Cofferdam to be built around battleship

WILMINGTON, NC (WWAY) — A cofferdam and Memorial Walkway will be built around the U.S.S. North Carolina so repairs can be done on the ship.

A cofferdam is a structure built within a body of water to allow the enclosed area to be drained to create a dry work environment. The cofferdam will allow workers to repair and restore the battleship’s corroded hull, while keeping the attraction open to visitors. The last major dry-docking and repair work was done in November 1953.

The cofferdam will cost $8 million to construct and will remain a permanent structure around the ship to allow for future repairs and maintenance. The construction costs and restorations are being funded by the state. The cost of the SECU Memorial Walkway is estimated around $4 million and is being funded by the U.S.S. North Carolina Battleship Commission. The fundraising effort, called “Generations Campaign”, is asking for the support of individuals, corporations, foundations, and organizations statewide and nationally. State Employees Credit Union Foundation donated $3 million for the naming rights of the walkway.

The walkway will be built at the same time as the cofferdam and will be a 1/2 mile long and 10 feet wide timber walkway. It will be above the waterline, but below the main deck of the ship, completely surrounding the ship so visitors can see the entire hull for the first time.

The walkway will include five bump-out areas to honor each five branches of the military: Army, Navy, Marine Corps, Air Force, and Coast Guard. The Merchant Marine will be honored by flying its flag on the quarterdeck.  Signs and displays will be placed along the walkway to educate visitors about the Battleship and surrounding natural areas. The public will be able to access the walkway free of charge and won’t need to purchase a Battleship tour pass.

Wilmington engineering firm, Andrew Structural Engineers (ACE), was hired in 2014 by the state to design the cofferdam and walkway.

President of Andrew Consulting Engineers Neal Andrew says, “This project is a once of a lifetime opportunity for a structural engineer. We’ve done a number of cofferdams, but the magnitude of this job is extraordinary. A cofferdam is typically a temporary structure used for underwater construction, but this cofferdam will be permanent and must not only be built to last, but be aesthetically pleasing.”

The only other permanent cofferdam of it’s kind in the United States surrounds the U.S.S. Alabama, a 680 foot long battleship moored since 1964 in Mobile Bay.

The cofferdam and walkway will be built over 18 months by Orion Marine Group of Norfolk, VA. In addition, Wilmington based companies BMH Architects and McFayden Engineers, and the Wilmington office of S&ME will help with the project. BMH Architects is the lead design firm and McFayden is providing engineering services for the walkway lighting. S&ME has provided geotechnical engineering and environmental testing services to assist in the permitting process and will continue to insist throughout installation.

Categories: Local, New Hanover