Support growing for Great Lakes Tunnel

26 June 2020

Following the March 2020 announcement confirming the selected contractors, and a recent ruling that the construction is constitutional, support for the US$500m Great Lakes Tunnel is growing.

Communities across Michigan, US have come out in favour of the project following a recent ruling by the Michigan Court of Appeals that legislators did not violate constitutional guidelines in allowing its construction. Furthermore, a recent problem which caused a partial shutdown on the existing pipeline has highlighted the need for a replacement.

The proposed 6.6km tunnel will convey a section of the Line 5 oil pipeline 30m beneath the bed of the Straits of Mackinac which link Lakes Michigan and Huron. It will be constructed for energy provider Enbridge by Great Lakes Tunnel Constructors, a partnership between JayDee Contractors and Obayashi Corporation’s US affiliate. Arup will be the designer. The project will replace the existing 1953-built line comprising two pipes anchored to the lake bed.

Excavation is currently envisaged to be by TBM to create a 3m internal diameter tunnel with a 300mm-thick segmental lining. Destined to become the biggest infrastructure project in Michigan, construction is expected to begin in 2021, take two years to construct and be operational in 2024.

Line 5 is a major North American pipeline stretching 645 miles (1,032km) eastwards from its starting point at the tip of Lake Superior, through Wisconsin, Michigan and below the Straits of Mackinac, and onto the city of Ontario, Canada.