Naval armour

Naval armor refers to the various protections schemes employed by warships. The first ironclad warship was created in 1859, and the pace of armour advancement accelerated quickly thereafter. The emergence of battleships around the turn of the 20th century saw ships become increasingly large and well armoured. Vast quantities of heavily armoured ships were used during the World Wars, and were crucial in the outcome. The emergence of guided missiles in the last part of the 20th century has greatly reduced the utility of armor, and most modern warships are now only lightly armored. Naval armour consists of many different designs, depending on what the armour is meant to protect against. Sloped armour and belt armour are designed to protect against shellfire; torpedo belts, bulges, and bulkheads protect against underwater torpedoes or naval mines; and armoured decks protect against air dropped bombs and long-range shellfire. The materials that make up naval armour have evolved over time, beginning with simply wood, then softer metals like lead or bronze, to harder metals such as iron, and finally steel and composites. Iron armour saw wide use in the 1860s and 1870s, but steel armor began to take over because it was stronger, and thus less could be used. The technology behind steel armour went from simple carbon steel plates, to increasingly complex arrangements with variable alloys. Case-hardened Harvey armor was the first major development, followed by chromium alloyed and specially hardened Krupp armour. Ducol steel came into use in the 1920s, and was widely used on World War II era ships. Futuristic armor designs include electric armour, which would use electric shielding to stop projectiles. Early ship armour probably had its origins in applying thin sheets of metal to ship undersides for preservative reasons. There are only a few exceptional examples of ships equipped with metal armor before Industrial Revolution. The Finis Belli was described as a possible candidate for "the first ironclad" by authors in the late 19th and early 20th century.