Warship

A warship is a ship that is built and primarily intended for war. Warships are usually built in a completely different way to merchant ships. As well as being armed, warships are designed to withstand damage and are usually both faster and more manoeuvrable than merchant ships. Unlike a merchant ship, a warship typically only carries weapons, ammunition and supplies for its own crew (rather than merchant cargo). Warships usually belong to a navy, though they have sometimes been operated by individuals or companies.

In wartime, the distinction between warships and merchant ships is often blurred. In war, merchant ships are often armed and used as auxiliary warships, such as the Q-ships of World War I and the armed merchant cruisers of World War II. Until the 17th century it was common for merchant ships to be pressed into naval service and not unusual for more than half a fleet to be composed of merchant ships. Until the threat of piracy subsided in the 19th century, it was normal practice to arm larger merchant ships such as Galleons. Warships have also often been used as troop carriers or supply ships, such as by the French Navy in the 18th century or the Japanese Navy during World War II.

The age of galleys
In the time of Ancient Greece and the Roman empire, the most common type of warship was the galley (such as biremes, triremes and quinqueremes), a long, narrow vessel powered by banks of oarsmen and designed to ram and sink enemy vessels, or come alongside the enemy so its occupants could be attacked hand-to-hand. Throughout antiquity and the middle ages until the 16th century, naval warfare relied on the ship itself, used as a ram, the swords of the crew, and various missiles such as bows and arrows and bolts from heavy crossbows fixed on a ship’s bulwarks. Naval warfare primarily involved ramming and boarding actions, so warships did not need to be particularly specialized.

The age of sail
Naval artillery was first developed in the 14th century, but cannon did not become common at sea until the guns were capable of being reloaded quickly enough to be reused in the same battle. The size of ship required to carry a large number of cannon made oar-based propulsion impossible, and warships came to rely primarily on sails. The sailing man-of-war began to emerge during the 16th century. By the middle of the 17th century, warships were carrying increasing numbers of cannon on their broadsides and tactics evolved to bring each ship's firepower to bear in a line of battle. The man of war now evolved into the ship of the line. In the 18th century, the frigate and sloop-of-war, too small to stand in the line of battle, evolved to convoy trade, scout for enemy ships and blockade enemy coasts.

Steel, steam and shellfire
During the 19th century a revolution took place in the means of propulsion, armament and construction of warships. Steam engines were introduced, at first as an auxiliary force, in the second quarter of the 19th century. The Crimean War gave a great stimulus to the development of guns. The introduction of explosive shells soon led to the introduction of iron, and later steel, armour for the sides and decks of larger warships. The first ironclad warships, the French Gloire and British Warrior, made wooden vessels obsolete. Metal soon entirely replaced wood as the main material for warship construction.

From the 1850s, the sailing ships of the line were replaced by steam powered battleships, while the sailing frigates were replaced by steam powered cruisers. The armament of warships also changed with the invention of the rotating barbettes and turrets, which allowed the guns to be aimed independently of the direction of the ship and allowed a smaller number of larger guns to be carried.

The final innovation during the 19th Century was the development of the torpedo and development of the torpedo boat. Small, fast torpedo boats seemed to offer an alternative to building expensive fleets of battleships.

The Dreadnought era
Another revolution in warship design began shortly after the turn of the century, when Britain launched the all-big-gun battleship Dreadnought in 1906. Powered by steam turbines, she was bigger, faster and more heavily gunned than all existing battleships, which she immediately rendered obsolete. She was rapidly followed by similar ships in other countries.

Britain also developed the first battlecruisers. Mounting the same heavy guns as the Dreadnoughts on an even larger hull, battlecruisers sacrificed armour protection for speed. Battlecruisers were faster and more powerful than all existing cruisers, which they made obsolete. But battlecruisers proved to be much more vulnerable than contemporary battleships.

The torpedo-boat destroyer was developed at the same time as the Dreadnoughts. Bigger, faster and more heavily gunned than the torpedo boat, the destroyer evolved to protect the capital ships from the menace of the torpedo boat.

Development of the submarine
The first practical submarines were developed in the late 1800s, but it was only after the development of the torpedo that submarines became truly dangerous (and hence useful). By the end of World War I submarines had proved their potential. During World War II the German Navy's submarine fleet of U-boats almost starved Britain into submission and inflicted huge losses on US coastal shipping. The success of submarines led to the development of new anti-submarine convoy escorts during the First and Second World Wars, such as the destroyer escort. Confusingly, many of these new types adopted the names of the smaller warships from the age of sail, such as corvette, sloop and frigate.

Development of the aircraft carrier
A major shift in naval warfare occurred with the introduction of the aircraft carrier. First at Taranto and then at Pearl Harbor, the aircraft carrier demonstrated its ability to strike decisively at enemy ships out of sight and range of surface vessels. By the end of World War II, the carrier had become the dominant warship.

Modern warships
Modern warships are generally divided into seven main categories, which are: aircraft carriers, battleships, cruisers, destroyers, frigates, submarines and amphibious assault ships.

However, battleships are extremely rare and the once distinct roles and appearances of cruisers, destroyers and frigates have blurred as the size of the vessels has grown and each has come to be armed with a mix of anti-surface, anti-submarine and anti-aircraft weapons.

Most navies also include many types of support and auxiliary vessels, such as minesweepers and patrol boats.

Types of warship

 * Amphibious Assault Ship
 * Aircraft carrier
 * Battle cruiser A lightly-armoured battleship.
 * Battleship a large, heavily-armoured and heavily-gunned warship. A term which generally post-dates sailing warships.
 * Bireme An ancient vessel, propelled by two banks of oars.
 * Capital ship
 * Commerce raider
 * Corvette
 * Cruiser
 * Cutter
 * Destroyer
 * Dreadnought An early twentieth century class of battleship.
 * Fireship A vessel of any sort, set on fire and sent into an anchorage with the aim of causing consternation and destruction. The idea is generally that of forcing an enemy fleet to put to sea in a confused, therefore vulnerable state.
 * Frigate
 * Galleass A sailing and rowing warship, equally well suited to sailing and rowing.
 * Galleon A sixteenth century sailing warship.
 * Galley A warship propelled by oars with a sail for use in a favourable wind.
 * Ironclad A wooden warship with external iron plating.
 * Longship A Viking raiding ship.
 * Man of war A sailing warship.
 * Minesweeper
 * Minehunter
 * Monitor A small, heavily gunned warship with shallow draft designed for land bombardment.
 * Quinquereme An ancient warship propelled by three banks of oars. On the upper row three rowers hold one oar, on the middle row - two rowers, and on the lower row - one man to an oar.
 * Ship of the line A sailing warship capable of standing in the line of battle.
 * Sloop
 * Submarine
 * Torpedo boat A small, fast surface vessel designed for launching torpedoes.
 * Trireme An ancient warship propelled by three banks of oars.