The first of two TBMs, Renny, was launched this week to dig the 6km twin tunnels between Renforth Drive and Scarlett Road. The second TBM, Rexy, will follow in about four weeks. The machines, which have a 6.58m diameter, will work at a 20m depth and progress about 10-15m a day.

The extension project will add six stations and 9.2km to the Eglinton Crosstown LRT, connecting Scarborough to Mississauga along one continuous route. The main Eglinton Crosstown LRT section, which has been under construction for about a decade, is expected to open by the end of this year. The western extension is due to be completed in 2030.

Plans are also being explored for an additional 4.7km extension connecting Renforth Drive and Toronto Pearson International Airport.