Tunnelling got underway Monday on the Eglinton Crosstown West Extension, a project that will add 9.2 kilometres to the nearly-ready Eglinton Crosstown line.

After roughly a decade of construction, the first stretch of the crosstown is expected to be “substantially complete” later this year. The 19-kilometre, 25-stop light rail line running between Kennedy and Mount Dennis is expected to open several months after that.

The extension project launched today will continue the line west of Mount Dennis, with stops at Jane, Scarlett, Royal York, Islington, Kipling, Martin Grove and Renforth.

Representatives from all three levels of government attended the launch Monday.

“We are getting shovels in the ground for this historic project and building world-class transit that will make life easier for the people of the GTA, while supporting the creation of thousands of jobs and spurring economic growth for decades to come,” Premier Doug Ford said.

Mayor John Tory lauded the cooperation of various governments in bringing the project to a start and said it will be good for the city.

“We know that this transit extension will be good for families, it’ll be good for jobs, it'll be good for investment, it'll be good for tourism, it’ll be good for the environment because it'll get cars off the road,” Tory said.

Federal Transport Minister Omar Alghabra lauded the project and said its importance for GTA residents “cannot be understated.”

“This is one of the many investments our government has made in public transit to connect residents across the GTA, and will transform the way people in our community get around," he said.

The extension will run mostly underground.

Rexy and Renny, the two massive tunnel boring machines at the Renforth launch shaft site, will dig the roughly six-kilometre twin tunnels under Eglinton Avenue West to Scarlett Road.

The boring machines will operate approximately 20 metres deep and move about 10 to 15 metres per day.

Tunnelling for the extension is expected to be completed sometime in 2023 to 2024.

Construction on the extraction shaft at Scarlett Road is expected to begin this spring.

The province says the extension will support as many as 4,600 jobs annually during construction and attract 37,000 daily rides by 2041.

Metrolinx says it is also working with the Greater Toronto Airports Authority on a possible connection of the line to Toronto Pearson Airport.

Construction of the initial $5.5 billion Eglinton Crosstown project began under the previous Liberal government a decade ago. The line was originally slated to be operational by 2019 or 2020, but has faced a number of construction delays.