Barbed bomb. Despite all of these technological advances, operating the sub involved a lethal learning process. Shortly after its arrival in Charleston, the sub sank during a test run due to a crewman's error, killing five of the sailors on board. A few months later, Hunley himself was on the ship when it sank a second time, killing everyone inside. The sub-and its dead crew and inventor-remained at the bottom for days before the Confederate Navy salvaged it.
Despite the reservations of Beauregard and others, Charleston's situation was desperate enough to organize one more try. The target was the Housatonic, an 11-gun Union steamship stationed at the mouth of Charleston Harbor. The plan was simple: The crew would crank its way more than 5 miles out to the Housatonic, ram a barbed bomb into the ship's wooden hull, and detonate it. On a cold night in February, the Hunley set out on the attack.
Just before 9 p.m., lookouts on the Housatonic spotted something slipping through the water nearby. Within minutes, an explosion ripped the Housatonic in half and killed five Union sailors. It was the first time a submarine sank a warship. "That night, she changed forever the way war was fought in the water," McConnell says.
It's what happened next that remains shrouded in mystery. After the Housatonic exploded, the Hunley surfaced long enough to send up a blue flare. Then it disappeared without a trace. For more than a century, Charlestonians and others obsessed over the demise of the Hunley. At one point, circus impresario P.T. Barnum offered a $100,000 prize to anyone who could find the ship. But it wasn't until 1970 that someone succeeded, when underwater archaeologist E. Lee Spence plotted the ship's location with a compass and maps. Then it took another 25 years before permission was granted by South Carolina to salvage the wreck. Divers feeling their way through murky water exposed part of the sub's hull. In 30 feet of water and beneath 3 feet of fine silt lay an almost perfectly preserved craft, listing at a slight angle.
Inside, excavators knew, artifacts and human remains would be suspended in a soup of mud. Disturbing the contents would erase volumes of information about the sub's final moments. Even the metal exterior of the craft was tremendously fragile. Project organizers had to throw out the rule book. "Normally when you have a shipwreck, you do the excavation underwater," Jacobsen says. "There was no way we could conduct a standard forensic excavation underwater and still gather the data we would need down the road."
So on Aug. 8, 2000, after years of planning, the Hunley was carefully lifted whole from its resting place and moved to a specially prepared tank. The effort was unique in the history of under water archaeology, involving 40 divers working around the clock and millions of dollars in equipment.
But the hull's corrosion also meant the researchers couldn't relax once it was out of the water. "Once you bring it up to the surface you have a ticking time bomb on your hands," says Jacobsen. "In a water-filled tank, you could have more corrosion in one year than in 140 years on the bottom." To deal with the challenge, the tank was constructed and filled with chilled water. A mild electrical current runs through the water, slowing the corrosion of the metal.
In 2001, researchers started to remove the iron plates from the top of the submarine. The ship's interior was filled with mud and sediment, some of which had hardened over time to the consistency of concrete. Everything inside-the crew's bones, the ship's controls, and any artifacts the sailors had brought aboard with them-had to be chipped out of this cement-like layer. As excavators pulled out artifacts, each item's location was plotted on a three-dimensional diagram of the Hunley's interior, creating a map of thousands of separate objects, including more than 1,600 bones.
The story the artifacts revealed has dramatically changed the way historians see the sub-and the society that sent it on its final mission. Though excavators still don't know for certain why the sub sank, the distribution of the bones inside shows that the men made no move to escape. "Each was found more or less where that individual would have been stationed," says forensic genealogist Linda Abrams, who is researching the Hunley's crew. "Either it happened so fast they were unable to react in time, or it happened in such a way that they were unable to react. Maybe they were unconscious."