CSS Fredericksburg was a casemate ironclad that served as part of the James River Squadron of the Confederate States Navy during the American Civil War. Laid down in 1862 and launched the following year, she did not see action until 1864 due to delays in receiving her armor and guns. After passing through the obstructions at Drewry's Bluff in May 1864, she participated in several minor actions on the James River and fought in the Battle of Chaffin's Farm from September 29 to October 1. On January 23 and 24, 1865, she was part of the Confederate fleet at the Battle of Trent's Reach, and was one of only two Confederate ships to make it past the obstructions at Trent's Reach. After the Confederate attack failed, Fredericksburg withdrew with the rest of the James River Squadron. On April 3, as the Confederates were abandoning Richmond, Fredericksburg and the other vessels of the James River Squadron were burned. Her wreck was located in the 1980s, buried under sediment.
Background and description
In mid-1862, Fredericksburg was laid down by the Confederate States Navy in the Rocketts Landing area of Richmond, Virginia to a plan by the Chief Naval Constructor, John L. Porter. The ship was one of the ironclads built to Porter's shallow-draft "diamond hull" configuration with a flat bottom and hull sides that met the base of the casemate at a 90° angle. By substituting straight lines and angles for the traditional keel and curving frame of the hull, Porter optimized his design to be quickly built by ordinary carpenters, rather than highly skilled shipwrights that were in short supply in the Confederacy, at the cost of being able to mount fewer guns than those ironclads built with traditional hulls. Their shallow draft and flat bottom restricted these ships to rivers and inland waters.
Porter supervised the work of constructing Fredericksburg, but it is uncertain how exactly he followed his design as surviving documents disagree in many ways. The plan showed an overall length of and a length between perpendiculars of with a maximum beam of , a moulded beam of and a depth of hold of . The naval historian Saxon T. Bisbee quotes a beam of with a depth of hold of and a draft of while US Navy historian Paul J. Marcello provides a figure of for the ironclad's draft. She had a tonnage of 700 long tons. The ship's casemate was shaped like a rectangle and Porter's plan showed two pilothouses on the casemate's roof, although operational reports from her captain make no mention of the rear pilothouse.
The Tredegar Iron Works in Richmond was contracted to produce her propulsion system, although Bisbee believes that it is possible that the Richmond-based Shockoe Foundry may have produced them. The ship was propelled by a pair of direct-acting steam engines that each drove a propeller. Porter's plan shows Fredericksburg as having three horizontal boilers measuring 7 feet tall, in diameter, and long, but it is not known if the final construction varied from the blueprints or not. Bisbee believes that the boilers probably were of the fire-tube type. Fredericksburg could move at a speed of about and had a crew of 150.