SEE END OF POST FOR IMPORTANT UPDATE

A while back, I read Confederate Saboteurs: Building the Hunley and Other Secret Weapons of the Civil War by Mark Ragan. The central theme of the book was the invention, more or less, of the submarine and the torpedo, curing the Civil War, but the South.

The torpedo was a very tricky idea at the time. Most of the first ones involved dragging an object with a bomb inside it, or the bomb itself, by a rope, behind a submarine. The submarine would approach the target vessel, and submerge, going under it, and the bomb would hopefully be dragged into the target and explode. This hardly ever worked.

The Hunley, no relation to George, was an early submarine (the central figure in the above mentioned book) intended for this use. Things didn’t go well with the Hunley. An early incarnation of the craft sank because it was sitting there at the dock with all the people in it and the hatches open, then it fell over and sank. Ooops.

Eventually, the Hunley was armed with an alternative style of torpedo, one that stuck out of the submarine on a long rod. I think the idea was that the torpedo latch onto the target, and the submarine moves away a bit, then the explosion happens. But when the Hunley went after the USS Housatonic in February 1864, things went both very well and terribly wrong. The Housatonic warship was sunk alright, but so was the Hunley. Confederate Saboteurs: Building the Hunley and Other Secret Weapons of the Civil War outlines the story up to a point, and is a VERY detailed accounting of all the things that ever had anything to do with confederate torpedoes and submarines. But at the time of publication, the actualistic studies had not been done.

Actualistic studies are, of course, experiments where you replicate a situation and then see what can happen and can not happen, or might happen, or might not happen. Like you make stone tools and butcher an elephant, then look at the stone tools and the bones to help understand ancient stone tools and bones.

In this case, the actualistic studies involved blowing up submarines to see if the explotion itself, at the hull of the Housatonic, was possibly fatal to the sailors in the sub.

Likely, it was.

Here is the Abstract from the paper reporting these results:

The submarine H.L. Hunley was the first submarine to sink an enemy ship during combat; however, the cause of its sinking has been a mystery for over 150 years. The Hunley set off a 61.2 kg (135 lb) black powder torpedo at a distance less than 5 m (16 ft) off its bow. Scaled experiments were performed that measured black powder and shock tube explosions underwater and propagation of blasts through a model ship hull. This propagation data was used in combination with archival experimental data to evaluate the risk to the crew from their own torpedo. The blast produced likely caused flexion of the ship hull to transmit the blast wave; the secondary wave transmitted inside the crew compartment was of sufficient magnitude that the calculated chances of survival were less than 16% for each crew member. The submarine drifted to its resting place after the crew died of air blast trauma within the hull.

The paper is in PLOS One: Lance RM, Stalcup L, Wojtylak B, Bass CR (2017) Air blast injuries killed the crew of the submarine H.L. Hunley. PLoS ONE 12(8): e0182244. https://doi.org/10.1371/journal.pone.0182244

UPDATE

The Hunley Project has issued the following rather startling press release:

Recently, Duke University issued a press release claiming one of their student’s discovered what caused the Hunley’s crew to perish and the submarine to sink in 1864. In today’s digital age, the story spread across the internet quickly due to the sensational headline. However, a spokesman for the Hunley Project said today, the story is not accurate.

The pioneering submarine and her history have captured the imaginations of people across the globe. The Hunley Project regularly receives theories from the public about what led to the submarine’s loss and other ideas related to their research. “The case of Duke University’s press release is a bit different as it has created quite a stir,” said Kellen Correia, Executive Director of Friends of the Hunley. Duke University is not part of the Hunley Project’s investigative team. They don’t have access to the detailed forensic and structural information related to the submarine, which would be essential to draw any sort of reliable or definitive conclusions.

The Hunley Project said they felt the need to issue a statement today to make sure the unsubstantiated theory claimed by the Duke University student does not continue to spread, in view of the comprehensive research conducted by the Hunley team on the submarine for more than 15 years. The idea of a concussive wave from the torpedo explosion killing the crew, as outlined in the Duke University release, has been previously considered and is one of many scenarios the Hunley Project team has been investigating.

“The Duke study is interesting, they just unfortunately didn’t have all the facts. If it were as easy as simple blast injuries, we would have been done a while ago. Though a shock wave can cause life-threatening injuries, this is something we discounted quite a while back based on the evidence,” said Jamie Downs, former Chief Medical Examiner for the State of Alabama.

The Hunley became the world’s first successful combat submarine in 1864 and then mysteriously vanished without a trace. She remained lost at sea for over a century and was raised in 2000. Since then, a collaborative research effort with the U.S. Navy, the Smithsonian Institution, Clemson University and others has been underway to uncover the reasons for the Hunley’s loss and conserve the vessel for future generations.

Using detailed information about the composition and dimensions of the Hunley’s iron structure, forensic analysis of the crew’s remains, and other research and archaeological data, the Hunley Project and its partners have conducted comprehensive digital and physical simulations for the past several years. While the likely cause of the submarine’s demise has not been concluded, the scenario of a concussive wave killing the Hunley crew has been deemed not likely by those working on the actual submarine and who have access to this key data.

Their most recent study was issued by the U.S. Navy this month and was conducted in collaboration with the Hunley Project. “Given the amount of uncertainty surrounding the vessel’s final mission, a bottom-up technical analysis was commissioned alongside ongoing archeological investigation of the Hunley. Calculations of Hunley’s engagement with the Housatonic were successfully completed and it was observed that the engagement would have been devastating to the Housatonic while resulting in relatively low levels of loading on Hunley,” according to their report. For the full report, go to: https://www.history.navy.mil/research/underwater-archaeology/sites-and-projects/ship-wrecksites/hl-hunley/hunley-incident-analysis.html

The Hunley Project remains committed to sharing the most accurate information about the submarine that is available and welcomes discussion and ideas from the public and other academic institutions about the Hunley and her history. Still, Correia cautions, “As tempting as it may be, we are careful not to jump to definitive conclusions until all the research has been evaluated.”

The Hunley Project
On the evening of February 17, 1864, the H. L. Hunley became the world’s first successful combat submarine by sinking the USS Housatonic. After signaling to shore that the mission had been accomplished, the submarine and her crew of eight mysteriously vanished. Lost at sea for over a century, the Hunley was located in 1995 by Clive Cussler’s National Underwater and Marine Agency (NUMA). The innovative hand-cranked vessel was raised in 2000 and delivered to the Warren Lasch Conservation Center, where an international team of scientists are at work to conserve the submarine for future generations and piece together clues to solve the mystery of her disappearance. The Hunley Project is conducted through a partnership with the Clemson University Restoration Institute, South Carolina Hunley Commission, US Navy Naval History and Heritage Command, and Friends of the Hunley.