Bridge accidents: Three ships collided with bridges in Argentina, China and Baltimore in just three months

Bridge accidents: Three ships collided with bridges in Argentina, China and Baltimore in just three months


Hong Kong
CNN

Deadly bridge collapse in Baltimore. A bridge in southern China collapses into two halves. Parts of a bridge crossing the hull of a huge ship in Argentina.

All of these events occurred within the first three months of this year, all after collisions with large commercial ships.

The incidents, and the toll – with at least five dead in China, and six more missing in Baltimore – have highlighted what experts say is an urgent need to improve or protect old bridges to accommodate larger, modern ships.

Tuesday’s collapse in Baltimore focused national attention on the issue, after a large container ship lost power and collided with the Francis Scott Key Bridge, sending people and vehicles plunging into the frozen Patapsco River.

“We have to remember that this bridge was built 50 years ago, and the ships at that time were a fraction of the size of today’s Dali,” said Sal Mercogliano, a former merchant sailor and maritime expert.

“The DALI is not even a large container ship, there are much larger ships out there,” he added. “So in many respects we have an infrastructure that was built for another time.”

The accident occurred in China in late February when a cargo ship collided with the Lixinsha Bridge in the Pearl River Delta in southern Guangzhou province – a major international shipping hub and the country’s industrial heart.

Dramatic photographs of the ruins showed the bridge split into two parts. Reinforcement work on the bridge due to structural concerns has been repeatedly postponed in recent years, state-run CCTV reported.

A month earlier, a large cargo ship collided with the Zarate-Prazo Largo bridges crossing the Prana River in Argentina, according to the now-closed state news agency Telam, severely damaging the ship, although the bridge remained intact.

Although these incidents may look similar on paper, such as a large ship colliding with a bridge, there may be different factors at play, said Bassem Andraos, a professor of structural engineering at the University of Illinois at Urbana-Champaign and an expert on bridge collapses.

For example, the accident in China appears to show the ship hitting the bridge body, not the bridge piers—the vertical columns that hold up the structure—suggesting that “the ship had a certain height that was ignored,” or the river may have hit the bridge body. “It was not suitable for such large ships,” Andrew said. “This could be human error.”

Initial investigations into the collision also indicate that it was caused by “inappropriate behavior by the ship’s crew,” according to the state-run China Daily newspaper.

By contrast, in the Baltimore example, the canal and bridge were wide and long enough to accommodate large ships — and Andrews said the freighter struck the bridge pier, not the bridge itself.

He added: “There are different reasons for all these cases.” “But there is now greater awareness that there is a possibility, and it is not a small possibility, but a very significant possibility, that a ship will strike part of the bridge – whether that is the pier or the superstructure.”

When ships hit bridge piers, it can be “catastrophic,” he said, because that is the weakest point in the bridge.

He pointed to the collapse of the Sunshine Skyway Bridge in Florida in 1980 after it was struck by a cargo ship, killing 35 people.

This incident prompted the engineering and transportation community to “really look at how we design piers that can withstand this,” he said.

There are ways to prevent this type of disaster – or at least reduce the damage.

Additional structures such as fenders could be added to bridges, underwater and out of sight, deflecting ships that drift too close to each other, Andrews said.

Many ports and waterways also use ‘dolphins’ – structures embedded in the sea or river bed, extending above the water, and usually made of wood or steel. While these are often used as a mooring point for ships, they can also protect bridges from ship collisions – the Sunshine Skyway Bridge implemented several “dolphins” around each pier when it was rebuilt.

Andrews added that bridges should be built with “redundancy” in their design — so that when one element fails, such as a pier that has been battered, other features can bear the load.

But even these measures can only do so much in the event of a large cargo ship collision, Mercogliano said, referring to the Baltimore collapse.

Steve Helper/AP

A Coast Guard cutter passes the freighter that brought down the Francis Scott Key Bridge in Baltimore

He added: “The protective measures – the dolphins and the barriers around them – were not actually designed to stop a ship of this size.” “And even when the ship hit those dolphins, the ship was so big that it rose over them and hit the bridge itself. So there’s not much the ship can do to prevent that from happening once the power goes out.”

Experts also say there is a long way to go to improve bridges built for small ships in a different era, even with modern regulations and design codes in place.

Although newer bridges – especially those crossing wide river beds – may have additional protective structures, bridges in smaller channels or in less developed countries may not.

“Infrastructure investment is critical to the public good, and it is critical to address that aging infrastructure,” said Jerome Hajjar, president of the Structural Engineering Institute of the American Society of Civil Engineers.

He added that besides improving old bridges to meet modern requirements, there is a need to develop infrastructure to keep pace with the latest developments in technology.

Just as there are developments in other parts of the transportation industry – high-speed rail, self-driving cars – there are new developments in shipping and ports to embrace.

“It is important to invest because of technological progress, and to keep our economy strong and progressive,” he said.

Andrews pointed to the $1.2 trillion infrastructure bill passed in 2021, which includes $110 billion for roads, bridges, and major infrastructure projects. He said that while the funding is welcome, it is far from the $4.5 trillion that studies have indicated is needed to upgrade America’s infrastructure to its target level of safety and efficiency.

“There are now more and more concerns about the future,” he added. “Are we still going to be doing the same old thing in 20, 30, 40 years? We can’t, because if we do, we can’t expect different results.”

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