Scientists examining the former Confederate submarine H.L. Hunley are disputing a new report from Duke University alumni who say they’ve concluded what sunk the submarine in Charleston harbor.
The Duke biomedical engineering project concluded it was the shockwave from the Hunley’s own torpedo which killed the crew shortly after it sank a Union vessel in 1864. Former doctoral student Rachel Lance performed explosive experiments on a scale model of the Hunley using compressed gas, then scaled black powder to simulate the submarine’s weapon.
“[The pressure wave] caused a really sharp, really fast deformation in that hull. And that little motion was enough to create a secondary pressure wave inside the boat,” Lance told the Duke Chronicle. “That secondary pressure wave inside the boat was of sufficient amplitude that it would’ve caused lethal blast traumas to the crew inside.” She speculated the explosive concussion caused fatal trauma in the lungs of the Hunley crew, explaining the apparent lack of injuries on their bodies.
But researchers who are actively working on the former sub at a North Charleston lab say the evidence is not there to support the idea.
Forensic consultant Jamie Downs said there was not evidence on the sub or bodies of the crew to reach that conclusion. “You have a speculation that was made from people that have no original data at all and no involvement with the project,” he told South Carolina Radio Network. “Therefore, they know nothing of what we’ve done along the way.”
The Hunley’s fate has captured the imagination of historians and underwater weapons experts ever since the sub disappeared below the waves shortly after sinking the USS Housatonic in February 1864. The wreck was found in 1995 and raised in 2000. Archaeologists have spent the past 17 years painstakingly cleaning and stabilizing the wreck for study and eventual display.
Downs said the Duke research never examined the actual wreckage and he believes the experiment risked confirmation bias — essentially meaning the project was set up to provide the answer researchers wanted.
“We have been very careful all along with this project not to have any public statements about what we think did or did not happen,” he said. “Certainly, we have looked at things and discounted them as not very likely. But that doesn’t mean they’re completely removed from the table.”
Hunley researchers realized in 2013 the explosive torpedo would have still been attached to the sub about 20 feet away when it exploded. Initially, a senior archaeologist speculated the close distance could have caused an ultimately-fatal concussion blast for the crew but said more research was needed.
A U.S. Navy survey also noted the black powder used in the torpedo would have produced a pressure pulse underwater, rather than a shockwave, according to the Charleston Post & Courier.