Gordie Howe bridge taking shape as towers enter final stage
The towers of the Gordie Howe International Bridge have reached an important construction milestone: crews are moving to extend them the final 262 feet (80 meters) into the sky.
Bridging North America began work earlier this month on the final portion of the tower — the pylon head — which will allow the two lower pylons to merge into one, giving each reinforced concrete tower an inverted Y-shape, bridge officials said.
"It is an exciting time as the towers — arguably the most visible aspect of construction to date — move into the next and final build phase," Bryce Phillips, the CEO of Windsor-Detroit Bridge Authority, said in a statement.
"With the towers currently standing at over two-thirds of their final 220 metres/722 feet height, they represent the significant progress the project team has been able to achieve."
The towers have been under construction since 2019 and are expected to be completely finished by the end of 2022. The bridge is slated to open to traffic by the end of 2024.
The $4.4 billion bridge project is touted by officials as one of the largest infrastructure projects in North America. BNA is the private-sector entity responsible for construction, operation and maintenance of the bridge and the United States and Canadian ports of entry.
Michael Hatchell, CEO, Bridging North America, said the company is completing a major engineering feat.
"The joining of the two tower legs will mean we’ve achieved an important milestone for the project," Hatchell said in a statement. "BNA has been able to reach this point in the project safely and efficiently and is extremely pleased with the work of our team."
The work of transitioning from the lower pylon to the pylon head is expected to be completed in the spring and involves concrete pours to construct an upper cross beam that will merge the tower legs into a single structure, bridge officials said.
Anchor boxes within the pylon head — which officials say are critical to the cable-stayed design — will house the cables that will connect the towers to the bridge and decks.
Each inverted Y-shaped bridge tower is made of cast-in-place reinforced concrete and has been built in sequential manner, bridge officials said, through ‘lifts’ or tower leg segments of approximately 15.3 feet (4.67 meters) tall.
"Before you can build up, you have to build down," Phillips said. "Substantial work was done underground to help support these massive towers that have become a very visible sign of the project’s progress."
Bridge official said each of the towers is supported by 12 shafts drilled into the bedrock to a depth of 118 feet (36 meters) — the equivalent of a 12-story building. Each of the shafts is filled with approximately 69,000 gallons (262,000 liters) of concrete and are connected by 5,250 feet (1,600 meters) of post tensioning cables to create a firm footing.
Once completed, the two towers will reach about 722 feet (220 meters) and will rival the height of Detroit’s tallest building, the 73-story center tower of the GM Renaissance Center. The full weight of just one tower will be approximately 66 million pounds (30,000 metric tons) — the weight of 165 jumbo jets. Together, the bridge towers and cable system are being constructed to support nearly 34 million pounds of weight.
The Gordie Howe International Bridge has surmounted more than a decade of legal and political challenges.
The owners of the private Ambassador Bridge, located two miles away from the Gordie Howe Bridge, had made 25 legal challenges to halt construction of the bridge and all of them failed.
"After more than seven years of hard work, today we broke ground on what will be a thriving legacy named for a legend," Snyder said, referring to the former Detroit Red Wing hockey great. "Gordie Howe represented the best of Canada and the United States."
A 2012 Michigan ballot measure — for which the Ambassador Bridge owners spent an estimated $50 million to support — that was aimed at thwarting, or at least delaying, the project also failed.