Ironclad warship
steam-propelled warship protected by iron or steel armor plates / From Wikipedia, the free encyclopedia
An ironclad is a ship protected by iron or steel armor plates. The first recorded use of an ironclad was during the Japanese invasion of Korea. Western use of ironclads began about the second half of the 19th century.[1] The Western ironclad was developed because up to then wooden warships were easily damaged by explosive or incendiary shells.