As larger and faster container ships began to take over the Delaware River in recent years, transportation officials feared the prospect of one going astray would lead to a repeat, or worse, of what happened in 1969, when a tanker struck its bridge Delaware. and caused significant damage.
So last year, work began on a $93 million project to build eight massive cylinders that would stand guard in front of the bridge’s piers to protect a system that carries tens of thousands of vehicles a day.
“The tankers and freighters of the 1950s are not the tankers and freighters of today,” said James Salmon, a spokesman for the Delaware River and Bay Authority.
The collapse of the Francis Scott Key Bridge in Baltimore, after a freighter crashed nearly three football fields long, killing six people, has raised questions about whether similar disasters could happen elsewhere.
But the work on the Delaware bridge reflects the fact that some transportation and shipping experts are considering the dangers of new cargo ships cramming under decades-old bridges. The problem is that there are no easy answers, in part because ships keep getting bigger.
Michael Rubino, a retired master navigator at the Port of Los Angeles, said the drafts — the distance between the water and the highest point of a vessel — of some newer ships have become so large that some vessels have to fold their masts and squish their masts. under a bridge.
“People don’t realize how huge these ships are,” he said.
Joseph Ahlstrom, a professor at SUNY Maritime College, a ship captain and New York State pilot commissioner, said that merchant ships have become so large in recent years that they are much more likely to damage infrastructure such as bridges.
“It’s going to do a lot to them,” he said of a modern ship and the danger it poses to a bridge like the one in Baltimore. “He’s going to throw it down, which he did.”
Many transportation officials say it’s hard to draw parallels with the Key Bridge because what happened in Baltimore appeared to be such an unusual event — a confluence of factors at the worst possible time. As the ship, the Dali, was passing through the harbor without a tug attached to it, it suffered a “total blackout” and lost control, then struck a jetty 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. “That’s not something we can really compare to.”
Even so, National Transportation Safety Board officials said Wednesday that they are not only reviewing the protection system around the Key Bridge, but are also looking for records of the protections around other bridges in Maryland.
Stray ships have long been considered a danger to bridges, particularly when a truck struck the Sunshine Skyway Bridge in Tampa Bay in 1980, killing 35 people.
After that disaster, officials in Maryland recognized that the Key Bridge, which opened in 1977, could collapse from a direct hit. But they said the concrete barriers placed in the river were intended to divert or slow an out-of-control boat.
As such, final contact may be just a “blink at a glance,” John Snyder, director of engineering for the state Toll Facilities Administration, told the Baltimore Sun at the time.
As part of rebuilding Tampa Bay, officials prioritized protection against a future disaster. They built a network of large concrete islands, called dolphins, that could absorb the impact of an out-of-control vessel. Since then, officials across the country have increasingly focused on strategies to strengthen the shields around bridges.
“Some modern bridges around the world, especially since the Tampa incident in 1980, have been designed with different features to mitigate impacts and protect their piers,” Pete Buttigieg, US Transportation Secretary, said Wednesday. “Right now, I think there’s a lot of debate among the engineering community about whether any of these features could have played a role in a situation like this.”
Efforts to strengthen bridges are often slowed by the many state and federal government agencies involved, the often frozen pace of funding, and the construction time required for such large-scale projects. However, some places have seen results.
In Minnesota, a vessel pushing 12 barges struck a Union Pacific railroad bridge near St. Paul in 2017, damaging a century-old pier. A protection system was then built around the new jetty.
In New York, the Bayonne Bridge was raised by 64 feet — or about seven stacked shipping containers — in 2019 to accommodate increasingly large vessels calling 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 have installed a sophisticated oceanographic system, courtesy of the National Oceanic and Atmospheric Administration, to broadcast the vertical distance to boats approaching two bridges to avoid collisions. The technology will soon be installed on five more bridges along the Mississippi River, and “we were notified of the availability of funding Monday morning,” said Matt Gresham, chief of government relations for the Port of New Orleans.
In Delaware, officials wanted the bridge to be able to handle modern boats, so they came up with a design that could handle ships even larger than the Dali. It was partially funded by the federal government.
The final product will include eight cylindrical islands, each 80 feet in diameter, reinforced with 540 tons of steel and filled with tens of thousands of cubic yards of sand, stone and boulders. The piles will be buried 45 feet deep in the river bed.
But even if solutions like the one in Delaware are implemented, the work is far from over.
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 regularly to ensure that the protection systems — many of which were installed before decades — are capable of handling modern threats.
“If they see much larger ships coming back and forth, they might have to re-evaluate their risk assessment,” he said.
Michael Forsyth contributed to the report.
