Attrition Rates of City-Class Ironclads

City-Class Ironclads off Cairo, Illinois 1862 (Naval History and Heritage Command)

Perhaps nothing is more identifiable with the Mississippi River valley’s naval campaigns as the city-class ironclads. With February 2022 marking the 160th anniversary of the Fort Henry/Fort Donelson campaign, where these ironclads were first extensively used, it is worth collectively examining their overall performance and effectiveness. These seven warships, with their sloped casemates, protected paddle wheels, and single gun decks, exemplify the industrial capacity of the United States. They participated in some of the most pivotal battles along the Mississippi, Tennessee, Cumberland, White, Arkansas, Yazoo, and Red rivers. Though they developed a reputation for reliability and hard-fought victory, the city-class ironclads sustained a significant attrition rate that highlights the improvised nature and vulnerability of early ironclad warships.

Named for urban centers along the Mississippi and Ohio rivers, the city-class ironclads were envisioned, designed, and constructed by Mississippi River captain James B. Eads and naval architect Samuel Pook. They were constructed using a uniform design, four in Saint Louis, Missouri, and three in Mound City, Illinois. To better distribute weight and navigate shallow river waters, they featured wide hulls, resulting in a small six-foot draft. Iron plating two and a half inches thick protected against artillery and small arms. Each was armed with thirteen cannon, mounted on a single deck, three on the bow, two astern, and four in each broadside. A large paddle wheel encased in the protective armored hull gave each ironclad their distinctive look, along with their collective nickname: Pook Turtles.

City-Class Ironclads under construction in St. Louis, Missouri. These would become the ironclads Carondelet, Louisville, Pittsburgh, and St. Louis/Baron de Kalb (Navy History and Heritage Command)

In mid-January 1862, Flag Officer Andrew Foote, the naval officer assigned to command riverine naval forces, “accepted the gunboats from Mr. Eads” on behalf of the United States.[i] The organizational structure that utilized the city-class ironclads was an odd one. Technically, they were not naval warships, but army ships that the Navy Department manned and operated on behalf of the War Department. Once accepted, they formed the core of Foote’s Western Gunboat Flotilla.

Despite the awkward organization, the seven ironclads were completed just in time. They participated fully in the 1862 Mississippi River valley campaigns, with Pook Turtles contributing at the Battles of Forts Henry and Donelson in February, Island Number Ten in March and April, Plum Point Bend in May, St. Charles and Memphis in June, and Vicksburg in July and August. Their part in the campaigns was a decisive element in why the United States reclaimed control over so much of the Mississippi in 1862.

Though powerful, the Pook Turtles were not invincible. Of the seven city-class ironclads, four were sunk in battle or destroyed in some capacity during the war, and a fifth was disabled under enemy fire and struck its colors. Seventy percent of these ironclads were defeated in engagements or sunk by torpedoes (the contemporary term for underwater mines), though thanks to circumstances of battle, only two of the seven were permanently lost.

City-Class Ironclads Bombard Fort Henry, February 1862. (Library of Congress)

Ironclad warships are imagined as well-protected with armor capable of withstanding enemy artillery, but these new ships remained vulnerable. Iron armor was only installed in certain parts of each Pook Turtle, focused on the main casemate, with no protection on their decks, roofs, or below the waterline. U.S. naval officer Seth L. Phelps, who commanded numerous river warships in 1862, grew skeptical of their armored protection, calling them “‘Iron Clad’ but far from being such.”[ii] These exposed elements were exploited. Confederate General Lloyd Tilghman, who faced the Pook Turtles at Fort Henry, took note of their vulnerabilities: “Several shots passed entirely through Cincinnati, while her outer works were entirely riddled. … The immense area, forming what may be called the roof, is in every respect vulnerable to either a plunging fire from even 32-pounders or curved line of fire from heavy guns.”[iii]

Two city-class ironclads were partially sunk in battle, though the circumstances of their loss allowed each to return to the fight. Both the ironclads Cincinnati and Mound City were rammed by vessels of the Confederate River Defense Fleet at the Battle of Plum Point Bend on May 10, 1862. Three Confederate steamers, General Bragg, General Price, and General Sumter, “rushed like the wind,” successfully striking Cincinnati.[iv] The same happened to Mound City, when the ram General Van Dorn struck its side. Crippled, both ironclads hastily made their way to the shallow riverbank “in a sinking condition.”[v]

Maintaining control over the Battle of Plum Point Bend’s water space allowed U.S. engineers to quickly refloat both Cincinnati and Mound City, implementing hasty repairs to the ships, whose injuries were, as Flag Officer Charles Davis informed Navy Secretary Gideon Welles, “much more serious than at first reported.”[vi] Mound City “joined the Fleet again” on June 3, 1862.[vii] A fortnight later, it was again disabled at the Battle of St. Charles, Arkansas, on the White River, when artillery in hastily-built Confederate fortifications struck the ironclad “through the bluff of her bow,” entering the engineering spaces and exploding a steam drum.[viii] The ship was disabled, with 85% of its crew killed or wounded. Soon after, Cincinnati also quickly rejoined active operations.

A third city-class ironclad, Carondelet, was disabled on the Yazoo River by CSS Arkansas on July 15, 1862. The two ironclads closed to within two hundred yards, exchanging heavy fire. “Our shot seemed always to hit his stern and disappear” Lieutenant Isaac Brown, captain of CSS Arkansas recalled, while Carondelet’s return fire “were deflected over my head and lost in air.”[ix] Commander Henry Walke, commanding Carondelet, reported “very extensive damages in our hull and machinery,” and to spare his crew, lowered his flag in surrender.[x] Brown did not have time to officially accept the surrender however, and continued steaming on to engage more U.S. warships. Walke took this as a sign his surrender had not officially been accepted, and he repaired damage, quickly rejoining the U.S. squadron.

USS Cairo was destroyed by a torpedo in December 1862. It was later recovered and is on display at Vicksburg National Military Park. (Navy History and Heritage Command)

Two more city-class ironclads were permanently lost to torpedoes after the Western Gunboat Flotilla was transferred to Navy Department control in late 1862 and redesignated the Mississippi River Squadron. USS Cairo, on an expedition to clear torpedoes from the Yazoo River, was lost on December 12, 1862, after “two sudden explosions” struck near the ironclad.[xi] The ship went under in just twelve minutes. Seven months later, on July 14, 1863, USS Baron de Kalb, originally named St. Louis until its transfer to the Navy Department, was lost after striking another torpedo near Yazoo City, highlighting the continued effectiveness of torpedo warfare.

Two city-class ironclads, USS Louisville and USS Pittsburgh, were never disabled, defeated, or destroyed in combat operations. They each were decommissioned and sold at the war’s conclusion, as were the repaired USS Mound City, USS Cincinnati, and USS Carondelet.

The attrition rate of the Pook Turtles serves as a stark reminder that even armored warships were vulnerable in battle, but it also highlights the perseverance of naval architects and engineers in construction and maintenance programs. Though two ships were lost permanently to enemy action, three others suffered catastrophic damage that was repaired to allow ships to return to the fight. It goes to show that ironclads were far from the invulnerable behemoths that many believed them to be at the time. Ultimately, the city-class ironclads highlight the industrial capacity of the United States, its adaptability to meet a vision of modern ironclad warships with real-world circumstances, and the cooperation between military and naval forces to achieve victory across the Mississippi River valley.


[i] Andrew H. Foote Endorsement, January 15, 1862, James Buchanan Eads Collection, 1776-1974, A0427, Missouri Historical Society Library and Research Center, St. Louis, MO.

[ii] Phelps to Whittlesey, June 23, 1862, Elisha Whittlesey Collection, MS 1200, Western Reserve Historical Society, Cleveland, OH.

[iii] Tilghman to Cooper, February 12, 1862. Official Records of the Union and Confederate Navies in the War of the Rebellion [ORN] (Washington: Government Printing Office, 1894-1922), series 1, Vol. 22, 560.

[iv] Donald J. Stanton, Goodwin F. Berquist, and Paul C. Bowers, eds., The Civil War Reminiscences of General M. Jeff Thompson, (Dayton, OH: Morningside Press, 1988), 156.

[v] Alexander Miller Diary, 1861-1864, May 18, 1862, MSS 296, Louisiana and Lower Mississippi Valley Collections, Hill Memorial Library, Louisiana State University.

[vi] Davis to Welles, May 16, 1862, “Letters Received by the Secretary of the Navy from Commanding Officers of Squadrons, 1841-1886” Year Range 9 May 1862-15 October 1862, Mississippi Squadron, M89, RG 45, US National Archives.

[vii] Katherine Bentley Jeffrey, ed., Two Civil Wars: The Curious Shared Journal of a Baton Rouge Schoolgirl and a Union Sailor on the USS Essex, (Baton Rouge, LA: Louisiana State University Press, 2016), 84.

[viii] Alexander Miller Diary, 1861-1864, June 17, 1862.

[ix] Isaac N. Brown. “The Confederate Gun-Boat ‘Arkansas’” in Battles and Leaders of the Civil War, (New York: The Century Co, 1887), Vol. 3, 574.

[x] Walke to Davis, July 15, 1862. ORN, series 1, Vol. 19, 41.

[xi] Selfridge to Walke, December 13, 1862. Ibid, series 1, Vol. 23, 549.

5 Responses to Attrition Rates of City-Class Ironclads

  1. This is an excellent contribution. Thanks. Obviously, the demise of the Cairo and the St. Louis/de Kalb was less attributable to design, construction, and operational aspects of this class of vessels in particular. As the article indicates, these boats performed good service and were a central component in the successful and crucial operations of the “Brown Water Navy”.

  2. “They take a licking and keep on ticking.”
    Those old enough to remember the Timex Watch would be familiar with the above advertising slogan; and that slogan could easily have been applied to the performance of Pook Turtles. The fact that these vessels suffered mission kills and mobility kills, as well as more minor damage, in battle after battle; and yet the squadrons engaged mostly “won” those engagements (with severely damaged vessels quickly restored and returned to service) demonstrates the sound design and craftsmen-like construction inherent in these warships. Survivability was achieved through thick armor and calm, conscientious Navy commanders weighing acceptable risks, knowing the limitations of their platform and crew, and then proceeding into harm’s way.
    Thanks to Neil P. Chatelain for producing the above thought-provoking report.

    1. Good points. I’d add that to some degree the “emergency” design and “warp speed” construction of these vessels for a specific, ultimately successful purpose anticipated the US military-industrial response in future wars – only for example, Liberty Ships in WWII.

  3. Pingback: Emerging Civil War

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