Painstaking work yields clues to understand Confederate sub

COLUMBIA, S.C. – The painstaking process of cleaning more than a century of sand, sediment and corrosion from the first submarine in history to sink an enemy warship continues to yield clues to how it worked.

But scientists say there's still more work needed before understanding exactly what happened the night in February 1864 when the Hunley and its eight-man crew sank a Union blockade ship off South Carolina.

The scientists who have spent nearly 17 years preserving the sub allowed reporters into the Hunley's North Charleston home on Wednesday to look at the recently cleaned crew compartment. They recently discovered that the sub's hand-operated crank, wrapped in cloth to prevent blisters, had a sophisticated set of gears that enhanced the output of the men's hard work.