Second TYSSE TBM makes final breakthrough

摘要

One of the four 6.12m diameter Caterpillar EPBMs mining the Toronto-York Spadina Subway Extension (TYSEE) has completed its final drive in early March. Breaking through the headwall of Downsview extraction shaft in Toronto, this is the second TBM, named Moley, to finish tunnelling on the project. The TBM tunnelled 1.2km in its final drive and placed 799 tunnel liners. The first TBM, Holey, completed excavation late last year. The contractor for both drives is the joint venture of McNally, Kiewit and Aecon, constructing the southern tunnels package including 5.8km of tunnels in four drives.