Confederate Submarine H. L. Hunley’s Historic Night and the Mysteries That followed
I want to thank a good friend and loyal historyarch.com reader (thanks Kurt) for making me aware of a good news story on the sinking of the H. L. Hunley. This Confederate submersible holds the distinction of being the world’s first submarine to sink an enemy ship in combat. Unfortunately, the Hunley never returned to port and was lost to history until an expedition funded by author Clive Cussler re-discovered the wreck in 1995. Since then the Hunley has been raised and undergone an intense effort to restore and preserve and remains. The restoration is still in progress as conservators remove debris, including over 1,000 lbs. of sand, shells and sea life that has hardened into a natural concrete encasing the iron hull. The reason the Hunley sank has remained a mystery since it disappeared in 1864. Last month, a group of researchers offered their theory that an intake pipe possibly became separated from the hull allowing enough water to enter the Hunley to sink it in 3 minutes. If you look carefully at the headline though, you will notice it says the broken pipe “could’ve sunk Hunley.” There is a lot behind that indefinite description. As one participant in the conservation has noted “the Hunley does not give up her secrets easily.” 1 There is a lot more to this tale both in the Hunley’s service during the Civil War and in the ongoing search to discover the reasons for the submarine’s demise.
The story of the Hunley is a fascinating study of innovation and desperation from the short history of the Confederate States of America. Southern states were at a significant disadvantage in virtually every category in fighting their northern cousins. One of the most glaring shortcomings was the lack of a navy. The Confederacy had no warships and very few merchant vessels at the outset of the Civil War. A small merchant marine was as serious as the deficit of fighting ships. With an almost nonexistent industrial base and a far less developed railroad system, the Confederates needed to import many necessities from Europe while shipping cotton to Europe for currency essential to fund the war effort. The Confederates could never match the strength of the conventional US Navy which had 42 active vessels and another 45 more available for recommissioning in 1860. Several northern states also had a long history of maritime trade and shipbuilding, a burgeoning industrial base and large cities which could provide a large and cheap labor force. The Confederacy had neither significant shipbuilding facilities nor the knowhow and resources to quickly build the necessary fleets.
The Confederacy had only one advantage, a large coastline. The Union’s Commanding General of the Army, Winfield Scott, was old and in ill health, but still mentally sharp and one of America’s most underrated military minds. Recognized the Union’s large navy was a great asset, he formulated his strategy to defeat the Confederates relying heavily naval dominance. Scott’s multi-phased Anaconda Plan called for the Navy to isolate and starve the Confederacy by blockading Confederate ports. Phase two envisioned cutting the Confederacy in half by seizing control of the Mississippi River. Union forces in the Western Theater would utilize the Mississippi and Tennessee Rivers to capture Mississippi, Alabama and Tennessee while troops in the East pushed south to capture the Confederate capital, Richmond, Virginia. The western Union army would split the Confederacy again by driving through Georgia to the Atlantic coast. Eastern and Western armies could then meet in the Carolinas completing the subjugation of the Confederacy.
Scott’s ambitious plan required significant contribution from the US Navy which had to blockade twelve major ports, cover 3,500 miles of coastline and then dominate interior rivers. Scott’s confidence in the Union’s prohibitive Union naval advantage and industrial base proved well placed. By 1865, the Navy had converted many US warships to steam power adding iron siding as well. Northern shipyards also grew the US fleets to an impressive total of 671 vessels. The numbers do not tell the whole story. By the midpoint of the war, the US Navy had largely completed two important objectives: blockading southern ports and seizing the Mississippi River with a diversified array of oceangoing warships and river gunboats including the innovative Monitor class ironclads.
The Confederacy had little choice but to compensate for the lack of ships, materials and resources with shortcuts. They created a few powerful ironclads. The few Confederate warships put up a brave fight but were too few to offset the Union advantage of numbers. As the Union Navy tightened the stranglehold, the Confederates turned to other means. One approach was to create torpedoes, which today we call mines. The Confederates did not just place floating explosives in rivers and ports. Some were designed to explode on contact, others were equipped with an electrical switch that an operator from shore could detonate when a Union warship came close.
They also experimented with alternative designs relying on stealth to overcome the lack of numbers. If the Confederates could not battle the Union Navy on open waters, they might be able to punch holes in the blockade fleets. One such example were David ships which were small steam powered torpedo boats with an open cockpit and low sides barely above the waterline which could approach Union vessels quietly and ram a torpedo into the hull disabling or sinking the warship to create space for incoming and outgoing blockade runners.
The Confederacy also turned to private enterprise offering bounties for sinking Union blockade vessels. Two mechanics in New Orleans who manufactured steam gauges named James McClintock and Baxter Watson came up with an ambitious plan to use a submarine to collect the bounties. At this time, the submarine was a mostly theoretical idea. A submerged vessel had the advantage of being able to approach an enemy without being subjected to cannon fire. In the Revolutionary War, David Bushnell invented a one-man submersible named the Turtle, a cylindrical vessel designed to attach explosives to the bottom of British warships. However, the Turtle never successfully engaged an enemy ship.
The Confederate submarine that eventually achieved immortality was named after Horace L. Hunley, but he had little to do with the design and construction of any submarine. Hunley joined McClintock and Watson soon after they began as the project’s promoter. McClintock and Watson were the brains behind the submarines built. Hunley navigated bureaucratic difficulties and secured financial support.
With no practical blueprint for a submarine, McClintock and Watson tried several approaches building a prototype, The Pioneer. Two men powered this small vessel via a hand crank to turn a propeller at the rear of the submarine. The Pioneer was difficult to maneuver and was exceedingly slow even operating in the tranquil waters of Lake Pontchartrain. Before improvements could be made, the would be submariners had the abandon The Pioneer when Union troops captured New Orleans in 1862.
The three men moved to Mobile, Alabama and built another, larger submarine named the American Diver which was tapered at the end “to make her easy to pass through the water.” 2 McClintock experimented with electromagnetic and steam propulsion, but neither engine was feasible. Little is known of the electromagnetic engine. The steam engine was still cutting-edge technology was bulky and heavy and required air to operate. Placing a steam engine in a submersible was untenable in the 1860s especially in the South where there were no factories to build a never before seen compact engine capable of operating underwater. Instead, the designers settled on a hand cranked shaft powered by four men that drove a propeller in the back of the ship. The American Diver sank in a storm while being towed to attack Union ships blockading Mobile Bay.
McClintock noted the American Diver was not powerful enough for the currents of rivers and seas with only four men turning cranks. So in the next design was a larger cylindrical vessel retaining the tapered shape, but enlarged to hold a crew of eight. Seven sailors manned cranks to turn the rear propeller. Ballast tanks at either end of the submarine could be filled with water to allow the vessel to submerge. The water could then be pumped by hand allowing the ship to surface. Eight iron keel weights were attached to the submarine and the largest could be unscrewed from the inside in the event the vessel needed to surface quickly.
The crew entered the submarine through two tiny hatches only 16 inches in diameter situated on short conning towers atop the vessel. Each conning tower had two small windows. The captain was the eighth member of the crew and sat in the forward conning tower looking out a window where he could guide the submarine with a joystick operated rudder to control diving planes installed on either side of the submarine. The captain also managed the flow of water in and out of the ballast tanks. The long thin hull with a diving fin on each side soon earned the nickname “fish boat.” Because of the small interior cabin, oxygen was limited so the ship could only remain submerged for two hours. Most of the time the fish boat sailed with only the two conning towers above surface with hatches open to allow the flow of fresh air.
Not long after completing construction, the builders had their first success. In its first major demonstration in July of 1863, the fish boat descended under a barge on the Mobile River dragging a torpedo. The torpedo hit the barge and with a spectacular explosion sank the target. Confederate Admiral Franklin Buchanan witnessed the test and immediately recommended the submarine to General P. G. T. Beauregard commanding beleaguered forces defending a besieged Charleston, South Carolina. The Confederates moved the fish boat by rail to Charleston, South Carolina.
Painting of Charleston Harbor from Fort Sumter with Union blockaders on the horizon by Conrad Wise Chapman 1863. The dilapidated state of the fort and tattered flag symbolize the ravages of a lengthy Union siege on Charleston.
A New Mission in Charleston
Because the technology was so new, problems abounded. McClintock arrived in Charleston with the submarine and began training a crew. Controlling the vessel was both difficult and laborious so training took time. The crew was learning all new techniques such as diving, resting on the bottom, traveling undersea and surfacing. The impatient Confederates soon seized the fish boat believing McClintock was overly cautious.
The Confederate Navy simply did not understand how little room for error there was in operating the submarine. McClintock’s apprehensions became clear soon after the Confederate Navy took over. While running with just the conning towers above water on August 29, 1863, the lines of a nearby ship pulled the fish boat onto its side drawing water into the vessel. It quickly sank drowning five of eight crewmen. The Confederates raised the submarine with Horace Hunley convincing Generl Beauregard to return the fish boat to his personal charge. Hunley recruited a new crew putting Lieutenant George Dixon in command.
Dixon was no stranger to the fish boat. Before the war he had worked as an engineer on Mississippi River gambling boats and joined the Confederate army in 1861. At the Battle of Shiloh, Dixon was shot in the hip but the bullet struck a $20 gold coin in his pocket. The coin was a gift from a female admirer and though the wound left him with a limp, the gold piece saved his life. Dixon kept the coin as a good luck charm. While recuperating in Mobile, Dixon became acquainted with the submarine builders and volunteered to serve aboard the fish boat. Though not accepted, he did not give up easily. When the fish boat moved to Charleston, Dixon obtained leave to go to Charleston hoping to join the submarine crew. His timing was perfect. Dixon arrived just as Hunley re-gained possession of the fish boat and Dixon’s wish to join the crew was finally fulfilled.
Training a second crew began well but soon ended in disaster. General Beauregard recalled:
Lieutenant Dixon made repeated descents in the harbor of Charleston, diving under the naval receiving ship [CSS Indian Chief] which lay at anchor. But one day when he was absent from the city Mr. Hunley, unfortunately, wishing to handle the boat himself, made the attempt. It was readily submerged, but did not rise again to the surface, and all on board perished from asphyxiation. 3
Hunley had never actually sailed the fish boat and did not understand the complicated workings of the vessel. However, he was ambitious and broke. He pushed the project hoping to make a name for himself and collect a bounty for sinking a Union blockade ship. Hunley’s impatience cost him and the seven other sailors their lives.
Beauregard decided the submarine experiment was simply too dangerous and cancelled the program. All the original investors and inventors were by now dead or had given up hope (McClintock left Charleston in a rage when the Confederates confiscated his submarine). Only one advocate remained: George Dixon. Beauregard wrote:
After this tragedy I refused to permit the boat to be used again; but Lieutenant Dixon, a brave and determined man, having returned to Charleston, applied to me for authority to use it against the Federal steam sloop-of-war Housatonic, a powerful new vessel, carrying eleven guns of the largest caliber, which lay at the time in the north channel opposite Beach Inlet, materially obstructing the passage of our blockade runners in and out. 4
Normally such a dangerous venture would be shelved after two unsuccessful attempts. But the besieged Confederates were desperate. Dixon’s determination paid off and the Confederate Navy raised the submarine again finally giving the vessel a name, the H. L. Hunley in honor of its most recently deceased captain and advocate. Union observers witnessed the Hunley’s sinking and subsequent recovery. Admiral John Dahlgren ordered his blockading vessels to anchor in more shallow waters with ropes and chains hanging over the sides. In addition to the difficulties of sailing the Hunley and back breaking effort required to propel it for miles, the Confederates had now lost the advantage of surprise.
Recognizing that diving below a Union ship was no longer possible, Confederates attached a 17 foot spar to the prow of the Hunley with a 135 lb black powder charge at the end. Slow speed and ungainly traits limited the Hunley’s effectiveness. To make an attack, Dixon needed the right conditions, light wind and calm seas. He and his crew trained while waiting for wind and sea to cooperate which finally occurred on February 17, 1864.
With Charleston Harbor placid and windless, the Hunley’s crew squeezed themselves through the hatches and began cranking the propeller on their historic voyage toward Union blockade ships. Moving at no more than 4 knots, Dixon directed the Hunley towards his target, the USS Housatonic. The submarine approached so quietly Union lookouts did not spot the attacker until too late to turn the ship’s cannon. Sailors fired rifles and pistols which had no effect on the Hunley’s iron hull.
The Housatonic’s executive officer, Lieutenant F.J. Higginson described what happened next:
At about 8:45 p.m. the officer of the deck… discovered something in the water about 100 yards from the moving 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. During this time the chain was slipped, engine backed, and all hands were called to quarters. The torpedo [mine] struck the ship forward of the mizzenmast, on the starboard side, in a line with the magazine. Having the after pivot gun pivoted to port we were unable to bring a gun to bear upon her. About one minute after she was close alongside the explosion took place, the ship sinking stern first and heeling to port as she sank. 5
For the first time in world history a submarine sank an enemy warship in combat. Ironically, Horace Hunley’s drive for immortality cost him his life, but his death was not in vain. Having the fish boat renamed in his honor had the unintentional effect of forever attaching his name to this unprecedented event. Hunley’s death resulted in his name being inscribed into history books over McClintock, Watson, Dixon and his crew.
After the attack, lookouts at the Confederate Battery Marshall saw a pre-arranged signal in the form of a blue flare from the Hunley and lit a bonfire to guide the Hunley home. Union witnesses also claimed to have seen a blue light in the darkness. The Hunley never arrived. For reasons that are still unknown, the submarine sank with all hands.
Re-discovery and Salvage of the Hunley
Over the years, the legend of the Hunley grew and with it, stories both true and exaggerated. Despite several searches, the location of the Hunley remained unknown for more than a century. Best selling author Clive Cussler always had a passion for history. He began funding searches for the Hunley in 1981 methodically mapping the Charleston Harbor and Atlantic floor with grids using a magnetometer to locate metal targets to explore further. Logically, Cussler and his team expected to find the Hunley between the attack site and the shore and spent most of their time searching that area. After 14 years of fruitless search, they finally discovered the shipwreck in an unexpected place, east and south of the wreck of the Housatonic. Cussler’s first expedition had identified and briefly explored the site in 1981 but did not expend much effort there because it seemed impossible the Hunley would be further out to sea than the Housatonic when it sank.
One of several mysteries that remains is why the Hunley was found further a sea than the Housatonic. But in 1995, that was the least of Cussler’s worries. The discovery of the Hunley set off a media firestorm and a thorny political controversy over the rights and possible salvage to the shipwreck. The US Government, and states of Alabama and South Carolina claimed ownership.
Cussler had to keep the coordinates of the Hunley secret to thwart looters and to prevent some government entity seizing the shipwreck. Over the succeeding years the parties worked out a compromise whereby the US Navy retained ownership, but South Carolina gained possession in perpetuity. Cussler insisted on overseeing the salvage of the Hunley and its final destination. Millions had to be raised to lift the Hunley and then preserve and restore the remains. Millions more were allocated to creating an adequate public display of one of the most unique and historic vessels in US History.
The salvage was heavily covered with onlookers on boats watching and cheering on August 8, 2000 as a hoist lifted 32 nylon straps supporting the Hunley above the waters of the Atlantic Ocean for the first time in 136 years. In many ways it was fortunate Cussler’s team overlooked the Hunley’s resting place in 1981. The vessel was in remarkably good shape but the corrosive effect of salt would have quickly destroyed the hull in 1981. Corrosion essentially removes electrons which destabilizes the iron. By 1995, techniques existed that to preserve hull that were not available in the early 1980s. The Hunley has been placed in a bath of cold water (to slow down enzymatic rates of corrosion from bacteria, etc. and later a chemical bath with a high pH to prevent the loss of electrons. Eventually, the hull will be stable enough to put on display. The millions spent, careful archaeological examination and conservation measures will be well worth the effort. The Hunley is the only remaining intact warship remaining from the Civil War.
The gradual excavation of the interior of the Hunley produced many artifacts and remains. Archaeologists recovered all eight crewmen along with their personal effects. The crew received a fitting funeral complete with a spectacular parade of reenactors, political notaries and a large crowd. They have finally been laid to rest in Magnolia Cemetery in Charleston near the graves of other Hunley crews.
Most sensationally, Dixon’s $20 gold piece was unearthed in 2001 in the silt around his body. Before this discovery archaeologists doubted it would be found. The coin could have disappeared any number of ways or may have been an apocryphal story. The coin helped establish the mythological aspect to this story.
The greatest mystery remains over why the Hunley sank and remains a source of debate. The location of the Hunley east of the Housatonic is unusual. However, on the night of attack the tide was going out meaning the Hunley lacked the power to return to shore immediately. Dixon knew the Hunley could remain submerged for 2 hours which was about the time it would take for the tide to reverse. He may have submerged to rest on the bottom to wait the tidal change and run out of air prematurely.
Further, there was no sign of panic. For example, the bilge pumps which would have been used to pump water out of the cabin were closed and therefore not in use. No attempt was made to loosen the keel blocks or open the hatches. The crew were still at their stations. Dixon was slumped over as if he had just gone to sleep. The condition of the remains and artifact placement confirmed that at least part of the interior of the Hunley remained dry for years. The evidence points to two conclusions: the crew ran out of air falling unconscious before asphyxiating or they died suddenly.
In 2017, Rachel Lance, an expert on underwater explosions, presented evidence for the latter theory. Lance opined that pressure waves from the detonation of the Hunley’s mine caused the instantaneous deaths of the entire crew.
An underwater explosion creates pressure waves that reverberate in the water and through the body of anyone who happens to be in it. The instantaneous increase in pressure can squeeze oxygen out of the lungs and pop blood vessels in the brain. The effects are often deadly. But the damage occurs exclusively in a victim’s soft tissue, like the gut, lungs and brain — from the outside, it can be impossible to tell that the person has been harmed. 6
Lance performed tests that indicated that the explosion of the torpedo created “pressure along the Hunley’s keel was about 1,100 pounds . . . psi — equivalent to being beneath 2,400 feet of water. Inside the ship, the pressure jumped to at least 28 psi after the explosion — similar to diving down to 64 feet below the surface.” 7 The pressure would be instantaneous which Lance has determined from previous work is often fatal. At the very least, the explosion likely rendered the crew unconscious and they ran out of air before recovering.
One of the unexpected findings from the Hunley was that the historical accounts were wrong about the mode of detonating the torpedo. It was previously believed the Hunley rammed the torpedo into the Housatonic’ hull and backed away causing a 100 foot lanyard to trigger the charge. In fact a screw and electrical equipment were found that indicated the torpedo was permanently attached to the 17 foot spar and detonated upon contact. That put the Hunley within 20 feet of the explosion which adds weight to Lance’s theory.
Cussler has a theory of his own. He believes the Hunley survived the attack but was run over by the USS Canandaigua which responded by sailing toward the sinking Housatonic based on the witness accounts of Union sailors. The top of the Hunley’s propeller shroud is missing and the remaining pieces have three cuts which match the damage a propeller would do. The Hunley’s rudder was also discovered under the hull implying it was knocked off before the Hunley settled on the bottom. Dixon may have lost steering control and decided to submerge to the bottom to consider his options.
One other piece of evidence remains. Both Union and Confederate witnesses reported a blue light after the attack. Dixon planned to give this signal and the fact that multiple witnesses recalled the light cannot be dismissed. The signal strongly implies the Hunley survived the attack and was not crippled. Interestingly, a lamp near Dixon’s position was discovered encased in concretion. But for this detail, I would find the theory that the torpedo blast killed or knocked out the crew. But if so, Dixon would not have been able to give the signal. Reviving the quote from above, “the Hunley does not give up her secrets easily.” 8
This brings us back to the article I referenced at the top of my post. The displaced pipe could have been fatal but like the other theories recounted above it is not a smoking gun. First, if the pipe broke after the explosion, the crew could have stuffed the pipe with a rag to slow the flooding. Further, the bilge pumps were not engaged. Had the Hunley’s compartment been flooded, the crew most certainly would have been trying to pump the water out. It seems unlikely they would have simply remained at their stations as water came rushing into the compartment.
The main issue with all these theories is that there is not sufficient evidence to support only one proposal or eliminate others. It is possible that several of these theories played a role. For example, the blast could have disabled the crew and broken the intake pipe.
Frankly, I like the fact that we cannot settle on one cause. Learning about the various theories is informative allowing us to learn more about the Hunley as a whole. The debate keeps interest alive which in turn elevates interest in history. I have never been to the Hunley Museum but a visit is definitely on the bucket list. From everything I hear the exhibits are great and Charleston is one of the more historic cities in America with much to offer from the Colonial Period through the Civil War. Now that I have taken off my South Carolina Department of Tourism hat, let me encourage you offer comments, suggestions and corrections—especially if you feel inclined to offer your own opinion on why the Hunley sank.
Author’s Note: This article features the work of Civil War artist Conrad Wise Chapman. He was the son of Virginia Governor, politician and Confederate General Henry Wise. Chapman is the only known artist who was actually commissioned to create art during the war. Confederate General P. G. T. Beauregard commissioned Chapman, then serving as a soldier, to paint images from around Charleston during the war. What you see here are images he actually witnessed and recreated. After the war Chapman painted in Europe and Mexico. Many of his works are now on display in Richmond at the American Civil War Museum, formerly the Museum of the Confederacy. For more of Chapman’s paintings, please see his Wikipedia page: https://en.wikipedia.org/wiki/Conrad_Wise_Chapman
Footnotes:
1 Hicks, Brian, Sea of Darkness: Unraveling the Mysteries of the H L Hunley. Ann Arbor MI: Spy Publishing LLC, 2014, p. 398.
2 Whipple, John, The Birth of Undersea Warfare – H.L. Hunley . The US Magazine of Submarine Warfare, Fall 2006, Vol. 8, No. 5. https://web.archive.org/web/20121016165452/http://www.navy.mil/navydata/cno/n87/usw/issue_32/hunley.html
4 Ibid.
3 Ibid.
5 Ibid.
6 Kaplan, Sarah, Science May Have Solved the 150 Year Old Mystery of a Sunken Civil War Submarine. Washington Post, August 24, 2017. https://www.washingtonpost.com/news/speaking-of-science/wp/2017/08/24/science-may-have-solved-the-150-year-old-mystery-of-a-sunken-civil-war-submarine/?noredirect=on&utm_term=.a86d8de96810
7 Ibid.
8 Hicks, p. 398.
Sources:
Hicks, Brian, Sea of Darkness: Unraveling the Mysteries of the H L Hunley. Ann Arbor MI: Spy Publishing LLC, 2014.
Whipple, John, The Birth of Undersea Warfare – H.L. Hunley. The US Magazine of Submarine Warfare, Fall 2006, Vol. 8, No. 5. https://web.archive.org/web/20121016165452/http://www.navy.mil/navydata/cno/n87/usw/issue_32/hunley.html
Byko, Maureen, Raising the Hunley: Archaeology Meets Technology. JOM, 53 (3), 2001, p. 12-14. https://www.tms.org/pubs/journals/JOM/0103/Byko-0103.html
Kaplan, Sarah, Science May Have Solved the 150 Year Old Mystery of a Sunken Civil War Submarine. Washington Post, August 24, 2017. https://www.washingtonpost.com/news/speaking-of-science/wp/2017/08/24/science-may-have-solved-the-150-year-old-mystery-of-a-sunken-civil-war-submarine/?noredirect=on&utm_term=.a86d8de96810
Daley, Jason, New Clues About Why the Confederate Submarine H.L. Hunley Sank. The Smithsonian Magazine Online, July 23, 2018. https://www.smithsonianmag.com/smart-news/new-clues-about-why-confederate-submarine-hl-hunley-sank-180969724/
Duncan, Charles, Researchers find new clues on sinking of Confederate submarine off South Carolina. The State, January 19, 2019. https://www.thestate.com/news/state/south-carolina/article224512110.html
Friends of the Hunley. https://www.hunley.org
All images are in the public domain and subject to Fair Use Laws/