With the successful Federal siege of Vicksburg, the naval “Anaconda” strategy was virtually complete: the Union Navy held nearly all of the major ports along the Atlantic and Caribbean coasts, and controlled access to all of the Mississippi River. The North had also begun building Monitor-type ironclads, and could do so at a far faster rate than the South. The Confederate flotilla of blockade-runners, meanwhile, was unable to transport enough supplies past the Federals. In desperation, the South once again sought a technological breakthrough that would allow them to lift the crippling blockade. And one of these concepts was the “submarine”.
For those who don't know, I live in a converted campervan and am traveling around the country, posting photo diaries of places that I have visited. :)
It was not a new idea. During the Revolutionary War in 1776, George Washington had attempted to break the British blockade of New York harbor with an underwater contraption called “Bushnell’s Turtle”, which made an unsuccessful attack with a black-powder “torpedo” on the Royal Navy flagship Eagle. But the Turtle had been a crude one-person craft made from wooden planks: the technology of the 19th century allowed for more advanced designs.
The Union Navy had already begun experimenting with submarines. Since they had enough wooden-hull and ironclad ships to seal off all the Southern ports, the primary purpose of the Federal submarines was to help clear the waters of defensive “torpedoes”. So most of the Union submarine designs had iron-plate hulls with a hatch for an underwater swimmer to exit, where he could cut the ropes that held the Confederate mines in place and disarm them.
One of the earliest US submarines was the Alligator, designed in late 1861 specifically to counter the Confederate ironclads then under construction. She was launched in May 1862. Originally, she was propelled by oars that extended from her sides: this was unworkable, however, and they were quickly replaced with a hand-cranked propeller. President Lincoln himself watched some of the submarine’s test runs. But the Alligator never saw action. While being towed to South Carolina in April 1862, she sank in bad weather.
Another early submarine was the Submarine Explorer. This design, already built privately by Julius Kroehl, was submitted to the US Navy in 1863, but was rejected for some reason. After the war, Kroehl took his submarine to Panama and used it for commercial pearl diving until he and his crew died of disease, when the Submarine Explorer was abandoned on a remote beach and sat forgotten until it was rediscovered in 2001.
In October 1863, a Union Army officer identified only as “Major Hunt” died while testing a submarine named the Sea Miner. Hunt was reportedly working on a new weapon system that he called an “underwater rocket”. Shrouded in secrecy and today mostly unknown, it may have been an early version of what we know today as the torpedo.
Another early Federal submarine was called Intelligent Whale. Designed in 1863, she was far advanced for her time, using compressed air to operate the ballast tanks. The Whale, however, did not finish construction until after the war ended.
But it was the Confederates who pursued the technology most eagerly. The submarine was viewed as a wonder weapon that could break the Federal blockade and save the South.
In early 1863, a boatbuilder named Horace Lawson Hunley designed an underwater warship made of riveted iron plates. A hand-cranked propeller would move it through the water, and a series of water-ballast tanks would raise and lower it. It would carry a “torpedo” loaded with 135 pounds of black powder at the end of a timber spar: the submarine would approach stealthily underwater, attach the bomb to an enemy ship and then withdraw before detonating it. The entire project would be privately-funded, and the craft would operate as a privateer, a sea-going mercenary that was never officially part of the Confederate Navy. Construction began in Mobile AL, and once the 40-foot cylindrical craft, christened Hunley, was finished it was transported to Charleston Harbor for testing.
The Hunley was, unfortunately, beset by disasters. In one test run, the craft accidentally submerged while its hatch was still open and filled with water, drowning five of its nine crew. Not long after, another mishap sunk the sub and killed all nine aboard, including Hunley himself.
On February 17, 1864, the submarine set out on its first combat mission, with its eight-man crew commanded by Lieutenant George Dixon. Because it was deemed unsafe to run the vessel submerged, the Hunley was on the surface, and had intentionally picked a calm moonless night to carry out the attack. Her target was the USS Housatonic, a 12-gun wooden-hulled steamer that was part of the Union squadron blockading Charleston Harbor.
One of the Housatonic’s lookouts spotted the Hunley as it approached. The Federals had pretty good intelligence about the submarine and knew what it was, so as soon as it was spotted in the water the ship let loose with her cannons. Small and low in the water, however, the Hunley was a difficult target, and, unscathed by cannonballs, made its way up to the Housatonic, attached her mine, and backed away.
The explosion tore open the Union ship’s hull, and within minutes she had begun to fill with water. The harbor here was only 30 feet deep, so as the Housatonic settled on the bottom, the tops of her masts and rigging poked above the surface. Five of her 135-man crew was killed in the explosion, but the rest got away safely, either by climbing the rigging or by launching the rowboats. But the ship was destroyed. The Housatonic became the first vessel ever sunk by a submarine.
Confederate military officers on shore saw the explosion and watched the Housatonic sink, and waited for the submarine’s triumphant return. The wonder weapon had demonstrated that it really could work.
But something was amiss: after several hours, the Hunley had not returned. She had been lost, with all eight of her crew.
In 1995, a team of divers from the National Underwater and Marine Agency located the sunken wreck of the Hunley, lying intact on the harbor floor. The submarine was raised and sent to the Warren Lasch Conservation Center in North Charleston where it was submerged in a 90,000 gallon tank filled first with a cold freshwater bath to extract the salt from the metal, then with a weak lye solution to remove the ocean concretions and stabilize the hull. She is now on display there, as restoration efforts are expected to continue for another five or six years. Fundraising efforts are already underway to construct a permanent museum to house the submarine once the conservation project is completed.
It is still not clear exactly what sank the Hunley. There are indications that the submarine may have been too close to the explosion and was sunk by its own torpedo. The bodies of the crew were still inside and the valves had not been set to pump water out of the hull, indicating that either the sub had sunk too rapidly for the crew to react, or that it had actually made its getaway intact after the explosion, and sunk later. Some have concluded that the crew died of asphyxiation while submerged on the return trip, having used up all their oxygen.
Some photos from my visit.