Full Speed Ahead

TTC’s Spadina Line Extension Surges Forward

Toronto, Ontario, is the capital of Canada’s most populous province, as well as the country’s commercial capital and largest metropolis. With a population of more than 6 million people in the greater Toronto area, efficient transportation is an ongoing challenge.

This was evident in 1921, when the Toronto Transit Commission (TTC) was created to consolidate street railways in and around the city; it was evident in 1954, when TTC built Canada’s first subway – the 4.6-mile long Yonge Street line; and it is evident today as TTC continues to build out its subway system.

Currently, TTC is building the Toronto-York Spadina Subway Extension (TYSSE), a $2.6 billion, 8.6-km extension from Downsview Station to Vaughan Metropolitan Centre Station in York Region. Construction began in 2009 with revenue service anticipated to begin in the fall of 2016. The project is unique in that it marks the subway’s first foray beyond Toronto’s city limits.

Not only does the alignment venture into new territory, but other project stakeholders are involved along the way, including federally owned Downsview Park, commuter rail lines, power corridors, highways and, perhaps most notably, York University, which the new subway traverses.

“Historically, we have built our subways under municipal roads, but this project goes under buildings at the university as well as other properties not owned by city,” said Joanna Kervin, TTC Director, Third Party, Planning and Property. “That not only creates technical challenges, but also creates a different dynamic with the property owners. We need to educate them on what the process is and what steps are involved in the construction of the facilities.”

Instead of hindering construction, as is the case in some instances, third parties played an instrumental role in getting the subway built. In fact, York University, home to some 60,000 students, had been a strong supporter of the line for many years.

Additionally, the City of Vaughan has been a proponent of the extension and is anticipating development in the vicinity of the new station. “A lot of the momentum for this project came from York University and City of Vaughan,” Kervin said.

The project is also unique in that there are four different funding partners from three different levels of government. The funding partners are the Canadian federal government (26.5 percent), Province of Ontario (40.2 percent) and the municipal governments of Toronto (20 percent) and York Region (13.3 percent).

Project Background

Construction is broken out into six main construction contracts that include twin tunnels and the construction of six new stations. The 8.6-km extension includes 6.7-km of mined twin tunnels through glacial and alluvial soils. The project extends northwesterly from the terminus of the Yonge-University-Spadina line at Downsview Station to Vaughan, passing through York University along its alignment.

To accelerate the construction schedule, TTC purchased four 6.12-m EPB from Caterpillar Tunneling (formerly Lovat) – a model the agency used successfully on the Sheppard Line project that opened in 2002. In some cases, TBMs can take 12 to 15 months for order, design, manufacture and delivery. By ordering the machines in advance, TTC can be assured that contractors can begin tunneling activities soon after award. Additionally, TTC procured the gasketed precast concrete tunnel segments in advance.

The contracts are broken down as follows:

Sheppard West Station and Southern Tunnels: Awarded Nov. 19, 2010, to Aecon/McNally/Kiewit for $279 million. Work is progressing and is approximately 50 percent complete. The project involves four tunnel drives using two EPB TBMs (nicknamed “Holey” and “Moley”). Starting at the Sheppard West Station location, two parallel tunnels were driven northerly to Finch West Station. TBMs were launched in summer/fall 2011 and completed in May/June 2012. From there, the TBMs were returned to Sheppard West Station to make the drive to the existing Downsview Station.

Highway 407 Station and Northern Tunnels: Awarded Jan. 19, 2011, to Spanish firms Obrascon Huarte Lain (OHL) and FCC Construccion for $404.4 million. The project involves six tunnel drives using two EPB TBMs (nicknamed “Yorkie” and “Torkie”). Starting at the Steeles West Station location, two parallel tunnels were launched toward York University station, completing this drive north of Finch West Station. From there, the TBMs will be moved to Highway 407 Station, where they mine southerly toward Steeles West Station, are extracted and returned to Highway 407 Station to make the final drive to Vaughan Metropolitan Centre Station. Tunneling began in November 2011.

• Finch West Station: Awarded June 2, 2011, to Bondfield Construction. Work is progressing and is approximately 25 percent complete.
• York University Station: Awarded July 25, 2012, to EllisDon Construction. Work is scheduled to begin in February 2013.
• Steeles West Station: Awarded Sept.28, 2011, to Walsh Construction Company Canada. Work is progressing and is approximately 15 percent complete.

Vaughn Metropolitan Centre Station: Awarded June 21, 2011, to Carillion Construction Company. Work is progressing and is approximately 25 percent complete.

Special Features

As the extension ventured into developing parts of Toronto and York Region, TTC was afforded the opportunity to break away from the more utilitarian station design approach predominant in its earlier subway projects. Each station used prominent architects and artists, resulting in stations that have a unique and signature style.

“The stations were intended to be attractive spaces in addition to being functional,” said Ian Trites, Facility Coordinator-Architectural for TTC. “The goal is ridership and having stations that are appealing help make people want to ride the subway, and it shows that TTC cares about improving the experience of the riders.”

Another unique design feature of the project is the tunnel alignment passing through York University. The new station is sited in the campus commons, shoe-horned in between two campus structures: the Schulich Building, which is part of the business school, and the York Lanes building, a campus retail mall. Given the inability to move the tunnels out from beneath the Schulich building, and the sensitivity of the structure, consultant Hatch Mott MacDonald developed a compensation grouting program to protect the building during tunnel construction.

Using three access shafts adjacent to the structure and a fanned array of ported grout injection tubes situated above the twin bore tunnel and below the Schulich building’s foundations, grout will be able to be injected at specific pressures and locations to compensate for any settlement that occurs above the tunnels, thereby mitigating impacts on the structure itself. Utilized in conjunction with a ground and structure instrumentation system, all parties will be able to track building performance as the TBMs mine under the structure. The contactor successfully passed under the buildings in fall 2012 without incident.

On the Move

Traveling along the route, construction is evident from start to finish as crews are in the fast track toward this major expansion. Tunneling crews are averaging about 15 m of advance per day as they work toward completion. On the northern tunnels, crews reached a milestone by installing 24 rings in 24 hours.

At the station locations, cranes and other construction equipment are buzzing about, building large scale excavations that will incorporate the track structures and stations. But despite the disruption to the patterns of daily life, people – for the most part – are dealing with construction in a positive manner.

“Despite the fact that there are impacts from construction, people have been pretty tolerant,” Kervin said. “People can see that we are making progress and that we are building something that is very exciting.”

At the northern terminus of the alignment, Vaughan Metropolitan Centre Station, developers are constructing office facilities that are planned to open at the same time revenue service begins.

“As the owner and operator of the subway, our ultimate goal is ridership,” Kervin said. “We are thrilled to see development occurring that will assure that we will have riders from Day 1.”

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Station Tour

Each of the six subway stations on the Toronto-York Subway Extension has a unique architectural style with the design of world-class architects. Here we take a tour of the new stations, starting with the northern terminus and heading south.

Vaughan Metropolitan Centre Station
Designed by: ARUP Canada
Lead Architect: Grimshaw Architects
Executive Architect: Adamson Associates
Artist: Paul Raff Studio, Atmospheric Lens
Located at the Highway 7 and Millway Avenue intersection

Highway 407 Station
Designed by: AECOM
Lead Architect: AEDAS
Artist: David Pearl, Facing West and Sky Ellipse
Located southwest of 407 ETR and Jane Street intersection

Steeles West Station
Designed by: TSGA
Lead Architect: Will Alsop
Artist: realities: united, Light Spell
Located at the intersection of Steeles West Avenue and North West Gate

York University Station
Designed by: ARUP Canada
Lead Architect: Foster + Partners
Executive Architect: Adamson Associates
Artist: Jason Bruges Studio, Piston Effect
Located at the Harry W. Arthurs Common at York University

Finch West Station
Designed by: TSGA
Lead Architect: Will Alsop
Artist: Bruce McLean, Columns
Located near the Keele Street, Finch Avenue West intersection

Sheppard West Station
Designed by: AECOM
Lead Architect: AEDAS
Artist: Panya Clark Espinal, Spin
Located at the northern end of Parc Downsview Park, near the intersection of Sheppard Avenue West and Bakersfield Street

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Caterpillar: Toronto’s TBM Partner

Founded as LOVAT in 1972, Caterpillar Tunneling is well known for its specialization in the custom design and manufacture of versatile tunnel boring machines (TBMs) utilized across many industry segments including metro, railway, road, sewer, water main, penstock, mine access and telecommunications tunnels.

Over the years with each new experience, the company developed new and innovative excavating methods to meet ever more demanding site conditions.

These innovations include patents such as pressure relieving gates, flood control doors and segment erector arms. Caterpillar was also the first to introduce variable frequency electric drive on large EPB TBMs.

The company has built over 280 TBMs and performed over 350 full refurbishments for more than 700 tunneling projects worldwide. The company’s TBMs have excavated more than 2,500 km (1,500 miles) of tunnel. Today, some of the original TBMs are still operating after more than 20 years, a testament to the company’s design and manufacturing philosophy: durable, robust and reliable.

Caterpillar acquired LOVAT in 2008. Since the acquisition, Caterpillar has made significant investment on expanding and upgrading the production facilities, which mainly include a new 180,000-sq ft Manufacturing & Logistic Center, multiple large machining centers including a new state-of-the-art Waldrich-Coburg vertical boring and mill machine, 200-tonne crane and a 15,000-sq ft remanufacture centre. As part of a larger Caterpillar global organization, the company can fully leverage the engineering resources of the corporation to strengthen its R&D capabilities, which will help to explore investment in further product range growth and improve cutting tools performance, all critical to the success of the customers.

To optimize the construction schedule and cost effectiveness, Toronto Transit Commission (TTC), the owner of Toronto-York Spadina Subway Extension Project, procured four 6.12-m earth pressure balance TBMs from Caterpillar Tunneling in August 2009. The TBMs will bore 8.6 km of tunnels from Downsview Station northwest through York University, within the City of Toronto and north to the Vaughan Corporate Centre in the Regional Municipality of York. The first twin tunnel section broke through in June 2012 and the second section was expected to break through in November 2012.

Another example of this owner-procured model is the Regional Municipality of York. In September 2009 the Municipality awarded Caterpillar Tunneling for supplying four 3.6-m earth pressure balance TBMs for the construction of 14.935-km of Southeast Collector Trunk Sewer tunnels. So far all of them have been delivered to site and three have started mining.

Also, Metrolinx purchased four TBMs in July 2010 for the construction of 11 km tunnel of Eglinton Crosstown LRT Project.

The TTC machines, as well as those for the other above-mentioned projects, are all equipped with chromium carbide-plated ripper teeth manufactured with high tensile steel, interchangeable with 394-mm (15.5 in.) disc cutters. The main drive consists of variable frequency drive electric water-cooled motors providing sufficient power to the cuttinghead. The fully loaded TBMs have the vacuum pick up for segment erection, advanced ground conditioning systems, wear indicator installed on the gauge and face rippers, as well as the CAT Tunnel Link system.