NORTH CHARLESTON, SOUTH CAROLINA – Scientists near the city where the Civil War began prepared Thursday to soak an encrusted Confederate submarine in a chemical bath to reveal its hull for the first time in 150 years, seeking to solve the mystery of the demise of the first sub in history to sink an enemy warship.
The hand-cranked H.L. Hunley, which rests in a giant conservation tank, will be treated with a solution of sodium hydroxide for about three months to loosen the encrustation coating the sub’s hull and interior. Conservationists will drain the tank each day, before refilling it each evening.
“This is the end of the beginning” of the preservation work, said Nestor Gonzalez-Pereyra, associate director of the Lasch Conservation Center at Clemson University’s Restoration Institute. “In a year, we may be able to have the clues.”
Removing the encrustation will reveal the original surface of the hull and show any damage that could yield new clues to its sinking off Charleston, South Carolina, in February 1864. The war had begun with the bombardment of Fort Sumter in Charleston Harbor three years earlier.
The sub and its crew of eight had set off a powder charge that sank the Union ship USS Housatonic as the Confederacy tried to break a Union blockade of Charleston. But the Hunley never returned, and its demise remains a mystery.
The wreck was discovered off the coast in 1995. Five years later, in August of 2000, cannons boomed, church bells rang and thousands watched from the harbor-side as the 12-meter sub was raised and brought by barge to the conservation lab. The silt-filled interior of the sub was later excavated, and the remains of the crewmen were removed.
In April 2004, thousands of men in Confederate gray and Union blue walked in a procession with the crew’s coffins from Charleston’s waterfront Battery to Magnolia Cemetery in what has been called the last Confederate funeral.
Last year, scientists announced it appears the charge that sank the Housatonic was attached to the 5-meter spar at the front of the sub. A closer look at the hull may provide clues.
“Chiseling away the concretion will allow us to travel back in time, potentially helping us learn what happened to the Hunley and her crew that night,” Lt. Gov. Glenn McConnell, chairman of the South Carolina Hunley Commission, said.
When the Hunley was raised, historians thought it was farther away from the Housatonic and speculated the crew had run out of air before they could crank the submarine back to the coast.
Gonzalez-Pereyra said that while the encrustation on the hull should be removed in a year, the sub will have to soak in the chemical bath for at least four more years to remove salts in the metal and prevent further corrosion.