Now that the Bonner Bridge replacement in the Outer Banks of North Carolina is open to traffic, the old 2.7-mile-long bridge on N.C. 12 will be demolished, but it won’t be done with explosives, the Herald Sun reports. Officials don’t want flying debris to damage the new bridge.
Instead, the bridge will be sawed apart and taken away on barges, piece by piece. The work, which has already begun, is being performed by Crofton Industries and is expected to take approximately 10 months. The bridge’s 4-foot-long end posts were saved and will go on display as historic artifacts. Concrete and metal pieces of the bridge will be added to existing man-made reefs 5 to 12 miles off of the Oregon Inlet.
“The whole thing will be dangerous, because we are compromising the structure of the bridge as we go,” said the project’s resident engineer, Pablo Hernandez, according to the news agency. “We’re doing it in a controlled fashion, but when you cut things loose, they can swing away from you in directions you didn’t predict.”
Hernandez told the news agency that there are several things that will make the job more difficult:
- Boulders, baskets, metal mattresses filled with rock, giant jacks, and more that were placed around the pilings under the bridge more than 30 years ago to help stabilize them over the years will have to be removed, but engineers aren’t sure where they are.
- The North Carolina Department of Transportation plans to leave 1,000 feet of the old bridge intact at the south end as a pedestrian and fishing pier, but also to keep from changing the flow of the strong current of water called the Davis Slough.
- If a marine mammal or reptile, such as a dolphin, sea turtle, manatee, or whale, comes near the bridge during the dismantling, all work must stop until the animal leaves the area. cannot disturb marine mammals and reptiles.
- Some pilings will remain in the marshes at the north end of the bridge so that the sensitive wetlands and marine life are not disturbed. The pilings will be cut off at water level.