Tourists at North Charleston's Warren Lasch Conservation Center get a sense of what sailors faced on the H.L. Hunley,a Confederate submarine that became the first to sink an enemy ship in battle in 1864. (Gannett, Laura Bly/USA TODAY)
Cathy Payne, USA TODAY
A torpedo casing may hold a key clue as to why the Confederate submarine H.L. Hunley sank during the Civil War, scientists say.
The new evidence suggests that the Hunley positioned itself much closer to its target -- the Union ship the USS Housatonic on Feb. 17, 1864 -- than previously believed. The Hunley torpedo sank the Housatonic, becoming the world's first successful combat submarine. But after signaling to comrades on Sullivan's Island that the mission was accomplished, the Hunley and its eight-member crew vanished.
Conventional wisdom has held that the hand-cranked Hunley used a spar, or large pole, to ram a torpedo into the Housatonic's hull and then pulled away. It was further believed that once at a safe distance, the Hunley detonated the torpedo.
The new evidence suggests the Hunley was less than 20 feet away from its torpedo when it exploded. Remnants of the 2-foot-long torpedo were found bolted to the 16-foot-long spar.
The discovery indicates that the torpedo, which held 135 pounds of gunpowder, did not separate from the spar but instead was placed under the Union ship. It was fired by command, not contact.
"There is overwhelming evidence to indicate this was not a suicide mission," South Carolina Lt. Gov. Glenn McConnell, a Hunley commissioner, said in a statement. "They must have believed this was a safe enough distance to escape any harm. If so, they were at least partially right. Thus far, no damage has been found on the actual submarine caused by the explosion."
Because of the Hunley's proximity to the Housatonic and the amount of gunpowder, the concussion from the explosion could have damaged the sub and injured the crew. "Were some or all of them knocked out?" McConnell asked. "How long were they knocked out? Did the submarine's structure with rivets have a similar problem as the Titanic did when it brushed against the iceberg?" He added, "If the rivets give, the pressure of the water could cause leakage."
Scientists will use the new information to create computer simulations of the attack. Scientists also will start peeling away a layer of rock, sand and silt from the sub.
The Hunley was found off South Carolina's Charleston Harbor in 1995 and raised five years later. It was taken to Clemson University's Warren Lasch Conservation Center in North Charleston, S.C., for research.
The finding is a great leap toward solving the mystery of the Hunley, McConnell said. "It brings us to the final moments and minutes, not the final hours, as to what sealed the fate of the Hunley."