- Historic Sites
The Submarine That Wouldn’t Come Up
The Confederates’ Hunley was the first submarine to sink an enemy warship, but her crude design made her a coffin for her crew
April 1958 | Volume 9, Issue 3
Somewhere an iron boiler was found, about twenty-five feet long and four feet in diameter, and the builders went to work to make a submarine out of it. They cut it in two longitudinally, tapered it fore and aft, inserted boiler-iron strips in the sides, and attached bow and stern castings. Inside the castings, bulkheads were riveted across to form water-ballast tanks for use in raising and lowering the boat. Of the tanks, Alexander noted later that “unfortunately these were left open on top”—a colossal understatement.
A strip twelve inches wide was riveted the full length on top, and flat castings were fitted to the outside bottom for ballast, fastened by bolts which passed through stuffing boxes inside the boat so they might be loosened to drop the ballast if necessary. Sea cocks were installed in the water-ballast tanks, and force pumps to eject the water.
Propulsion was the big problem. Coal could not be burned below water, both because of the limited air supply and for lack of a smokestack. A storage battery adequate to operate even the smallest submarine had not yet been invented. The builders spent weeks trying to devise some kind of electromagnetic engine but finally gave it up and settled for manual power. A propeller shaft was installed almost the length of the boat, supported on the starboard side by brackets, with eight cranks spaced so that the crew could sit on the port side and turn the cranks. The arrangement left no room to pass fore and aft, but at least it assured some motion in the water.
For depth control another shaft was installed, passing laterally through the boat just forward of the end of the propeller shaft. This controlled lateral fins, live feet long and eight inches wide, on the outside. A lever amidships allowed the fins to be raised or lowered. For the pilots guidance, a mercury gauge was attached to the shell near the forward ballast tank to indicate the depth of the boat when submerged, and a compass was installed nearby. A wheel, acting on rods that ran the length of the boat, operated the rudder.
Fore and aft on the boat’s flat deck, hatchways were installed with coamings eight inches high. Glass panes installed in the coamings provided the only means of seeing out of the boat when the hatches were closed. There was no periscope. An air box was set between the hatchways and equipped with a pipe so that fresh air could be taken in on the surface without opening the hatches. All in all, it was a fantastically primitive affair.
The boat was boarded from both ends, part of the crew passing through the forward hatch with the skipper entering last, and the rest entering through the after hatch with the second officer in the rear. The seven crew members took their seats facing the propeller shaft, the two officers fastened down the hatch covers, and the skipper lit a candle which would provide illumination under water and also give warning when the oxygen supply ran low.
When all was ready, the first and second officers let water into the ballast tanks until the water level outside reached the glasses in the hatch coamings, an indication that the deck was about three inches under water. Then the sea cocks were closed, the second officer took his seat with the others at the propeller shaft, and the cranking began. The captain, still standing, lowered the fin lever and the boat slid deeper under the water, the mercury gauge indicating its depth. When he was ready to rise, he raised the lever, elevating the forward ends of the fins; as the boat reached its normal ballast trim of three inches below the surface, or earlier if the captain chose, he and the second officer operated the pumps to force water from the tanks, lightening the boat. When they were safely afloat and ready to land, the second officer opened his hatch cover, climbed out, and passed a line ashore.
She could go four miles an hour in smooth water and remain submerged as long as the air lasted. She was named the H. L. Hunley , in honor of her chief financial backer.
The torpedoes were copper cylinders holding charges of ninety pounds of explosive each, with percussion and friction primer mechanisms set off by flaring triggers. The plan for firing them was as desperate as everything else connected with the project. A torpedo attached to the submarine by a line two hundred feet long would float behind the boat, which would approach its prey, dive under it, and surface on the far side. The torpedo would thus be dragged against the target and explode.
Almost from the moment she was put into the water, the Hunley was plagued with trouble and disaster. Her first trial in the smooth waters of the Mobile River was a success; as General Maury watched, she towed a floating torpedo, dived under an old flatboat and scored a hit, blowing fragments a hundred feet into the air. But once she was taken out into the choppy waters of the bay, it was another story. She responded poorly, she was in constant danger of swamping, and that deadly torpedo trailing behind her was continually swinging in the direction of the wrong boat.
In later months, when the Hunley ’s latent tendency to drown her crews had become virtually a fixed habit and she had become known as the Peripatetic Coffin, it was generally reported that she sank first in Mobile Bay, drowning a full crew of nine men. This is apparently incorrect; but though she did not sink until later, General Maury and her owners alike agreed that her future in Mobile Bay was exceedingly dubious.