By: Michael Singleton, former CWRGM Assistant Editor

            In the last two posts, we examined some of the more exceptional documents in the CWRGM collection that featured civilian suggestions to Governor John J. Pettus about defending Mississippi’s waterways, namely the Mississippi River. These proposals ranged from more conventional plans for fixed fortifications to—as we looked at last time—a unique plan for an ironclad warship with a rapid-fire battering ram. Today’s post continues the theme from that second article as it details perhaps the most unconventional of all the proposals: a plan for a manned, steam-powered submarine designed to attack Federal ships on the state’s rivers and in the ocean.

The advent of submarine warfare is near the top of the list of important technological innovations brought about by the American Civil War. The successful (albeit suicidal) attack by the submarine CSS Hunley on a Federal warship in Charleston Harbor in February 1864 heralded a new age of naval warfare that forced commanders to consider threats from below the waves, not just on the surface. When Thomas P. Hall of De Soto Parish, Louisiana, forwarded Governor Pettus a plan for a submarine in December 1862, however, that revolutionary change was by no means certain.[1] Hall’s letter contained a design by a local acquaintance, Charles J. Provost, that Hall felt deserved the Governor’s attention because of its potential to “prove a most efficient weapon for driving the enemy out of all our rivers and away from our harbors & seacoast.” According to Hall, Provost’s plan had been examined and approved by “some of our ablest engineers” in Louisiana and recommended that the Governor seek further confirmation of its potential from other experts.

Figure 1. Charles Post’s schematic drawing of his submarine design. Note the conning tower, rotating mechanism, and “arm holes.” Courtesy Civil War & Reconstruction Governors of Mississippi Project. Click on image to view entire document.

Provost’s plan was complex. It called for a vessel built around a boiler taken from a steamboat with a screw attached to a propeller as the primary means of propulsion. A “driving wheel” with “long hands extending forward having knobs to them” would allow the crew to crank the wheel and move the boat forward and backward. Ropes extending from the rudder would allow a crewmember in the bow to steer the vessel as necessary. Ballast meant to keep the submarine horizontal and aid in depth changes would be “distributed uniformly” along its length. Air for the crew would be pumped in by a tube extending to the boiler from a buoy on the water’s surface. If needed, he proposed that the crew condense “a sufficient quantity of air and take it aboard to last the men several hours.”  Provost did not elaborate on the submarine’s total size, but it can be inferred that by necessity, it would have been large to accommodate room for a steam boiler, crew, and machinery. Likewise, he did not specify the total number of crew the vessel required. Still, at least three men would likely have been needed to, at a minimum, man the “driving wheel,” service the boiler, and control navigation and the vessel’s weaponry.

The design also featured a few curious characteristics of note. Provost planned that a crew member of the crew would navigate the vessel from a revolving, conning tower-like feature extending from the top of the submarine. Made out of “india rubber or water proof leather,” this two-and-a-half-foot extension would contain “a glass in front to look through and two arm holes for the man to run his arms and hands into.” This navigator would also be the individual that manipulated the harpoon and explosive torpedo that extended from the bottom of the boat. This spar would be eight or nine feet long and be capable of swiveling to the left or right as necessary to deliver the torpedo against a Federal ship. According to Provost’s plan, to activate the torpedo, “the force of the boat in motion in the right direction will drive the harpoon in [to the enemy ship], and drive the collar back on the rod so as to disengage the harpoon instantly.” Once attached, the navigator would detach the torpedo manually via a chain and have the submarine back out from the area. In the event of a misfire, Provost detailed a procedure in which the navigator would use his arm-holes to manually mount the torpedo to the side of the enemy ship.

Figure 2. Diagram of the H. L. Hunley. Note the eight crew members driving the propeller shaft, the pilot’s position, and the forward torpedo spar. Image by Matthew Twombly (Smithsonian Magazine).

Despite the apparent thought put into his design, Charles Provost’s plan went unsatisfied—and probably for good reason. Provost’s design was mechanically complicated and would have required a large, and likely unwieldy vessel, considering its use of an adapted steam boiler. Likewise, the navigator’s role in the conning tower with its curious “arm holes” appears out of proportion to the size of the rest of the submarine and likely not functionally possible. The manipulation and activation of the spar torpedo also were overly intricate and not likely to be successful given its location on the boat’s underside. Finally, little thought seems to have been given about how the boiler smoke would be expended during operation.

By contrast, the designers of the H. L. Hunley employed a more straightforward design that favored manpower over complex engines. In their experiments at Mobile, Alabama, in 1862 and 1863, the Hunley’s inventors tested electric motors and a steam engine but found them both unworkable as a means of propulsion. They instead determined to use a screw cranked by eight crew members to turn the propeller and push the boat. Like Provost’s plan, the Hunley featured a two-foot-tall conning tower, but it did not rotate nor have “arm holes.” Instead, the pilot steered the boat with a forward wheel and manipulated the spar torpedo with wires (mounted to the submarine’s bow rather than the underside). No mechanism was used to supply air as the crew breathed what was contained in the ship after its twin hatches were closed.[2] This simpler design—while undoubtedly taxing for its crew—allowed it to function in a realistic manner not likely possible with Provost’s plan.

All told, Charles Provost’s submarine plan can be added to the list of the other plans that, while sincerely submitted, were disregarded by Pettus and other Confederate authorities. Nevertheless, together they build a picture of several industrious Southern civilians who sought to employ tactical and technical ingenuity to aid the Confederate war effort. Like the higher-level discussions of strategy and military operations contained in the documents of the CWRGM collection, theirs is also a part of the larger story of the American Civil War that deserves to be told. I hope you have enjoyed learning about them as much as I have and would encourage you to dig further into the collection to find other unique stores and voices from the past. Enjoy! 

Michael Singleton was the CWRGM Assistant Editor from 2021-2022. He earned his M.A. in History from the University of Southern Mississippi in August 2022 and his B.A. in History from the Virginia Military Institute in 2013. While a student at USM, Michael served as a Public History Intern on the CWRGM project in the summer of 2021 and a graduate Teaching Assistant from 2020-2021. He also served as an active-duty Infantry officer in the U.S. Army from 2013 to 2020. 


[1] By December 1862, experiments with submarine prototypes were ongoing within the Confederacy but still not yet completed. The first tests occurred in New Orleans, LA, in the spring of 1862 when a group of inventors built the Pioneer, a 30 ft. long, cigar shaped, submarine. It suffered from navigational and steering issues, but demonstrated the feasibility of underwater movement. It was scuttled when Federal forces seized New Orleans that April. Trials resumed in Mobile, AL, some months later when the same inventors built a second prototype, The American Diver. This boat was 36 ft. long and used a propeller shaft cranked by its four-man crew.  The Diver sank during sea trials in Mobile Bay in January 1863. The lessons learned from these two ventures would serve as the basis for their third (and ultimately successful) attempt, the H. L. Hunley in 1863 and 1864. See, Mark K. Ragan, Confederate Saboteurs: Building the Hunley and Other Secret Weapons of the Civil War (College Station: Texas A&M University Press, 2015) 10-11, 25-27.

[2] Ragan, Confederate Saboteurs, 29-30.