Archaeologists detail the process for preserving of 18th-Century cannon that’s been underwater for centuries

PortCityDaily.com is your source for free news and information in the Wilmington area.

“This is not a hands-off operation. It requires constant monitoring …”

Looking into the tank of a Colonial-era cannon: Deputy State Underwater Archaeologist Billy Ray Morris (left), stands next to Site Manager Jim McKee, with Alan Ferrell at the end.
Looking into the restoration tank of a Colonial-era cannon: Deputy State Underwater Archaeologist Billy Ray Morris (left), stands next to Site Manager Jim McKee, with Alan Ferrell at the end. (Photos by Christina Haley.)

BRUNSWICK COUNTY — Let the preservation begin.

Underwater Archaeologists with the state and those at Brunswick Town/Fort Anderson State Historic Site are working to restore an 18th-century cannon that was recovered from the Cape Fear River just before Christmas.

The Colonial-era cannon was discovered by a dredging company contracted by the U.S. Army Corps of Engineers in an area of the river just outside the site on Dec. 21. The old cannon was an “early Christmas gift” for the historic site, Brunswick Town/Fort Anderson Site Manager Jim McKee said.

Assistant State Underwater Archaeologist Nathan Henry makes final preparations before a bolt is put at the cannon's rear. Morris (right) and McKee (middle) eager to get the cannon in the tank.
Assistant State Underwater Archaeologist Nathan Henry makes final preparations before a bolt is put at the cannon’s rear. Morris (right) and McKee (middle) eager to get the cannon in the tank.

McKee was joined by Deputy State Underwater Archaeologist Billy Ray Morris and Assistant State Archaeologist Nathan Henry on Thursday for the official start of the cannon’s restoration process, the first of its kind to take place at the historic site.

The cast-iron cannon has remained at Brunswick Town/Fort Anderson wrapped in wet burlap until a tank was built for the process. The completion of the 250-gallon tank took place this week, constructed with wood materials and lined with a tarp.

Thursday afternoon, the crew worked to lift the cannon off a trailer and lower it into a water bath. The tank is now the cannon’s permanent resting place throughout the process, which could take anywhere from one to three years.

Like many of the centuries-old cannons pulled from underwater, archaeologists have to put the artifact through electrolysis to remove the concretion, a thick and compact layer of sediment and minerals that has built up on the cannon’s surface over hundreds of years.

“A gun that’s been under the water for this long, particularly with any kind of salt water environment, we need to get all of the chlorides out of the iron. We also need to force out the corrosion product,” Morris said.

The electrolysis process will eventually strengthen the iron of the cannon, Morris said.

McKee checking the bolt placed at the rear of the cannon.
McKee checking the bolt placed at the rear of the cannon.

The electrical source for the restoration should be coming in next week, McKee said. Wires will be attached to a bolt drilled into the cannon. That will keep an electrical current on the cannon that will allow the electrolysis to work. The bolt attached to the artifact “does not hurt the cannon,” McKee said. 

This process that will remove outer sediment layer that’s possibly hiding any markings archaeologists could use to identify the cannon, thought to be from the early 1700s.

Archaeologists have been able to determine the cannon measures 93-inches long with an 80-inch bore and is 4-inches in diameter. The cannon also has a break at the end of the muzzle, only furthering the mystery of the cannon for archaeologists.

Once the restoration process is competed, the cannon will be removed from the tank and any sediment left on the surface will be removed. After that, the cannon will be placed indoors for the final part of the restoration and observation, Morris said.

The cannon rests in its tank and will be covered in water until the electrolysis can start.
The cannon rests in its tank and will be covered in water until the electrolysis can start.

“This is not a hands-off operation,” Morris said. “It requires constant monitoring, which is why it’s right here where Jim and his guys can keep their eyes on it.”

Morris and Henry will be guiding McKee and his team through the process.

“They don’t know it yet but they’ll be on speed dial,” McKee said jokingly. “If there’s any questions we’ll be calling them.”

The Underwater Archaeology Branch of the Office of State Archaeology is a part of the North Carolina Department of Natural and Cultural Resources.

Visit the North Carolina Department of Natural and Cultural Resources website to learn more about the state’s Underwater Archaeology Branch. For more information about Brunswick Town/Fort Anderson State Historic Site, visit its website or follow the site on Facebook.

Watch the full video of the cannon drop:

Comments