 By 1862 , navies across Europe had adopted ironclads . Britain and France each had sixteen either completed or under construction , though the British vessels were larger . Austria , Italy , Russia , and Spain were also building ironclads . However , the first battles using the new ironclad ships involved neither Britain nor France , and involved ships markedly different from the broadside @-@ firing , <unk> designs of Gloire and Warrior . The use of ironclads by both sides in the American Civil War , and the clash of the Italian and Austrian fleets at the Battle of <unk> , had an important influence on the development of ironclad design . 
