Past scientific, technological feats shape engineering marvels today
Separated by more than five decades, moon walk, Great Lakes Tunnel Project have commonalities
July 20, 2022
Fifty-three years ago, on July 20, approximately 650 million people riveted to television sets across the globe watched U.S. Astronaut Neil Armstrong step off the Apollo 11 lunar module, becoming the first man on the moon.
Captivating the imaginations of millions, that 1969 engineering and technological feat resulted from engineers, scientists, mathematicians, geologists, safety experts, and others working together.
While it might not captivate millions on television, another engineering and technological advancement awaits Michigan and the region.
Enbridge is investing more than $500 million to construct the Great Lakes Tunnel under the Straits of Mackinac. The Tunnel will house a replacement section of Enbridge’s Line 5 and may also support fiber optic cable, improving connectivity.
“The Great Lakes Tunnel is not as grand as the moon landing, though it is an engineering marvel forged by technological and engineering advancements over the last century,” said Bob Lehto, Enbridge’s operations manager for the northern Michigan area.
“The Tunnel will enable the region to continue to receive safely from Line 5 the energy that helps keep millions of furnaces, households and businesses running.”
Placed deep below the lakebed in the Straits, the concrete tunnel will house a replacement section of Line 5. The tunnel will eliminate the chance of an anchor strike and reduce the chance of a release to near zero.
Designed for the Straits
Similar to a submarine though with a giant drill on it, a tunnel-boring machine (TBM) will be a key part of constructing the Great Lakes Tunnel.
Designed specifically to manage the bedrock and other underwater geological conditions of the Straits, the TBM will be approximately 500 feet long. It operates in a closed mode that seals it from the surrounding water.
As the TBM moves under the lakebed, it will install a ring of concrete lining segments behind it to seal the Tunnel. Enbridge anticipates the TBM will move approximately 40 feet a day, five days a week over approximately two years.
“Construction of the Great Lakes Tunnel exemplifies the best in technology, engineering, science, and safety,” said Lehto.
“It will enable us to enhance protections of Michigan waterways without compromising the safe delivery of the propane, fuel and other energy on which the region depends.”
