Oda Nobunaga, a Japanese daimyo, had six iron-covered Ōatakebune (大安宅船) made in 1576. He defeated Mori's navy with them at the mouth of the Kizu River, Osaka in 1578. They are regarded as floating fortresses rather than warships.
The Koreans developed Geobukseon ("Turtle[-shaped] ships") in the 16th century to thwart the repeated attempts by Japan to invade Joseon. The geobukseon--designed by the admiral Yi Sun-sin--were said to be ironclads; however, they were not fully covered but just roofed with iron plates or metal thorns so that enemy soldiers could not take the ships.
In 1856, the French navy experimented with ironclad floating batteries as a means of reducing the fearsome Russian defenses at Sevastapol. In 1857, the British constructed two similar devices to reduce Russian coastal defenses in Lithuania, but failed to use them before the conclusion of hostilities. While these devices were ironclad, and built on floating "rafts", they had to be towed into position and had no motive power of their own.
The first steam-powered Ironclads were utilized during the American Civil War. The first of these vessels to see action, CSS Manassass, was a turtleback ironclad steam-tug formerlly known as the Enoch Train. She was used in combat against the U.S. Navy and proved somewhat effective initially until U.S. ships learned to exploit her rather weak armor. The first engagement of two ironclad warships was the Battle of Hampton Roads, from March 8-9, 1862. Though the engagement was inconclusive, the Confederate ironclad CSS Virginia and its Federal counterpart, USS Monitor, became somewhat legendary, and helped to usher in a new age of armored, steam powered warships.
The largest battle involving ironclads of this type was the Battle of Lissa in 1866. Waged between the Austro-Hungarian and Italian navies, the battle pitted combined fleets of wooden ships of the line and ironclad warships on both sides in the largest European naval battle since the Battle of Trafalgar. The victory won by Austria-Hungary established it briefly as the predominant naval power in the Mediterranean.
The ironclad continued to be the dominant style of warship and developed into what is sometimes called the Old Battleship before being replaced by more advanced, far more seaworthy vessels known to history as Pre-Dreadnoughts. These, in turn of course, helped to usher in the age of the Battleship.
While the ironclad warship suffered from numerous flaws, the fact that it became the prominent naval weapon of its era and inspired nearly a century of progressively heavier armored warships can be ascribed to its massive advantage over the previous ships of the line in terms of protection. While a ship of the line could resist some damage, it was terribly vulnerable to fire and found itself completely outclassed by the new developments in naval armament beginning in the middle of the nineteenth century. Combined with the phenomenon of the steam engine, the ironclad warship could outfight, outgun, and eventually outrun even the most powerful three decker.
The age of the ironclad officially ended with the birth of the pre-dreadnought; however, its influence continued to be felt until the end of the Second World War, when naval theorists argued that the armored warship had outlived its usefulness. Recent naval encounters, however, have caused the concept of the armored warship to be re-evaluated, and perhaps the ironclad will live on in some form, after all.
See also: BattleshipsPremodern Ironclads
Modern Ironclads