H. L. Hunley

Inside a conservation facility on the Cooper River in North Charleston, a battered iron cylinder rests in a tank of specially treated water. It is thirty-nine feet long and less than four feet wide. Eight men crawled inside it in February of eighteen sixty-four and made history, then vanished into the harbor and were not found for a hundred and thirty-one years.

The H. L. Hunley was a Confederate submarine built in Mobile, Alabama, in eighteen sixty-three. It was fashioned from a repurposed iron steam boiler, propelled by eight men turning a hand crank connected to a propeller. Its mission was to break the Union naval blockade strangling Charleston's port. The vessel had already sunk twice during test runs, drowning two separate crews, including its namesake inventor, Horace Lawson Hunley, in October of eighteen sixty-three. A third crew volunteered anyway.

On the night of February seventeenth, eighteen sixty-four, the Hunley slipped out of Charleston Harbor carrying a spar torpedo, essentially a canister of gunpowder mounted on a long pole extending from its bow. It approached the USS Housatonic, a Union sloop-of-war anchored four miles offshore, drove the torpedo into the ship's hull, and detonated it. The Housatonic sank in minutes. It was the first time in history a submarine had sunk an enemy warship in combat.

The Hunley was seen signaling toward shore with a blue lantern afterward. Then it disappeared. For over a century, no one knew what happened to the crew or where the vessel had gone.

In nineteen ninety-five, underwater archaeologists located the wreck buried in sediment four miles off Sullivan's Island. In August of two thousand, a team raised it with a specialized lifting cradle and brought it to the Warren Lasch Conservation Center. The eight crew members were found at their stations, seated as if still working the crank, no signs of panic or struggle.

Scientists still debate what killed them. The most compelling recent theory holds that the shock wave from their own torpedo, traveling through the water and flexing the iron hull, delivered a fatal pressure blast to the crew compartment in an instant. They may not have known what hit them. The Hunley remains in conservation today, slowly giving up its secrets to researchers who have spent decades unwrapping one of the Civil War's most enduring mysteries.