Yonge North Subway Extension tunnel project welcomes first boring machine

A special delivery has arrived for the Yonge North Subway Extension. 

The first of two tunnel boring machines (TBMs) that will dig the extension’s twin 6.3-kilometre tunnels has arrived at the tunnel launch shaft site in York Region

Emblazoned with a bright red maple leaf, the TBM’s large circular cutterhead will eventually rotate and carve out one of the new subway tunnels, after the machine is fully assembled and ready.  

Work to assemble the first TBM is now underway, with a crane being used to lower its pieces into the launch shaft, where the machine will be put together – bringing the Yonge North Subway Extension one step closer to tunnelling.  

The second TBM will go through a similar process when it arrives. 

Meanwhile, crews are getting the launch shaft site ready for future tunnelling by installing equipment and support systems the TBMs will need once they start digging. 

The Yonge North Subway Extension will extend TTC Line 1 subway service approximately eight kilometres farther north, building rapid transit from downtown Toronto to Vaughan, Markham, and Richmond Hill. 

Once assembled, the two TBMs will tunnel south from the launch shaft toward Finch Station, each digging one of the twin tunnels that will connect the subway extension to existing Line 1 service at Finch Station. 

The Yonge North Subway Extension will add more than 94,000 transit rides to the network each day, reducing travel times by up to 22 minutes and cutting greenhouse gas emissions by more than 4,800 tonnes annually.  

In August, Infrastructure Ontario closed the Request for Proposals (RFP) stage and shortlisted 11 teams for the Yonge North Subway Extension – Stations, Rail and Systems contract (YNSE SRS).

Featured image: (Metrolinx)