Scientists Remove Hunley's Rear Hatch Tuesday, September 12, 2006 By BRUCE SMITH, Associated Press Writer CHARLESTON, S.C. — Scientists on Tuesday removed the rear hatch on the Confederate submarine H.L. Hunley, although the work won't immediately remove the questions surrounding the sinking of the sub in 1864.
The 40-foot, hand-cranked sub, the first in history to sink an enemy warship, sank off Charleston after sending the Union blockade ship Housatonic to the bottom on Feb. 17, 1864.
The eight Hunley crew members went down with the sub.
The Hunley has two towers with hatches but the rear hatch apparently was locked. After it was removed from the sub, which is in a conservation tank at a lab in North Charleston, the hatch was taken to the lab for X-rays.
The way the sub was configured, most of the crew would have had to have opened that hatch and escaped through the back tower.
The fact it was locked indicates the crew didn't sense an emergency in the last minutes of the sub, said state Sen. Glenn McConnell, R-Charleston and chairman of the South Carolina Hunley Commission.
"It ends any speculation that there was panic on board,"he said.
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Earlier this summer, scientists found that the forward hatch, where Capt. George Dixon would have been piloting the craft, was unlocked.
It's unclear whether that might have been an attempt to escape or simply bring more air into the submarine. Scientists have also speculated it may have simply been damaged while the submarine sat on the ocean floor for 136 years.
"I don't think there was any attempt to escape the submarine that night,"McConnell said."Any attempt to get out of the submarine would have been to the back."
The remains of the crewmen, he said, were all found at their duty stations.
Removing the rear hatch will allow scientists a chance to study a section of the sub that they have not been able to get to sinceit was raised more than six years ago.
The rear hatch also contains a glass view port which must be removed before scientists can conserve the Hunley.
With the rear hatch locked"the story turns back to the front tower and why was it unlocked,"McConnell said."Did it get damaged or did he (Dixon) have it unlocked for a purpose?"
McConnell said the explanation may turn again to whether the crew suffocated, perhaps miscalculating the amount of oxygen they had.
One important clue will be an X-ray of the valves of the pumping system which are now encrusted with sediment.
The position of the valves should indicate whether the pump was set to take water in or out of the ballast tanks or, in the event the Hunley had taken on water, to pump it out of the crew compartment, McConnell said.
From the Charleston Post and Courier
Down the hatch Hunley scientists crack open place where last crew boarded sub
BY BRIAN HICKS The Post and Courier
The last time the rear hatch of the H.L. Hunley was opened, a small band of men climbed into the submarine by lantern light and never came out.
On Tuesday, more than 142 years after that night, scientists took off that hatch and, for the first time, peered into the Confederate sub the same way its crew did.
Looking into the sub's aft conning tower like it was a passage to history, scientists immediately began looking for clues to tell them why the Hunley disappeared after sinking the Housatonic, why those men never came back.
What they initially found was a mixed bag. It appears the hatch was latched - that's what they expected - but the archaeologists were amazed by what seems to be a brass pressure valve in the hatch.
"This is pure speculation, but it may have been to relieve pressure in case of an emergency," said Maria Jacobsen, the project's senior archaeologist.
Hunley firsts have become somewhat routine at the Warren Lasch Conservation Center, but this was an exception to the people who know the project - every scientist in the place was watching the hatch open, as if it were a moonshot.
"It's been this way since Ridgaway closed it," said Hunley senior conservator Paul Mardikian, evoking the ghost of the sub's first officer, Joseph Ridgaway. "It's bigger than I would have thought."
The hatch - which seems impossibly small for anyone to squeeze through - is bigger than original estimates.
The oval-shaped conning tower is about 16.5 inches wide and nearly 21 inches long - practically spacious for gaunt 19th century sailors to slip through. Some historical records of the first attack submarine suggest tighter confines, claiming the hatches were merely 15 inches wide and "under two feet" long.
Part of the reason the opening seemed smaller was because of the mass of concretion - sand and mud that has hardened like concrete on its skin - is thicker than anyone realized. With the hatch removed, it's easy to see that the cast-iron walls of the conning tower are only a centimeter or so thick.
Scientists had to remove the rear hatch to get the last glass deadlight out of the sub. Unlike the other deadlights, all mounted from the outside, the aft hatch's glass porthole is accessible only from the inside.
And since the hatch was still secured, its locking mechanism stood between the scientists and the glass. The forward hatch will not have to be removed; its glass could be removed from the outside.
It took about a week to get the rear hatch off, a tricky proposition given that the hinge on the cast iron hatch had been sanded nearly off by harsh ocean currents and was so brittle it could break off in your hand.
Jacobsen said scientists were helped by the rubber gasket, which expands and contracts with temperature. It had expanded enough to crack the concretion. They were also helped by the fact that the part of the locking mechanism that held the hatch in place has long since disintegrated. All that was holding the hatch on was the concretion and a extremely fragile hinge pin.
The hatch is now in the lab, where the scientists will X-ray it, study it and try to see if it opens up anything else.