Submarine H.L. Hunley: 'Difference of opinion' arises at talk claiming torpedo shock wave killed its 8 crew members

(Courtesy of Friends of the Hunley)

Rachel Lance made a big splash this summer when her research on what may have caused the Civil War submarine H.L. Hunley to disappear got national attention.

Testing and analysis eliminated several theories and showed the eight crew members were killed by blast injuries caused by the detonation of their own torpedo, she wrote. Some news coverage had headlines indicating the mystery of the Confederate vessel’s loss may finally have been settled.

Dr. Lance

But there’s been pushback, including from the Friends of the Hunley and the U.S. Navy, which conducted its own tests. One of those experts challenged Lance’s theory after she spoke Monday in Washington, D.C., about the first submarine to sink an enemy vessel.

Dr. Lance, who conducted three years of research and tests on a 6-foot scale model of the 40-foot Confederate sub, detailed her findings at the William G. McGowan Theater at the National Archives. Research included studying human respiration and the transmission of blast energy.

When the torpedo blew up, sinking the USS Housatonic in Charleston Harbor, shock waves passed through the iron hull of the sub and fatally injured the crew, Lance said, reiterating findings she and others described in a paper published in August. She did the research while a PhD candidate at Duke University.

After the Hunley was raised in 2000, conservators found the men were still at their stations, indicating there was no rush to escape or movement to bring air into the boat. There were no obvious physical injuries.

Evidence of blast injuries

Lance said she ruled out suffocation, a “lucky shot” that brought torrents of water through a hole in the conning tour, and a concussive force. Rather, she said, it was pressure from the explosion. The torpedo was still attached to the Hunley by a spar when it was set off.

1/6th scale model used in testing (National Archives YouTube broadcast)

“The blast does not move you. It does not throw you,” she said. “It does not break bones. It does not destroy the material of your brain. That is exactly how the crew was found.”

On Feb. 17, 1864, the Hunley left its base on Sullivan’s Island and placed its torpedo into the Housatonic, one of many blockade vessels on the edge of the harbor. Those on board desperately opened fire on the attackers. Five U.S. sailors were killed in the explosion and a chaotic scene ensued as other Federal ships came to the rescue. The Hunley vanished, and there have been many theories – but no proof -- of what happened to it.

While Lance’s research brought a sense that the mystery had been solved, the Friends of the Hunley – a part of the Hunley Project, which was not involved in the new research – was skeptical and said the matter has not been resolved.

A week after the findings of Lance’s team were released, the Friends of the Hunley issued a press release that said Lance’s work is “unsubstantiated.”

“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,” the organization said.

Lance did not have access to detailed forensic and structural information about the sub, it said. “As tempting as it may be, we are careful not to jump to definitive conclusions until all the research has been evaluated,” Friends executive Kellen Correia said in the statement.

A difference of opinion

At the Q&A that followed Lance’s talk Monday, Robert Neyland, who was involved in the recovery of the submarine and is head of the Naval History and Heritage Command’s Underwater Archaeology Branch, said there is a "difference of opinion."

Whereas Lance’s team had to use a smaller test explosive charge because of safety concerns, another team was able to do a full-scale test of a black powder charge for a 135-pound torpedo, Neyland said. “We have come up with different results that counter that.” 

Conrad Wise painting of H.L. Hunley (Wikipedia)

The blast did not cause fatal injuries to the Hunley crew, he said. “Maybe some heave on the motion of the submarine, but it would not have injured the crew.”

Lance, who previously worked with Navy civil service, said she has collaborated with some of the other scientists and agrees with some of their data. But she said two different theories have incorrectly been blended in the discussion. She said the other researchers’ project was on the theory of concussion. “They were not studying the (wave) propagation through the hull.” That confusion has been used to try to discredit her results, Lance said.

The researcher is a biomedical engineer and has studied respiratory physiology. She told the audience that one misconception is that a blast of the type she said killed the Hunley crew would have caused their bodies to move and show obvious injury.

While her team did not have the money to build a full-scale model, Lance said, the use of 6-foot scale model CSS Tiny was sufficient to replicate the impact of the torpedo detonation on the Hunley crew. The model included ballast tanks and was tested several times in North Carolina ponds.

Lance’s talk was promoted and carried on YouTube by the National Archives, where she found research materials that buttressed her theory.

Navy's study of pressure wave from Housatonic blast

Several scenarios, or combination, possible

Earlier this year, a new archaeological report issued by the U.S. Navy, South Carolina Hunley Commission and Friends of the Hunley looked at six theories on what might have happened. Among those are that a Federal vessel hit the sub, the Hunley submerged and lost oxygen, or the hull was breached.

Those organizations have cautioned that it could have been a combination of factors that caused the disappearance.

The Navy found the “imparted load” of the blast to the submarine was “relatively modest.” The primary response of the Hunley to the explosion was a rapid vertical motion resulting from the flow of water around the bubble, it said.

Hole in conning tower has raised questions (Friends of the Hunley)

While the archaeological report said there’s a possibility that a “lucky shot” from small arms fire by the Housatonic crew caused enough damage to a conning tower, leading to its sinking, Lance disagreed.

Analysis doesn’t show a clean bullet hole or wide fracturing of the armor from a shot, she said. A study of tides and currents on that cold, moonlit night showed it took 13-14 minutes for the sub to drift to where it was found nearly 140 years later. A shot from a single bullet meant it would take 58 minutes to sink, and the hole that it is evident on the tower would have caused it to sink in about 5 minutes, she said.

“Why were they not pumping out the water, or trying to get out of the boat?” Lance said.

Her team also ruled out suffocation.

“The crew had about a 30-minute air supply before they would have had painful and uncomfortable symptoms from carbon dioxide,” Lance said. “They made no efforts to try to save themselves or bring air into the boat.”

And the researchers ruled out the concussion, or blunt force, theory. There was no sign of skull fractures or other potentially fatal fractures. “They did not necessarily hit their heads hard enough to cause any kind of significant trauma.”

Lance also addressed accounts by a lone Housatonic sailor and Confederate battery officer on shore of seeing a blue light coming from the sub, a signal that it succeeded in its mission. She said the sailor had been exposed to miserable conditions in the water while awaiting rescue, a factor that may have affected his recollection.

As for the citing by the Rebel officer, there was no corroboration, no evidence of a signal fire to guide the sub home and the officer was several miles from the sub, meaning he would have had a hard time distinguishing a light, the engineer said.

Pressure waves fatal, she says

So that leaves, she said, blast, or wave, trauma that pushed into the submarine and killed the crew. Such strong pressure would rupture lungs and damage neurons and blood vessels and cause traumatic brain injuries that left the organ intact. The brains of the Hunley crew were found to be intact, she said.

USS Housatonic (Wikipedia -- public domain)

“It is just pressure waves. …. We are not saying people are getting hit, just the pressure exposure.”

The Navy has questioned why World War II submariners survived close depth charges while the Hunley crew did not survive the torpedo blast. Lance said modern hull armor is much thicker and would have provided more protection.

Lance said the watch of sub commander Lt. George Dixon provides further evidence of a traumatic blast. The hands stopped at 8:23 p.m, the estimated time the torpedo went off.

The audience saw a rendering showing the position of Dixon’s skeletal remains. It appears the officer’s body was locked in place by silt that filled the submarine after it sank.

“He seems to have simply been slumped over to the side. The position of his legs indicate he likely was still sitting on his bench.”

H.L. Hunley: New report addresses 6 theories on how Confederate submarine was lost

(U.S. Navy -- 1902 drawing by R.G. Skerrett)

A new report that calls the recovery of the H.L. Hunley in 2000 “part archaeology, part engineering and part spectacle” details six fascinating theories about the loss of the first submarine to sink an enemy vessel.

The archaeological report by the U.S. Navy, South Carolina Hunley Commission and Friends of the Hunley coincides with today’s 153^rd anniversary of the bold attack off Charleston Harbor that took down the USS Housatonic but also doomed the Hunley and its eight crew members.

Up front, we need to say no one knows for sure why the Confederate sub vanished on the moonlit, cold evening – as the report says, it could be a combination of factors. The Friends of the Hunley, in a Facebook post marking the Feb. 17, 1864, anniversary, said, “An international team of scientists (is) working to save the vessel and solve the mystery of her disappearance.”

The theories are at the end of the extensive report on the recovery of the Hunley, from planning stages to execution.

(USS Housatonic / Wikipedia -- public domain)

The hand-cranked Hunley left its base on Sullivan’s Island and placed a torpedo in the Housatonic, one of many blockade vessels on the edge of the harbor. Those on board desperately opened fire on the attackers. Five U.S. sailors were killed in the explosion and a chaotic scene ensued as other Federal ships came to the rescue. The Hunley vanished.

Robert S. Neyland of the Naval History and Heritage Command Underwater Archaeology Branch summarized the theories on what may have happened.

THEORY 1: Sub’s hull breached as a result of the explosion

Neyland writes that of the three “significant” breaches, only the missing viewport in the forward conning tower appears to have occurred close to the time of the attack -- but it is still possible this occurred after the sinking. He says the damage may have come from gunfire by the Housatonic crew or explosion debris. The forward hatch was found to be slightly ajar.

He writes: “The conning tower was above the surface of the water and (Lt. George) Dixon would have had time to block the hole to prevent water from flooding the submarine. 

(Courtesy of Friends of the Hunley)

"However, weather and sea state could also have been a contributing factor. With the wind building from the northwest at the time of the attack and immediately afterwards, and the tide setting to the northeast, seas would have been building with waves that could have thus been lapping over the conning towers. The damage to the forward conning tower alone should not have been sufficient to sink the submarine, provided it stayed above the surface. The hole could have been plugged with a garment or rag to prevent water …. If water did get in, it could have been removed with the pumps.”

Experts wrote in the hull analysis that that Hunley was streamlined and better balanced than its predecessors. “Still, there was a fragile balance between safety and disaster that required expert, careful handling.”

THEORY 2: Crew saw another Union vessel, decided to submerge

This scenario said the Hunley’s skipper saw the USS Canandaigua and took the boat to the seafloor to wait for enemy forces to disperse. The crew, ostensibly, died because of the lack of oxygen.

Neyland questions this theory: “If the damage to the forward conning tower occurred at the time of the submarine’s attack, Dixon would not have been able to take the boat down to the bottom to wait or to run the submarine fully submerged. Although the damage might not be a serious problem on the surface it was too large for Dixon to have sealed it securely enough to prevent flooding when underwater.”

(Friends of the Hunley)

“ … Hiding on the bottom until things quieted down on the surface or the tide changed might have been a short-term strategy but an attempt to hide on the bottom could only have been a momentary escape. He had conditioned his crew to submerge until they ran low of oxygen and he knew the limits of their endurance, which would be only an hour or two at most."

The report says the Hunley’s final location, so close to Housatonic seems to indicate that the submarine had not navigated away from the site underwater.

THEORY 3: A Federal vessel struck the Hunley on the surface

Neyland writes: “The least likely scenario is that Hunley was struck by Canandaigua as it came to render assistance. Had this been the case, the submarine would likely have suffered massive damage to the hull, possibly even been cut in half.”

THEORY 4: Damage to conning tower caused by small weapons fire, causing the sub to flood

The report states: “The recovery did not reveal a large breech caused by the explosion that led to catastrophic flooding … the damage to the forward conning tower could have been caused by gunfire or shrapnel from the explosion, but should not have been enough to sink the vessel. However, the concussion resulting from the detonation of the torpedo would have created an underwater shock wave and the force could have been severe enough to damage the hull or the crew. … It is possible this could have caused distortion or fracturing of the metal components of the hull, allowing water to enter around rivets or seams, and physical injuries to the crew.”

Damage to forward conning tower (Friends of the Hunley)

Neyland argues a slow leak would be consistent with a report that Hunley remained at the surface after the explosion. “It seems likely the crew would have attempted to stop the leaks and man the pumps, and, if unable to do so, they would have had sufficient time to unfasten both hatches and abandon the submarine to escape. If, on the other hand, the crew was disoriented or disabled by the shock wave, there is a chance slow leaks went unchecked and the boat slowly sank without an attempt to stop it.”

The report indicates an examination of Dixon’s remains showed no evidence he was hit by enemy fire.

THEORY 5: Crew tried to use grapnel anchor

Facial reconstructions (Picket photo)

This theory holds the discovery of a grapnel anchor at the wreck site indicates the Hunley’s crew used to the anchor to combat the outgoing tide until the tide change “but were inadvertently pulled under due to the low freeboard of the submarine and lack of buoyancy.”

Neyland writes no historic accounts mention the deployment of an anchor and he said the one found was too light for the purpose. It’s possible another vessel lost the anchor while the U.S. Navy dragged the waters for Hunley.

THEORY 6: The crew was rendered unconscious

That scenario contends the men were unable to man the pumps or respond to any damage

Some of that argument is covered in Theory 4, but Neyland writes there’s a possibility “that the crew was sufficiently disoriented from the explosive shock wave that they were unable to respond efficiently to the danger of hull leakage. If they lost their interior light and were unable to relight the candle or lantern soon after the explosion, their situation would have been compounded.”

Interestingly, the Navy also this week released findings of a team looking into the effects of the explosion on the crew; it’s known the torpedo was attached to a spar connected to the Hunley when it went off.

(U.S. Navy)

It found the “imparted load” of the blast to the submarine was “relatively modest.” The primary response of the Hunley to the explosion was a rapid vertical motion resulting from the flow of water around the bubble.

“While the occupants may have experienced some bumps and bruises, it does not appear there was enough force to cause concussion or other forms of complete incapacitation."

That report cites a broken outlet pipe in the forward ballast tank. It would have allowed water to flow into the crew compartment. “Tests revealed that the vessel would sink in approximately 3 minutes from the initial failure of the pipe.”

But, like much of the report, this team found mysteries remain. It said examination of drift models show something more than the pipe alone may be responsible for the sinking.

In his summary, Neyland discounts the Hunley being struck, the grapnel anchoring and damage alone to the forward conning tower.

“Given the lack of a proverbial ‘smoking gun,’ it is possible that several smaller problems occurred simultaneously that, when combined, could not be overcome.”

The research and conservation of the vessel at the Warren Lasch Conservation Center in North Charleston, S.C., continue. Reports documenting the excavation of the interior, including crew remains, personal effects and hull components will be published later, the Navy said.

The little sub that could: H.L. Hunley made warfare history; anniv. events planned

(Naval Historical Center)

The story of the H.L. Hunley, a war machine marked by innovation that overcame limitations, is a classic example of if at first you don’t succeed, try, try again.

Whether inspired by nationalistic pride or the profit move – likely both – a group of New Orleans businessmen and innovators made three Confederate submersibles before an eight-member crew in one of the “curious” vessels made warfare history.

The Pioneer and the American Diver never saw action. But the Hunley, named for a member of the shipbuilding coalition, did eventually see combat as the Confederacy tried to break a Northern blockade of Charleston, S.C., during the Civil War.

On the moonlit evening of Feb. 17, 1864, the 40-foot iron vessel -- bullets pinging off its iron exterior -- planted a torpedo in the hull of the Union ship USS Housatonic, setting off a charge that sent the Federal vessel and five crew members to the sandy bottom outside Charleston Harbor within minutes.

The Hunley was the first submarine to sink an enemy warship.

Hunley rests in a conservation tank in North Charleston, S.C.

"It was the first successful use of submarine in warfare,” said Rick Hatcher, historian at Fort Sumter National Monument. “It is not just a Civil War event, not just an American event. It is a world-history event."

Sesquicentennial events next week in the Charleston area, culminating with a memorial service at the exact time of the mission, will remember the daring innovation of the Hunley and the early dangers of manning a submarine. The eight men aboard the Confederate submarine died, a fate that befell the two previous crews, including Horace Lawson Hunley himself, during trial runs.

Discovered a few miles off Charleston in 1995, and raised in 2000 by a group led by author Clive Cussler, the Hunley is being conserved at the Warren Lasch Conservation Center in North Charleston.

Historians and others continue to ponder mysteries of why the Hunley sank and reports of a blue light emanating from the doomed vessel.

Hatcher will give free talks on Feb. 15-17 at Fort Moultrie, a few miles south of where the Hunley churned through Breach Inlet on its way toward the Housatonic.

"My main thrust is to cover the history of the evolution of the boat up through its recovery,” Hatcher told the Picket this week. “I will leave it to the specialists to give the science."

The story of the Hunley is rich in both science and history.

Union naval forces were wary

Likened to the appearance of a whale, the Hunley was fashioned from a large boiler piece in Mobile, Ala. Innovations included watertight hatches, two short conning towers, sea cocks, pumps and ballast tanks.

But there were shortcomings. There was constant concern about a sufficient oxygen supply for the crew, which limited its dive time.

The Hunley, like its predecessors, was dependent on the crew hand-turning a crank to power the single propeller. The captain had the inability to measure the horizontal movement while running submerged.

Still, the Union fleet paid close attention to the development of the Hunley and other torpedo boats. And they were aware of the loss of life aboard the Hunley in 1863.

 

Rear Adm. John A. Dahlgren in January 1864 ordered defensive measures against the torpedo boats lurking on the islands around Charleston and off the city itself.

“I have reliable information that the rebels have two torpedo boats ready for service, which may be expected on the first night when the water is suitable for their movement. One of these is the ‘David,’ which attacked the Ironsides in October; the other is similar to it,” Dahlgren wrote.

“There is also one of another kind [H. L. Hunley], which is nearly submerged and can be entirely so. It is intended to go under the bottoms of vessels and there operate.”

Another letter said the Hunley was “on the lookout for a chance.”

That chance came on the chilly evening of Feb. 17, 1864.

Working the hand crank, heading to target

Lt. George Dixon, the submarine’s commander, had seen distinguished service above water. Now he was leading a small crew in a naval attack.

(Naval Historical Center)

Dixon would carry with him a unique, misshapen $20 gold coin. He had been wounded in the thigh at the Battle of Shiloh nearly two years before. He credited the coin with blunting the bullet’s impact and saving his life.

The officer had the coin engraved and carried it as a charm.

He would need all the luck he could get that night, given the wariness of Union ships and the constant anxiety of operating the Hunley. Five members of the first crew died in August 1863 while the hatches were still open. The second crew’s eight members succumbed in October when they were apparently unable to open a forward sea valve while underwater.

Still, the Confederates were determined to strike fear in the enemy and sink vessels.

In the early evening that day, the Hunley set out from the shadow of Battery Marshall on the north end of Sullivan’s Island. Breach Inlet separated that island and Long Island, now called the Isle of Palms.

Friends of the Hunley, a non-profit group that is organizing some of the sesquicentennial events, provides a history of the ship and current conservation updates on its website.

“While the cold bit through the lookout's coat, 8 men poured sweat over hand cranks that powered a spinning propeller while their captain manned the dive planes -- steering man, iron, anxiety and raw courage towards its final destination."

The Housatonic was at anchor four of five miles away. The Friends’ website further details the Hunley’s appointment with history.

“A lookout aboard the Union Navy's largest ship was tired, cold -- but restless. Talk of a Confederate secret weapon was in and out of his thoughts. Suddenly he spotted something move in the chilly waters. A porpoise? There were certainly a lot of them around. But something about this one didn't seem right."

‘In an instant, the ship was struck’

An account posted by the Naval History & Heritage Command details the alarm raised onboard the Housatonic, which carried 12 guns.

Lt. Higginson, the ship’s executive officer, wrote, “About 8:45 p.m. the officer of the deck, Acting Master J. K. Crosby, discovered something in the water about 100 yards from and moving toward the ship. It had the appearance of a plank moving in the water. It came directly toward the ship, the time from when it was first seen till it was close alongside being about two minutes.”

The Hunley was too close and low to be hit by artillery fire, so crew and officers of the Union ship fired small arms, rifles and even a shotgun at the approaching menace. 

“The officer of the deck perceived a moving object on the water quite near and ordered the chain to be slipped; the captain and executive officer went on deck, saw the object, and each fired at it with a small arm,” Dahlgren wrote. “In an instant the ship was struck on the starboard side, between the main and mizzen masts; those on deck near were stunned, the vessel begun to sink, and went down almost immediately.”

Five crew members died; 150 others were soon rescued.

The Hunley had disappeared from view. What happened to it has become the stuff of legends and research for decades. Various parties searched for the wreckage, but they believed it went down near the Housatonic wreck. Instead, it sank about 100 yards or so beyond that point, covered by several feet of silt.

For a long time, one prevailing view held that a lucky shot broke the glass in one of the Hunley’s portholes, bringing in rushing water and causing the sub to sink. But research has not proven that theory.

In January 2013, Hunley scientists reported a significant discovery.

“Until now, the conventional wisdom has been the Hunley would ram the spar torpedo into her target and then back away, causing the torpedo to slip off the spar,” a press release said. The men may have run out of air at some point, the theory held.

Instead, research showed the submarine was less than 20 feet from her 135-pound torpedo when it exploded. The Hunley had a 16-foot spar that carried the weapon.

“There is overwhelming evidence to indicate this was not a suicide mission. The crew no doubt knew the dangers facing them, but still, they hoped to make it back home. They must have believed this was a safe enough distance to escape any harm,” said Hunley Commissioner Lt. Gov. Glenn McConnell.

It’s possible that the force of the explosion incapacitated the crew, eventually causing the sub to slide down into the chilly depths.

A crew member on the Housatonic reported seeing a blue light, but research on the Hunley’s recovered lantern thus far shows no evidence it had glass with a blue tint. While there were several reports of a signal being sent by the Confederate vessel to shore, experts say it likely was not done by the lantern. Some speculate it may have been sent by a hand-held pyrotechnic flare.

Schedule of events for anniversary

The conservation of the Hunley has continued for nearly 14 years after it was hauled to the surface and taken to the large laboratory where visitors can take a tour, see films and learn more about the Hunley and its final crew. 

The vessel sits upright in a 90,000-gallon freshwater tank, as time and workers chip away at concrete-like sediment and salinity.

Friends of the Hunley’s Kellen Correia told the Picket she expects the vessel’s conservation to be complete in about five to six years. It will be housed in a North Charleston museum, but a site has not yet been determined.

The eight men who trained and fought in her were laid to rest on April 17, 2004, in Magnolia Cemetery after a 4.5-mile funeral procession through the city. Experts are learning more about their murky past – several were immigrants – and produced facial reconstructions that are on view at the Lasch lab.

Next weekend’s observances will remember their sacrifice and of those lost on the Housatonic. Friends of the Hunley said events will mark the vessel’s “against-all-odds mission that changed naval warfare for all time.”

In addition to events at Fort Moultrie, the following is planned at the Warren Lasch Conservation Center:

-- Friday, Feb. 14, is military appreciation day, with tours from 10 a.m. to 5 p.m. Active and retired personnel will pay $6, half the usual admission cost. An honor guard and living historians will be present.

William Waud drawing of attack (Library of Congress)

-- Saturday, Feb. 15, tours from 10 a.m. to 5 p.m. The first 150 guests will receive free replicas of Dixon’s life-saving gold coin, which was found during excavation of the boat’s interior. An honor guard and living historians will be present.

-- Saturday, Feb. 15, evening reception and presentation “The Men Behind the Machine,” 6 p.m. to 8:30 p.m. $50 for cocktail hour, light snacks and viewing of the submarine hosted by experts conducing the preservation work. A forensic genealogist will discuss what is known about the crew.

-- Sunday, Feb. 16, tours from noon to 5 p.m. The first 150 guests will receive free replicas of Dixon’s life-saving gold coin, which was found during excavation of the boat’s interior. An honor guard and living historians will be present.

-- Monday, Feb. 17, tours from 10 a.m.-5 p.m. Admission is $1.50. Living history presentation.

On Feb. 17, the Confederate Heritage Trust will sponsor a 7 p.m. memorial service for those lost on the Hunley and Housatonic at Sunrise Presbyterian Church at Breach Inlet. “After the church service, you will be asked to join the ladies dressed in black gently toss flowers from the ocean shore into the water of the men they represent.”

Some 150 years later, the Hunley is still remembered for the bravery of three crews that gave all.

Fittingly-named Lt. J.H. Tomb of the Confederate Navy called the vessel a “veritable coffin.”

Rich Wills, former assistant underwater archaeologist for the Naval Historical Center, wrote that Confederate subs acted as powerful psychological warfare tool.

“It was the H.L. Hunley's attack on the Housatonic that defined to the U.S. Navy the danger of the submersible torpedo craft in Southern waters, and demonstrated to the world the vast potential of the submersible vessel in future naval strategy.”