Collapse of local bridges unlikely but not impossible, experts say

Are the Ambassador Bridge and the new Gordie Howe International Bridge prone to collapse if struck by a ship?

“There is no way we can design a structure with a probability of failure zero,” said Dr. Faouzi Gherib, a civil engineering professor at the University of Windsor.

He explains that thought to his students when they first learn to design.

From an engineering point of view, Gherib said the Francis Scott Key Bridge in Maryland collapsed for one simple reason.

“The bridge was hit at the weakest point possible,” he explained.

Turning to the Ambassador Bridge, there is a pier on the Canadian side that could expose the bridge to a possible collision.

“It is surrounded by shallow water,” said Harbourmaster Peter Berry, who believes it would be difficult for a ship to hit the pier. If the ship did manage to make it that close to the concrete post, the impact wouldn't be catastrophic because there are reinforcements underwater.

“First you're going to hit a concrete pier,” Berry explained. “Secondly you're going to hit steel superstructure. You're not going to make contact to the road deck and the suspension of that road deck is contingent on the wires.”

Berry said the height of the bridge, built in the late 1920s, accounted for vessels of the day that had masts. Today's ships aren't as tall.

Down river, the design of the new bridge is very conventional and standard. The Gordie Howe International Bridge has two piers and a cable system.

According to Gherib, it's a sound build proven around the world.

“As a society we have to accept a certain risk to be able to build structures in an economic way,” he said.

The Gordie Howe International Bridge, like many other builds and construction projects, was designed to consider the probability of something serious happening, he added.

“We take that into account in designing the cables, the shape of the deck. The shape of the pillars. Everything is taken into account,” he explained.

If an event like Baltimore were to happen locally, Berry said, “We do have assets and resources and the mind power locally to start to resume the recovery of that traffic system.”

The U.S. Coast Guard released a statement Tuesday saying they are responsible for the safe flow of people and goods through the waterway. The release adds a contingency plan is in place involving many partners in the event they are called upon to respond to a major incident.

The plans are reviewed regularly and exercised.