CSS Arkansas was the lead ship of her class of two casemate ironclads built for the Confederate States Navy during the American Civil War. Completed in 1862, she saw combat in the Western Theater when she steamed through a United States Navy fleet at Vicksburg in July. Arkansas was set on fire and destroyed by her crew after her engines broke down several weeks later. Her remains lie under a levee above Baton Rouge, Louisiana at .
Design and description
At the outset of the American Civil War, the Confederate States of America had a lack of warships. Seeking to offset the Union's advantage in numbers through technology, Stephen R. Mallory, the Confederate States Secretary of the Navy, decided to build ironclad warships. An experienced steamboat man from Memphis, Tennessee, named John T. Shirley visited Mallory in mid-August 1861 and offered to build a pair of such ships to defend the middle portion of the Mississippi River. Acutely aware of the lack of Confederate naval facilities in the region able to build ironclads, Mallory and Shirley signed a contract for two ships, Arkansas and her sister ship , at $76,920 each on August 24. Neither Shirley nor his master builder Primus Emerson owned a facility suitable for building a ship, and none were available for use in Memphis. The pair ultimately settled on a riverfront site below the bluff on which Fort Pickering sat on the southern edge of Memphis where Arkansas was laid down in October 1861.
Shirley consulted with naval architect John L. Porter and gun designer John M. Brooke during his trip and their views greatly influenced the design. Unlike virtually every other Confederate ironclad, the Arkansas-class ships were built with a traditional keeled-hull design with vertical sides to their casemates, probably to improve their seakeeping abilities in the Gulf of Mexico. The ships measured between perpendiculars, had a beam of , and a depth of hold of . As designed they would have displaced about and had a draft of . They were equipped with a pair of horizontal direct-acting steam engines, each driving one propeller using steam provided by four coal-burning, high-pressure boilers, although two additional boilers were added to Arkansas while she was under construction. The ship had a maximum speed of in still water, but mechanical problems reduced that speed considerably in service. The boiler combustion gases exhausted through a single funnel in diameter made from thin iron plates. Although the amount of coal storage aboard the ships is unknown, Arkansas demonstrated a range in excess of during her brief career.
The Arkansas-class ships were equipped with a pointed cast-iron ram that was bolted to their bows at or just below the waterline. They were designed to mount four guns, two on each broadside, but Arkansas was modified while under construction to accommodate 10 guns, three on each broadside and two each on the fore and aft faces of the casemate. Sources differ as to the exact numbers of each type, but the ship was armed with two 64-pounder Columbiads in the front face of the casemate and a pair of 32-pounder smoothbore guns converted to be rifled cannons in the aft face while the broadside armament consisted of two Dahlgren guns and four 32-pounders of which at least two had been rifled, according to naval historian Myron J. Smith. The side gun ports allowed the guns there to traverse somewhat, but the oval gun ports on the fore and aft faces of the casemate were very narrow which badly restricted those guns' ability to traverse and severely limited the ability of the gun crews to see their targets.