We talk a lot about tunnelling.

But that’s because there has been a lot to talk about, given the progress that’s been made since tunnelling started on the Eglinton Crosstown West Extension this past April.

In the last six months Renny, the first tunnel boring machine to start tunnelling, has tunnelled 1.9 km, while Rexy, the second tunnel boring machine, has tunnelled 1.1 km since late July. (You can keep track of Renny and Rexy’s progress here.)

When these two tunnel boring machines are finished, they will have dug more than 6 km of tunnel between Renforth Drive and just west of Scarlett Road – a significant section of the 9.2-km route.

Once the Eglinton Crosstown West Extension is complete, you will be able to travel quickly and easily from the east end of Toronto, through the heart of the city and into Mississauga — no transfers needed.  

West End Connectors Construction (WECC), the team building the tunnels between Renforth Drive and Scarlett Road, are not just working on the tunnels, but also busy with work at key points along the route.

All about headwalls 

Headwalls are an important part of the building the tunnels.

Headwalls are the underground support structures made up of a series of concrete columns, called piles, that create a watertight wall around the area of future subway stations and emergency exit buildings.

To build the headwalls, piles will be drilled into the ground using large drill rigs, which are usually over 33 metres high.

They must be built before the tunnel boring machines arrive at each location. It takes about four to eight months for crews to build each headwall.

The headwalls will then be used as frames for building the future stations and emergency exit buildings.

Headwall construction for the project has been underway since the spring.

Since it needs to be complete before the tunnel boring machines arrive at each site, the headwall construction is moving from west to east along the alignment ahead of the arrival of the TBMs.

Headwall construction at Martin Grove Avenue started this spring and will wrap up this month (October), while construction at Kipling Avenue started this summer and will wrap up in spring 2023.

Work for the emergency exit building at Wincott Drive also began this summer and will last until next spring.

Looking ahead, headwall work at Islington is expected to begin later this fall and last until the spring of 2023, while headwall construction at Royal York is slated to begin in the winter. 

Realigning Eglinton Avenue West

Once Renny and Rexy reach their destination just west of Scarlett Avenue, they will be dismantled and removed from the ground through an extraction shaft.

This shaft is also the portal for where the trains will transition between the tunnel and the elevated guideway.

Construction for the extraction shaft will begin this winter – but first crews are making room by shifting Eglinton Avenue West 10 metres (or 33 feet) south.

Starting in April, crews began realigning the road, including excavating the existing sidewalk, multi-use path and grass patches lining the road, and built a retaining wall, which will eventually keep a brand-new sidewalk and multi-use path separate from the newly-shifted traffic lanes.

Crews have also been building a new ramp that connects to the pedestrian bridge just west of where the portal will be.

This work is anticipated to be completed by the end of this year, at which point WECC will switch to construction of the extraction shaft. 

Virtual open house

To learn more about upcoming construction work, register for the virtual open house on Nov. 2.

For those interested in getting more involved, there is an opportunity to join the Construction Liaison Committee (CLC).

Quarterly CLC meetings provide a forum for residents, businesses or other local interested parties to communicate and share concerns directly with project staff.  For more details on how to join the CLC, email eglintonwest@metrolinx.com.

Visit Metrolinx.com/EglintonWest to sign up for the project newsletter and get the latest project information.