The Don Yard is one of the largest construction sites for the Ontario Line. Located in Toronto’s east end, this is where Ontario Line trains will transition between underground and above-ground tracks on the Lakeshore East rail corridor. Although the site will not be home to a station, local residents will be a short walk from the future Corktown station.

The first two Ontario Line tunnel boring machines (TBMs) will end their six-kilometre journey from just east of Exhibition Station at the Don Yard, which will serve as one of the subway line’s four tunnel portals.

Piling and excavation

Foundation work at the Don Yard began in August 2024 with piling, which involves drilling interlocking vertical concrete and steel columns into the ground to create a watertight retaining wall for safe excavation. More than 880 piles have been drilled for the tunnel and portal, with another 270 to come. Crews have installed more than 520 rock anchors that will support the retaining walls during excavation.

Excavation is now underway in areas where piling is finished. More than 60,000 cubic metres of material have been excavated to date, with an additional 70,000 to come.

Excavators will dig as deep as 22 metres to reach the end of the tunnel, which will have a ramp that will allow trains to climb gradually to the surface before crossing the Lower Don Bridge. The tunnel ramp will be about 500 metres long, making the Don Yard the largest worksite on the Ontario Line.

Bridge building

Ontario Line trains will travel along the Lower Don Bridge, a brand-new, 120-metre-long bridge at the east side of the Don Yard that will pass over the Don Valley Parkway (DVP) and the Don River.

Currently, a temporary bridge is under construction, which will serve as an access ramp and platform for crews to build the permanent bridge. Parts of the permanent bridge are being constructed in Nova Scotia and will be assembled in Toronto. Thanks to the temporary bridge, overnight closures of the DVP will only be required for a few weekends.

Managing disruption and noise

We’re minimizing potential construction impacts on local residents as much as possible.

A new five-metre sound barrier will limit construction noise, and we continuously monitor noise, vibration and air quality to ensure acceptable levels.

The Don Yard is home to a manual auger cleaner — a first in North America – which is used for any piling work done after 7 p.m. Augers use rotating blades to bore holes in the earth for piling. Normally, augers are cleaned by shaking, which causes a loud banging noise. Auger cleaners brush dirt and debris off the machine, minimizing noise.

Every truck leaving the construction site goes through a wheel wash to remove dust. We supplement this with frequent street sweeping and street washing around the site.

We also use beet juice on site to limit dust. Beet juice powder mixed with water creates a sticky substance that picks up dust, won’t corrode metal, has a low freezing point and is safe for plants and animals.

Once complete, the Ontario Line will give people more time back in their day, with a full trip across the line taking less than 30 minutes. The Ontario Line will offer connections to more than 40 other travel options, including the TTC’s Line 1 and Line 2, three GO Transit rail lines and Line 5 Eglinton.

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