Ironclads

An ironclad is a warship that is partially or fully shielded with iron plating. Some textbooks incorrectly state that ironclad ships were invented during the CiviL War. In fact, the first ironclads were constructed more than 250 years prior by Korean admiral Yi Sun Shin, who led a fleet of armored ships to victory over Japanese naval forces in the late 16th century. Shin was ahead of his time; after his death ironclads were not utilized by any of the world’s navies until the Crimean War of the 1850s. During the conflict, both the British and French navies relied upon ironclads, demonstrating their superiority over wooden ships to the rest of the world.

When the Civil War broke out, it was clear to leaders on both sides of the conflict that they needed ironclad technology. The Union, with its superior industrial capacity, was the first to act. In the first few months of the war, the Union navy commissioned and began construction on three ironclad warships: the New Ironsides, the Galena, and the Monitor These ships were finished by early 1862, and numerous others followed. By the end of the Civil War, the Union navy had constructed 71 ironclad ships, vastly more than any other naval power of that era.

The Confederate navy did its best to keep up with the Union, but they faced several handicaps. Raw materials were in short supply in the South. This was particularly true of iron, which was needed not only for ships but for railroad rails and for armaments. Even if supplies had been abundant, the South did not have any factories capable of manufacturing all of the parts necessary to build an ironclad ship. So, the Confederate navy was compelled to modify existing vessels, usually damaged ships that had been abandoned by the Union navy. The Confederates had some success doing this, and by the end of the war their navy had 25 ironclads in service that had been constructed in this fashion. Southern leaders also tried to purchase some European-made ironclads, which utilized technology vastly superior to that possessed by the Union navy. However, diplomatic pressure from Northern authorities largely compelled France and Britain to turn a deaf ear to the Confederates. The rebel navy did manage to purchase one ship from France, the Stonewall, but it did not arrive in the United States until after the war was over.

There was a great deal of variety among Civil War ironclads, but most can be grouped into two basic classes: Casemates like the USS New Ironsides were iron boxes, usually with slanted sides, placed on top of a wooden hull. Sailors and guns would be contained within the iron box, which protected them from enemy fire. Casemates were typically very large and not very maneuverable, so they were most effective when used for defensive purposes or for bombardment of targets on land. Most Southern ironclads were casemates.

The other class of ironclad was the monitors, named after the USS Monitor Monitors were low-freeboard steamships, meaning that their decks were very close to the water. While casemates tended to have fixed guns, monitors had turrets that could be rotated to aim their guns. The majority of Union ironclads were monitors, although most Northern naval leaders, including Adm. David Glasgow Farragut, preferred casemates.

Ironclad ships played a role in most of the major naval battles of the Civil War. They achieved their greatest fame, however, in an engagement that had very little to do with the outcome of the war. In March 1862, several Union warships were destroyed or severely damaged by the CSS Virginia, a casemate ironclad that had been built by converting the abandoned USS Merrimack. In order to save the remaining Union ships, John L. Worden, commander of the recently completed USS Monitor, was ordered to engage the Virginia at Hampton Roads, Virginia. The Monitor arrived early on the morning of March 9, just as the Virginia was preparing to finish off the USS Minnesota, a wooden ship. The two ironclads fired at one another all day, inflicting very little damage. Finally, Worden was wounded, and the Monitor had to withdraw temporarily so he could be relieved. By the time the ship had returned to the fray, the Virginia had backed off, ending the engagement.

Although Hampton Roads did not impact the Civil War, it was still among the war’s most significant engagements. Ironclads had been used in warfare before, but Hampton Roads marked the first time that two ironclad ships had faced off against one another. Both Northerners and Southerners took pride in the accomplishment, and a wave of songs, poems, and newspaper articles praising the ironclads swept across the country. Union and Confederate naval leaders knew from the outset that wooden ships would soon be replaced by ships made of metal, and now the general populace knew it too. The value of existing wooden ships was vastly reduced in popular and professional opinion, setting the stage for an arms race in the construction of iron and, eventually, steel ships, a trend that would last for nearly a century.

See also Monitor-Merrimack.

Further reading: Jack Greene and Alessandro Massig-nani, Ironclads at War: The Origin and Development of the Armored Warship, 1854-1891 (New York: Da Capo Press, 1998); David A. Mindell, War, Technology, and Experience Aboard the U. S.S. Monitor (Baltimore: Johns Hopkins University Press, 2000); Arthur Mokin, Ironclad: The Monitor and the Merrimack (Novato, Calif.: Presidio, 1991).

—Christopher Bates