Review - "Engines of Rebellion: Confederate Ironclads and Steam Engineering in the American Civil War" by Saxon Bisbee

[Engines of Rebellion: Confederate Ironclads and Steam Engineering in the American Civil War by Saxon T. Bisbee (University of Alabama Press, 2018). Hardcover, photos, line drawings, appendices, notes, bibliography, index. Pages main/total:186/280. ISBN:978-0-8173-1986-1. $59.95]

With an industrial base and pool of skilled marine carpenters and engineers that paled in comparison to the vast human and material resources available in the northern states, the Confederacy was nevertheless able to initiate construction of fifty ironclad warships, completing nearly two dozen (and almost finishing the outfitting of four more) before the Civil War ended. Even though Confederate States Navy ironclads proved effective in combat and several had quite impressive individual careers, inadequate engines were among the chief criticisms of the entire program. It is analysis of the design and performance of this vital internal machinery that is the chief focus of Saxon Bisbee's Engines of Rebellion: Confederate Ironclads and Steam Engineering in the American Civil War.

The book begins with a brief overview of the three general design types of mid-nineteenth century steam power plants used by both sides during the war. Readers without a background in steam engineering will likely find the descriptive text a bit unforgiving in places, but the author does thoughtfully insert a fairly extensive glossary inside the book that helps with the technical terminology. Much of the data provided will have mostly reference value anyway. The section does a good job of introducing antebellum developments in steam propulsion systems and their variations in shipboard arrangement. Particular design elements are helpfully explained in terms of their benefits and drawbacks, both in general and for warships. For example, long tubular boilers help with distributing weight and lower a vessel's center of gravity. With even armored warships subject to penetrating shot, the placement of such potentially dangerous vital mechanicals well below the waterline was of obvious benefit. Also briefly explored is the genesis of the Confederacy's ironclad program along with select profiles of the most important individuals involved (two of the more towering figures being chief naval constructor John L. Porter and Engineer in Chief William P. Williamson).

Bisbee's organization of the twenty-three finished and four unfinished ironclads into eight categories usefully distinguishes ship classes¹ while also illustrating progressive design enhancements, improvements in propulsion systems (adapted and purpose-built), and evolving operational directives. While the Union Navy hurriedly constructed timberclads as a stopgap measure until a sizable class of purpose-built ironclads could be deployed, the Confederacy strove immediately to put three ironclad conversions into commission (CSS Manassas, Virginia, and Baltic). As one might expect in these early conversions, the engines proved less than efficient in all three. However, in withholding the blanket criticisms often advanced in the general literature, Bisbee effectively reminds readers that marine steam engines were still relatively new technology in 1861, and Confederate engineers deserve more credit that they typically get for their creative repurposing of existing engines². Indeed, as Bisbee asserts, the fact that the Virginia's already condemned engines, rescued after further insult by extensive saltwater immersion when the Merrimack was burned and scuttled, were put in decent working order at all was an impressive feat.

The next group of vessels, the first keel-up constructed ironclads termed by Bisbee the "early nonstandard" designs (CSS Louisiana, Arkansas, and Georgia), had similar mechanical problems that plagued the conversions, but, as the author argues, were equally weakened by compromise design decisions (ex. large size and unconventional mechanical layout) related to dual-purpose objectives of harbor defense and offensive (i.e. blockade-breaking) cruising capabilities. On paper, the engines for all three should have performed well, but teething problems related to wedding the then current propulsion technology to experimental warships of completely original conception and design were inevitable. Indeed, the author makes the case that the final failure of the Arkansas's famously temperamental engines was most likely the result of human error in operation rather than intrinsic defects in the engine and its supporting mechanical apparatus.

The resource-starved Confederacy's urgent need for a smaller, simpler standardized hull designed for a single, specialized purpose (with harbor defense judged to be the highest priority) was first met with the six completed vessels of the Richmond-class. According to Bisbee, this ship series conclusively demonstrated that Confederate industry and engineering had the ability to construct numerous effective ironclads and employ them in the defense of key ports, but challenges remained in reducing draft and in finding or producing compatible engines. In the process, industrial facilities like those at Richmond, Virginia and Columbus, Georgia proved capable of "learning, adapting, and improvising to meet the demands of war." (pg. 117), providing either new or reconditioned engines and parts to ironclads that were being built all across the Confederacy.

The next stage in the evolution of standardized hull designs were the two vessels of the Tennessee-class. Though larger, they were more maneuverable, better armed and armored, and drew less water than the Richmond-class ironclads. While the Tennessee benefited from an unusual success in converting a riverboat engine to screw propulsion, the Columbia had an excellent new purpose-built engine.

Another group of standard, or likely standard, hull ironclads were also completed (the Charleston, Virginia II, and Nashville) before alternative hull forms meant to lower draft, require less skilled labor (via the elimination of curves), and speed construction could be realized. As one might expect after the introduction of big design changes, the first two experiments in alternate diamond-hull designs were failures even with good engines, their poorly anticipated hydrodynamic characteristics leaving them essentially immobile. However, the next generation of diamond hulls (the Albemarle being the most prominent representative) would prove much more successful, and though three of the four operated on borrowed riverboat engines, the ones for which documentation exists seem to have worked well.

In the remaining four uncompleted ironclads would be seen the entire evolution of Confederate ironclad building, including some of the most significant improvements and innovations (at least in theory). The Mississippi was a very early design, but three of the four vessels were the product of extensive learning processes in the areas of construction, armor configuration, mechanical systems, and combat capability. In the end, the author considers the Milledgeville and Wilmington to be the "pinnacle" of Confederate ironclad design, even though neither was ever tested in combat.

Unfortunately, many Confederate naval records were destroyed in the waning moments of the war, and available documentation varies widely among the twenty-seven ironclads referenced in the book. Where possible, for each ironclad Bisbee discusses vessel specifications; information and dates associated with the construction process (including building firms and prominent individuals involved); and engine type and provenance. Brief ship commander and engineer profiles are included, along with operational summaries. Results of archaeological studies help fill some of the gaps in historical documentation, and accounts written by ship's engineers that directly address the mechanical systems and how they performed are reproduced at length. The last offer rare and valuable insights into the operational history of Confederate ironclad engines.

Throughout the book, the text is supported by period photographs, numerous line drawings, and modern reproductions of vessel and engine design plans. Unfortunately, most of the latter are so reduced in size (only filling 1/3 of the page) that details and labels are difficult to recognize. In addition to the aforementioned glossary of terms, another useful supplement is the compiled appendix of engine specifications for each ship.

In the final estimation, Bisbee persuasively dispels the persistent myth that all Confederate ironclads were intrinsically flawed, particularly in the quality and make of their steam machinery and propulsion systems. Beyond reminding us that even resource-rich Union naval designers and builders struggled mightily to harness period steam engine technology to adequately power their own heavy ironclads, the book amply demonstrates that Confederate vessels operated and fought very effectively when given the opportunity. Generally speaking, their engines performed as well as could be expected given the available steam technology of the period and infant state of armored warship design and architecture.

A recent book postulated that it was Union engineering superiority combined with Confederate inferiority that proved to be the most decisive factor in winning the Civil War³. Though exaggerated, there's some merit to that view, but Bisbee's Engines of Rebellion offers a powerful counterpoint. At least in the area of ironclad construction, Confederate builders and engineers were able to overcome severe limitations in heavy industry, money, skilled labor (particularly naval carpenters and mechanics), raw materials, and transportation to complete nearly two dozen powerful modern warships. The book very effectively argues that the Confederate ironclad program, operating under enormous wartime pressures, was a remarkable achievement of engineering improvisation and skill. This fascinating study of Confederate ironclads and the machinery that drove them is a significant contribution to Civil War naval history and technology.


Notes:
1 - The use of the term "class" is generous in describing a series of vessels with somewhat similar construction but rather significant variations in physical dimension, armament, and design. Nevertheless it's usefully employed for lack of a better word.
2 - The Confederates were also able to re-engineer a number of steam engines originally built for powering paddlewheel riverboats into driving screws (the overwhelming majority of CSN ironclads were screw steamers), a difficult task that met with varying degrees of success.
3 - Engineering Victory: How Technology Won the Civil War by Thomas F. Army, Jr. (Johns Hopkins University Press, 2016).