Scientists removing encrustation from Confederate sub Hunley

NORTH CHARLESTON, S.C. (WCIV/AP) - Scientists have started the long job of removing the encrustation from the hull of Confederate submarine H.L. Hunley.

When they are finished in about a year they hope to have the clues as to why the hand-cranked Hunley sank after becoming the first sub in history to sink an enemy warship.

For more than three months, the sub has been in a conservation tank in North Charleston soaking in chemicals to help loosen the hard sand, sediment and rust clinging to the sub.

Conservators on Tuesday started using tools similar to those a dentist might use to gently remove the encrustation.

"It's really delicate process, we're expecting that the outside of the submarine will be faster than the inside," said Stephanie Crette, Director of the Lasch Conservation Center where the Hunley is being restored.

Crette said conservators will use tools that will allow them to see details of the original submarine as it appears. That's key because archaeologists are following a painting of what's thought to be the original shape.

"The Chapman painting is the painting that we've been following a lot, because more and more, it's getting to be really exact in its details.

The sediment scrapped off will be kept for analysis by the archaeologist. The last part of the restoration processes is expected to reveal the cause of the Hunley's demise.

"At least we will be closer, to better understanding and uncovering that surface, that's going to get us more clues. What happened or what may have happened. We won't be 100 percent sure. I don't believe so because, always something gets erased with time," said Crette.

Four full time conservators will scrape away at the Hunley for three days a week, documenting findings as they go.

The deconcretion process could take 12 months to complete.

The Hunley sank off Charleston in 1864 after sinking the Union blockade ship Housatonic. The sub was raised in 2000 and brought to the lab.