As the bizarre craft proceeded out in the direction of the Federal blockading fleet, perceptive viewers, perhaps with a high quality telescope, could see the hatch covers close, and suddenly, in a surge of bubbles, the boat would disappear beneath the surface.Little did the residents of the city realize that they were historic witnesses to what would become the world's first successful submarine. Forerunner of all the great and fearsome undersea craft to come in a later century, this historic vessel they were watching was the Confederate submarine, CSS H.L. Hunley. No other vessel built by or for the Confederacy is as intriguing and innovative as the Hunley. This vessel, as events have shown, introduced a whole new concept and dimension to naval warfare which still influences our lives today.
Designed and financed by James R. McClintock, Baxter Watson, and Horace L. Hunley. To save time in construction, they used an existing ship's boiler that was twenty-five feet in length and four feet in diameter as the basis for the hull. This was cut in half lengthwise and reinforcing iron bars added to the inside of each half. The upper and lower halves were then rejoined by riveting two twelve-inch strips of iron between them on either side, and all seams were tightly caulked and sealed. Tapered sections were bolted to both ends to form the bow and stern, while on the exterior, a twelve-inch strip of iron was bolted to the top to form a deck. Inside the boat, bulkheads were fabricated front and back. The space between these bulkheads and ends of the boat served as water-ballast tanks which were, unfortunately, left open at the top causing at least one accident by allowing the interior to flood when they overflowed. Both ballast tanks were equipped with inlet valves or "sea cocks" which opened, would allow sea water to fill the tanks, causing the boat to sink. In addition, each tank was equipped with a hand pump to force water out causing the boat to rise. In an emergency, these pumps could also operate as bilge pumps.
To give the boat a weighted keel, which would serve to keep it upright, additional iron ballast was placed under the hull. These were attached with special T-bolts that could be turned from inside, which would drop the ballast in case of an emergency. Diving vanes, five feet long and eight inches wide, were positioned on either side of the forward part of the boat. A one and one-quarter inch rod passed through stuffing boxes at the rear of the commander's station and connected these vanes to the diving lever. This lever was positioned by the commander's side, and when raised or lowered would change the depth of the boat without having to disturb the water level in the ballast tanks.
Running front to back through the center of the boat, and supported by brackets attached to the starboard side, was a long crankshaft which was connected to the propeller. Power was supplied by eight crewmen sitting along the port side of the hull, each turning his respective part of the crank. Around the three-bladed propeller was a shroud to prevent fouling, and attached to this was the rudder. Approximately 14 feet apart on the top of the hull were two small hatches, 16 by 12 inches, each with 8-inch coamings containing three glass portholes. Both hatches were equipped with heavy hinged lids using rubber gaskets, and special bolts that could be tightened from inside or out.
All seams and crevices were tightly on the interior, and wrought iron ladders led up to each hatch. The captain stood so that when the boat was partially submerged, he could sight through the glass of the coamings of the forward hatch. At his hands were the diving lever which controlled the vanes on the exterior, a sea cock used to flood the forward ballast tank, a hand pump to pump out the water, a mercury depth gauge(Manometer), a magnetic compass, and a small ship's wheel connected to the rudder. A petty officer occupied the rear hatch position with a sea cock and hand pump to control the rear ballast tank. Interior light was provided by a single candle, and when the flame went out in 20 to 25 minutes, it was an indication that it was time to surface for air. When the Hunley was launched in the spring of 1863, she measured forty feet long and was the best underwater boat that had been built to date. Considering all the handicaps and shortages under which the Confederacy was struggling, it is amazing that such a unique and sophisticated craft was designed and built at all.
The Hunley's spar torpedo was a copper cylinder which held ninety pounds of explosive. Percussion primers on the front and sides would detonate the charge when contact was made against the hull of a ship.It appears from existing records, however, that the Hunley used a different type of torpedo when it made its final attack on the Housatonic.
On Saturday, August 29, 1863, the Hunley was being towed across Charleston Harbor when disaster struck. The boat became entangled in some ropes and was drawn over on its side. The hatches were open, the craft quickly filled with water and five crewmen drowned. As a consequence, General Beauregard, commander of the city's defenses, asked Hunley to come to Charleston to take charge of the project. Hunley brought with him, Lieutenants George E. Dixon and W.A. Alexander, of the 21st Alabama Infantry Regiment. Both of these men had been with the project since its inception in Mobile. On October 15, 1863, with Dixon absent on business in Charleston, Hunley determined to continue the crew's training with himself at the controls. Tragically, on this day, the submarine claimed another crew, including its designer.
Undaunted, Dixon and Alexander were now more determined than ever to turn this novel and dangerous craft into an offensive weapon, and strike a blow at the Federal blockading fleet. After refurbishing the boat, now officially named CSS H. L. Hunley in honor of her designer, Dixon sought yet another crew from the sailors on board the tender Indian Chief. He and Alexander established America's first submarine training school at Mount Pleasant, on the north side of the harbor. The submarine was moored off Battery Marshall on Sullivan's Island, and as the long nights of winter approached, the crew became more and more proficient. With Dixon at the helm, and Alexander controlling the rear ballast tank, they began to undertake nightly sorties of up to five miles each way.
In February, Alexander, much to his disappointment, was ordered to another project, and a replacement volunteer quickly took his place. As dusk settled over Charleston on Wednesday evening, February 17, 1864, the Hunley, with no fanfare and few observers, cast off her lines for the last time and sailed into history...
Some of the citizens of Charleston, South Carolina had become accustomed to the sight; others had not. Visible from the waterfront and the "Battery" almost every evening during the approaching winter of 1863 was the long, low shape of a peculiar looking vessel. Usually around sundown, observers would see a lone sailor cast off the lines and then disappear into the boat's interior.Slowly, the strange craft would ease into the channel and begin making its way out of the harbor. With no protruding sail or smokestacks, its upper surface was barely visible above the water. Occasionally, as the boat would rise on an unusually large swell, a long spar could be discerned protruding from the bow with a sinister looking black cylinder attached to the end.
