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New discovery
This video from Friends of the Hunley shows how three of the submarine’s cast-iron keel blocks could be dropped from the submarine if the crew needed to surface in an emergency.
Video courtesy of Friends of the Hunley
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Losing weight
Archaeologists studying the historic vessel still can’t explain why the crew didn’t drop the extra weight as they sat on the bottom after sinking the USS Housatonic on Feb. 17, 1864. The release mechanism was found intact and in working order.
Illustration by Dan Dowdy
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On display
Shown here in the conservation lab, this detachable keel block from the H.L. Hunley is one of three now on display during weekend tours of the Warren Lasch Conservation Center in North Charleston.
Photo courtesy of Friends of the Hunley
Scientists working to conserve the wreck of the H.L. Hunley submarine began their 18th year of painstaking work this summer by revealing another clue in one of the greatest unsolved mysteries of the Civil War.
The human-powered Hunley made naval history on the night of Feb. 17, 1864, when her crew exploded a torpedo beneath the USS Housatonic off Sullivan’s Island, becoming the first submarine to sink a ship in combat. Historical records indicate the captain signaled their success to shore, but the vessel never returned to port.
Divers discovered the submarine—intact and half-buried in the sand 300 yards away from the Housatonic wreck site—in 1995, launching an ambitious maritime archaeology project that began on Aug. 8, 2000, when the sub was lifted off the sea floor and moved to a state-of-the-art conservation facility in North Charleston. Scientists with Clemson University’s Restoration Institute have been working ever since to preserve the historic sub for public display while excavating the interior to recover the crew’s remains, recover important artifacts and ultimately answer the burning question: What happened to the Hunley?
In July 2018, researchers unveiled their latest fully restored artifacts—three of the sub’s cast-iron keel blocks. Archaeologist Michael Scafuri says the streamlined blocks, together weighing more than 1,000 pounds, helped stabilize the vessel, and were designed to be dropped if the crew needed to surface in an emergency.
“The Hunley designers thought about problems that might arise and I think they understood the need for contingency plans,” Scafuri says. “The keel blocks are a perfect example of the many innovative design features we see installed on the submarine.”
Still unanswered: Why the crew apparently made no attempt to release the weights as the vessel sat on the bottom. The release mechanism was found intact and in working order. See the video above for an animated view of how this ballast system was designed to work.
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Get There
Visitors can view the keel blocks and other artifacts recovered from the submarine during weekend tours of the Warren Lasch Conservation Center. Tours are offered every Saturday from 10 a.m. to 5 p.m., and Sunday from noon to 5 p.m. Tickets are $16 for adults, $8 for children 6–17. The conservation center is located on the old Charleston Navy Base at 1250 Supply Street in North Charleston. For more information and to order tickets online, visit hunley.org or call (843) 743-4865 ext. 10.