Twin TBMs Ready to Launch for Vancouver, B.C. Tunnels
A $2.34-billion extension of Vancouver's Millenium Line subway will include tunnels and elevated guideway. Rendering courtesy of Acciona-Ghella
Two parallel 5.7-kilometer tunnel excavations will soon start in Vancouver, B.C., as part of the Millennium Line subway extension that includes six new stations.
The twin earth-pressure-balance tunnel-boring machines are each 19.6 ft in diameter, about the height of a three-story home. The machines are 328 ft long and weigh about 1,000 tons.
The $2.34-billion Broadway Subway Project, funded and delivered by the province of British Columbia with $740 million from the Canadian federal government and $82 million from the city, will be delivered by the joint venture of Acciona and Ghella in a design-build-finance contract.
The extension for TransLink, the regional transit operator, will reduce congestion and greenhouse gas emissions, according to Gigi Chen-Kuo, TransLink interim CEO.
“We are excited to begin the major works on this signature project, which will help put Vancouver back to work,” Carlos Planelles, ACCIONA North America manager director said in a statement.
In preparation for the tunnel work, the construction team has prepped the site, demolished buildings and relocated utilities. Crews will now build traffic decks to allow the tunnel boring to occur below ground without disrupting vehicle movement through the city. This engineering solution drills and places vertical columns to support steel plates needed for the traffic decks.
The majority of the line will be underground thanks to the twin tunnel-boring machines. Later in 2021, work will begin on the elevated guideway and tunnel portal to provide access to the underground portion of the new line. In 2022, both machines will be launched in a staggered manner from the Great Northern Way-Emily Carr Station. Tunnel excavation will occur about 50 ft below ground through mainly sandstone and some glacial till. The tunnel’s deepest point reaches 65 ft deep and the tunnel overburden ranges between 23 and 60 ft.
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The province expects the six new underground stations to connect communities and make it easier to travel along Broadway. Once opened in 2025, the commute from VCC-Clark to Arbutus Station will take 11 minutes, an average savings for transit users of almost 30 minutes per day and will relieve congestion along Broadway.
Transportation Investment Corp., a Crown corporation as a subsidiary of the BC Transportation Finance Authority, is leading the delivery of the Broadway Subway Project on behalf of the Ministry of Transportation and Infrastructure. It will provide controls, practices and oversight. BC Infrastructure Benefits, a provincial Crown corporation, is recruiting, hiring, supporting and paying skilled trades workers on the project, aiming to increase training opportunities for apprentices so they can complete their certification and help build the province’s skilled-trade workforce.
Kennedy Stewart, Vancouver mayor, said the Broadway corridor helps generate $11.56 billion in gross domestic product and the Broadway Subway line “will move us all forward in a way that not only supports people, but also ideas, innovation and investment.”
The naming of the twin TBMs is underway.
