naval ship

Introduction

      the chief instrument by which a nation extends its military power onto the seas. Warships protect the movement over water of military forces to coastal areas where they may be landed and used against enemy forces; warships protect merchant shipping against enemy attack; they prevent the enemy from using the sea to transport military forces; and they attack the enemy's merchant shipping. Naval ships are also used in blockade—i.e., in attempts to prevent an enemy from importing by sea the commodities necessary for prosecution of the war. In order to accomplish these objectives, naval ships have been designed from earliest times to be faster and sturdier than merchant ships and to be capable of carrying offensive weapons.

      In the modern era the word craft has come to denote small surface vessels that operate usually in coastal waters.

      This article traces the development of the major surface warships and craft from their beginnings to the present day. For a discussion of submarines, which operate below the surface, see submarine. Detailed discussion of weapons used by warships can be found in other articles. For early naval cannon, see military technology; for guided antiship and antiaircraft missiles, see rocket and missile system; for naval airplanes, jets, and helicopters, see military aircraft.

The age of oar and ram

      The first craft fitted purposely to make war were conversions of the dugouts, inflatable bladders, papyrus rafts, or hide boats used in everyday transport. It is probable that the conversion at first consisted simply of a concentration of weapons in the hands of a raiding party. In time conversions added offensive and defensive powers to the craft itself. As vessels became more seaworthy and more numerous, warships designed as such developed both as marauders and as defenses against marauders. The first craft designed and built especially for combat may have sailed in the fleets of Crete and Egypt (Egypt, ancient) 5,000 years ago.

Egypt

      The first recorded appearance of warships is on the Nile River, where Egypt's history has centred since antiquity. These boats were built of bundles of reeds lashed together to form a narrow, sharp-ended hull and coated with pitch, and they were hardly suited for tempestuous seas. By 3000 BC larger wooden seagoing versions of the reed craft sailed for distant cruising, trade, and conquest.

      Egyptian wooden ships had both oars and sails, being fitted with a bipod (inverted V) mast and a single, large, square sail. The whole mast could be lowered when under oars. Large Egyptian ships had more than 20 oars to a side, with two or more steering oars. The war galley was built to the same pattern but was of stouter construction. Modifications that could be easily incorporated in a merchant ship's hull under construction included elevated decks fore and aft for archers and spearmen, planks fitted to the gunwales to protect the rowers, and a small fighting top high on the mast to accommodate several archers. Some galleys had a projecting ram, well above the waterline, which may have been designed to crash through the gunwale of a foe, ride up on deck, and swamp or capsize him.

Crete

      By about 2000 BC Crete had evolved into a naval power exercising effective control of the sea in the eastern Mediterranean. Little record exists of Minoan (Minoan civilization) seapower, yet these maritime people may have been the first to build a warship designed as such from the keel up, rather than as a modification of a merchant ship. Thus it was probably the Minoans who began to differentiate between war craft and merchantmen and between the rowing galley and sailing vessel.

      Sometime in the 2nd millennium BC the commodious merchantman evolved as a beamy “round ship” powered by sails and emphasizing cargo capacity at the expense of speed. By contrast, the fast fighting “long ship” was narrower, faster, and more agile than the tubby cargo ship. Developing as both predator on and protector of maritime trade and coastal cities, it hoisted its sails for cruising but depended on oars when in action.

      The Cretan warship had a single mast and a single bank of oars. The sharply pointed or “beaked” bows suggest an emphasis on the tactical use of the ram.

Phoenicia

      Beginning about 1100 BC, the Phoenicians dominated the eastern Mediterranean for about three centuries. Information about Phoenician ships is fragmentary, but they appear to have been built primarily for trading, with a capacity to fight effectively if necessary.

      Phoenician trading ships were apparently galleys, mounting a single pole mast with a square sail and with steering oars to port and starboard. Their war galleys show a Cretan influence: low in the bow, high in the stern, and with a heavy pointed ram at or below the waterline. Oars could be carried in a staggered, two-bank arrangement, allowing more oars to be mounted in a ship of a given length and increasing power and momentum. Because the ram was the principal weapon, the vessel's slender build and greater rowing power were important in providing more speed for the decisive shock of battle.

Greece (ancient Greek civilization)

      Unlike the Egyptians, for whom wood was scarce and costly, the Aegean peoples had an abundance of timber for shipbuilding. The earlier Greek warships were used more to carry attack personnel than as fighting vessels. No mention is made in the Iliad, for instance, of sea warfare. Even the pirates of the time were sea raiders seeking their booty ashore rather than in sea actions. The so-called long penteconter, mentioned by Herodotus, was employed in exploring, raiding, and communicating with outlying colonies. Light and fast, with 25 oars to a side, it played an important role in the early spread of Grecian influence throughout the Mediterranean. As the Greek maritime city-states sped the growth of commerce and thus the need for protection at sea, there evolved a galley built primarily for fighting. The first galleys, called uniremes (Latin: remus, “oar”), mounted their oars in a single bank and were undecked or only partially decked. They were fast and graceful with high, curving stem and stern. In Homeric times some carried an embolon, a beak or ram, which became standard in succeeding centuries.

Biremes and triremes (trireme)

      The bireme (a ship with two banks of oars), probably adopted from the Phoenicians, followed and became the leading warship of the 8th century BC. Greek biremes were probably about 80 feet (24 metres) long with a maximum beam around 10 feet (3 metres). Within two or three generations the first triremes (ships with three vertically superimposed banks of oars) appeared. This type gradually took over as the primary warship, particularly after the Greeks' great sea victory at the Battle of Salamis (480 BC).

      Like its predecessors, the trireme mounted a single mast with a broad, rectangular sail that could be furled. The mast was lowered and stowed when rowing into the wind or in battle. Built on an entirely different system from the Egyptians—with keel, frames, and planking—these were truly seagoing warships.

      After Salamis, the trireme continued as the backbone of the Greek fleet, with the ram continuing as its primary weapon. Its keel, like those of its predecessors, formed the principal-strength member, running the length of the ship and curving upward at each end. The ram, usually shod in bronze, formed a forward prolongation that gained effectiveness from the heavy keel back of it. Additional longitudinal strength came from a storming bridge, a gangway along the centreline from bow to stern along which the crew raced to board when a foe was rammed. Gradually, with ships becoming steadily heavier, boarding assumed greater importance and the ram lost some of its importance.

      A trireme of the 5th century BC may have had a length of about 125 feet (38 metres), a beam of 20 feet (6 metres), and a draft of 3 feet (1 metre). Manned by about 200 officers, seamen, and oarsmen (perhaps 85 on a side), with a small band of heavily armed epibatai (marines), under oars it could reach seven knots (seven nautical miles per hour; one knot equals 1.15 statute miles per hour or 1.85 km per hour). Extremely light and highly maneuverable, the classical trireme represented the most concentrated application of human muscle power to military purposes ever devised. The oarsmen sat on three levels, which were slightly staggered laterally and fore and aft to achieve the maximum number of oarsmen for the size of the hull. In rowing, the oarsmen slid back and forth on leather cushions strapped to their buttocks; this enabled full use of the powerful muscles of the thighs and abdomen.

      With only scant room for provisions, such warships could not remain long at sea, and a voyage usually consisted of short hops from island to island or headland to headland. Even the largest triremes put into shore and beached for the night, resuming the passage in the morning, weather permitting. Light construction and little endurance made short distances between bases essential and frequent refits imperative.

Later developments

      The trireme reached its peak development in Athens. By the middle of the 4th century BC, Athenians employed quadriremes (four-bank seating), with quinqueremes appearing soon thereafter. In the late 4th and early 3rd century BC an arms race developed in the eastern Mediterranean, producing even larger multibanked ships. Macedonia's rulers built 18-banked craft requiring crews of 1,800 men. Ptolemaic Egypt capped them with 20s and 30s. Ptolemy III even laid down a 40 (tesseraconter) with a design length of over 400 feet and calling for a crew of 4,000 rowers. The vessel was never actually used. (The multiplicity of “banks,” once a puzzle to historians, signifies the number of rowers on each oar or row of oars rather than an almost unimaginable vertical piling-up of banks.)

      This same arms race brought other changes of significance. Until the late 4th century BC, maneuver, marines, and the ram constituted a warship's offensive strength, and archers provided close-in fire. Demetrius I Poliorcetes of Macedonia is credited with introducing heavy missile weapons on ships at the end of the century, starting a trend that has continued to the present day. Demetrius' ships mounted crossbowlike catapults (catapult), for hurling heavy darts, and stone-throwing machines of the type the Romans later called ballistae. From this time on, large warships carried these weapons, enabling them to engage a foe at standoff ranges, though ramming and boarding also continued. Temporary wooden turrets—forecastles and sterncastles—were similarly fitted to provide elevated platforms for archers and slingers.

      Following the fragmentation of the brief empire of Alexander the Great, sea power developed elsewhere. The city-state of Rhodes built a small but competent fleet to protect its vital shipping. Meanwhile to the west, Carthage, a state with ancient maritime origins, rose to prominence on the north coast of Africa and by about 300 BC had become the foremost Mediterranean naval power. Carthage's navy consisted probably of the same ram-galley types developed by its ancestral Phoenicians and by the Greeks.

Rome (ancient Rome)

      Coincidentally, across the sea to the north the city-state of Rome expanded to include most of the southern Italian peninsula, with its extensive seacoast and maritime heritage. Rome's growth southward collided with Carthage's ambitions in Sicily, leading to the First Punic War (Punic War, First), which began in 264 BC. Unlike their seafaring opponents, the Romans were not a naval power. When in the fourth year of the war Carthage sent a fleet against Sicily, Rome realized its fatal disadvantage and moved to remedy it. The Greek city-states it had conquered had long seagoing experience. Employing their shipbuilders and learning also from the foe, Rome built a fleet of triremes and quinqueremes, the latter patterned after a Carthaginian warship that ran aground in Roman territory early in the war.

      Not content with copying the enemy's tactics, the Romans took land warfare to sea and forced the Carthaginians to fight on Roman terms. Each Roman galley had fitted in the bow a hinged gangplank with a grappling spike or hook (the corvus) in the forward end, thus providing a boarding ramp. They added to the crews many more marines than warships usually carried.

      The Phoenicians and Greeks had emphasized ramming, with boarding as a secondary tactic. A Roman captain rammed and then dropped the gangplank. Ram and corvus locked the galleys together, and the Roman marines boarded, overwhelming the opponent. The Roman fleet had extraordinary success in the great naval Battle of Mylae (Mylae, Battle of) off northeast Sicily, destroying or capturing 44 ships and 10,000 men. After other victories, and some defeats, by the end of the First Punic War, 241 BC, Rome had become the leading sea power.

      As the Roman navy evolved, so did its warships. Though pictorial evidence is ambiguous, it seems clear that the gangplank and corvus disappeared as the Romans gained experience in sea warfare. Later Roman warships appear to have been conventional fully decked ram-galleys mounting one or two wooden turrets (probably dismountable) for archers. To the single mast with rectangular sail was added a bowsprit carrying a small sail, the artemon, Falces, or long spars tipped with blades, were used by Julius Caesar's fleet against the sailing vessels of the Veneti of northwestern Gaul to cut their rigging and immobilize them. Catapults and ballistae served as mechanical artillery, and it was under their fire that Caesar's legions landed in England.

      Early Roman warships were all large; to escort merchantmen and combat pirates Rome found need for a lighter type, the liburnian. Probably developed by the pirates themselves, this was originally a light, fast unireme to which the Romans added a second bank of oars. In the Battle of Actium, 31 BC, Octavian's skilled fleet commander, Agrippa, used his liburnians to good effect. Although polyremes continued to be built after Actium, the liburnian became the predominant Roman man-of-war.

The Byzantine Empire

      With the breakup of the western Roman Empire, naval organization and activity in the west decayed. In the eastern Roman Empire, however, the need for sea power was well appreciated. During the 11 centuries that the Roman Empire centred on Constantinople, the Byzantine rulers maintained a highly organized fleet. Their original type of warship was the liburnian, called in Greek the dromōn; it was built in several different sizes, the heavier designed to bear the weight of battle and the lighter single-bank dromons serving as cruisers and scouts.

      Throughout the eastern Roman Empire's existence warships changed little except in rig and armament. An average large dromon measured up to 150 feet (46 metres) in length, with 100 oars and one or two fighting towers for marines. At some point early in the Christian era, the lateen sail, three-cornered and suspended from an angled yard, probably adopted from the Arabs, came into general use. Eastern warships had two or three masts. In a departure from classical customs, these were left in place in battle. Contemporary pictures show rams above the waterline.

      Missile-launching weapons grew in size, some hurling projectiles as large as 1,000 pounds (450 kg) up to 750 yards (685 metres). Greek fire, a combustible material for setting fire to enemy ships, was invented in the 7th century or earlier. The various compounds passing under the name used a blend of some of the following: pitch, oil, charcoal, sulfur, phosphorus, and salt. As the composition of Greek fire was improved, tubes shaped into the mouths of savage monsters were placed in the bows of war galleys and the flaming substance, which water merely spread, was hurled on the enemy. Greek fire was an important factor in terrifying and repelling the Muslim fleet in sieges of Constantinople from the early 8th century on.

Viking vessels

 By the beginning of the Viking period, about AD 800, the early and primitive Scandinavian craft had evolved into the well-known Viking ship (longship), a sturdy, double-ended, clinker-built (clinker construction) (i.e., with overlapping planks) galley put together with iron nails and caulked with tarred rope. It had a mast and square sail, which was lowered in battle; high bow and stern, with removable dragon heads; and a single side rudder on the starboard (steer-board) quarter.

      Viking vessels were essentially large open boats. Like the Homeric Greeks, the Vikings at first made no distinction between war and cargo ships, the same vessel serving either purpose as the occasion demanded. Later, however, they built larger ships specifically designed for war. By AD 1000 they sailed three categories of these: those with fewer than 20 thwarts (40 rowers); those with up to 30; and the “great ships” with more than 30, which might be considered the battleship of the time. Expensive and unwieldy, though formidable in battle, the great ships were never numerous. The middle group, maneuverable and fast, proved most valuable.

      Viking “long ships” played an important role in exploration (reaching Greenland and America before Columbus), in the consolidation of kingdoms in Scandinavia, and in far-ranging raids and conquests. In them the Norsemen invaded the British Isles and established themselves in Normandy, whence their descendants under William I the Conqueror crossed the Channel in 1066.

The age of gun and sail

      To about the end of the 13th century, the typical ship in northern European waters remained a clinker-built, single-masted, square-rigged descendant of the long ship. In that century, and even more in the 14th, changes began that would bring an end to the long dominance of the oar in battle. About AD 1200 came one of the great steps in the history of sail: the introduction, probably in the Netherlands, of the stern rudder. This rudder, along with the deep-draft hull, the bowsprit and, in time, additional masts, transformed the long ship into the true sailing ship, which could beat into the wind as well as sail with it.

      Until the 15th century, northern ships probably continued to have single masts, though in the Mediterranean a two-mast rig carrying lateen (fore-and-aft) sails had existed for some time. Then change came rapidly in the north, spurred on by Henry V of England's construction of large and strongly built warships for his cross-Channel French campaigns. The remains of one of these, the Grâce Dieu, reflected the clinker-built construction of the Viking long ship, but they had a keel to beam ratio of about 2.5:1 and now carried a second mast.

      Some historians believe that the Grâce Dieu carried a third mast. At any rate, in a few decades ships had three and, by the end of the century, large vessels mounted four masts carrying eight or more sails. A three-master carried a large sail on each mast and in addition a main topsail and the spritsail under the bowsprit—the rig, in fact, of Christopher Columbus' Santa Maria in 1492. Ships, no longer dependent on fair winds, could and did range the world.

      The beamier round sailing ship used for commerce also became the warship when the need arose. In times of war, temporary wooden castles (castle) were added at the bow and stern to provide bulwarked platforms for archers and slingers. A complement of men-at-arms embarked, in addition to the ship's seamen. Tactics were usually simple and straightforward, opposing fleets closing and attempting to beat down each other's archers before grappling and boarding. At war's end, off came the castles, and the ship went back to trading.

      The trading vessel that could be promptly adapted to war did not, however, fulfill the need of the European nations for navies. The coming of gunpowder and the period of world exploration brought changes that were to cause the sailing man-of-war to become more and more distinct from the merchantman.

Gun-armed (gun) warships

      The employment of guns afloat, bringing a slow but progressive revolution in warship construction and naval tactics, had its first small beginnings by the 14th century. The first guns used at sea, undoubtedly hand weapons, were probably in Mediterranean galleys in the 13th or early 14th century. Such weapons played a minor role. In fact, in the numerous sea battles of the Greeks, Genoese, Moors, Turks, and Venetians during this period there is no mention of guns. But by the middle of the 14th century, the English, French, Spanish, and other navies mounted guns. Most were relatively small swivel pieces or breech-loading deck guns located in the castles fore and aft, but heavier guns were added later. The Mediterranean galleys of Venice, Turkey, and Spain at first simply mounted a heavy gun rigidly in a timber bed that was fixed to fire the gun forward over the bow. By the late 15th century these rigid mounts gave way to sliding mounts for the main centreline bow gun, as the pieces were called. Though some of these pieces were quite large, the light structure of a galley meant that there was only one large gun per vessel.

      European guns were originally built up of wrought-iron bars welded together to form a tube, then banded with a thick iron hoop. Initially, they were breechloaders with an open trough at the rear of the barrel through which the ball was loaded and a cylindrical chamber, filled with powder, inserted and wedged tight. They were replaced after 1500 by brass muzzle-loaders, cast in one piece. Some of these muzzle-loaders attained great size for their day; by the mid-16th century even some 60-pounders (firing 60-pound [27-kg] solid shot) were mounted in the largest ships. In this century also, increasing knowledge of iron metallurgy led to the production of cast-iron cannon that slowly replaced the brass guns in ships, though brass remained predominant for the lighter calibre well into the 19th century.

      The Portuguese and Spanish, and then the French, seem to have been the first to cover transoceanic distances with cannon-armed warships. Vasco da Gama reached Calicut in India in 1498 with a squadron of cannon-armed carracks, and the Portuguese gained a number of signal victories over their Muslim opponents in the East in the early years of the 16th century using standoff artillery tactics that their foes could not match. The Spanish were patrolling the waters of the Caribbean in ships well-provided with wrought-iron breech-loading cannon by the 1520s or '30s, if not before, and heavily armed French raiders were not far behind.

      Henry VII of England created the first true oceangoing battle fleet. The “king's ships” carried many guns, but most of these weapons were small breechloaders. Following him, Henry VIII initiated gunports in English warships, a development that was to have a far-reaching effect on man-of-war design. Neither stability nor structural strength favoured heavy guns in the high castles built upon the deck, so that Henry's introduction of gunports, at first low in the waist of the ship and afterward along the full broadside, made possible the true heavy-gun warship. The cutting of gunports in the hull must also have been a factor in causing the northern nations to shift from clinker-built ships to caravels (caravel) with flush-fitting planks, a change that took place in the early 1500s.

      The armament of an English man-of-war of the early 16th century consisted of four or five short-barreled cannon, or curtals, a similar number of demicannon, and culverins (culverin). The average cannon, a short-range gun, hurled an iron ball of about 50 pounds (23 kg), and the demicannon one of 32 pounds (14 kg). The culverin, a longer and stronger gun, fired a smaller shot over a longer range and was likely to be more accurate at other than point-blank range. Supplementing these standoff “ship killers,” in descending size of ball fired (down to only several ounces), were the smaller demiculverin, saker (quarter culverin), falcon (half saker), falconet, and robinet.

      A great warship of the 16th century mounted a total of large and small pieces approximating the numbers mounted in battleships of World War II. For its original complement in 1514, Henry VIII's best-known warship, the Henry Grâce à Dieu, had 186 guns. Most of these were small, but they also included a number of iron “great guns.”

      As the 17th century advanced, guns and gunpowder improved. Gun carriages were given heavy wooden sides called brackets, which had sockets for the gun trunnions and were joined by similar flat timbers called transoms. The carriage was supported on wooden trucks and hauled out after recoil by heavy tackle.

From oar to sail

The galleass

      The coming of mighty men-of-war did not mean the immediate end of oared warships. In fact, some types of galleys and oared gunboats continued to serve well into the 19th century. Indeed, the Battle of Lepanto (Lepanto, Battle of) (1571), in which a combined European fleet defeated the Turkish fleet, differed little from traditional galley warfare with two exceptions. First, the scale of the action was very large, with more than 200 cannon-armed galleys on each side. Each of those galleys was propelled by 50 to 200 oarsmen and carried at least 50 additional men to fight and to man the guns and sails. Second, the European line of battle included six Venetian galleasses, a compromise type developed in the transition from oar to sail. These huge vessels, which depended on sail as well as oar, bristled with guns, including heavy ones in broadside. Although cumbersome to maneuver, their concentrated fire contributed importantly to victory.

      Galleasses outside the Mediterranean differed somewhat from Venice's in that they were basically full-rigged sailing ships carrying broadsides of heavy guns and a bank of auxiliary oars for mobility. The hybrid existed only in small numbers and soon passed out of fashion to the north.

The galleon

      The “great ships” of Henry VII and Henry VIII were carracks: starting basically with the lines of beamy, seaworthy merchant ships, designers had added stronger timbers, masts, sailpower, broadside guns, and high-built forecastles and aftercastles. In the galleon, the successor to the carrack, the general principles of design of sailing men-of-war were established, and they ruled, without fundamental change, for three centuries. The galleon retained certain characteristics of the galley, such as its slender shape, and in fact it had a greater length-to-beam ratio than the carrack. But the carrack's high-built forecastle, which tended to catch the wind and thus make the ship unmaneuverable, was eliminated from the galleon's design. The resulting ship was much more seaworthy. Like carracks, the larger galleons might carry a single mizzenmast or two relatively small masts, the second being called the bonaventure.

      In the longer, leaner galleon, the number of heavy guns was increased until they ran the full length of the ship's broadside in one or two tiers (and later three).

      The galleon came into favour in northern Europe during the middle of the 16th century. The far-ranging experience of mariners and improved construction techniques led to great fighting ships that were both lower in the water and more seaworthy than their predecessors. The sides now sloped inward from the lowest gun deck up to the weather deck. This “tumble home” helped concentrate the weight of the large broadside guns toward the centreline, improving the ship's stability.

      By this time it had become normal for warships to mount powerful broadsides of 28 or more ship-smashing guns, a much heavier armament in proportion to their size than their predecessors. For their handy, maneuverable ships, the British had relatively large cannon carried in broadsides. Thus they were designed for off-fighting, permitting the English fleet to get the most out of its ships' superior maneuvering qualities. When the Spanish Armada arrived in 1588, the British sought and fought a sea battle with ship-killing guns, rather than the conventional fleet engagement of the past that concentrated on ramming, boarding, and killing men in hand-to-hand combat. With superior ability and long-range culverins, the English ships punished the invading fleet outside the effective range of the heavy but shorter-range cannon the Spanish favoured. This historic running battle of July 1588 closed one era and opened a greater one of big-gun sailing navies.

ship of the line

      The late Elizabethan galleon that began the true fighting ship of the line reached its culmination in England's Prince Royal of 1610 and the larger Sovereign of the Seas of 1637, along with similar great ships in other European navies. These two English ships mounted broadside guns on three decks; the Sovereign of the Seas, the most formidable ship afloat of its time, carried 100 guns. In this mobile fortress displacing approximately 1,500 tons, there was some reduction of height; the bonaventure mizzen disappeared, leaving the standard three masts that capital ships thereafter carried.

      Soon ships began to be standardized into different categories. James I organized his ships into four ranks, and, by the mid-17th century, six “rates” existed as a general concept, though not yet a system. The number of guns a ship carried determined its rate, with a first-rater mounting 100 guns and a sixth-rater 18. An important improvement came in the standardization of batteries in the higher rates so that guns on the same deck were of the same weight and calibre rather than mixed, as originally in the Sovereign of the Seas. Near the end of the century, guns began to be described by their weight and calibre, with the 32-pounder long gun favoured as the standard lower-deck weapon for British warships.

      The frequent hard-fought sea battles of the 17th century, particularly in the Anglo-Dutch wars, led to the column formation of heavy warships called line ahead (ship-of-the-line warfare). In the line formation, each warship followed in the wake of the ship ahead so that every ship in the line had a clear field of fire for a broadside discharge of its guns. The adoption of line-ahead tactics made it necessary to standardize the battle line, which had consisted of ships of widely varying strength. Now only the more powerful warships were considered suitable “to lie in the line of battle.” Hence the origin by the 1700s of the term line-of-battle ship, or the ship of the line, and, in the second half of the 19th century, the derived term battleship—ships that could hit the hardest and endure the most punishment.

      Some first-raters were built to carry as many as 136 guns, but, because the biggest ships were often cumbersome, relatively few were built. The handier 74-gun third-rater proved particularly successful, combining sufficient hitting power with better speed and maneuverability. Most of the ships of the line of the late 18th and early 19th centuries were 74s. One of these might be approximately 175 feet long with two full gun decks, the lower mounting the heaviest guns, by the Napoleonic Wars usually 32-pounders. The upper gun deck customarily carried 24-pounders, while the forecastle and quarterdeck mounted lighter guns. The bigger ships were similar but had three covered gun decks instead of two. Viscount Nelson's Victory, launched in 1765 and preserved in dry dock as it was at Trafalgar in 1805, is a classic example of this powerful type.

      Warships gradually improved in design through the 17th and 18th centuries. New types of sails, providing more canvas and more versatile combinations for varying weather conditions, such as staysails and the jib sail, came into use in the 17th century. Soon thereafter the steering wheel replaced the old whip staff, or tiller.

Frigates (frigate) and smaller vessels

      Ships of the line, first to fourth rates, had strong, fast frigates as consorts. This ancestor of the modern cruiser evolved during the mid-18th century for scouting, patrol, and escort, as well as for attacking enemy merchantmen. The frigate carried its main battery on a single gun deck, with other guns on forecastle and quarterdeck. Like ships of the line, they varied in size and armament, ranging from about 24 guns in early small frigates to as many as 56 in some of the last. Two classic examples, still preserved, are the U.S. Navy's Constitution, with 44 guns, and Constellation, with 38.

      Smaller vessels aided frigates in their blockade, escort, commerce raiding, and other duties. The single-masted cutter served as scout and coastal patrol craft. Brig and schooner-rigged types, generally called sloops of war, by the time of the American Revolution grew into the three-masted, square-rigged “ship sloop.” Called a corvette on the Continent, the fast ship sloop complemented frigates on the fringes of the fleet. Smaller sloops, schooners, brigs, and luggers were widely used for special service. Fleets also needed ordnance and supply ships and other auxiliaries; these were usually merchantmen taken into service in war emergency. Converted merchantmen, such as John Paul Jones's Bonhomme Richard, often played combat roles. Fleets also had various special types, such as fire ships and bomb ketches. The latter, with two large mortars hurling bombs of about 200 pounds (91 kg), were developed by France in the late 1600s and were used with devastating effect against Barbary pirate ports.

The age of steam and iron

      As the Industrial Revolution unfolded in the 19th century, the age of wooden-hulled sailing ships gave way to that of steam-powered iron ships. Phenomenal changes took place in nearly every aspect of warship design, operation, and tactics. These changes ended the reign of the majestic ship of the line by the mid-1800s, but another half century elapsed before it was clear what form its replacement as the backbone of fleets would take.

Toward the ironclad

      The change from wood to iron came slowly, in considerable part because the introduction of steam power required new techniques and experience in shipbuilding. The general use of iron for warships awaited the full realization of the value of the shell gun and the resulting need for armour, which were first demonstrated in the employment of armoured batteries in the Crimean War and in the battle between the Monitor and Merrimack in the American Civil War. The changes may be summarized under three headings: propulsion, armament, and armour.

Propulsion

      Steam (steam engine) for propulsion of vessels was tried with varying success in several countries during the late 18th century. Engines and supporting machinery were at first not adequate for this fundamental advance in ship capability, but useful steam craft appeared in the early 1800s, suitable for operation on inland and coastal water-ways. The earliest steam warship was the Demologos of the U.S. Navy (renamed Fulton after its designer, Robert Fulton). Built in the War of 1812, this well-gunned, double-hulled, low-powered ship cruised briefly in the New York Harbor area before the war ended and later was destroyed by an accidental fire.

      The earliest steam warships in action were small paddle wheelers used by British and American navies against pirates and other weak foes. As engines gradually improved, navies experimented with them in standard warships, first as auxiliaries to sail, which was then essential for endurance. The paddle wheels were particularly vulnerable to enemy fire. In 1843, through the drive of Captain Robert Field Stockton (Stockton, Robert F.) of the U.S. Navy and the inventive skill of John Ericsson (Ericsson, John), a Swede whom Stockton brought to America, the United States launched the world's first screw-driven steam man-of-war, USS Princeton, a large 10-gun sloop.

      The screw propeller was an old idea going back to Archimedes, but, with Stockton's assistance, Ericsson had made it effective for large warships, as Sir Francis Pettit Smith was doing at about the same time in England for large merchantmen. By the mid-1840s, boilers, engines, and machinery had improved to the point that thereafter practically all of the new warships had steam propulsion, though they also still carried sails.

      Among the advances of this period were two other milestones. In 1834 Samuel Hall (Hall, Samuel) of England patented a type of steam condenser that made it possible to use fresh instead of corrosive salt water for boilers. In 1824 James Peter Allaire of the United States invented the compound-expansion steam engine, in which the steam was used in a second cylinder at a lower pressure after it had done its work in the first. Eventually it was made practical by progress in metallurgy and engineering; in 1854 John Elder, shipbuilder on the River Clyde, installed a successful two-stage engine in the merchant steamer Brandon. The higher efficiency was of great importance for ocean-keeping navies.

Armament

      The basic changes in armament that were to take place in the 19th and 20th centuries had begun in the 18th century. In the British navy steps to make possible heavier long-range guns began with the introduction of strong springs to take up the first shock of the gun's recoil after firing, aided by inclined-plane wedges behind the trucks to coax the gun forward into firing position after recoil. Flintlocks pulled by a lanyard, instead of match, fired the guns. Sights also improved. In the early 1800s navies began to employ mercury fulminate in percussion caps to initiate firing. Efficient percussion locks came into use within a few years.

      Smoothbore guns were still inaccurate, and successful efforts were made to bring back the rifled barrels, as well as the breech loading, of early guns, thus increasing their speed and accuracy of fire. The bore of a rifled gun barrel had spiral grooves cut into it that caused a projectile fired from it to spin in flight; if this projectile was shaped in the form of a cylinder with a cone-shaped forward tip, spin enabled it to fly through the air with its pointed end forward at all times. This improved aerodynamics gave the shell a more accurate course of flight and a longer range. Because a projectile could not be rammed down the muzzle of a rifled barrel, the use of rifling had to await the design of an efficient breech-loading mechanism. In the 1840s, Italian and Austrian inventors brought out sliding-wedge breechblocks. Later the French developed an interrupted screw system, originally an American invention. A British firm produced a rifled breech-loading gun that the Royal Navy used until 1864, when a number of accidents brought a temporary reversion to muzzle-loaders. But defects were eventually remedied, and breech loading brought phenomenal increases in rates of fire.

      French 6.5-inch (165-mm) cast-iron rifled guns in the Crimean War demonstrated superiority in range, destructive power, and accuracy. They helped impress all of the navies with the need for rifling. Slower-burning powder (gunpowder) was also badly needed. Black powder had gradually been improved during 600 years of use in firearms, but it still retained its primary defect, too-rapid burning (and hence the creation of gas pressures so high that they could burst a gun barrel upon firing). The use of rapid-burning powder required keeping the size of the charge down (and therefore the range) to prevent the bursting of even the best guns. Just before the American Civil War the U.S. Army developed large, perforated, dense grains of black powder that burned more slowly and thus were a start toward the controlled burning ultimately achieved with smokeless powder.

      A development equal in importance to the rifling of naval guns was the replacement of solid iron cannonballs with large shells (shell) that exploded upon impact. Shell guns in warships' main batteries were preceded by bombs fired from mortars, small shell guns, and solid hot shot heated to cherry red. A principal architect in bringing big shell guns to sea was Henri-Joseph Paixhans, a general of French artillery. The first large shell guns from Paixhans' design, chambered howitzers firing a 62.5-pound (28.5-kg) shell (thicker-walled than bombs to penetrate before exploding) was tested in 1824 against a moored frigate with remarkable accuracy and incendiary effect.

      The new guns began to come into use afloat in the 1830s, a French squadron firing them in the bombardment of Vera Cruz, Mexico. The U.S. Navy began installation of the new guns, including 16 eight-inch (20-cm) shell guns in the three-decker Pennsylvania, along with 104 32-pounder solid-shot guns. The British made similar installations. There was good reason for navies to proceed cautiously, as the production of shell guns at first encountered many manufacturing problems. (Indeed, in a gala demonstration of the 12-inch shell guns on the USS Princeton for President John Tyler, one of the guns blew up, killing the secretary of the navy and several others.) In the event, improvements in metallurgy, gun construction, and fire control—along with the maneuverability of steam warships—at last led to the important extension of range that the big gun had promised from the beginning.

      In 1853 the dramatic destruction of a weaker Turkish squadron by a Russian fleet in the harbour of Sinop of Turkey's Black Sea coast attracted world attention and increased interest in shell guns. England, the United States, and others built big steam frigates (as they were misleadingly called) with big shell guns. Their great striking power and maneuverability under steam made them the capital ships of the day, superseding the ship of the line for a brief time before the ironclads took over.

      Larger guns, increased powder charges, and greater tube pressures were made possible by the replacement of cast iron by built-up wrought-iron guns (later, cast steel and, eventually, forged steel were used). Hoops were shrunk on over the powder chamber and breech end of the tube to give the strength required for the greater internal pressures sustained by these guns upon firing.

Armour

      The use of larger guns with more penetrating power and explosive shells made armour plating imperative. Among early experiments were floating armoured batteries built for the Crimean War. Heavy wrought-iron plates over a thick wooden backing gave these flat-bottomed vessels outstanding protection as they carried large-shell guns close inshore.

      Other developments followed swiftly. The British soon built the first iron-hulled floating batteries. The French followed with the Gloire, the first seagoing armoured warship, protected throughout her entire length by a wrought-iron belt of 4.3- to 4.7-inch (10.9- to 11.9-cm) armour backed by 26 inches (66 cm) of wood. Displacing 5,617 tons, she mounted 36 large shell guns and could steam at 13.5 knots; a three-masted sailing rig supplemented the engines. Gloire was the first of a series of ironclads (ironclad) laid down by Napoleon III; 13 similar ships soon followed, then two-decker armoured rams. Great Britain countered with the Warrior, the first iron-hulled, seagoing, armoured man-of-war. Much larger than the Gloire, she displaced 9,210 tons, mounted 28 seven-inch (18-cm) shell guns, had slightly lighter armour, carried sails, and was one knot faster.

      These first ironclads were commissioned on the eve of the American Civil War, in which ironclads were destined to take a decisive part. The war itself produced several spectacular developments, including pioneer submarines, the first aircraft carriers (to handle balloons for observation), and the torpedo boat, one of several means the Confederates explored in trying to break the blockade. These little craft had weak steam engines and mounted a torpedo lashed to a spar projecting from the bow. Called Davids, they were weak but definite forerunners of the torpedo boat and the versatile destroyer.

      Ironclad warships were crucial, perhaps decisive, in the North's victory over the South. Partial ironclads appeared early on the western rivers and spearheaded Union general Ulysses Grant's victories in 1862. River and coastal ironclads (ultimately, mostly monitors) dominated the war against the South in attacks from the sea and in decisive support of land operations from the Mississippi system to the Chesapeake Bay and James River. Most memorable of the combats was the duel between the Monitor (Monitor and Merrimack, Battle of the) and Virginia (better known as the Merrimack). When the Federal forces lost Norfolk Naval Shipyard in Portsmouth, Virginia, in April 1861, they burned several warships, including the heavy steam frigate Merrimack. The Confederates raised the Merrimack, installed a ram and slanting casemates made from railroad track over thick wooden backing, as had been done in the Gloire, and renamed it Virginia. Mounting 10 guns, including four rifled ones, the Virginia, with yard workmen still on board finishing up, sailed on March 8, 1862, for its trial run. Defying concentrated fire of ship and shore batteries, it sank two ships of the Union's wooden blockading fleet before retiring with the ebbing tide. In this dramatic moment John Ericsson's Monitor arrived from New York during the middle of the night. Displacing fewer than 1,000 tons, less than one-third of the Virginia, the Monitor had a boxlike iron hull supporting an iron-plated wooden raft on which revolved the turret. The 172-foot- (52-metre-) long vessel had little freeboard except for the thickly armoured rotating turret within which were mounted two 11-inch (28-cm) smoothbores.

      The Monitor had many deficiencies. Not really a seagoing warship, it had nearly sunk on its voyage down from New York and did sink on its next sea voyage. Yet it proved the equal of its rival in their duel on March 9. The battle ended in a draw with neither ship seriously injured, but the repercussions of this first duel between completely ironclad warships swept the world.

      On April 4, scarcely more time than required for a ship to cross the Atlantic, Great Britain ordered the 131-gun ship of the line, the Royal Sovereign, to be cut down, armoured, and fitted with turrets. Only three and a half weeks later Great Britain laid down the Prince Albert, the Royal Navy's first iron-hulled turret ship, mounting four turrets.

      The Union Navy ordered 66 coastal and river monitors; these were low freeboard ships that were unsuitable for high-seas action and rarely suitable for long voyages. Many were not completed in time for war service. Besides the Virginia, the Confederates began a number of other ironclads. Several of these rendered valuable service and probably lengthened the war, but most had to be destroyed before completion. Out of a combination of characteristics of the Monitor and Virginia types evolved the battleship, which was next to rule the sea.

Toward the battleship

      The later 19th century continued to be a time of great flux in warship design. European nations tried numerous arrangements of guns and armour, such as centreline turrets, a central armoured citadel with large guns on turntables at each corner, lightly armoured big guns topside in barbettes (open-top breastworks), torpedoes (torpedo) in even the largest vessels, and substitution of high speed for armour.

      For a time even the ancient ram was revived. When the Austrians won the Battle of Lissa from the Italians in 1866 by ramming, its value for the future seemed confirmed. Hence for years most large ships carried rams, which proved to be more dangerous to friend than foe when ships were sunk in peacetime collisions.

      This period also saw a fundamental advance in underwater weaponry with the invention of the locomotive torpedo. After being presented with the idea by an Austrian naval captain in 1864, a British engineer named Robert Whitehead (Whitehead, Robert) produced a projectile that was driven by compressed air and was designed to strike a ship's unprotected hull below the waterline. The Whitehead torpedo, as it was quickly adapted by the European navies, was about 16 inches (41 cm) in diameter and had a range of about 1,000 yards (914 metres) at approximately seven knots.

      Engines for all the types of warships steadily improved as stronger metals made possible higher steam pressures and weight reduction. In the 1870s a third cylinder was added onto the two-stage compound steam engine to make the triple expansion engine, and in the 1890s a fourth cylinder was added. These improvements on the traditional reciprocating steam engine provided a marked increase in speed that was surpassed only by the radical innovation of the steam turbine at the end of the century.

Ships

      A trend toward the centreline-turret, big-gun battleship finally became clear. In it were combined the seagoing hull, armour, and habitability of the Virginia, Gloire, and Warrior with the revolving turret and big guns of the Monitor.

      HMS Monarch, 8,300 tons, mounting four 12-inch (30-cm) guns in two turrets, and commissioned in 1869, was perhaps the first true seagoing turret warship. HMS Devastation, 9,330 tons, four 12-inch (30-cm) guns in two turrets, and massively armoured, was completed four years later without sail and was a next step toward the ultimate 20th-century battleship, a ship with an armoured citadel around the propulsion plant, powder magazines, and handling rooms. Rising out of it, protecting big guns and crews, were barbettes and turrets. The main battery shrank to a few powerful guns, but these took the place of many in broadside because of their great size and ability to fire through a wide arc of bearings.

      The change was vividly illustrated by the “new navy” the United States began building in the 1880s, consisting not of improved monitors but of powerful seagoing capital ships with mixed-calibre main batteries. Displacing 11,700 tons, these vessels had 18-inch (46-cm) belt armour and a speed of 15 knots and mounted four 13-inch (33-cm) guns in two turrets. They also mounted eight eight-inch guns in four turrets, smaller guns for defense against torpedo boats, and six torpedo tubes. The plan was, as in other navies, to employ the heavy guns against an enemy ship's armour-protected machinery and magazines while the faster-firing eight-inch guns attacked its relatively unprotected superstructure.

      The armoured cruiser was developed in this period as a large, fast vessel armed with intermediate-calibre guns and protected by armoured deck and medium-weight belt armour. Designed for commerce protection and raiding, as well as to cooperate with the battle line in fleet action, it was considered powerful enough and sufficiently protected to fight any ship capable of catching it and able to outrun battleships. Some even held it should become the principal warship.

      Less heavily armoured was the protected cruiser, the engines and magazines of which were shielded by an armoured deck, but which lacked an armour belt. Unprotected cruisers had little or no armour, carried fairly light guns, and were designed primarily for scouting, patrolling, and raiding.

      Carrying the new self-propelled torpedo, the torpedo boat had great potential, particularly under conditions of low visibility. Small, unseaworthy, and useful only in restricted waters with the then-short-range, slow torpedoes, the new boats did not immediately live up to expectations; nevertheless, as craft and torpedo improved, they were soon regarded as a major menace.

Armour

      Early hull armour had been of wrought iron backed by wood. To increase resistance against ever more powerful rifled guns, compound armour of steel backed with iron was devised to combine steel's surface hardness with iron's resiliency. The firm Schneider & Cie in France invented an oil-tempering process to produce a homogeneous steel plate that had good resiliency and greater resistance than compound armour. The later addition of nickel further improved its resistance.

      Steel-armour-piercing shells came into use in the late 1880s, again threatening the armoured ship. Accordingly, an American engineer, Hayward Augustus Harvey (Harvey, Hayward A), perfected a face-hardening process, applying carbon to the face of the steel plate at very high temperatures for an extended period and tempering. Harvey nickel-steel armour superseded earlier types. Then, in 1894, the Krupp (Krupp AG) firm of Germany devised hot-gas tempering, based on Harvey's process, which in turn became standard with world navies. Later, the addition of chromium to nickel steel was found to be a further improvement.

Armament

      The impact of developments in guns and powder exceeded even that of warship design in their effect upon navies. In the two decades after the American Civil War the main difficulties with breech mechanisms were resolved. Better guns, along with breech-loading, made possible both longer ranges and higher rates of fire.

      New powders (gunpowder) were equally important. About 1880 brown or cocoa powder appeared, employing incompletely charred wood. It burned slower than black powder and hence furnished a sustained burning that was effective ballistically but did not create excessive pressures within the gun barrel. To take advantage of this for longer-range firing, gun-barrel lengths jumped to 30–35 times bore diameter.

      Several nations began to achieve success with smokeless powder of nitrated cellulose and usually some nitroglycerin. With greater striking power available, armour-piercing projectiles became more formidable. These were originally solid shot designed simply to punch through armour plate. In the 1890s, better steel and fuses made it possible to add an explosive charge. The resulting semi-armour-piercing shells became highly destructive, and in time all of the armour-piercing projectiles carried explosive charges.

      In 1881 the British Admiralty advertised for an anti-torpedo-boat gun to fire cased ammunition at a rate of 12 shots per minute. Benjamin Berkeley Hotchkiss, an American ordnance engineer with a factory in Paris, produced a series of one-, three-, and six-pounder rapid-fire guns that vastly increased the rate of fire for small guns.

Ernest McNeill Eller Robert L. Scheina John C. Reilly, Jr. John F. Guilmartin, Jr.

The age of big gun and torpedo

      From the late 19th century through World War I, the greatest driving force in warship development was the rivalry between the big gun and the torpedo. Improvements in these weapons had immense influence on the design and use of surface warships, from the huge dreadnought battleships to the small torpedo boat.

Armament

Guns

      By 1900 a major change had occurred in the handling of the very heavy main guns, those of 11 to 13.5 inches calibre that fired shells weighing up to 1,300 pounds. In the 1890s such weapons often fired no faster than once every five minutes, compared to the five to 10 rounds per minute fired by a six-inch gun. As power control became easier and more precise, the big guns became more effective. By 1900 it was possible for a 12-inch gun to fire one or two aimed shots per minute.

      Meanwhile, the standard of heavy-gun marksmanship began to improve. Although rifled guns had grown bigger and muzzle velocity had increased throughout the late 19th century, there had been no corresponding improvement in fire control. For this reason, effective battle ranges had not extended much beyond 3,000 to 4,000 yards. Then it was discovered that a ship's roll and pitch could be systematically compensated for, so that each shot could be fired at the same angle to the sea and reach almost exactly the same range. Greater accuracy could be achieved by firing groups of shells, or salvos, bunched around the estimated range. The pattern of splashes raised by a salvo would then make corrections possible. By the end of World War I, fire control had improved enough that guns firing 15,000 to 20,000 yards could attain a hit rate of 5 percent. This meant that a ship firing 10 heavy guns at the rate of once or twice per minute could expect a hit after two or three minutes.

      Increased range was valuable for two reasons. First, a ship that could hit at ranges beyond the capabilities of its enemies could stand off and destroy them at leisure. Second, improved gun range increased protection against the new, longer-range torpedoes.

Torpedoes

      Modifications and adaptations of the original Whitehead design quickly made the torpedo a formidable weapon. Directional control was greatly improved in the 1890s by the use of a gyroscope to control the steering rudders. Another significant improvement was the use of heat engines for propulsion. British firms, introducing both heat engines and contrarotating propellers, advanced to the high-performance, steam-driven Mark IV torpedo of 1917. Concurrently with this development, an American firm, E.W. Bliss Company, successfully used a turbine to drive a modified Whitehead design. (This Bliss-Leavitt torpedo remained in extensive use until World War II.) By 1914, torpedoes were usually 18 or 21 inches in diameter and could reach almost 4,000 yards at 45 knots or 10,000 yards at close to 30 knots.

Armour

      The torpedo threat forced ship designers to provide battleships with underwater protection. Schemes to place coal bunkers near the outside of the ship proved impractical, but research during World War I showed that the basic idea of keeping the underwater explosion at a distance from the interior of the ship was correct. In the Royal Navy, existing ships were fitted with external bulges or “blisters” to keep the explosion farther outboard, and new ships were built with specially designed layers of compartments designed to absorb the shock of explosion.

      During the war it also became apparent that the longer firing ranges meant that more shells would fall onto a ship's deck than on its side armour. Because these ranges were experienced at the Battle of Jutland, ships designed afterward with stronger deck armour were called post-Jutland.

Propulsion

      Steam turbines. While weapons were the main driving force in warship development, changes in propulsion were also important. In 1890, propulsion was exclusively by reciprocating (i.e., piston) steam engines, which were limited in power and tended to vibrate. To escape these limits, warship designers adopted steam turbines, which ran more smoothly and had no inherent limits. Turbines were applied to destroyers (destroyer) from about 1900 and to battleships from 1906.

      The main drawback of turbine propulsion was that really efficient turbines ran too fast to drive efficient propellers. The solution was to reduce turbine speeds to acceptable propeller speeds through gearing (gear). By 1918, single-reduction gearing was commonplace. Late in the interwar period, the U.S. Navy adopted double-reduction gearing, which permitted even higher turbine speeds without requiring propellers to run any faster.

Fuel

      Fuel also became a major issue. coal was relatively inexpensive and easily available; however, it did not burn cleanly and was difficult to transfer from ship to ship at sea. Oil (petroleum), on the other hand, burned cleanly, and it could be transferred easily at sea. Also, it had a higher thermal content than coal, so that the same weight or volume of oil could drive a ship much farther. The United States shifted to oil fuel in new ships in about 1910 and converted its remaining coal-burning warships after World War I. Beginning with the Queen Elizabeth class of battleships in 1915–16, Britain switched to oil. The other navies followed suit after the war.

Internal combustion (internal-combustion engine)

      In contrast to the steam engine, a gasoline or diesel engine often needed no tending at all, could be very compact, and could start and stop quite easily. Such engines made it possible to build small, fast coastal minesweepers, subchasers, and motor torpedo boats. Internal combustion was thought to be especially suitable to subchasers, which would have to stop their engines while listening for a submarine and then start them up suddenly when something was heard.

Battleships

      A battleship entering service in 1900 typically mounted a mixed battery of four heavy (11- to 13.5-inch) guns in two twin turrets, about a dozen secondary guns of six to nine inches, and small, fast-firing guns of three inches or less for beating off torpedo-boat attacks. These ships usually displaced 12,000 to 18,000 tons.

      By 1904 studies reinforced by battle experience in the Spanish-American and Russo-Japanese wars indicated that fire from large guns at longer ranges was more effective than mixed-battery fire closer in. Only bigger shells could do serious damage to well-armoured ships. Moreover, the shells fired from guns of many different calibres produced a confusing pattern of splashes in the water that made the correcting of aim and range quite difficult. Effectively increasing range, then, depended upon abandoning the multiple-calibre pattern of previous battleship armament in favour of a single-calibre armament. Several navies reached this conclusion simultaneously, but the British were the first to produce such a ship, HMS Dreadnought, completed in 1906. Displacing about 18,000 tons, it carried 10 12-inch guns; its only other armament consisted of three-inch weapons intended to fight off destroyers.

      The Dreadnought gave its name to an entirely new class of battleships of the most advanced design. By 1914 the Royal Navy had 22 dreadnoughts (another 13 were completed during World War I), Germany built a total of 19 (five completed after 1914), and the United States completed 22 (14 of them after 1914). Japan and Italy built six, while Russia and France each built seven. Not all of these ships were strictly equivalent. Unlike its immediate German and American contemporaries, the Dreadnought had steam turbines in place of reciprocating engines. These enabled it to attain a speed of 21 knots, which was hitherto achieved only by cruisers. (Contemporary battleships were generally limited to about 18 knots.) Thus, in mobility as well as in size, the Dreadnought began a new era.

      HMS Dreadnought also marked a beginning of rapid development in big-gun firepower. In 1909 the Royal Navy laid down HMS Orion, the first “super dreadnought,” which displaced 22,500 tons and was armed with 13.5-inch guns. The U.S. Navy followed with ships armed with 14-inch guns. Then, on the eve of World War I, the Royal Navy went a step further with HMS Queen Elizabeth, armed with 15-inch guns and capable, in theory, of 25 knots. World War I stopped the growth of British and German battleships, but the United States and Japan continued to build ships exceeding 30,000 tons displacement. In 1916 both countries adopted the 16-inch gun, which fired a shell of approximately 2,100 pounds. Such guns could be aimed to hit at ranges as great as 20,000 yards.

      The battleship saw little combat in World War I, yet, despite submarines, aircraft, and destroyers, the outcome of the war still hinged upon control of the sea by the battleship. Had superiority in battleships passed to Germany, Britain would have been lost, and the Allies would have lost the war. The one moment when this might have happened was the only large-scale clash of battleships, the Battle of Jutland (Jutland, Battle of). Fought in May 1916 in mist, fog, and darkness, Jutland revealed the strengths and weaknesses of battleships and battle cruisers. Three British battle cruisers were lost. Several German battleships, thanks to watertight subdivision and efficient damage-control systems, survived despite more hits. But the British advantage in numbers was decisive, and Germany turned to the submarine to counter the Allied blockade.

Cruisers

      HMS Dreadnought made earlier large cruisers obsolete, since it was nearly as fast as any of these ships. Consequently, the Royal Navy built a series of ships it called battle cruisers. These were as large as the newest battleships and were armed with battleship guns, but they were much faster (initially a top speed of 25 knots, compared with the 21 knots of battleships). The first was HMS Invincible, completed in 1907. Many of these ships were built: 10 for the Royal Navy before 1914, seven for Germany, and four for Japan.

      Battle cruisers gained their superior speed by sacrificing heavy armour; as a consequence, they could not stand up to battleships. This was proved at the Battle of Jutland, where the Invincible was blown in two by a single salvo and sunk along with two other battle cruisers. These losses led many to argue that the battle cruiser was a mistake, but during the war Britain laid down six more, three of which were eventually completed. The last of them, HMS Hood, launched in 1918, could be described as a new stage in warship development. It was so large, at 41,200 tons, that it could combine contemporary battleship armour and armament (equivalent to that of HMS Queen Elizabeth) with the very high speed of 31 knots. Although classed as a battle cruiser, it was actually the first of a new generation of very fast battleships.

      At the other end of the cruiser spectrum were small, fast “scout” cruisers used for reconnaissance and escort duties. These ships displaced from 3,000 to 7,000 tons and, by 1915, attained speeds as high as 30 knots. They were armed with guns of smaller calibre, usually six or 7.5 inches. The British built many of this type of cruiser, as well as larger types that were nevertheless smaller than their battle cruisers.

Destroyers

      The self-propelled torpedo had its greatest impact on the design of small surface ships. Beginning in the 1880s, many nations built hundreds of small steam torpedo boats on the theory that they could bar coastal waters to any enemy. Because their hulls could be crammed with machinery, torpedo boats were quite fast. By the early 1890s, speeds as high as 25 knots were being reported. As a defense against this new fast threat, Britain deployed oversized torpedo boats, calling them torpedo boat destroyers. These craft were successful in hunting down torpedo boats, and eventually they were renamed destroyers.

      The first destroyers were essentially coastal craft, displacing only about 200 tons, but their larger successors could accompany battle fleets to sea. There it soon became apparent that a destroyer was in effect a superior sort of torpedo boat, capable of delivering its weapon against capital ships during or immediately after a fleet engagement. By 1914, 800- or even 1,000-ton ships were quite common.

      During World War I British destroyer design changed radically, creating what became the postwar formula of the V and W destroyer classes: four four-inch guns superimposed fore and aft, a high forecastle forward for greater seakeeping ability, and two sets of twin (later triple) torpedo tubes amidships. These vessels, displacing about 1,200 tons and capable of 34 knots, made all earlier British destroyers obsolete.

      When Germany adopted unrestricted submarine warfare in February 1917, shipping losses soon forced the diversion of destroyers from fleet duty to convoy protection and antisubmarine warfare. Destroyers were not ideally suited to the escort role, as they had limited steaming range and their high-speed design made them less seaworthy than the merchant ships they were required to escort. The Royal Navy therefore built several types of specialized convoy escort, but the U.S. Navy found it easier to mass-produce its current destroyer design. These vessels, equipped with hydrophones and depth charges, as well as guns and torpedoes, overcame the submarine threat and had a large share in the safe convoy of two million American troops to Europe without loss of a single soldier.

The age of the aircraft carrier

      Although naval strategists continued to extol the battleship and battle cruiser after World War I, these capital ships soon were swept away by the new art of naval aviation. Conventional naval guns were limited to a range of perhaps 20 miles, but by World War II the aircraft carrier—a ship capable of launching, recovering, and storing aircraft that could themselves destroy ships—had extended the battle range of surface fleets by as much as 300 miles. In doing so, it had a profound effect on naval warfare.

The last capital ships

      In 1922 the Five-Power Naval Limitation Treaty, signed in Washington, D.C., by emissaries of the victorious Allies of World War I plus Japan, changed the character of navies by limiting battleship inventories. With a few exceptions, new battleship construction was prohibited until 1931, and most remaining pre-dreadnought battleships were ordered scrapped. The new battleships allowed by the treaty could not mount guns of greater calibre than 16 inches, and they could not displace more than 35,000 tons.

      Battleships were defined as warships armed primarily with guns over eight inches in calibre or displacing more than 10,000 tons. This definition of a battleship in effect defined a new kind of cruiser, which would displace about 10,000 tons and would be armed with eight-inch guns. In 1930 a new treaty, signed in London, extended the battleship-building “holiday” through 1936 and divided cruisers into two classes: ships armed with guns of up to 6.1 inches and ships armed with guns of 6.1 to eight inches. In U.S. parlance the former were light, and the latter heavy, cruisers.

      One peculiarity of the Washington (Washington Conference) Treaty was that it defined warship size by devising new “standard” tonnages, which excluded the weight of fuel and reserve feed water. (Standard tonnage remains a means of measuring ship displacement in many cases, and it is used here when ship tonnages are listed.) The effect of the London Treaty's limit on cruiser tonnage was the saving of weight in warship design. Several navies used aluminum in structures not contributing directly to the strength of their ships, and there was considerable interest in welding (which was lighter than riveting) and in more efficient hull structures. Lighter machinery was also developed. The U.S. Navy, for example, built higher-pressure, higher-temperature boilers and more efficient turbines.

      Most of the battleships that survived the scrappings were rebuilt during the 1920s and '30s with added deck armour and with new blisters to improve their resistance to underwater explosions. In many cases, lighter engines and boilers were fitted, so that weight and internal volume were freed for other purposes such as improved fire-control computers.

      New battleships were also built. The Treaty of Versailles limited Germany to 10,000-ton capital ships, but in the 1930s that country built three large cruisers of about 12,000 tons, each armed with six 11-inch guns. These so-called pocket battleships, by combining heavy armour with great speed (provided by diesel engines), could defeat any contemporary cruiser. They also reignited the race in battleship construction. In 1935 France produced the Dunkerque; at 26,500 tons, armed with eight 13-inch guns, and reaching 30 knots, this was the first of the new generation of “fast battleships” presaged by HMS Hood. In 1937, after the Washington and London treaties had expired, Japan laid down the Yamato and Musashi. These two 72,800-ton ships, armed with 18.1-inch guns, were the largest battleships in history.

      As World War II began, Britain was constructing five battleships of the King George V class. These displaced about 36,000 tons and carried 14-inch guns. The United States completed five 35,000-ton battleships before entering the war and one in 1942, and four 45,000-ton Iowa-class ships were built during wartime. The Iowa ships, carrying 16-inch guns, were the last battleships completed in the United States. Germany completed five ships (including the 42,000-ton Bismarck and Tirpitz and the 32,000-ton Scharnhorst), France completed four, Italy completed three, and Japan completed two. Most of these fast battleships could exceed 30 knots.

      Before the war began, the new arts of dive-bombing and torpedo-bombing from carrier-based aircraft did not promise enough velocity and destructive power to penetrate battleship armour. But by the end of the war, even modern capital ships maneuvering at sea could be sunk by carrier aircraft. In October 1944 and April 1945, U.S. carrier-based airplanes sank the Musashi and Yamato; more than any other event, these marked the end of the long reign of the battleship.

Aircraft carriers

World War I

      The airplane had just begun to go to sea on the eve of World War I. In November 1910 the American scout cruiser USS Birmingham launched the first airplane ever to take off from a ship, and two months later a plane was landed on an improvised flight deck built onto the armoured cruiser USS Pennsylvania. In 1913 a British cruiser, HMS Hermes, was converted to carry aircraft. In 1916, flying-off decks were built aboard several British ships, and by 1918 the Royal Navy had a converted passenger liner, HMS Argus, that could land and launch planes on a flight deck extending from bow to stern. The Argus was the world's first true through-deck aircraft carrier and was thus the prototype for all later carriers.

      Aircraft carriers were valuable in World War I primarily because their planes vastly extended a ship's ability to scout, or reconnoitre, large areas of ocean. The wartime Royal Navy developed a series of torpedo-carrying seaplanes and carrier-based light bombers, but both the aircraft and their weapons were too weak to pose a serious threat. For this reason, the aircraft carrier was considered an essential element of the fleet but not a replacement of the battleship.

Improvements between the wars

      Throughout the interwar period, naval aircraft performance gradually improved, and dive bombers and torpedo bombers made aircraft carriers effective ship killers. In the opinion of many experts, this made other carriers so vulnerable that the only way to protect them was to find and destroy the enemy's carriers first. Another option was to protect the carrier with its own fighters. This option was not practical without some means of detecting an enemy air attack at a great distance, so that defending fighters could be sent up in time. The key to such a defense was radar. The phenomenon of radar was observed in the 1920s, and by the late 1930s prototype sets with huge antennas were operating. Radar was first installed aboard British and U.S. carriers in 1940–41.

      As another defensive measure, in 1936 the Royal Navy decided to provide its new carriers with armoured hangars, the armour including part of the flight deck. The U.S. Navy, on the other hand, built its flight decks of wood, on the theory that damage from bombs to the decks could be repaired relatively easily. (Substantial armour lower in the ships was intended to preserve them from more serious bomb damage.)

      Aircraft carrier operation required three elements: a means of launching from the ship, a means of recovering aircraft aboard ship, and a means of stowage. Landing aircraft were caught by arresting wires strung across the deck that engaged a hook fastened under the planes' tails. Originally, arresting wires were needed to keep the very light wood-and-cloth airplanes of the World War I era from being blown overboard by gusts of wind. After heavier steel-framed and steel-skinned airplanes were introduced, wires were no longer necessary. The Royal Navy abandoned arresting gear about 1926. The U.S. and Japanese navies continued to use it, but for a very different purpose: to keep landing airplanes from rolling into aircraft that were stowed at the forward end of the flight deck. In British practice this was unnecessary, because aircraft were stowed below immediately upon landing, so that each pilot faced a clear deck when he landed. Stowage was accomplished by elevator lifts, which were usually located in two or three places along the centreline of the flight deck.

World War II

      The Washington Treaty of 1922 permitted each of the major powers to convert two capital ships to carriers, within a 33,000-ton limit. New carriers could not displace more than 27,000 tons, and no carrier could have guns of more than eight inches. The United States and Japan converted heavy battle cruisers just under construction into the USS Lexington and Saratoga and the Japanese Akagi and Kaga. These ships actually exceeded the 33,000-ton limit, the U.S. vessels carrying about 80 aircraft and the Japanese about 40. Two new U.S. carriers built in the 1930s to treaty specifications were the Yorktown and Enterprise, which displaced more than 20,000 tons and carried about 80 aircraft. Their Japanese equivalents were the Hiryu and Soryu, which operated about 50 aircraft. Britain, which had suspended new capital-ship construction during the war, converted two light battle cruisers completed in 1916, HMS Courageous and Glorious. For economic reasons Britain did not build a new carrier to the treaty specifications until 1935, when HMS Ark Royal was laid down.

      Under a new treaty of 1936, new carriers were limited to 23,000 tons, but the limit on the total number of carriers was removed. In response, the Royal Navy laid down the Illustrious class of 23,000-ton carriers. These vessels did not enter service until after the outbreak of World War II in 1939. With the commencement of war, the United States produced the 27,500-ton Essex class. Carrying more than 100 aircraft, these vessels became the principal fleet carriers of the Pacific Theatre. Between 1940 and 1943, the United States also designed a series of 45,000-ton ships partly inspired by Britain's Illustrious carriers. Completed after the war ended in 1945, this Midway class was the first of the U.S. carriers to be built with armoured flight decks.

      During the war Britain built second-line carriers, called light fleet carriers, which were designed for quick construction. These became the Colossus and Majestic classes, vessels of approximately 15,000 tons that carried about 40 aircraft each. The U.S. war program, meanwhile, included the conversion of a series of cruisers into light carriers of the 11,000-ton Independence class.

      For protecting merchant convoys from submarine attack, escort carriers were built in large numbers, mainly in the United States. Many were converted merchant ships, and others were specially built on hulls originally designed for merchant service. The Royal Navy also added flight decks to some tankers and grain carriers, without eliminating their cargo role. These were called MAC ships, or merchant aircraft carriers.

      Carriers played a dominant role in every aspect of operations at sea in World War II. The Pacific conflict began with the Japanese carrier strike against Pearl Harbor and ended with American and British carriers operating with impunity against the Japanese homeland. In between, the Battle of the Coral Sea (Coral Sea, Battle of the), in May 1942, was the first naval battle in history in which opposing fleets fought without ever coming in sight of each other. A month later off Midway atoll, carriers again played the decisive role. The Battle of Midway (Midway, Battle of) reinforced a conviction already clear, especially from British operations in the Mediterranean with and without air support, that control of the sea also meant control of the air over the sea. In the autumn of 1942 the Solomon Islands campaign underlined the importance of both aircraft and submarines in fleet operations, emphasizing that modern sea power was a trident of air, surface, and undersea forces.

Destroyers and escort ships

      Most destroyers built between the two world wars repeated Britain's V and W formula, sometimes with more powerful guns or with more torpedo tubes and generally displacing from 1,300 to 1,500 tons. The London Treaty of 1930 prohibited destroyers larger than 1,500 tons, but by the late 1930s several navies had exceeded the limits.

      Besides delivering a bomb with enough velocity to damage a capital ship, the dive bomber forced the addition shipboard of large numbers of automatic guns, of 40 millimetres or less, to supplement the more powerful but slower-firing three- to five-inch antiaircraft guns. The Royal Navy converted some of its small World War I cruisers into antiaircraft ships, replacing their single six-inch guns with twin four-inch weapons controlled by special antiaircraft directors. The Japanese built large destroyers (the Akitsuki class) for much the same role; these were armed with a special 3.9-inch gun. The U.S. Navy provided virtually all of its destroyers with effective antiaircraft guns.

      As in World War I, destroyers were used for convoy escort against submarines, if only because they were available in large numbers. However, they were not especially suited to that purpose; like their pre-1914 forebears, they were still primarily fast fleet escorts optimized to deal with surface torpedo attack. The likelihood of such attack declined as radar became widely available, but aircraft remained an important threat to major fleet units, so that the destroyer naturally evolved into an antiaircraft escort.

      One important exception to the general abandonment of surface torpedo attack was the Imperial Japanese Navy. By 1941 Japanese doctrine envisaged concentrated night attacks by cruisers and destroyers carrying large numbers of unusually powerful, oxygen-fueled, wakeless torpedoes. These torpedoes were the Type 93 Long Lances, which proved extremely effective in the U.S.-Japanese naval battles around the Solomon Islands in 1942–43.

      The submarine threat in World War II placed Britain, the United States, and Japan in desperate need of escorts for merchant convoys. Besides converting existing destroyers, each navy built huge numbers of specialized escorts adapted to mass-production techniques. Britain led in these measures, building relatively small escorts of limited endurance, which it called corvettes, and much larger escorts, which it called frigates. The U.S. Navy built a somewhat faster equivalent, which it called a destroyer escort. The Japanese built a series of escorts roughly equivalent to the British corvettes.

Torpedo boats

      In the 1930s the German, Italian, British, and U.S. navies regained interest in motor torpedo boats, which had been largely discarded after World War I. All four navies built them in substantial numbers to fight in narrow seas during World War II. Against convoys in the English Channel and the North Sea, the Germans used their S-boats (Schnellboote, “fast boats”; often called E-boats by the British). The U.S. Navy's PT (Patrol Torpedo) boats harassed Japanese traffic in the South Pacific. Some of these wooden-hulled craft, which were powered by diesel or gasoline engines, could reach speeds of 40 knots. In addition to torpedoes, they could carry significant gun armament.

Amphibians

      The internal combustion engine (internal-combustion engine) made possible the most spectacular naval innovation of World War II, the shallow-draft landing craft used to bring large forces quickly to enemy beaches during amphibious assaults. The most famous example of these was the LST ( landing ship, tank), a large beaching craft that could embark and disembark troops and vehicles directly from shore to shore. The LST displaced about 4,000 tons full load and transported about 150 troops with equipment at 10 knots.

      A beaching craft of intermediate size, which the U.S. Navy called the LCT (landing craft, tank), was carried over oceanic distances and launched at the time of assault. The LCT was too large to fit the davit of a conventional transport, so a new type of ship, the LSD (landing ship, dock), was created specifically to carry it. The LSD had a floodable well deck aft, like a miniature dry dock. It could carry tank-laden LCTs over oceanic distances then flood its well deck off a landing beach and launch the craft.

      Not all of these vessels were powered by internal combustion engines; some LSTs and many LSDs used steam. Nevertheless, the vital smaller craft, such as the LCTs and a series of small infantry carriers called LCVPs (landing craft, vehicle, personnel), could not have been built without using diesel power plants. Only because their engines and fuel consumed so small a portion of their total displacement could these craft carry such massive loads on shallow drafts.

The age of the guided missile

      By the middle of World War II, carrier-borne aircraft had become so effective that the aircraft carrier was clearly replacing the battleship as the core of the modern navy. After the war, the development of jet aircraft and nuclear-powered ship propulsion magnified the range and speed of operations, but they did not alter the central role of the carrier.

      At the same time, though, a new equalizer was being developed: the antiship guided missile. This weapon, which could be mounted onto the smallest surface vessels as well as aircraft and submarines, was especially dangerous to aircraft carriers because it could be launched outside antiaircraft range and, being unmanned, could not be distracted easily by defensive fire. The main defense was to provide the fleet with its own guided missiles capable of destroying either the missile or its launching platform.

Propulsion

Nuclear power (nuclear energy)

      The ultimate development in steam propulsion was the use of the energy released by nuclear fission to heat the boilers of steam turbines. Nuclear power was proposed for ships, particularly submarines, in 1945, and by 1955 the United States had a nuclear submarine, USS Nautilus, in service. Other navies followed suit, so that within 20 years Britain, the Soviet Union, France, and China all operated nuclear submarines. In the 1950s the United States also developed nuclear power plants for surface ships, subsequently installing them aboard aircraft carriers and their escorts. The Soviet Union and France followed with more limited programs in the 1970s and '80s.

      For a surface ship, the advantage of nuclear power was effectively infinite range at high speed. The disadvantage was the high cost, which limited such power to a few valuable ships.

Gas turbines (gas-turbine engine)

      After 1945 the gas turbine, a turbine in which the combustion of fuel generates a stream of gases that turns the rotor, became available for ship propulsion. Gas turbines shared with internal combustion piston engines the great virtues of quick starting and stopping as well as relatively simple operation. They were also quite reliable. Their main defect was that they were efficient only over a relatively narrow speed range. For this reason, the first gas turbine warships employed combination power plants, such as combined steam and gas turbine (COSAG) or combined diesel and gas turbine (CODAG). Using such a plant, a relatively small ship, such as a frigate, could achieve much higher speed than with a conventional steam turbine. The next step was to combine two gas turbines, one sized for cruising and the other for high speed. Such an arrangement might be either combined gas and gas (COGAG), with both plants able to operate together, or combined gas or gas (COGOG), with only one plant being used at a time.

      Systems employing the gas turbine proved useful in smaller escort ships such as destroyers and frigates, although they were also installed in cruiser-sized vessels. A related system, called combined diesel, electric, and gas turbine (CODLAG), was especially valuable in submarine warfare. In order to minimize engine noise, which might interfere with sonar sensors, diesel generators powered electric motors, which in turn drove the ship's propellers. For higher speeds, electricity was supplemented or replaced by gas turbines.

Armour

      The role of armour greatly declined after 1945 because aircraft, the greatest threat to warships, now carried guided missiles and bombs capable of penetrating the thickest deck armour that any viable ship could accommodate. At the same time, warships' new missile weaponry occupied much more space than did the earlier guns, shells, and powder. Modern weapon systems also required room for computers and radars and for their operators. To cover such spaces with anything but the lightest plating would have added enormous weight and thus required very large and expensive hulls. The high cost of protection (in ship size as well as money) was a major reason for the abandonment of heavy, extensive armour in the guided-missile era.

      Armour was not abandoned altogether, however. Thin armour, for example, could protect aircraft and missiles from the steel splinters of exploding warheads and thus could keep a ship hit elsewhere from being destroyed by a huge explosion of jet fuel or its own missiles. For this reason most modern warships adopted thin (about one- or two-inch) splinter protection around their missile magazines.

      Aircraft carriers, at least in the U.S. Navy, retained armoured flight decks, though in their case the armour provided structural strength as well as limited protection.

Aircraft carriers

      After World War II the heavy attack aircraft carrier developed three roles: to deliver air strikes (both conventional and nuclear) against sea and shore targets; to provide a long-range air-defense umbrella for other ships; and to support antisubmarine operations (leaving it to other ships actually to destroy the submarines). In order to carry out these roles, jet carriers became so huge that only a first-rate power could afford to build and operate them. Within 35 years of the end of World War II, only the United States and France operated full-scale carriers (although the 27,000-ton French Clemenceau class was closer in size to the World War II Essex carriers than to the 80,000-ton, 1,000-foot behemoths built by the United States in the 1970s and '80s). The Soviet Union began to build large carriers in 1983.

      Navies that could not afford the large carrier divided its three roles among escort ships and new light aircraft carriers. To the light aircraft carriers was given the role of antisubmarine warfare, along with limited ground-attack and air-protection capabilities.

Large carriers

      The main wartime technical development in aircraft carrier design was the hydraulic catapult, but this was barely powerful enough to launch the heavier jet aircraft coming into service after 1945. The problem was solved in 1951, when the British first tested an effective catapult driven by steam from a ship's boilers.

      Jet aircraft landed at much higher speeds than had propeller-driven planes, making the installation of better arresting gear necessary. Also, landing control had to be improved, because the approaching pilot had to make crucial decisions much more quickly. As in the case of the steam catapult, the British supplied the solution, in the form of the angled deck and the mirror (later the Fresnel-lens) landing sight. By building an extension of the flight deck to one side and angling the landing strip onto that extension, the British system allowed a pilot to land away from aircraft parked at the end of the flight deck. If he missed the arresting wires, the pilot could fly off to try again. In this way mistakes became much less serious.

      The mirror landing sight, in effect, allowed the pilot to see his own position relative to the required glide path and to make corrections instantly. Previously, an officer on deck, observing the landing, had generally ordered the corrections.

      By 1955 the modern jet aircraft carrier had emerged, with steam catapults, an angled deck, and a mirror landing system. The first full jet carrier was USS Forrestal, commissioned in 1955. The 60,000-ton Forrestal carriers were built with rectangular extensions to the after part of the flight deck; these considerably widened the deck and allowed the angled landing strip to be merely painted on rather than extended over the side. The elevators were shifted to the edge of the flight deck, so that they could operate while aircraft were landing and taking off.

      The first nuclear-powered carrier, USS Enterprise, was commissioned in 1961. It was equipped with eight nuclear reactors and steamed for more than three years before refueling was necessary. The Enterprise displaced 75,700 tons, carried 100 jet aircraft, and could reach more than 30 knots. Beginning in 1975, the Nimitz class superseded the Enterprise. These 81,600-ton carriers were powered by only two nuclear reactors, yet they reached speeds comparable to the Enterprise, and their uranium cores needed replacement only once every 13 years. The smaller propulsion system created more room for the storage of aviation fuel, which greatly extended the operation of the 90 aircraft carried on these ships.

      In 1983 the Soviet Union laid down a 65,000-ton nuclear-powered carrier, and in 1989 France laid down the 34,000-ton Charles de Gaulle, a nuclear-powered ship designed to carry 40 aircraft.

Light carriers

      The expense of large carriers was due partly to the huge amounts of fuel, ammunition, and maintenance required to keep as many as 80 aircraft operational, but it was also due to the complexity and size of the catapults and arresting gear needed for jets. In the late 1960s Britain developed a jet fighter, the Harrier, that was capable of taking off vertically or (with a heavy payload) after a short roll. A carrier equipped with these V/STOL (vertical/short takeoff and landing) jets could be much smaller than a full jet carrier, because it would need neither catapults nor arresting gear. In the 1970s and '80s, Britain built three such ships, constituting the Invincible class. These 20,000-ton ships carried eight Sea Harriers and about a dozen antisubmarine helicopters. They also incorporated a further British contribution to aircraft carrier design: the upward-sloping “ski jump” at the end of the flight deck to assist the Sea Harriers in short takeoff.

      The Italian and Spanish navies also constructed light carriers for helicopters and V/STOL jets. Like the Invincibles, they were powered by gas turbines. The Soviet Kiev class, at more than 30,000 tons, carried a larger complement of rotary and V/STOL craft.

      In the 1960s, '70s, and '80s the United States constructed the Iwo Jima, Tarawa, and Wasp classes of amphibious assault ships, descendants of the World War II escort carriers that could transport close to 2,000 marines as well as their weapons and vehicles. The Tarawa and Wasp classes, besides carrying helicopters and Harriers, were built with well decks for the launching of landing craft.

      Occupying a position between cruisers and the through-deck light carriers were helicopter carriers, whose flight decks occupied only the after section of the ship. The 17,000-ton Moskva class of the Soviet Union, introduced in 1967, was a prominent example.

Fleet escort ships

      In the surface ships supporting aircraft carriers, the most important trend after 1945 was an amalgamation of types. In 1945 cruisers were armoured big-gun ships that were capable of operating independently for protracted periods. Destroyers were part of the screen protecting a main fleet, and frigates were slower ships designed for merchant convoy protection against air and submarine threats—primarily the latter.

      This series of distinctions began to collapse in the late 1950s. First, in order to hunt the new fast submarines, frigates had to match destroyer speeds. This made them more like small destroyers. At the same time, most cruisers were converted to carry long-range antiaircraft missiles. This conversion made it clear that cruisers were not solitary raiders or ship killers but fleet escorts—in effect, super destroyers. Eventually all three types became capable of antiaircraft, antisubmarine, and antiship warfare, although individual classes often specialized in one role.

      The most prominent trend in armament was a shift from guns (gun) to guided missiles. Beginning in the mid-1950s, existing ships had at least some of their guns replaced by missiles, and thereafter new ships were built with missiles making up their main batteries. By 1990 the ranges of these weapons varied from about four nautical miles for a short-range antimissile missile to more than 300 nautical miles for a long-range antiship missile. Some of these traveled at more than twice the speed of sound.

      Main guns became fewer and smaller. By 1990 the most prominent guns were dual-purpose weapons (for antiaircraft as well as surface fire) measuring from 76 to 130 millimetres, or three to five inches. Close-in protection against missiles was provided by fully automatic or Gatling-type guns of 20 to 40 millimetres. All guns were now remotely controlled and directed by radar.

Cruisers (cruiser)

      The era of big-gun cruisers ended with the completion of ships laid down during World War II. In 1961 the United States commissioned USS Long Beach, the first vessel designed from the keel up as a guided-missile cruiser and the first surface warship to steam under atomic energy. This 14,000-ton ship was followed by a series of nuclear-powered U.S. cruisers that ended, in the 1970s, with the 10,400-ton Virginia class. This class was supplemented in the 1980s by the 7,400-ton, gas-turbine-powered Ticonderoga cruisers. Both the Virginia and Ticonderoga ships were fitted with a broad array of weaponry, including surface-to-air and antiship missiles, tube-launched and rocket-launched antisubmarine torpedoes (torpedo), and two five-inch and two 20-millimetre guns. In addition, they were supplied with Tomahawk cruise missiles, which could be fitted with conventional or nuclear warheads. The Ticonderoga vessels carried two submarine-hunting helicopters, and they were equipped with the extremely sophisticated Aegis radar system for tracking hostile targets and directing missile defense.

      As the guided-missile cruiser evolved into an escort for aircraft carriers, it ceased to be built by navies that had allowed their large carrier capacities to expire. Britain, for example, sold its County-class ships (which were officially classed as destroyers but were effectively cruisers) in the 1970s and '80s, relying thereafter on smaller escorts to protect its light carriers. The Soviet Union, on the other hand, laid down the first of its 22,000-ton, nuclear-powered Kirov cruisers in 1973. With armament, speed, and steaming range comparable to the Virginias, these cruisers were logical escorts for the new nuclear-powered aircraft carriers that were expected to give the Soviet Navy the ability to project its power around the world. Until then, Soviet guided-missile cruisers had emphasized a heavy complement of long-range antiship missiles, giving some of them a ship-killing role similar to that of the big-gun cruisers.

Destroyers (destroyer) and frigates

      Because of the high cost of cruisers, smaller escort ships became the backbone of lesser navies in the guided-missile age. The destroyer completed its transition, begun during World War II, from surface-ship killer to antiaircraft escort. To this duty was added antisubmarine warfare, the traditional role of the frigate. Often the latter was distinguished from the destroyer only by its lesser displacement, armament, and speed.

      As submarines became faster, many classes (aircraft carrier) of destroyer and frigate adopted the helicopter (often housed in a hangar in the after section) as a help in hunting them down. Like cruisers, they bristled with an array of sonar and radar sensors and were packed with electronic gear for the swift detection and identification of hostile targets and the computation of firing data. Such complex equipment, packed into ships that must also have high speed (30 knots and more), excellent seakeeping ability, and long endurance, meant that destroyers and frigates became larger than their World War II predecessors. Guided-missile destroyers ranged from 3,500 to 8,000 tons displacement, while frigates ranged between 1,500 and 4,000 tons.

Amphibians

      The diesel-powered Newport LSTs, which entered service in the U.S. Navy in the 1960s, displaced more than 8,000 tons full load and transported amphibious craft, tanks, and other combat vehicles, along with 400 men, at speeds of up to 20 knots. Instead of merely beaching, like their World War II predecessors, they were fitted with an extendable ramp supported by huge projecting derrick extensions on each side of the bow. As the ship grounded, the ramp would shoot forward hydraulically 112 feet. Vehicles and troops would land over the ramp, while amphibious craft in the tank deck would disembark from stern gates.

      The Alligator-class LST was a smaller Soviet equivalent of the Newport.

      Beginning in the 1970s, gas-turbine power allowed the deployment of air-cushioned landing craft, which were naval hovercraft that could bring tanks and troops to shore at speeds of about 50 knots.

Norman Friedman

Additional Reading

Naval ships and craft are the subject of voluminous literature. For early history, William Ledyard Rodgers, Naval Warfare Under Oars, 4th to 16th Centuries (1939, reprinted 1967), and Greek and Roman Naval Warfare (1937, reprinted 1973), are older but still the most comprehensive sources on the classical era. J.S. Morrison and J.F. Coates, The Athenian Trireme: The History and Reconstruction of an Ancient Greek Warship (1986), treats in detail design evolution and technological developments. John H. Pryor, Geography, Technology, and War: Studies in the Maritime History of the Mediterranean, 649–1571 (1988), explores both military and commercial navigation in the region. John Francis Guilmartin, Jr., Gunpowder and Galleys: Changing Technology and Mediterranean Warfare at Sea in the Sixteenth Century (1974), examines the way in which gunpowder changed the nature of warfare on land as well as at sea. Philip Cowburn, The Warship in History (1965); Richard Hough, Fighting Ships (1969); and Donald MacIntyre and Basil W. Bathe, The Man-of-War: A History of the Combat Vessel, rev. ed. (1974), discuss and illustrate the general evolution of the warship from early to modern times.John F. Guilmartin, Jr. The modern era is covered in Peter Hodges, The Big Gun: Battleship Main Armament, 1860–1945 (1981); Norman Friedman, Battleship Design and Development, 1905–1945 (1978), and Modern Warship: Design and Development (1979); and David R. Frieden (ed.), Principles of Naval Weapons Systems (1985). Historical characteristics of the major navies of the world are found in Roger Chesneau and Eugene M. Kolesnik (eds.), Conway's All the World's Fighting Ships, 1860–1905 (1979); Robert Gardiner and Randal Gray (eds.), Conway's All the World's Fighting Ships, 1906–1921 (1985); Roger Chesneau (ed.), Conway's All the World's Fighting Ships, 1922–1946 (1980); and Robert Gardiner (ed.), Conway's All the World's Fighting Ships, 1947–1982, 2 vol. (1983). For characteristics by country, see: (United States): Norman Polmar, Ships and Aircraft of the U.S. Fleet, 14th ed. (1987); Norman Friedman, U.S. Battleships (1985), and U.S. Cruisers (1984); and Paul H. Silverstone, U.S. Warships Since 1945 (1987); (Great Britain): D.K. Brown, A Century of Naval Construction: The History of the Royal Corps of Naval Constructors, 1883–1983 (1983); and Alan Raven and John Roberts, British Cruisers of World War Two (1980), and British Battleships of World War Two (1976). (Other countries): John Jordan, Soviet Warships: The Soviet Surface Fleet, 1960 to the Present (1983); Norman Polmar, Guide to the Soviet Navy, 4th ed. (1986); Henri Le Masson, The French Navy, 2 vol. (1969); Hansgeorg Jentschura, Dieter Yung, and Peter Mickel, Warships of the Imperial Japanese Navy, 1869–1945 (1977; originally published in German, 1970); and Erich Gröner (ed.), Die deutschen Kriegsschiffe, 1815–1945 (1982– ), with six out of a projected seven volumes published by 1988.On aircraft carriers, see David Brown, Aircraft Carriers (1977); Roger Chesneau, Aircraft Carriers of the World, 1914 to the Present: An Illustrated Encyclopedia (1984); Norman Friedman, Carrier Air Power (1981), U.S. Aircraft Carriers: An Illustrated Design History (1983), and British Carrier Aviation: The Evolution of the Ships and Their Aircraft (1988).Norman Friedman

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