used by the public.
At that point, the problem was contained in a way that might have limited disruption to passengers when rush hour started in a few hours.
However, TTC employees who thought the leak had stopped decided to move RT56 to the Greenwood yard. It was towed there, leaving a slick and unusable track behind it. What followed was hours of work for the crews who had to clean it up properly — and a chaotic work day for tens of thousands of people.
"The initial plan to temporarily park the work car … at Bay Lower to evaluate RT56 and assess the hose for further leakage could have prevented the 12-hour service disruption," the report said.
The APTA’s report said there were a lack of TTC personnel on hand with the experience to make an educated decision on whether the car should be moved.
“The delay in assessment by qualified work car maintenance personnel meant that RT-56 was moved without fully knowing the extent of the hydraulic fluid leak nor if the leak was contained. This ultimately resulted in a service interruption of 730 minutes (from 6:50 a.m. to 7 p.m.)”
In normal conditions, the Bloor-Danforth line carries an average of over 23,000 passengers an hour and sees about half a million trips per weekday.
In two earlier incidents, trains slid as they tried to enter stations, though they stopped while all doors were still able to open onto the platform.
