On the 04/10/2021 the joint venture  between Aecon (40%) /Traylor Bros Inc. (60%) completed for Metro Vancouver excavation of the Second Narrows Water Supply Tunnel, located in North Vancouver, British Columbia. The tunnel underneath the Burrard Inlet – with a 5.8 m internal diameter - is one of the largest tunnels ever built by Metro Vancouver. It had also been excavated with the first slurry TBM machine to be used in Canada. The TBM - 135 m long, with a 6.69-m cutting diameter and nicknamed Lynn Marie - was launched from the north shaft in August 2020. In order to complete the tunnel, first, a 50-m-deep vertical entry shaft was excavated on the north side of the inlet, followed by a vertical exit shaft more than 100 m deep on the south side.  

The new 6.3-m-diameter and 1.1-km-long tunnel was excavated 30 m (100 feet) below the bottom of Burrard Inlet, east of the Ironworkers Memorial Bridge. It runs between a Metro Vancouver works yard in the District of North Vancouver and Second Narrows Park (also known as Montrose Park) in Burnaby.  

This project is one of five new regional water supply tunnels that are being designed to meet current seismic standards to ensure the reliable delivery of drinking water in the region in the event of a major earthquake.  

The new tunnel and water mains will replace three existing shallow buried water mains that went into service in 1948, 1954 and 1978, which are vulnerable to damage during an earthquake and are nearing the end of their service lives.  

Now that the tunnel is complete, three steel water mains - one 1.5 m in diameter and two 2.4 m - will be installed inside and connected to the existing water system with new valve chambers.  

Construction on the Second Narrows Water Supply Tunnel began in 2019 and the project is expected to be complete in 2025. The construction budget is EUR 305.96 million (CAD445 million). Visit http://www.metrovancouver.org. 40/21.