The massive cargo ship that lost control and crashed into a major bridge in Baltimore on Tuesday wasn’t the primary to accomplish that. In 1980, a wayward cargo ship struck the identical bridge.
On August 29 this 12 months, a container ship called Blue Nagoya entered the pier supporting the structure, the Francis Scott Key Bridge, after losing control roughly 500 meters away. based on a 1983 report by the US National Research Council.
However, when Blue Nagoya hit the Key Bridge, it destroyed a few of the protective concrete but didn’t topple the structure. So what was different this time?
Both ships were traveling at roughly the identical speed. The Blue Nagoya was traveling at about six knots, or nearly seven miles per hour, when it hit. The ship that struck Key Bridge early Tuesday morning, the Dali, was traveling at slightly below seven knots, the National Transportation Safety Board said. he said on Wednesday.
The full story of how and why the two.6-mile bridge collapsed could take years. On Wednesday, investigators were still collecting evidence on the scene.
For now, structural engineers say no bridge could withstand a direct impact from a 95,000-ton cargo ship just like the Dali. However, additionally they noted that the bridge had no obvious protective barriers that might have diverted the ship or prevented the ship from hitting its piers.
So-called impact protection devices have been common in the industry since a freighter struck a support column on the Sunshine Skyway Bridge in Tampa Bay, Florida, in 1980, collapsing the structure and killing 35 people. But the Key Bridge opened in 1977.
Other experts say that resulting from the numerous increase in the scale and weight of cargo ships for the reason that Seventies, ships just like the Dali are generally more dangerous to bridges than the Blue Nagoya.
The National Research Council report didn’t specify how heavy Blue Nagoya was when it hit the Key Bridge in 1980. Amar Khennane, a researcher on the School of Engineering and Technology on the University of New South Wales in Canberra, Australia, said in his report by email that Dali appeared “much larger and heavier than the one involved in the 1980 incident, and his proportions were three times larger.”
Ships weighing as much as 100,000 tons “can have a disastrous impact on pillars if impact protection is not provided,” Raffaele De Risi, a civil engineer on the University of Bristol in England, – wrote in the statement.
Benjamin W. Schafer, professor of civil and systems engineering at Johns Hopkins University in Baltimore, he told Scientific American this week that the accident will likely provide lessons on find out how to protect bridge support structures from shipping traffic.
“If you look at the size of ships from the 1970s, when the bridge was built, to now, it has changed dramatically,” Professor Schafer told the magazine.
Andrés R. Martínez reporting contributed.
