H.L. Hunley Will Be Set Upright For First Time Since Its Sinking In 1864
CHARLESTON, S.C. – The Confederate submarine H.L. Hunley will be rotated early in 2011 to an upright position for the first time since it sank on Feb. 17, 1864. That night the Hunley became the world’s first successful combat submarine by sinking an enemy vessel, the USS Housatonic, on blockade duty off Charleston. The Hunley has been kept at the same 45-degree angle to starboard (right side) she had when first discovered in 1995 and recovered from the ocean in 2000. Officials with the Friends of the Hunley, which raises funds for the historic vessel’s ongoing conservation, made the announcement on Aug. 8. It was the 10th anniversary of the submarine’s recovery off Sullivan’s Island, near the entrance to Charleston Harbor. “This is a historic milestone for the Hunley Project,” said S.C. State Senator Glenn F. McConnell, chairman of the Hunley Commission, in a subsequent phone interview. “We’re rotating the Hunley upright, which gives us access to areas that we have never seen, and it also allows us to begin the deconcretion of the vessel, which may unlock the final clues to why the Hunley didn’t come home,” McConnell said. “It’s really a turning point in the project,” Chris Watters, Hunley Project assistant conservator, said in a phone interview. The deconcretion of the Hunley’s surface as well as conservation required to remove the salts embedded in the iron vessel from its 136 years in the ocean require that the large slings attached to a truss which have held the submarine at its 45-degree angle be removed. “For the public, it’s going to be great because the Hunley will be much easier to be seen without the truss there,” Watters said. “During the chemical treatment, it needs as much surface contact as possible,” he noted. Currently the slings obscure as much as a third of it. Rotating the Hunley “is an extraordinarily complex engineering feat,” according to Watters. “We’ve been working with engineers, Detyens Shipyards in Charleston and professional riggers.” The rotation will be based on studies of the finite element model of the Hunley created by Dr. Vincent Blouin, assistant professor in the Clemson University Department of Materials Science and Engineering. Blouin’s model has been developed and refined since 2006. Among other things, it conveys a “great understanding now of areas of stress ‘hot spots’ on the Hunley,” Watters said. This will be crucial for the maneuver. The rotation will be accomplished by pulling on the starboard side of the slings while simultaneously releasing on the port side. The process will be “very slow and controlled” and should take about a week, according to Watters. “We’ll have load cells attached to the slings and that’s going to give us a measurement of the tension, which is directly related to the weight or load that’s being placed on the slings,” he explained. Keel blocks, which are opposable wedges that can move up and down, will hold the Hunley upright after it is rotated. There will be 12 or 13 keel blocks, made by nearby Detyens Shipyards. As shown in Conrad Wise Chapman’s iconic painting of the submarine sitting on a dock, the Hunley was designed to sit upright when out of the water, Watters said. That is how it will be after the rotation. More than the keel blocks will hold it up. “We’ll probably have shaped supports so it distributes a little of the weight,” he said. “And we’ll probably also have some kind of support mechanism a little bit higher up in case of an earthquake or something like that.” McConnell said that after deconcretion is completed the final conservation treatment of the Hunley can begin — sometime around 2015, he estimated. Then the Hunley will be moved from the Warren Lasch Conservation Center on the old Navy base in North Charleston to a state-of-the-art display facility in the redevelopment area on the waterfront. “It will be upstream,” McConnell said. “The facility would sit out on the Cooper River. It will not be built as a ‘glass box museum,’ so-to-speak, but will be an interactive facility.” He said the state, years ago, bought the Southern Maritime Collection. “We will combine that with the Hunley to create a world-class interactive exhibit on Civil War maritime history.” In order to prevent further corrosion of the iron while the Hunley is on display, it will need to be sealed in an environmentally-controlled structure with very low humidity. “You can’t have corrosion in a totally dry environment,” Watters explained. One option would be an argon enclosure, similar to how the original U.S. Constitution is kept in a sealed display case at the National Archives. McConnell wants to explore building a working replica, but with some modern safety features like air tanks for the crew, for the 2014 sesquicentennial of the Hunley’s history-making voyage. An obstacle to building this working replica has been the lack of a complete design specification for the vessel. The rotation will reveal some final areas of the Hunley not fully understood. “Once we deconcrete her and get the final specs on her and see her equipment, we could build her,” McConnell said. “It really would be exciting to see the Hunley sail again.” The Hunley Commission will discuss that when it meets in early fall. For an animation of the planned rotation see www.youtube.com/watch?v=2S1s87Z0oqk&feature=player_embedded The Friends of the Hunley site is www.hunley.org
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