The Pook Turtles, or City-class gunboats to use their semi-official name, were war vessels intended for service on the Mississippi River during the American Civil War. They were also sometimes referred to as "Eads gunboats." The labels are applied to seven vessels of uniform design built from the keel up in Carondelet, Missouri shipyards owned by James Buchanan Eads. Eads was a wealthy St. Louis industrialist who risked his fortune in support of the Union.Joiner, Mr. Lincoln's Brown Water Navy, pp. 17–18.
The City-class gunboats were the United States' first ironclad warships.
The gunboats produced by Eads formed the core of the United States Army's Western Gunboat Flotilla, which later was transferred to the US Navy and became the Mississippi River Squadron. Eads gunboats took part in almost every significant action on the upper Mississippi and its tributaries from their first offensive use at the Battle of Fort Henry until the end of the war.
Early connection between Eads and the US government
In the early days of the Civil War, before it was certain that the secession movement had been thwarted in St. Louis, and before it was known that Kentucky would remain in the Union, James B. Eads offered one of his salvage vessels, Submarine No. 7, to the Federal government for conversion to a warship for service on the western rivers. In a letter he wrote to Secretary of the Navy Gideon Welles, he pointed out that the catamaran-type hull of his boat was already divided into several watertight compartments, and therefore could sustain numerous hits by enemy artillery without danger of sinking. As the interior of the country was the responsibility of the Army and not the Navy, Welles passed the letter on to Secretary of War Simon Cameron, who in turn referred it to Major General George B. McClellan for consideration.Joiner, Mr. Lincoln's Brown Water Navy, pp. 18–20. McClellan was commander of the Department of the Ohio, with responsibilities that included defense of the Ohio River and the parts of the Mississippi that were not in Confederate control.ORA ser. I, v. 2, p. 2. Official Atlas, plate 158.
At about the same time that McClellan received the letter, he also had a naval officer, Commander John Rodgers, added to his staff. Rodgers came with orders to provide the department with gunboats, either by acquiring civilian craft and converting them, or by having them built from the keel up. As the Eads letter meshed with the orders carried by Rodgers, McClellan passed responsibility on to him, ordering him to St. Louis to consult with Eads and see if his ideas were feasible. Rodgers did not like Submarine No. 7, but his negative assessment was overruled by Major General John C. Fremont, who succeeded McClellan when the latter was called to Washington to serve as General-in-Chief. Although Rodgers had opposed Eads's proposal, the two men were able to work together. This was the beginning of their short-lived but productive collaboration.Joiner, Mr. Lincoln's Brown Water Navy, p. 25.
City-class gunboats; Pook Turtles In furtherance of Rodgers' orders, he and Eads drew up a set of requirements for a fleet of armored gunboats that would operate on the Mississippi. Rodgers knew, as his colleague did not, what characteristics would be required for a successful war vessel. Eads' contribution was equally vital, as he knew the characteristics of boats that could operate on the Mississippi, and also how to assemble the industry to build them. Together, they decided that the gunboats should have adequate armor to withstand direct shot from the artillery of the day; speed sufficient to be able to move against the current; shallow draft; and enough guns to present a serious and credible threat to the enemy. Not stated but well understood was the necessity of providing adequate accommodations for the crew, who would likely be forced to fight inside the protective shell of armor in the heat of a Southern summer.
To assist in the design of a vessel that would satisfy all of these requirements, Rodgers called for help from John Lenthall, the head of the Navy Department's Bureau of Construction, Equipment, and Repair. Lenthall provided some preliminary plans, but he had to devote most of his attention to ocean-going ships, so he withdrew. Fortunately, he was able to provide a substitute. The Navy Department already had under contract a man who had experience in designing river craft, one Samuel M. Pook, working at the time in Cairo, Illinois.ORA ser. III, v. 2, p. 815. Pook came to dominate the design so thoroughly that the contributions of the others are often forgotten. Pook should not be confused with his son, Samuel Hartt Pook, also a noted naval architect.
Pook designed a vessel, or rather a set of vessels, that drew only while carrying 13 guns. Capable of , each bore of armor on the casemates and half that on the pilot house. In order to carry the machinery that would drive the great weight forward at speed while maintaining the light draft, the boats had to be made quite broad in relation to their length. Pook's solution was to give the hull three keels, the outboard pair somewhat longer than the one on the centerline. Propulsion was provided by a single paddle wheel at the after end of the center keel; the casemate armor that was carried back along the longer outboard keels provided the paddles a measure of protection from enemy gunfire from forward and abeam but not from astern. Each vessel as completed had a length overall of and a beam of . The length to beam ratio thus was a very small 3.4.Ocean-going warships of the time typically had length to beam ratios of about 6 to 1 or greater; for comparison, the famed raider CSS Alabama had a ratio of 6.95. The casemates had sloping sides, somewhat suggestive of the general shape of the best-known Confederate ship of the war, CSS Virginia (ex-USS Merrimack). When they were finally in the water, their awkward appearance struck the fancy of the farm boys who saw them, and they christened them "Pook's Turtles." The unofficial name stuck.Gibbons, Warships, p. 16.
Eads submitted the winning bid for the contract to build seven boats to Pook's design. His bid was $89,600 per vessel, and he agreed to complete them by 10 October 1861.The contract was signed 7 August 1861. ORA ser. III, v. 2, pp. 816–832. Because of changes in the design in the course of construction, the completion date was not met, and the cost more than doubled. By the end of January 1862, however, all had been delivered to the Army, where they were incorporated into the Western Gunboat Flotilla. The seven gunboats in the class were named for cities on the Mississippi or its tributaries. They were: USS Cairo, Carondelet, , Louisville, Mound City, Pittsburgh, and St. Louis (later renamed USS Baron DeKalb). The first four Eads gunboats were built at the Carondelet Marine Ways (today part of St. Louis). This was a logical choice as St. Louis had the dry dock facilities, was a machinery center, and had a ready supply of skilled tradesmen to do the required work. Most importantly, since the gunboats were to be used on the Mississippi River, building them at St. Louis meant that at completion, the boat could be quickly put into service. This was 1861 and the thinking still was that the war would be short. The three other gunboats were built at the Mound City Marine Railway & Shipyard facilities.Gibbons, Warships, p. 17.
Design
Armament Positions were provided for 13 guns. Three gunports faced forward, four were on each side, and two aft. When they were first commissioned, the armament of most vessels of the class consisted of six 32-pounder and three 8-inch Dahlgren smooth bore guns and four 42-pounder army rifles. The exception was St. Louis (later Baron De Kalb), which had seven 32-pounders and two 8-inch Dahlgrens. In addition, some carried a single 12-pounder boat howitzer that is not counted as part of the armament.ORN ser. II, v. 1, pp. 42, 49, 52, 59, 129, 180. No description is given for Mound City. The mix of guns was changed later in the war; as this was done irregularly, refer to the individual ship articles.
Armor The casemate armor was thick, rolled in plates wide and long. Total weight of the armor was 75 tons (68 tonnes). Pook's initial design called for armor only on the sides abreast the engines; Commander Rodgers, however, extended the plating to cover the forward casemate. The after casemate, hull, and deck not covered by the casemate were left unprotected.Milligan, Gunboats, pp. 29–30. An additional 47 tons (43 tonnes) of armor was put on following the battle of Fort Pillow. At the same time, protection against ramming was given to the hulls by railroad iron at the stems and sterns.Gibbons, Warships, p. 17.
Engines
The engines were designed by engineer Thomas Merritt.Milligan, Gunboats, p. 14. For a detailed description (unfortunately with no drawings), see ORA ser. III, v. 2, pp. 820–832. The paddlewheel was driven by two steam engines, mounted at opposite ends of the axle, 90 degrees apart. Five boilers, in diameter and long, gave steam to a cylinder in diameter with a six-foot (1.8 m) stroke.Gibbons, Warships, p. 17.
The initial placement of the boilers proved to be unsatisfactory. In order to protect them from enemy shot, they had been crowded into shallow holds, causing the engines to work both water and steam. To remedy the problem, the steam drums had to be moved to the top of the boilers. This meant that they were no longer fully protected.Milligan, Gunboats, p. 23. ORN ser. I, v. 22, p. 493. The Mound City disaster was the result of an exposed steam drum.
Battles and other operations in which City-class gunboats participated
After the gunboats were completed but before their crews were filled out, several of them were pushed forward into the Battle of Fort Henry, February 6, 1862. The boats involved sustained some minor battle damage, but they achieved a complete victory unassisted by the Army.Joiner, Mr. Lincoln's Brown Water Navy, pp. 40–41. Tucker, Blue and Gray Navies, pp. 123–126. Their success at Fort Henry engendered exaggerated opinions of their effectiveness that were dashed only a week later. At the Battle of Fort Donelson, February 14, 1862, four of the gunboats bombarded the fort and received return fire. All four gunboats were forced out of action by damage they sustained, although the armor minimized casualties.Joiner, Mr. Lincoln's Brown Water Navy, pp.42–48. Tucker, Blue and Gray Navies, pp. 127–131.
Two gunboats were vital in assisting the Army in blocking the escape of the Confederate garrison at the Battle of Island Number Ten, April 7, 1862. By running past the Confederate guns under cover of darkness, they gave the first example of the new tactic of bypassing fixed fortifications. The garrison at Island No. 10 made a point of surrendering to the Gunboat Flotilla.Joiner, Mr. Lincoln's Brown Water Navy, pp. 60–62. Tucker, Blue and Gray Navies, pp. 135–140.
Following the seizure of Island No. 10 and New Madrid, Missouri, the next target was Fort Pillow, upstream from Memphis. The mortar bombardment of the fort began on April 14, 1862, and continued until June 4, 1862. The gunboats assisted by protecting the mortars from Confederate counterattacks. One such counterattack, the Battle of Plum Point Bend, May 10, 1862, caught the flotilla unprepared for an assault by Rebel rams. Two of the gunboats were severely damaged, and avoided sinking only by grounding themselves in shallows.Joiner, Mr. Lincoln's Brown Water Navy, pp. 63–67. Tucker, Blue and Gray Navies, pp. 140–146.