ARMORED SHIPS, first developed in Europe by the French and British navies, entered the U.S. Navy during the Civil War, where they made their combat debut. The Union navy, although generally associated with monitors, the low-freeboard, large-gun, turreted ironclads that captured the public's imagination during the war, contained a variety of designs suited for both riverine and coastal operations. The Confederate navy, whose paucity of industrial facilities limited experimentation, used fewer and simpler designs for the same purposes. Both sides employed several different armor schemes, depending on application, including thick wooden enclosures, cotton bales, sheets of tin on a wooden backing, layers of iron bolted to reinforced wooden hulls and superstructures, and laminated iron armor.
The period of naval retrenchment that followed the Civil War saw little innovation in the United States. Monitors remained the navy's only armored vessels until the late 1880s, when more modern battleships and armored cruisers were authorized and began joining the fleet. These vessels reflected the substantial changes in naval technology introduced in Europe since the Civil War: breechloading steel cannon, steel hulls, more powerful engines, and stronger armor. Armor, for example, evolved from iron plates to compound plates of iron and steel fused together to new steel alloys to steel plates tempered by the Harvey and Krupps processes. Initially introduced in small numbers, these armored warships grew in number as the United States began expanding its international presence.
The writings of the American naval theorist Alfred Thayer Mahan, which argued for the primacy of capital ships and were accepted worldwide, accelerated the navy's growth. Following Mahan's precepts, the navy reinvented
itself, rejecting its traditional commerce-raiding mission for a strategy based on fleet actions by armored capital ships. Although armored warships existed in a variety of sizes and configurations, battleships became the measure of a nation's international standing by the turn of the century. The launching of H.M.S. Dreadnought in 1906 confirmed the battleship's dominance and set the standard for armored vessels. The first all-big-gun warship, it was quickly copied by Great Britain's competitors, including the United States. Another class of lightly armored biggun warships that sacrificed some protection for speed, the battle cruisers, soon joined the world's leading navies.
Countries jealously compared numbers, types, and technical sophistication of armored capital ships, convinced that these massive weapons would play a vital role in future wars. But by the end of World War I, proponents had little direct evidence of their effectiveness. The Battle of Jutland, the only major fleet action of the war, proved inconclusive, while the greatest threat to the Allied war effort presented itself in the form of the commerce-raiding submarine, the antithesis of the armored capital ship. Still, the concept of fleet actions conducted by armored capital ships emerged from the war still enjoying strong support among the navy's planners. Subsequent American war plans, especially War Plan Orange (for war against Japan), still envisioned titanic fleet encounters between contending nations.
Even as navy planners continued to express their faith in battleships and cruisers, a potent challenge emerged. Airpower proponents argued that the armored ships' days were numbered because of their vulnerability to aerial attack. In an embarrassing publicity stunt, General William ("Billy") Mitchell successfully bombed and sank a stationary captured German battleship, the Ostfriesland, in 1921. Within the navy, Fleet Problem IX, conducted in 1929, demonstrated the unarmored aircraft carrier's potential to project force over great distances and sink armored warships. Still, the battleship and its armored consorts remained supreme in the eyes of naval strategists.
The Japanese attack on Pearl Harbor in December 1941 shattered those illusions. With five of the navy's finest battleships destroyed or severely damaged, it had no choice but to use those ships that remained for offensive operations, including three aircraft carriers. Those carriers, and others that followed, became the core of the fast carrier task forces that spearheaded the war in the Pacific. Armored ships also played an important part in these campaigns, but lost their dominant role even as ship design peaked with the wartime introduction of the Iowa-class battleships. Postwar strategic thinking that saw future wars in terms of atomic conflict found little use for armored warships built to engage each other. Although they periodically reappeared during the Korean and Vietnam wars, as well as the late 1980s, their expense and lack of distinct mission made them anachronistic, each time leading to decommissioning.
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Baxter, James Phinney. The Introduction of the Ironclad Warship. 1933. Reprint, Hamden, Conn.: Archon, 1968.
Muir, Malcolm. Black Shoes and Blue Water: Surface Warfare in the United States Navy, 1945–1975. Washington, D.C.: Naval Historical Center, 1996.
O'Connell, Robert L. Sacred Vessels: The Cult of the Battleship and the Rise of the U.S. Navy. Boulder, Colo.: Westview Press, 1991.