Overview: With their menacing dark silhouettes belching fire and smoke, the Ironclad warships of the mid 19th century burst onto the naval scene like hulking metal monsters. Combining iron plating, steam propulsion and the biggest and most powerful guns afloat, the Ironclads represented a radical advance over all previous warships. Although pioneered by the French and British with ships like HMS Warrior, today they are best remembered for the part they played in the American Civil War.