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full screen Two of the bridge piers and parts of the bridge ended up over the ship Star Clipper when it ran into the bridge between Tjörn and the mainland in January 1980. Photo: Kent Östlund/Svd/TT
The container ship that rammed a steel bridge in Baltimore in the US brings to mind the Tjörnbro disaster, says structural engineering expert Karin Lundgren.
– It looks like the ship has driven straight into one of the bridge supports.
Pictures from the accident in Baltimore show how the steel Francis Scott Key Bridge has been destroyed after a collision with a container ship from the Danish shipping company Mærsk.
– I think of the Tjörnbron, I think most people in Sweden do that when a ship hits a bridge so that it collapses, says Karin Lundgren, professor of concrete construction at Chalmers University of Technology in Gothenburg.
Not designed for crashes
Eight people died when a Norwegian tanker ran into a pillar that held up the bridge between Stenungsund and Tjörn in January 1980. Both the accident in Tjörn and the one in Baltimore could have been avoided if there had been collision protection on the fairway, so-called rudders, which guide the ships in and makes it more difficult to collide with the bridge supports, she continues.
– Collision protection makes it easier for the crew to recognize that the ship is heading in the wrong direction, and absorbs some of the energy and slows down in the event of a collision. You can’t design bridges so that they can handle a ship coming and driving straight into them, it’s like driving a car into a concrete wall and hoping the car is safe afterwards.
“Much more foresight”
The Tjörnbro disaster led to increased safety at Swedish bridges, among other things by installing collision protection, but also by placing the bridge supports outside the fairway and where it is too shallow for ships to reach them. It is therefore less likely that a similar accident will occur in Sweden as the one in Baltimore, according to Lundgren.
– I’m not going to say that it can never happen again, but I can still say that you are much more foresight now than you were before.