Enbridge’s Great Lakes Tunnel Information Centre expansion includes a working model of the TBM that will drill under the Straits of Mackinac.
Situated in a long, darkened room that simulates a tunnel, the 6.7m-long TBM model includes cutterheads that slowly rotate, giving visitors an idea of how the tunnel will be excavated.
The actual TBM that will build the tunnel for Enbridge’s Line 5 pipeline, will be about 183m long with an internal diameter of 6.4m.
The pipe itself will be installed on rollers bolted to the side of the tunnel, leaving room for regular inspections. The tunnel could also house fibre-optic cables or other equipment to boost internet connection and emergency communications.
The tunnel will lie at least 30.5m below the lakebed of the Straits, eliminating the chance of an anchor strike to Line 5 and reducing the risk of a spill into the Straits.
In May last year Enbridge appointed Mackinac Straits Partners, a joint venture of Barnard Construction Company and Civil and Building North America, to lead the tunnel construction.
“For more than a year, we have been doing pre-construction work for the Great Lakes Tunnel,” said Jordan Hoover, Mackinac Straits Partners project manager. “Once final permits are received and we have the green light to construct, we’ll be ready to go.”
The US Army Corps of Engineers (USACE) expects to release the draft Environmental Impact Statement on May 30. That will begin a 30-day public comment period, with a final USACE decision anticipated in the autumn.
In April, the USACE granted national energy emergency status for Enbridge’s proposed tunnel for its Line 5 oil pipeline fast-tracking the environmental review process.
With the final permits on the horizon, Enbridge has launched a competition to name the TBM. The name should honour a local female from any period in history who lived in or made contributions to the Straits. Entries should be submitted to Line5Info@Enbridge.com by June 7.
