The Alligator
Union Submarine of the Civil War (1862)


America's First Custom-Built Attack Submarine

History - read on.    |    Specifications    |    Historic Firsts    |    Pictures    |    Links

Preceding the more successful Hunley by some months, the Alligator was the first (marginally) poracticable submarine in the Civil War, actually taking part in an operation in 1862. Given the newness of the technology, it is not surprising that she was awkward and not entirely successful. It is uncertain how successful she might have been, for she sank and was lost to the Union before she could be used in a genuine operation in her improved configuration. It should be noted that none of her crew was killed in training, or in the final sinking.

Alligator was the brainchild of French inventor Brutus de Villeroi, who constructed a prototype while in France and saw that this vaunted breakthrough was well publicized. He was called in by the Union navy at the end of 1861, when they were frantically searching for means of advantage in the American Civil War. The vessel contracted for was a 47-foot iron submersible propelled by human-powered oars to be worked from inside the hull. For attack capability, Villeroi proposed and delivered a technological first: a pressurized hatch for launching a diver from the submerged hull, in order to plant explosive limpet mines on the hulls of enemy ships. These mines were to be electrically detonated from a safe distance. The diver's suit was pressurized by a human-powered air compressor attached to the diver's suit by hose -- essentially a crude version of the deep-sea diving outfits through the present day.

Alligator was built at Neafie & Levy in Philadelphia and launched there on May 1, 1862. Due to the delays in delivery and Villeroi's inability to get along with others on the project, he was dismissed, but not before his brains had been thoroughly picked by the other technicians. At the time, only weeks after the CSS Virginia's foray into Hampton Roads and the inconclusive Battle of the Ironclads, the sub was viewed as insurance against further depradations by the Virgnia. Accordingly the sub was brought to Hampton Roads and released into the James River to land and destroy a Confederate-held railway bridge on the Appomattox River. However, with low water in the river and a full-scale battle developing around her objective, she was not able to submerge or carry out the mission. In order to avoid the possibility of capture by the Confederates, she was ordered withdrawn. But in retreat, her oar propulsion proved awkward and insufficiently powerful to maneuver in current. Alligator's crew panicked when the air aboard started to grow foul. In stampeding to squeeze out a single hatch crewmen trampled their fellows. Her commander found himself literally up to his anus in Alligators. Following the failure of the Appomattox Bridge mission, the ship was returned to the yard for improvements and a complete change of crew.

The oar ports were replaced by a screw driven by a single, human-driven crankshaft not dissimilar to the system used in the Hunley. This shaft was geared to a single, 3-foot screw at the boat's aft end. Trials with this system yielded a satisfactory four-knot speed on the surface. The ship's crew and commander were entirely replaced after the James River panic and the boat was trialed with the new rig -- trials that were observed by President Abraham Lincoln. The Alligators were then ordered to join the Adm. Du Pont's Union forces besieging Charleston, S.C. with the likely task of sneaking in and sinking the several Confederate casement ironclads in port. However, en route to the assignment, the ship ran into insurmountable seas. Unmanned, the Alligator was proceeding under tow by the paddle steamer Sumpter. The ships ran into a terrific gale off Cape Hatteras on March 31, 1863. Trying to preserve the unmanned sub was endangering the Sumpter and regretfully, rather than risk adding his and his ships' bones to the Graveyard of the Atlantic, Sumpter's commander ordered the towline cut. The Alligator was seen thrashing through the foam for a few minutes before upending and plunging to the depths. And nought of her has been seen since then.

Historic Firsts of the Submarine Alligator
  • First submarine to be ordered and built for the U.S. Navy (but never formally commissioned).
  • First submarine to have a diver's lockout chamber.
  • First submarine to be deployed to a combat zone.
  • First submarine to have onboard air compressors for air renewal/diver support.
  • First submarine to be commanded by a U.S. Naval officer (who would later achieve Flag rank).
  • First submarine to be designed with an air purifying system.
  • First submarine to have an underway test witnessed by a U.S. president.
  • First submarine to have electrically-detonated limpet mines.
  • First submarine to undergo an overhaul in a U.S. naval shipyard.


Plans and Specifications

Comparative plans showing the 2 propulsion systems of the ALLIGATOR, 1862 (top) and 1863 (bottom)
The Alligator's two propulsion schemes: by hinged oars, 1862, top; and by hand-turned screw, 1863, bottom.

Specifications for the Alligator:
Dimensions: 47' x 4'6" x 6'   Displacement: 275 tons surfaced, 350 tons submerged. Propulsion: (16) oars, changed to 8-man human-powered crankshaft, single screw. Maximum speed: 2 knots under oar power, 4 knots under screw. Diving equipment: Watertight pressurized hatch for releasing diver, hand-powered air compressor. Armor: None. Armament: (2) electrically detonated limpet mines. Crew: 12. Cost: $14,0000 at 1860 valuation.

Metric Specifications:
Dimensions: 14m x 1.37m x 1.83m   Displacement: 275 tons surfaced, 350 tons submerged. Propulsion: (16) oars, changed to 8-man human-powered crankshaft, single screw. Maximum speed: 3.7 km/hr under oar power, 7.4 km/hr under screw. Diving equipment: Watertight pressurized hatch for releasing diver, hand-powered air compressor. Armor: None. Armament: (2) electrically detonated limpet mines. Crew: 12. Cost: $14,0000 at 1860 valuation.

Wood-engraved illustration of the ALLIGATOR


An Bite of the Alligator

Model of VESUVIUS

Drawing of the de Villeroi's prototype in Europe that convinced the USN to build the Alligator. Note that this is a screw-powered vessel, although the original build of the Alligator was to be oar-powered.

Bow view of VESUVIUS
Alligator with her tenders in the James River; watercolor by Jim Christley.

Wood-engraved illustration of the ALLIGATOR

The classic rendering of Alligator skulking through the depths, seeing ahead with illuminated lamps (how?), barely troubled by the waves that buffet ships on the surface, her prey. It is not surpising that only a few years after the first practical subs went to war, Jules Verne's imaginative masterwork 20,000 Leagues went to print and became an international sensation. Enlarge

Elevation of USS ALLIGATOR by Joe Hinds

Rendering of the Alligator by artist Joe Hinds. Our thanks, as always, for his kind permission to show his work, which can be seen in full at Primedia.com.


Alligator Weblinks

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