In 2007, when a 274-meter-long container ship struck the San Francisco-Oakland Bay Bridge, it stood firm. No one died, either on the ship or the road above.
The bridge’s supports were protected by a fendering system of materials that were designed to soften such a strike.
Now, people are asking if such a system, or other safety measures, could have saved Baltimore’s Francis Scott Key Bridge. The Key Bridge recently collapsed after the container ship Dali lost power and struck it.
Sherif El-Tawil is a University of Michigan engineering professor. He said there are several safety measures that “would have made a huge difference” had they been in place for the Baltimore bridge.
El-Tawil said a fendering system could have softened the 300-meter-long ship’s strike. The system includes long tubes called pilings attached to the river bottom that would have helped move the container ship away from the bridge. Another possible protection could have been an island of rocks around the bridge’s supports.
“It may seem like a very large force,” El-Tawil said of the cargo ship. “But I think you can design around it, either through a protective system or by designing the bridge itself to have massive towers.”
Such protections are being questioned after the disaster, which took the lives of six workers on the Key Bridge. Experts say the 47-year-old bridge did not appear to have the protections that are common among newer bridges.
The incident is raising questions about how much money American taxpayers are willing to spend to protect against these rare but deadly accidents. And not everyone agrees the Key Bridge could have been saved.
Pete Buttigieg is the Transportation Secretary of the U.S. He recently said at a White House press conference that there has been a lot of debate about whether any of those protections could have avoided the disaster. He said it was a massive strike where the force of about 91,000 metric tons, much larger than a building, hit the bridge.
Buttigieg did not directly answer a question about whether steps should be taken to protect the nation’s bridges. But he noted that many bridges have been designed to better protect against strikes since a large truck hit Florida’s Sunshine Skyway Bridge in 1980. That disaster killed 35 people.
Baltimore’s Key Bridge opened three years before the disaster in 1977. That was a time when container ships were much smaller. In recent years, the ships have grown to carry more containers to save on shipping costs.
Mark Luther is a professor at the University of South Florida (USF) and a director of the USF Center for Maritime and Port Studies.
Luther said that to go back and add protections to an existing bridge, like the Key Bridge, would be extremely costly. He added that to his knowledge no one has done it. Officials, he said, have accepted that there is a risk with bridges that were built in the 70s with what was then the latest technology.
Roberto Leon is a Virginia Tech engineering professor. He said the technology is available to protect a bridge against a strike with a massive cargo ship like the Dali.
But he warned that governments will always be weighing the costs and the risks. He questioned whether anyone would design protections for such a massive strike.
He said, “Would you design it for such an enormous load? Because as the load increases, it becomes much more expensive.”
I’m Gena Bennett.
