Scientists in South Carolina began the painstaking job Wednesday of righting the Confederate submarine H.L. Hunley, which sank on its side during the Civil War after becoming the first sub in history to sink an enemy warship.
Workers rotated the famed submarine by about 10 degrees by midafternoon Wednesday in a delicate effort that is expected to take two days to complete.
The Hunley was resting on its side at a 45-degree angle when it sank off Charleston in 1864 and was raised in slings that way 11 years ago. The hand-cranked sub and its crew of eight went down after sinking the Union blockade ship Housatonic but why it sank remains a mystery.
Rotating the sub upright and removing the slings will reveal the entire hull for the first time in nearly 150 years and may provide clues as to its fate.
But Paul Mardikian, the senior conservator on the Hunley project, doesn't expect to see any obvious clues once the sub is upright and the slings obscuring the hull are removed.
"I don't think there have been any smoking guns on the submarine so far. We were expecting we would find a quick answer 10 years ago. But I think it's more subtle," he said.
He said any new clues will probably have to wait until the sediment encrusted on the hull is removed, a process that will take a year or more.
When the sub was raised, there were 15 slings supporting it. Last week, the Hunley was raised 3 feet from the bottom of its water-filled conservation tank and in recent days half the slings were removed.
The remaining slings were fitted with sophisticated sensors which can tell how much weight each is supporting.
Workers lined the inside of the drained 90,000-gallon conservation tank on Wednesday and periodically eased the tension on the remaining slings as the Hunley was slowly rotated toward an upright position.
Once upright, the sub will be supported by keel blocks beneath the vessel.
"Everything's going according to plan," said Mardikian who noted it took several years modeling the delicate process of righting the sub both in a computer simulation and using a model of the hull.
Theories as to why the Hunley sank include that it was damaged by fire from the Housatonic or the crew was knocked out by the concussion from the blast that the ship's fire produced. It may also have been damaged by another Union vessel rescuing the Housatonic.
Studies showed the crew died of a lack of oxygen, which can overtake a person very quickly. The remains of the crew members, who were buried in 2004 in what was called the last Confederate funeral, were found at their stations and there seemed no rush to the escape hatch.
At the time of its development, the Hunley was considered a secret weapon developed to try to break the Union blockade that held the South in a stranglehold. It would not be until World War I that submarines were commonly used in warfare.