A problem for reinforcing bridges? Ships are getting bigger.

As larger, faster container ships began plying the Delaware River in recent years, transportation officials feared the possibility of one going off course and repeating, or worsening, what happened in 1969, when a tanker truck crashed into the Delaware Memorial Bridge. and caused significant damage.

So work began last year on a $93 million project to build eight massive cylinders that would stand guard in front of the bridge’s pylons to protect a system that carries tens of thousands of vehicles a day.

“The tankers and freighters of 1950 are not the tankers and freighters of today,” said James Salmon, spokesman for the Delaware River and Bay Authority.

The collapse Tuesday morning of the Francis Scott Key Bridge in Baltimore after a cargo ship the size of nearly three football fields crashed into it, killing six people, has raised questions about whether similar disasters could occur elsewhere .

But the Delaware Memorial Bridge work reflects the fact that some shipping and transportation experts have long pondered the dangers of new ships of goods trapped under decades-old bridges.

The problem is that there are no easy answers, also because the ships continue to grow.

Michael Rubino, retired chief pilot at the Port of Los Angeles, said this air currents (the distance between the water and the highest point of a boat) of some newer boats has become so great that some boats require bend the antennas. and trees to pass under a bridge.

“People don’t realize how huge these ships are,” he said.

Joseph Ahlstrom, a SUNY Maritime College professor, ship captain and commissioner of the New York State Pilot Board, said commercial vessels have grown so much in recent years that they are much more likely to cause damage to infrastructure such as bridges .

“This is going to affect them,” he said of a modern ship and the danger it poses to a bridge like the one in Baltimore.

“It’s going to knock him down, and that’s what happened.”

Single case?

Many transportation officials say it’s difficult to draw parallels to the Key Bridge because what happened in Baltimore appeared to be a very unusual event:

a confluence of factors at the worst possible time.

When the ship, the Dali, passed through the harbor without a tug attached, it experienced a “total blackout” and lost control, then crashed into a shoulder that had small protective barriers.

The Key Bridge situation is “unique,” ​​said Jim Tymon, executive director of the American Association of State Highway and Transportation Officials, which represents state transportation departments.

“This is not something we can really compare to.”

However, National Transportation Safety Board officials said Wednesday that they were not only examining the protection system around the Key Bridge, but were also seeking documents on protections around other bridges in Maryland.

Aimless ships have long been seen as a risk to bridges, particularly after a cargo ship crashed into the Sunshine Skyway Bridge in Tampa Bay, Florida, in 1980, killing 35 people.

After that disaster, Maryland officials recognized that the Key Bridge, which opened in 1977, could have been knocked down by a direct hit.

But they said the concrete barriers installed on the river were intended to deflect or slow an out-of-control vessel.

Therefore, the final contact may only be an “indirect hit,” John Snyder, director of engineering for the state Tolling Facilities Administration, told the Baltimore Sun at the time.

As part of rebuilding in Tampa Bay, officials have prioritized protection against a future disaster.

They built a network of large concrete islands, called dolphinswhich could absorb the impact of a fleeing ship.

Since then, officials across the country have increasingly focused on strategies to improve shields around bridges.

“Some modern bridges around the world, especially since the Tampa accident in 1980, have been designed with different features to mitigate impacts and protect their piers,” the U.S. Secretary of Transportation said. Pete Buttigieg.

“Right now, I think there’s a lot of debate in the engineering community about whether any of these characteristics could have played a role in a situation like this.”

Efforts to improve bridges are often slowed due to the large number of state and federal government agencies involved, the often slow pace of funding, and the construction time required for large-scale projects.

However, some places have seen results.

In Minnesota, a vessel pushing 12 barges crashed into a Union Pacific rail bridge near St. Paul, Minn., in 2017, damaging a century-old pier.

Subsequently, a protection system was created around the new dock.

In New York, the Bayonne Bridge was raised 64 feet (about seven containers stacked) in 2019 to accommodate increasingly larger ships docking at container ports in New Jersey and Staten Island.

In Long Beach, California, the new Gerald Desmond Bridge was raised 50 feet in 2020.

And in New Orleans, officials installed a sophisticated oceanographic system, courtesy of the National Oceanic and Atmospheric Administration, to transmit vertical clearance to ships approaching two bridges to avoid collisions.

The technology will soon be installed on five more bridges along the Mississippi River, and “we actually received notification Monday morning that the funding was available,” said Matt Gresham, chief of government relations for the Port of New Orleans.

In Delaware, officials wanted the bridge to be able to support modern ships, so they came up with a design that could support ships even larger than the Dali.

It was funded in part by the federal government.

The final product will include eight cylindrical islands, each 24 meters in diameter, reinforced with 540 tonnes of steel and filled with tens of thousands of cubic meters of sand, stone and boulders.

The piles will be buried in the river bed at a depth of 14 metres.

But even if solutions like Delaware’s were implemented, the work would not be finished.

Hyun-Joong Kim, an assistant professor of civil engineering at Liberty University who has studied dolphin protection systems around bridges, said vulnerabilities around bridges should be reviewed periodically to ensure that protection systems, many of which were installed decades ago, are capable of handling modern threats.

“If they see much larger ships coming and going, maybe they need to review the risk assessment,” he said.

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