Submarines in the Civil War

By Chuck Veit
(Photographs, reconstructions, and diagrams appear at the end of the article)

Contrary to the opinions of the popular press, the story of undersea warfare in the Civil War is not limited to nor initiated by the C.S.S. Hunley. That boat’s only unique claim to fame is that it was the first submarine to engage and sink an enemy vessel. Other submarines had sortied on combat patrols almost two years previous and another Confederate boat may also have sunk a Union warship in Mobile Bay. All told, there is evidence for over a score of Northern and Southern submarines in the course of the war. Many of these boats had features not seen again until the 20^th century, including airlocks, electric motors, air purification systems, and periscopes.

Information for this short overview came from Mark Ragan’s 1999 book, “Union and Confederate Submarine Warfare in the Civil War” and a variety of online sources. In that work, Ragan cites the paucity of official records as the single greatest challenge to submarine research for this period. On the Southern side, many submarines operated under the aegis of the Secret Service rather than the Navy. Submarine warfare was considered almost illegal, the term “infernal machine” being used liberally in Northern reports. Because of this, records relating to submarines and underwater mines were intentionally destroyed toward the end of the war to keep the identities of those involved secret. Others might be pardoned upon taking the Oath of Allegiance, but anyone connected with building submarines couldn’t be certain. The North, while publicly denouncing undersea warfare, engaged in its own building program and so had good reason to keep most references to such craft out of the Official Records. The few that survive repeatedly insist upon secrecy.

From the beginning, submarines played a different role on the two sides. Because the Confederacy was confronted by a large enemy fleet intent upon blockade, their vessels were intended for offensive work against ships. Being faced by obstructed harbors, the Northern Navy perceived of submarines as a means to clear underwater obstacles rather than as attack craft. Throughout the nation, the feasibility of designing, building, and successfully employing submarines was not doubted. The public perception of undersea warfare in 1860 is perhaps analogous to our own modern acceptance of “starships” (á la Star Trek), which, although beyond our current technological means, are largely accepted as something in the not-too-distant future. And, just as NASA’s shuttles have made the once-extraordinary seem ordinary, seemingly fantastic underwater vessels had been demonstrated in everyday use prior to the Civil War.

In the early 1850s, Lodner Phillips designed and employed a submarine for salvage work on the Great Lakes. They continued successfully in this business for fully five years, 1851-55. Interestingly, their boat used an underwater cannon to blast obstructions. Seeing the military value of their vessel, Phillips and Peck offered it to the Navy, which responded by informing the inventors that “the ships of the Navy go upon the water, not under it.” Brutus De Villeroi had demonstrated an even earlier boat in Nantes, France in 1832.[1]

The perception of submarine warfare as a possibility is nowhere better evidenced than in a letter published on June 10, 1861 in the Columbia (Tennessee) Herald by Reverend Franklin Smith. A respected chemist and inventor, Smith owned “one of the finest laboratories in the South.” Calling upon Southerners citizens to assist in the building of submarines to defend their shores, the Smith letter was reprinted in newspapers across the Confederacy. Although it cannot be known how many citizens responded to the Reverend’s call, Smith himself did build at least one “submarine propeller.” Operational by the fall of 1861, it was sabotaged and sunk while at dock, perhaps by a Union sympathizer.

Interest in submarines among the people of the North was similarly kindled as early as May 1861. On the 16^th of that month, Philadelphia harbor police stopped and boarded a strange contraption they had spotted moving down the river. The thirty-foot vessel, “sharkish in appearance,” had a crew of four – which included its designer, Brutus de Villeroi. Although the Frenchman claimed to have been heading to the Navy Yard for tests, officers there disavowed any knowledge of him; his voyage may have been only a publicity stunt – which worked very well. In the days following, de Villeroi gave an astonishing interview to reporters: his vessel (he claimed) could remain submerged for several hours, utilized an airlock that permitted a diver to exit and enter the boat while submerged, and employed an air purifying device that supplied air to the crew while underwater. Possibly under public pressure, Captain Samuel Du Pont, Commandant of the Philadelphia Navy Yard, ordered a thorough examination of the de Villeroi submarine. The resulting report of 7 July 1861 indicated that “the services of the distinguished French engineer would be very valuable to the government and that the possession of his invention would be of the greatest importance.”

The summer of 1861 also witnessed the development of another new submarine, this one in the James River off Richmond, Virginia. Designed by underwater explosives engineer William Cheeney, this unnamed boat may possibly lay claim to the first underwater combat mission of the war. Given the fact that the well-known Hunley required a crew of eight men to move at its sluggish pace, it is interesting to note that Southern naval engineers designed this boat to be powered by only two men. No schematics or drawings of this boat survive – only a receipt from the Tredegar Iron Works for construction of a 46” propeller. Did Cheeney’s boat employ a series of gears that allowed the crew of two to effectively turn this large prop?[2] As remarkable as this seems, a demonstration of the vessel was witnessed off Richmond by a Union spy, Mrs. E. H. Baker, proving that it did work. Towards the end of September 1861 Mrs. Baker attended the trials of the Cheeney submarine. A sea green flotation collar that supported an air hose from the boat marked its progress under the James River; while extending the duration of a cruise indefinitely, the float system would prove to be the boat’s weak spot. The Union spy reported that as the float approached a target barge in the river, it was seen to stop. At this time, the third member of the crew, a diver, would have exited the boat and placed a charge on the hull of the barge; air was supplied the diver by a hose from the submarine. Once back inside, the vessel backed away from the target (as evidenced by the movement of the float). A few minutes later, a large explosion sent the barge to the bottom. The crowd cheered and Mrs. Baker quickly sent a report of the demonstration to Washington. In her report she described the submarine attack she had watched and also mentioned a visit on the following day to the Tredegar Works to see a second boat under construction. This accurate eyewitness account spurred the Navy in Hampton Roads to devise and rig the first anti-submarine nets around their ships. These were simply an arrangement of spars encircling each vessel, from which either heavy nets or chains were suspended to a depth of fourteen feet. It was hoped that an approaching vessel intent upon attaching a torpedo either via diver or spar would be entangled and caught. Given that concerns about the Virginia (Merrimack) were mounting, simultaneous fears over “infernal machines” prowling the waters of the James must have given many a Union sailor cause for concern.

In early October of 1861 this remarkable submarine was transported to Sewall’s Point for an attack upon the Union fleet. Its intended target was the U.S.S. Minnesota. Fortunately for the Yankees, the vessel ran afoul of the anti-submarine net and barely escaped; the boat was beached and later transported back to Richmond. On October 12, a reporter for the New York Herald submitted an incredible interview with a “gentleman” who had on the day previous crossed into the Union lines under flag of truce. In his article, he described the vessel and the attack:

On arriving at the place desired, a grapple catches the cable of a vessel, and the machine is veered away until it is supposed to be near one of the magazines, the water ballast is pumped out, and the machine floats up under the ship’s bottom. By means of an India-rubber sucking-plate this machine is attached to the bottom of the ship, while a man-hole plat is opened and the torpedo screwed into the vessel. It is fired by means of a time fuse.

The reporter verified Mrs. Baker’s information that the submarine employed a hose and float to supply air and claimed that the crew was only two (not three) men. Three weeks later the Rebel sub made another attempt, which came to grief for the crew when sharp-eyed sailors on picket patrol spotted the “camouflaged” float and cut the hose supplying air to the Confederate crew. No further mention of this first boat appears in Confederate records, and the employment (and fate) of its sister ship is likewise unknown (although Cheeney was still charging work done by Tredegar to “the submarine boat” as late as mid-December).

1861 also saw an unnamed Confederate submarine of twenty-foot length sighted in New Orleans. Whether operational or still being tested is not known. Boats are also evidenced in Mobile and Savannah at this time, that in the latter city being lost in trials in January of 1862.

Two months later (in March), Baxter and McClintock – with their partner Horace Hunley – launched their first submarine, Pioneer, in New Orleans. This vessel was significant in that it was the first submarine to be granted a letter of marque from the Confederate government. The team moved to Mobile later in 1862 (after Farragut took New Orleans) and began work on another submarine, Pioneer II. Recognizing the limitations of a human-powered boat, the team experimented with both electric and steam engines. Electric motors of sufficient size were available for $5,000 in New York City, but attempts to purchase one and smuggle it into the Confederacy failed; the motors developed locally proved to be understrength and the idea was discarded. Similarly, as no means of venting the exhaust from the boiler fires of a steam engine could be devised, this means of propulsion was also scrapped.

Further north, there is evidence that William Cheeney had completed another submarine at Tredegar, this time using a trailing charge to be detonated electrically rather than a diver. There is, however, no further mention of this vessel. On the other side of the front line, Brutus de Villeroi’s expertise had finally resulted in a new “submarine propeller” 47 feet in length with a crew of 26. One of the many delays in the construction of this boat was the inventor’s insistence upon the use of certain very expensive chemical which he claimed were needed for the air filtration system. The exact means by which de Villeroi “scrubbed” the air of carbon dioxide is unknown, but possibly his system used a series of motorized pulleys that drew long sheets of woolen cloth through a bath of lime-impregnated water. This would serve to remove a quantity of CO₂ from the atmosphere of the boat while returning a small amount of oxygen at the same time. The cost of the chemicals was $15,000 (which, in modern dollars, translates to $225,000-$300,000). Little wonder that the Navy balked at the expenditure.

Unlike other period submarines, the boat designed by de Villeroi was not powered by a central screw propeller; it used a row of oars down either side. The paddles of the oars were made to fold in on the return swing so as to reduce drag and two crewmen manned each oar. An officer and a diver completed the compliment of the ship. As Mark Ragan suggests, the interior of the boat must have resembled that of a Viking longboat as the sailors hauled away at the oars.

True to the Northern philosophy of using submarine craft to clear obstacles, the as yet-unchristened “screw propeller” headed up the James River in June of 1862. Unfortunately, this first-ever combat sortie of a U.S.N. submarine had to be called off when the Army retreated from the Peninsula – leaving shoal water where the sub would have been visible behind enemy lines. Returning to Fortress Monroe, the boat was redesigned with a central screw and christened the U.S.S. Alligator. The vessel was also taken out of the hands of de Villeroi and given to a Navy crew. Its first commander was a veteran of the U.S.S. Cumberland and had served as skipper of the Monitor immediately following its famous battle – Thomas O. Selfridge. For two weeks, Selfridge and his crew struggled to get the Alligator back in action, unsuccessfully. Frustrated and disgusted with submarine warfare, Selfridge was relieved and given command of U.S.S. Cairo – which struck an underwater mine on 12 December 1862 and went to the bottom of the Mississippi.

The autumn of 1862 witnessed an incredible experiment in the Potomac River off Washington City. There, inventor Pascal Plant demonstrated his rocket-propelled underwater torpedo to Navy officials. True to his claims, Plant successfully sank a ship – unfortunately, it was the schooner Diana, which lay tied up next to the target vessel! A second torpedo “porpoised” out of the water and flew through the air for 100 yards. Missing the potential of both attacks, the navy Department declined to pursue Plant’s ideas.

1863 saw both sides set up official commissions to deal with underwater warfare. In the North, the Permanent Commission was created by the Navy to evaluate all new inventions (including submarines), while the Singer Submarine Corps was founded in the South. The Singer Corps was already responsible for the bulk of torpedoes used by the Confederate Navy. In April, the Triton Company was also founded in Richmond, and immediately began construction of a submarine with an external diver compartment. While this was not an innovation (the airlock already having proven successful in both the Cheeney subs and the Alligator), the Triton system used two air hoses for the diver: one supplying air to him an a second carrying exhaled breath back to the submarine, thereby eliminating the tell-tale trail of bubbles that could warn ships on the surface. This boat may have been transported to Charleston and seen service.

  In this same year, the Baxter, McClintock, and Hunley team launched their second boat, the Pioneer II, in Mobile. “Three or four other” subs were claimed to be operational in the bay at this time as well. In April, the Alligator, like the Monitor before her, was lost off Cape Hatteras while under tow to Charleston. In July, the U.S.N. received schematics for a 55’ submarine from a “Professor Horstford” of Cambridge, Massachusetts. While it is doubtful this boat was ever built, what is interesting is that it is believed to have been based almost entirely on the design of the Alligator: the same diver compartment, air scrubbing system, and crew complement, but with the addition of a periscope and blowers to move the purified air to the back of the boat (furthest from the scrubber). The scrubber may have been powered by an electric motor, as the schematic shows a box plainly marked “motor.” The Horstford sub also carried large tanks of compressed air to refresh the atmosphere and extend dive time. At this same time (July), Confederate records claim that a Colonel E.H. Angamar made an attack on the Union fleet off Mobile with rocket-propelled torpedoes launched from a similarly-powered boat. The first mention of this craft appeared in November of 1862, but whether the supposed attack ever took place or not is unknown (the U.S. Navy has no record of it). July also saw the launch of the C.S.S. Hunley in Mobile.

That submarines were accepted as commonplace is evidenced by a brief reference in the Official Records to a request made by Admiral Dahlgren for “3-4 submarines” to clear obstructions in Charleston harbor. His off-handed petition suggests that he recognized their use, assumed they were available, and expected them to be delivered. While the Union records make no mention of the delivery or use of any such vessels, a subsequent Confederate report indicates spotting a Union submarine being towed over the bar into the harbor and slipping under the surface – and out of the historical record.

The closing months of 1864 and the first half of 1865 were active ones for submariners North and South. Records of the Tredegar Works indicate a hand in a submarine built at Wilmington. Another submarine of 69 foot length along with “3-4 others” were supposedly active in Mobile Bay; these may all have been private ventures. February saw the attack of the Hunley on the U.S.S. Housatonic, resulting in the first recorded sinking of a warship by a submarine vessel. In the summer, Lodner Philips offered his salvage craft to the Navy once again (after having been rebuffed in the 1850s). Whether the boat ever went into action is unknown; the design was significant in that it used a system of buoyancy tanks to dive and ascend. Air was pumped into the cabin and water allowed into the tanks to descend and the process reverse to rise. This would not be seen again until the world wars. Simultaneously, Halligan designed a Confederate boat in Selma, Alabama that was also ahead of its time. The Saint Patrick had two means of propulsion: a steam engine for surface running to its operational area, and then traditional manpower once engaged. This foreshadowed later diesel / electric motors combinations. One of the more fantastic but proven-effective designs was that of Julius Kroehl’s Exporer, offered to the U.S. Navy in June. Kroehl’s Explorer carried a great amount of compressed air that allowed the crew to so pressurize the interior of the sub that the boat could run with its bottom open to the ocean! As chief engineer of the Pacific Pearl Company, Kroehl’s innovation made perfect sense. Rejected by the Navy, Explorer was towed to Panama, where it functioned well for years; the company divers working the pearl beds from Explorer suffered fewer injuries and harvested more pearls than those of any other company.

On August 5, 1864 occurred one of the more mysterious submarine attacks of the entire Civil War. As is well known to students of the battle of Mobile Bay, the Union ship Tecumseh supposedly veered out of line and into a known minefield – and paid the price for the impetuosity of her captain, going down so quickly that only a handful of its crew survived. Oddly, no other mine in the bay worked that day. Farragut’s brave admonition to “Damn the torpedoes! Full speed ahead!” was unnecessary, since the detonations of the percussion caps as the Hartford struck mines could not ignite the waterlogged black powder in those devices. Did the Tecumseh unhappily find the one mine that did work?  Shortly after the Tecumseh went down, three Confederate sailors were pulled from the Bay. One of them, Captain Albert Pierce, claimed to have attached a mine to an unidentified Yankee ship. Immediately after doing so, the boiler on the submarine he commanded, the C.S.S. Captain Pierce, exploded, killing a number of his crew and injuring his legs. Since Pierce believed the vessel that plucked him out of the water to be the one he had targeted, he assumed that his mine had not worked. But had he instead struck at the Tecumseh? A sunken vessel reportedly lies buried in the sand near the Tecumseh – is it the Captain Pierce?

As the war entered its fourth year, Halligan’s Saint Patrick joined the battle, making an unsuccessful attack against the U.S.S. Octorora in Mobile Bay. The Saint Patrick ended the war running supplies under the blockading squadron to the outlying forts ringing the Bay. In the final act of the Civil War, Union naval forces were sent up the Red River to Shreveport to demand the surrender of the C.S.S. Missouri and a small CSN squadron stationed there. The Confederate squadron included four boats of the Singer Submarine Corps, of which the Union ships had been warned. By the time the Yankee sailors arrived, however, the submarines had all been scuttled.

A Gallery of Civil War Submarines
(generated imagery courtesy of and copyright 2000 Daniel Dowdey, www.dowdey.com/default.htm)

Pioneer I	Pioneer I	Pioneer II (above) C.S.S. Hunley (right)
U.S.S. Alligator Paddled design (top) Screw Propeller (below)			Intelligent Whale (post-war sub)

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