Toronto permanently closes Scarborough RT, its version of SkyTrain

Toronto permanently closes Scarborough RT, its version of Vancouver's SkyTrain

TTC's Line 3 Scarborough RT (TTC)

Nearly a month after a catastrophic train derailment of the Scarborough RT, a decision was made late last week by the Toronto Transit Commission (TTC) to unceremoniously officially permanently shutter the system, effective immediately.

This system, unaffectionately also known as Line 3, was originally scheduled to close forever in mid-November 2023. But a derailment in late July that injured a handful of people pulled that date forward, as the task of repairing the system would be too expensive and lengthy in duration for Line 3’s very short remaining planned lifespan. All services on the system had already been suspended since the incident.

Instead, the TTC is now fast-tracking the implementation of its temporary replacement frequent bus service, with the use of up to 70 buses per hour during peak periods. And by 2025, this interim bus service will be further improved by a new temporary busway using a portion of Line 3’s right-of-way.

The permanent replacement solution is the Line 2 subway’s future 8 km extension into Scarborough with three additional subway stations. It is not expected to open until 2030 at the earliest. The project’s latest estimated cost is $5.5 billion.

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Unlike the TTC’s existing two subway lines, the Scarborough RT is a physically separate, lower capacity system, and it is short with a length of only 6.4 km and six stations, starting from Kennedy Station — where passengers transfer between the subway and Line 3.

Line 3 opened in early 1985, just before Metro Vancouver opened its first SkyTrain line, now known as the Expo Line, later that year.

Toronto’s Scarborough RT and Metro Vancouver’s mainline SkyTrain were born from technology created by the same manufacturer — the Urban Transportation Development Corporation (UTDC), which was a crown corporation of the Ontario provincial government.

Time-lapse video of Line 3 Scarborough RT:

TTC’s Line 3 Scarborough RT. (Shutterstock)

ttc line 3 scarborough rt scarborough centre station

Scarborough Center Station on TTC’s Line 3 Scarborough RT. (A Great Capture/Flickr)

UTDC had a mandate to design an intermediate capacity rail system — meeting the sweet spot between light rail and heavy rail subways — and it achieved this by creating a fully driverless technology that uses linear induction motors (LIM) for its propulsion. LIM propels the train forward on a continuous aluminum magnetic strip between the two running rails, and it effectively reduces the number of moving parts found inside a train, the required height of a train, and even maintenance levels.

In the early 1990s, UTDC and its technology were sold to Bombardier Transportation, which is now owned by Alstom.

Both Line 3 and SkyTrain still use UTDC’s original Mark I cars designed in the early 1980s. But as far as similarities go, it ends there.

Compared to Line 3, immense investments have been made in SkyTrain over the decades. By leaps and bounds, SkyTrain is in much better shape than Line 3, even though the original Expo Line is now similarly nearly four decades old.

The Mark I trains in use on both the Scarborough RT and SkyTrain are in poor condition. The difference with SkyTrain is there is a plan to fully replace and retire its original Mark I trains between 2024 and 2027 with the newest generation of Mark V cars from Alstom. And by the early 2030s, the initial batch of Mark II trains from the early 2000s will also be retired.

TTC’s Line 3 Scarborough RT. (Fareen Karim/blogTO)

TTC’s Line 3 Scarborough RT. (TTC)

Conversely, Line 3’s only model of the train is the Mark I, while SkyTrain’s Expo and Millennium lines are also served by the Mark II trains that were introduced in the 2000s, and the Mark III trains from the 2010s, with each new generation of the train being markedly superior to the Mark I.

The primary reason for the TTC’s inability to keep up and ultimately retain the Scarborough RT is the decision to not reinvest in Line 3.

In 2006, the TTC’s report studying options to overhaul the Scarborough RT recommended a $190 million upgrade to handle newer generations of cars, specifically the Mark II. In order to conduct these changes, it would require a relatively short eight-month-long disruption to Line 3 services.

The upgrade project would address Scarborough RT’s primary problem: the sharp curve of the guideway immediately after departing Kennedy Station. The sharp curve with a 26-metre turning radius is sufficient for the short Mark I cars but cannot be overcome by the longer Mark II cars.

The problematic sharp curve at Kennedy Station on the TTC’s Line 3 Scarborough RT. (Shutterstock)

The problematic sharp curve at Kennedy Station on the TTC’s Line 3 Scarborough RT. (Google Maps)

Another $120 million would be spent towards acquiring new Mark II cars for both complete fleet replacements and added capacity by 2015.

The Mark I model of the train has long been discontinued by manufacturers. Custom-designed new-generation trains for Line 3 could theoretically be ordered to overcome the sharp curve without reconstruction of portions of the system, but the cost of these one-of-a-kind trains would be immense, according to the TTC at the time.

The recommended upgrade project would have built a new Kennedy Station to eliminate the sharp curve, in addition to extending the length of station platforms to enable the use of longer trains for more long-term capacity and other upgrades, such as maintenance and storage facility improvements.

Line 3 had a fleet of only 28 Mark I cars configured as four-car trains, which meant these trains, due to their limited number, saw significant wear and tear.

With maximum frequencies of about one train every three minutes, Line 3 had a peak hour capacity of only 3,800 passengers per hour per direction (pphpd), according to the TTC.

Even in the 2000s, when the study was performed, Line 3 was already overcapacity, with actual demand being 4,200 pphpd. Due to a lack of capacity, Line 3’s ridership growth has been stagnant, with average boardings hovering at just over 40,000 passengers per day until the pandemic.

For perspective, Metro Vancouver’s busiest bus route, the 99 B-Line, has a peak hour capacity of about 2,000 pphpd with a pre-pandemic average daily ridership of over 50,000.

SkyTrain’s Expo Line has a peak hour capacity and demand of over 15,000 pphpd.

The TTC’s future Line 5, the Eglinton LRT, will have a capacity of about 14,000 pphpd, with actual peak hour demand upon opening in the early 2030s being just over one-third of the capacity.

After recent upgrades relating to adopting some degree of automatic train control, Line 1 of the TTC subway can now handle up to about 36,000 pphpd.

In addition to the reconstruction costs and the new train fleet, in 2006, the TTC estimated a further investment of $50 million would be needed to handle the Scarborough RT’s forecast ridership demand of 6,500 pphpd by 2021 and 8,000 pphpd by 2031.

However, subsequent decisions made by Toronto’s political leaders steered away from the TTC’s outlined solution of a relatively easy and cheap fix for the Scarborough RT in favour of the multibillion-dollar subway extension, which eliminates the previous Kennedy Station transfer between the subway and Line 3. The subway extension is projected to see an average of 105,000 daily boardings by 2041.

SkyTrain Mark I car on the Expo Line. (Shutterstock)

Mark I SkyTrain cars during snowfall. (Shutterstock)

SkyTrain Mark I car. (Kenneth Chan/Daily Hive)

Add in major reliability issues due to poor maintenance and underinvestment — made particularly evident by the recent major derailment — it is understandable why Line 3 gained an infamous reputation amongst Toronto’s public transit riders over the decades, with a dishonourable sendoff last week to say the least.

But another key difference between the Scarborough RT and SkyTrain is how it is operated. Although Line 3 is capable of being fully automated without any onboard operator presence, the TTC deployed an operator on each Line 3 train due to union opposition to running unmanned trains.

In 2020, TTC staff examined the possibility of acquiring SkyTrain’s Mark I cars entering retirement as a measure to help extend the lifespan of the Scarborough RT. Although SkyTrain’s Mark I cars are “substantially similar,” there are still some key design differences unique to Line 3 that would require an expensive retrofit, specifically the installation of secure compartments at the end of the heads of the train for driver cabins.

As well, TransLink previously informed the TTC the Mark I cars would not be available for sale until 2024, when the retirement process is scheduled to begin. This would be “too late to avoid cannibalizing Scarborough RT vehicles for maintenance parts,” and “it is likely these vehicles would present similar structural concerns due to their advanced age.” TransLink’s SkyTrain system has a total of 150 Mark I cars.

In contrast, without the requirement to have an operator onboard, SkyTrain enjoys the complete benefits of a fully automated system, with lower operating (labour) costs and greater flexibility in train frequencies and schedules with just the push of the deployment buttons from the control room. The fully automated system is a contributing factor to SkyTrain becoming one of the busiest metro/subway systems in Canada and the United States as of early 2023.

But Toronto’s future Ontario Line, currently under construction, will see the unrestrained benefits of a fully automated system without the need for operators. Inspired by Metro Vancouver’s success with SkyTrain, particularly the Canada Line, the 15.6 km Ontario Line with 15 stations is expected to open in 2031 at a cost of about $19 billion. It will have a capacity of 30,000 pphpd, with ridership forecast to reach an average of 388,000 daily boardings by 2041.

In July 2023, Montreal opened the first 16.6 km, five-station segment of its REM light metro — a fully automated train system also inspired by SkyTrain. By 2027, the entire $6.9 billion REM network of 67 km and 26 stations will fully open, including a segment reaching Montreal Pierre-Trudeau International Airport. Upon full opening, the entire REM is expected to see an average of 190,000 daily boardings.

The original SkyTrain Mark I cars (left) will be fully retired by 2027, while the Mark II cars (right) will be retired starting in the early 2030s. (Kenneth Chan/Daily Hive)

A Mark III train at SkyTrain Edmonds Station. (TransLink)

mark v skytrain translink test alstom kingston ontario august 2023

The first Mark V SkyTrain train being tested at Alstom’s facility in Kingston, Ontario, August 2023. (TransLink)

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