A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying passengers or goods, or in support of specialized missions, such as defense, research and fishing. Historically, a "ship" was a sailing vessel with at least three square-rigged masts and a full bowsprit. Ships are generally distinguished from boats, based on size, shape, load capacity, and tradition.
Ships have been important contributors to human migration and commerce. They have supported the spread of colonization and the slave trade, but have also served scientific, cultural, and humanitarian needs. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to the world population growth. Ship transport is responsible for the largest portion of world commerce.
|Tonnage:||to 120,000 DWT (New Panamax)|
|Length:||to 289.56 m (950 ft) (New Panamax)|
|Beam:||to 134 ft (41 m) (Gerald R. Ford-class aircraft carrier on waterline)|
|Draft:||to 15.2 m (50 ft) (New Panamax)|
|Propulsion:||steam turbine (fossil fuel, nuclear), diesel, gas turbine, sterling, steam (reciprocating)|
|Sail plan:||for sailing ships – two or more masts, variety of sail plans|
Ships are generally larger than boats, but there is no universally accepted distinction between the two. Ships generally can remain at sea for longer periods of time than boats. A legal definition of ship from Indian case law is a vessel that carries goods by sea. A common notion is that a ship can carry a boat, but not vice versa. A US Navy rule of thumb is that ships heel towards the outside of a sharp turn, whereas boats heel towards the inside because of the relative location of the center of mass versus the center of buoyancy. American and British 19th Century maritime law distinguished "vessels" from other craft; ships and boats fall in one legal category, whereas open boats and rafts are not considered vessels.
In the Age of Sail, a full-rigged ship was a sailing vessel with at least three square-rigged masts and a full bowsprit; other types of vessel were also defined by their sailplan, e.g. barque, brigantine, etc.
A number of large vessels are usually referred to as boats. Submarines are a prime example. Other types of large vessel which are traditionally called boats are Great Lakes freighters, riverboats, and ferryboats. Though large enough to carry their own boats and heavy cargoes, these vessels are designed for operation on inland or protected coastal waters.
In the northern parts of Europe and America a ship is traditionally referred to with a female grammatical gender, represented in English with the pronoun "she", even if named after a man. This is not universal usage and some English language journalistic style guides advise using "it" as referring to ships with female pronouns can be seen as offensive and outdated. In many documents the ship name is introduced with a ship prefix being an abbreviation of the ship class, for example "MS" (motor ship) or "SV" (sailing vessel), making it easier to distinguish a ship name from other individual names in a text.
The first known vessels date back about 10,000 years ago, but could not be described as ships. The first navigators began to use animal skins or woven fabrics as sails. Affixed to the top of a pole set upright in a boat, these sails gave early ships range. This allowed men to explore widely, allowing for the settlement of Oceania for example (about 3,000 years ago).
By around 3000 BC, Ancient Egyptians knew how to assemble wooden planks into a hull. They used woven straps to lash the planks together, and reeds or grass stuffed between the planks helped to seal the seams. The Greek historian and geographer Agatharchides had documented ship-faring among the early Egyptians: "During the prosperous period of the Old Kingdom, between the 30th and 25th centuries BC, the river-routes were kept in order, and Egyptian ships sailed the Red Sea as far as the myrrh-country." Sneferu's ancient cedar wood ship Praise of the Two Lands is the first reference recorded (2613 BC) to a ship being referred to by name.
The ancient Egyptians were perfectly at ease building sailboats. A remarkable example of their shipbuilding skills was the Khufu ship, a vessel 143 feet (44 m) in length entombed at the foot of the Great Pyramid of Giza around 2500 BC and found intact in 1954.
It is known that ancient Nubia/Axum traded with India, and there is evidence that ships from Northeast Africa may have sailed back and forth between India/Sri Lanka and Nubia trading goods and even to Persia, Himyar and Rome. Aksum was known by the Greeks for having seaports for ships from Greece and Yemen.
Elsewhere in Northeast Africa, the Periplus of the Red Sea reports that Somalis, through their northern ports such as Zeila and Berbera, were trading frankincense and other items with the inhabitants of the Arabian Peninsula well before the arrival of Islam as well as with then Roman-controlled Egypt.
A panel found at Mohenjodaro depicted a sailing craft. Vessels were of many types; their construction is vividly described in the Yukti Kalpa Taru, an ancient Indian text on shipbuilding. This treatise gives a technical exposition on the techniques of shipbuilding. It sets forth minute details about the various types of ships, their sizes, and the materials from which they were built. The Yukti Kalpa Taru sums up in a condensed form all the available information. The Yukti Kalpa Taru gives sufficient information and dates to prove that, in ancient times, Indian shipbuilders had a good knowledge of the materials which were used in building ships. In addition to describing the qualities of the different types of wood and their suitability for shipbuilding, the Yukti Kalpa Taru gives an elaborate classification of ships based on their size.
The Phoenicians, the first to sail completely around Africa, and Greeks gradually mastered navigation at sea aboard triremes, exploring and colonizing the Mediterranean via ship. Around 340 BC, the Greek navigator Pytheas of Massalia ventured from Greece to Western Europe and Great Britain. In the course of the 2nd century BC, Rome went on to destroy Carthage and subdue the Hellenistic kingdoms of the eastern Mediterranean, achieving complete mastery of the inland sea, that they called Mare Nostrum. The monsoon wind system of the Indian Ocean was first sailed by Greek navigator Eudoxus of Cyzicus in 118 BC.
In China, miniature models of ships that feature steering oars have been dated to the Warring States period (c. 475–221 BC). By the Han dynasty, a well kept naval fleet was an integral part of the military. Sternpost-mounted rudders started to appear on Chinese ship models starting in the 1st century AD. Ship technology advanced to the point where by the medieval period, water tight compartments were developed.
In the 1st century A.D., the people from Nusantaran archipelago already made large ships over 50 m long and stood out 4–7 m out of the water. They could carry 700-1000 people and 260 ton cargo. These ships known as K'un-lun po (ships of Southern country) by the Chinese or kolandiaphonta by the Greeks. It has 4-7 masts and able to sail against the wind due to the usage of tanja sails. These ships reaching as far as Ghana.
The Swahili people had various extensive trading ports dotting the coast of medieval East Africa and Great Zimbabwe had extensive trading contacts with Central Africa, and likely also imported goods brought to Africa through the Southeast African shore trade of Kilwa in modern-day Tanzania.
It is known by historians that at its height the Mali Empire built a large naval fleet under Emperor Mansa Musa in the late 13th and early 14th century. Arabic sources describe what some consider to be visits to the New World by a Mali fleet in 1311.
Before the introduction of the compass, celestial navigation was the main method for navigation at sea. In China, early versions of the magnetic compass were being developed and used in navigation between 1040 and 1117. The true mariner's compass, using a pivoting needle in a dry box, was developed in Europe no later than 1300.
Until the Renaissance, navigational technology remained comparatively primitive. This absence of technology did not prevent some civilizations from becoming sea powers. Examples include the maritime republics of Genoa and Venice, Hanseatic League, and the Byzantine navy. The Vikings used their knarrs to explore North America, trade in the Baltic Sea and plunder many of the coastal regions of Western Europe.
Towards the end of the 14th century, ships like the carrack began to develop towers on the bow and stern. These towers decreased the vessel's stability, and in the 15th century, the caravel, designed by the Portuguese, based on the Arabic qarib which could sail closer to the wind, became more widely used. The towers were gradually replaced by the forecastle and sterncastle, as in the carrack Santa María of Christopher Columbus. This increased freeboard allowed another innovation: the freeing port, and the artillery associated with it.
In the 16th century, the use of freeboard and freeing ports became widespread on galleons.
At this time, ships were developing in Asia in much the same way as Europe. Japan used defensive naval techniques in the Mongol invasions of Japan in 1281. It is likely that the Mongols of the time took advantage of both European and Asian shipbuilding techniques. During the 15th century, China's Ming dynasty assembled one of the largest and most powerful naval fleets in the world for the diplomatic and power projection voyages of Zheng He. Elsewhere in Japan in the 15th century, one of the world's first iron-clads, "Tekkōsen" (鉄甲船), literally meaning "iron ships", was also developed. In Japan, during the Sengoku era from the fifteenth to 17th century, the great struggle for feudal supremacy was fought, in part, by coastal fleets of several hundred boats, including the atakebune. In Korea, in the early 15th century during the Joseon era, "Geobukseon"(거북선), was developed. The "turtle ship", as it was called is recognized as the first armored ship in the world.
During the Age of the Ajuran, the Somali sultanates and republics of Merca, Mogadishu, Barawa, Hobyo and their respective ports flourished, enjoying a lucrative foreign commerce with ships sailing to and coming from Arabia, India, Venetia, Persia, Egypt, Portugal and as far away as China. In the 16th century, Duarte Barbosa noted that many ships from the Kingdom of Cambaya in what is modern-day India sailed to Mogadishu with cloth and spices, for which they in return received gold, wax and ivory. Barbosa also highlighted the abundance of meat, wheat, barley, horses, and fruit on the coastal markets, which generated enormous wealth for the merchants.
Middle Age Swahili Kingdoms are known to have had trade port bullship and trade routes with the Islamic world and Asia and were described by Greek historians as "metropolises". Famous African trade ports such as Mombasa, Zanzibar, and Kilwa were known to Chinese sailors such as Zheng He and medieval Islamic historians such as the Berber Islamic voyager Abu Abdullah ibn Battua. In the 14th century AD, King Abubakari I, the brother of King Mansa Musa of the Mali Empire, is thought to have had a great armada of ships sitting on the coast of West Africa. This is corroborated by ibn Battuta himself who recalls several hundred Malian ships off the coast. This has led to great speculation, with historical evidence, that it is possible that Malian sailors may have reached the coast of Pre-Columbian America under the rule of Abubakari II, nearly two hundred years before Christopher Columbus and that black traders may have been in the Americas before Columbus. Fifty years before Christopher Columbus, Chinese navigator Zheng He traveled the world at the head of what was for the time a huge armada. The largest of his ships had nine masts, were 130 metres (430 ft) long and had a beam of 55 metres (180 ft). His fleet carried 30,000 men aboard 70 vessels, with the goal of bringing glory to the Chinese emperor.
At the same time Zheng He made his expedition, Portuguese explorer Gil Eanes sailed on a square-rigged caravel beyond Cape Bojador the end of what was then considered the known world opening the route to deep sea exploration, continental sea communication technology and the spherical earth principle.
The carrack and then the caravel were developed in Portugal. After Columbus, European exploration rapidly accelerated, and many new trade routes were established. In 1498, by reaching India, Vasco da Gama proved that the access to the Indian Ocean from the Atlantic was possible. These explorations in the Atlantic and Indian Oceans were soon followed by France, England and the Netherlands, who explored the Portuguese and Spanish trade routes into the Pacific Ocean, reaching Australia in 1606 and New Zealand in 1642. In the 17th century Dutch and Spanish explorers such as Abel Tasman and Luís Vaz de Torres explored the coasts of Australia, while in the 18th century it was British explorer James Cook who mapped much of Polynesia.
Parallel to the development of warships, ships in service of marine fishery and trade also developed in the period between antiquity and the Renaissance.
Maritime trade was driven by the development of shipping companies with significant financial resources. Canal barges, towed by draft animals on an adjacent towpath, contended with the railway up to and past the early days of the industrial revolution. Flat-bottomed and flexible scow boats also became widely used for transporting small cargoes. Mercantile trade went hand-in-hand with exploration, self-financed by the commercial benefits of exploration.
During the first half of the 18th century, the French Navy began to develop a new type of vessel known as a ship of the line, featuring seventy-four guns. This type of ship became the backbone of all European fighting fleets. These ships were 56 metres (184 ft) long and their construction required 2,800 oak trees and 40 kilometres (25 mi) of rope; they carried a crew of about 800 sailors and soldiers.
During the 19th century the Royal Navy enforced a ban on the slave trade, acted to suppress piracy, and continued to map the world. A clipper was a very fast sailing ship of the 19th century. The clipper routes fell into commercial disuse with the introduction of steam ships with better fuel efficiency, and the opening of the Suez and Panama Canals.
Ship designs stayed fairly unchanged until the late 19th century. The industrial revolution, new mechanical methods of propulsion, and the ability to construct ships from metal triggered an explosion in ship design. Factors including the quest for more efficient ships, the end of long running and wasteful maritime conflicts, and the increased financial capacity of industrial powers created an avalanche of more specialized boats and ships. Ships built for entirely new functions, such as firefighting, rescue, and research, also began to appear.
In light of this, classification of vessels by type or function can be difficult. Even using very broad functional classifications such as fishery, trade, military, and exploration fails to classify most of the old ships. This difficulty is increased by the fact that the terms such as sloop and frigate are used by old and new ships alike, and often the modern vessels sometimes have little in common with their predecessors.
In 2007, the world's fleet included 34,882 commercial vessels with gross tonnage of more than 1,000 tons, totaling 1.04 billion tons. These ships carried 7.4 billion tons of cargo in 2006, a sum that grew by 8% over the previous year. In terms of tonnage, 39% of these ships are tankers, 26% are bulk carriers, 17% container ships and 15% were other types.
In 2002, there were 1,240 warships operating in the world, not counting small vessels such as patrol boats. The United States accounted for 3 million tons worth of these vessels, Russia 1.35 million tons, the United Kingdom 504,660 tons and China 402,830 tons. The 20th century saw many naval engagements during the two world wars, the Cold War, and the rise to power of naval forces of the two blocs. The world's major powers have recently used their naval power in cases such as the United Kingdom in the Falkland Islands and the United States in Iraq.
The size of the world's fishing fleet is more difficult to estimate. The largest of these are counted as commercial vessels, but the smallest are legion. Fishing vessels can be found in most seaside villages in the world. As of 2004, the United Nations Food and Agriculture Organization estimated 4 million fishing vessels were operating worldwide. The same study estimated that the world's 29 million fishermen caught 85,800,000 tonnes (84,400,000 long tons; 94,600,000 short tons) of fish and shellfish that year.
Because ships are constructed using the principles of naval architecture that require same structural components, their classification is based on their function such as that suggested by Paulet and Presles, which requires modification of the components. The categories accepted in general by naval architects are:
Some of these are discussed in the following sections.
Freshwater shipping may occur on lakes, rivers and canals. Ships designed for those venues may be specially adapted to the widths and depths of specific waterways. Examples of freshwater waterways that are navigable in part by large vessels include the Danube, Mississippi, Rhine, Yangtze and Amazon Rivers, and the Great Lakes.
Lake freighters, also called lakers, are cargo vessels that ply the Great Lakes. The most well-known is SS Edmund Fitzgerald, the latest major vessel to be wrecked on the Lakes. These vessels are traditionally called boats, not ships. Visiting ocean-going vessels are called "salties." Because of their additional beam, very large salties are never seen inland of the Saint Lawrence Seaway. Because the smallest of the Soo Locks is larger than any Seaway lock, salties that can pass through the Seaway may travel anywhere in the Great Lakes. Because of their deeper draft, salties may accept partial loads on the Great Lakes, "topping off" when they have exited the Seaway. Similarly, the largest lakers are confined to the Upper Lakes (Superior, Michigan, Huron, Erie) because they are too large to use the Seaway locks, beginning at the Welland Canal that bypasses the Niagara River.
Since the freshwater lakes are less corrosive to ships than the salt water of the oceans, lakers tend to last much longer than ocean freighters. Lakers older than 50 years are not unusual, and as of 2005, all were over 20 years of age.
SS St. Marys Challenger, built in 1906 as William P Snyder, was the oldest laker still working on the Lakes until its conversion into a barge starting in 2013. Similarly, E.M. Ford, built in 1898 as Presque Isle, was sailing the lakes 98 years later in 1996. As of 2007 E.M. Ford was still afloat as a stationary transfer vessel at a riverside cement silo in Saginaw, Michigan.
Merchant ships are ships used for commercial purposes and can be divided into four broad categories: fishing, cargo ships, passenger ships, and special-purpose ships. The UNCTAD review of maritime transport categorizes ships as: oil tankers, bulk (and combination) carriers, general cargo ships, container ships, and "other ships", which includes "liquefied petroleum gas carriers, liquefied natural gas carriers, parcel (chemical) tankers, specialized tankers, reefers, offshore supply, tugs, dredgers, cruise, ferries, other non-cargo". General cargo ships include "multi-purpose and project vessels and roll-on/roll-off cargo".
Modern commercial vessels are typically powered by a single propeller driven by a diesel or, less usually, gas turbine engine., but until the mid-19th century they were predominantly square sail rigged. The fastest vessels may use pump-jet engines. Most commercial vessels have full hull-forms to maximize cargo capacity. Hulls are usually made of steel, although aluminum can be used on faster craft, and fiberglass on the smallest service vessels. Commercial vessels generally have a crew headed by a sea captain, with deck officers and engine officers on larger vessels. Special-purpose vessels often have specialized crew if necessary, for example scientists aboard research vessels.
Fishing boats are generally small, often little more than 30 meters (98 ft) but up to 100 metres (330 ft) for a large tuna or whaling ship. Aboard a fish processing vessel, the catch can be made ready for market and sold more quickly once the ship makes port. Special purpose vessels have special gear. For example, trawlers have winches and arms, stern-trawlers have a rear ramp, and tuna seiners have skiffs. In 2004, 85,800,000 tonnes (84,400,000 long tons; 94,600,000 short tons) of fish were caught in the marine capture fishery. Anchoveta represented the largest single catch at 10,700,000 tonnes (10,500,000 long tons; 11,800,000 short tons). That year, the top ten marine capture species also included Alaska pollock, Blue whiting, Skipjack tuna, Atlantic herring, Chub mackerel, Japanese anchovy, Chilean jack mackerel, Largehead hairtail, and Yellowfin tuna. Other species including salmon, shrimp, lobster, clams, squid and crab, are also commercially fished. Modern commercial fishermen use many methods. One is fishing by nets, such as purse seine, beach seine, lift nets, gillnets, or entangling nets. Another is trawling, including bottom trawl. Hooks and lines are used in methods like long-line fishing and hand-line fishing. Another method is the use of fishing trap.
Cargo ships transport dry and liquid cargo. Dry cargo can be transported in bulk by bulk carriers, packed directly onto a general cargo ship in break-bulk, packed in intermodal containers as aboard a container ship, or driven aboard as in roll-on roll-off ships. Liquid cargo is generally carried in bulk aboard tankers, such as oil tankers which may include both crude and finished products of oil, chemical tankers which may also carry vegetable oils other than chemicals and LPG/LNG tankers, although smaller shipments may be carried on container ships in tank containers.
Passenger ships range in size from small river ferries to very large cruise ships. This type of vessel includes ferries, which move passengers and vehicles on short trips; ocean liners, which carry passengers from one place to another; and cruise ships, which carry passengers on voyages undertaken for pleasure, visiting several places and with leisure activities on board, often returning them to the port of embarkation. Riverboats and inland ferries are specially designed to carry passengers, cargo, or both in the challenging river environment. Rivers present special hazards to vessels. They usually have varying water flows that alternately lead to high speed water flows or protruding rock hazards. Changing siltation patterns may cause the sudden appearance of shoal waters, and often floating or sunken logs and trees (called snags) can endanger the hulls and propulsion of riverboats. Riverboats are generally of shallow draft, being broad of beam and rather square in plan, with a low freeboard and high topsides. Riverboats can survive with this type of configuration as they do not have to withstand the high winds or large waves that are seen on large lakes, seas, or oceans.
Fishing vessels are a subset of commercial vessels, but generally small in size and often subject to different regulations and classification. They can be categorized by several criteria: architecture, the type of fish they catch, the fishing method used, geographical origin, and technical features such as rigging. As of 2004, the world's fishing fleet consisted of some 4 million vessels. Of these, 1.3 million were decked vessels with enclosed areas and the rest were open vessels. Most decked vessels were mechanized, but two-thirds of the open vessels were traditional craft propelled by sails and oars. More than 60% of all existing large fishing vessels were built in Japan, Peru, the Russian Federation, Spain or the United States of America.
A weather ship was a ship stationed in the ocean as a platform for surface and upper air meteorological observations for use in marine weather forecasting. Surface weather observations were taken hourly, and four radiosonde releases occurred daily. It was also meant to aid in search and rescue operations and to support transatlantic flights. Proposed as early as 1927 by the aviation community, the establishment of weather ships proved to be so useful during World War II that the International Civil Aviation Organization (ICAO) established a global network of weather ships in 1948, with 13 to be supplied by the United States. This number was eventually negotiated down to nine.
The weather ship crews were normally at sea for three weeks at a time, returning to port for 10-day stretches. Weather ship observations proved to be helpful in wind and wave studies, as they did not avoid weather systems like other ships tended to for safety reasons. They were also helpful in monitoring storms at sea, such as tropical cyclones. The removal of a weather ship became a negative factor in forecasts leading up to the Great Storm of 1987. Beginning in the 1970s, their role became largely superseded by weather buoys due to the ships' significant cost. The agreement of the use of weather ships by the international community ended in 1990. The last weather ship was Polarfront, known as weather station M ("Mike"), which was put out of operation on 1 January 2010. Weather observations from ships continue from a fleet of voluntary merchant vessels in routine commercial operation.
Naval vessels are those used by a navy for military purposes. There have been many types of naval vessel. Modern naval vessels can be broken down into three categories: surface warships, submarines, and auxiliary ships.
Modern warships are generally divided into seven main categories: aircraft carriers, cruisers, destroyers, frigates, corvettes, submarines and amphibious assault ships. The distinction between cruisers, destroyers, frigates, and corvettes is not rigorous; the same vessel may be described differently in different navies. Battleships were used during the Second World War and occasionally since then (the last battleships were removed from the U.S. Naval Vessel Register in March 2006), but were made obsolete by the use of carrier-borne aircraft and guided missiles.
Most military submarines are either attack submarines or ballistic missile submarines. Until the end of World War II the primary role of the diesel/electric submarine was anti-ship warfare, inserting and removing covert agents and military forces, and intelligence-gathering. With the development of the homing torpedo, better sonar systems, and nuclear propulsion, submarines also became able to effectively hunt each other. The development of submarine-launched nuclear and cruise missiles gave submarines a substantial and long-ranged ability to attack both land and sea targets with a variety of weapons ranging from cluster munitions to nuclear weapons.
Most navies also include many types of support and auxiliary vessel, such as minesweepers, patrol boats, offshore patrol vessels, replenishment ships, and hospital ships which are designated medical treatment facilities.
Fast combat vessels such as cruisers and destroyers usually have fine hulls to maximize speed and maneuverability. They also usually have advanced marine electronics and communication systems, as well as weapons.
Some components exist in vessels of any size and purpose. Every vessel has a hull of sorts. Every vessel has some sort of propulsion, whether it's a pole, an ox, or a nuclear reactor. Most vessels have some sort of steering system. Other characteristics are common, but not as universal, such as compartments, holds, a superstructure, and equipment such as anchors and winches.
For a ship to float, its weight must be less than that of the water displaced by the ship's hull. There are many types of hulls, from logs lashed together to form a raft to the advanced hulls of America's Cup sailboats. A vessel may have a single hull (called a monohull design), two in the case of catamarans, or three in the case of trimarans. Vessels with more than three hulls are rare, but some experiments have been conducted with designs such as pentamarans. Multiple hulls are generally parallel to each other and connected by rigid arms.
Hulls have several elements. The bow is the foremost part of the hull. Many ships feature a bulbous bow. The keel is at the very bottom of the hull, extending the entire length of the ship. The rear part of the hull is known as the stern, and many hulls have a flat back known as a transom. Common hull appendages include propellers for propulsion, rudders for steering, and stabilizers to quell a ship's rolling motion. Other hull features can be related to the vessel's work, such as fishing gear and sonar domes.
Hulls are subject to various hydrostatic and hydrodynamic constraints. The key hydrostatic constraint is that it must be able to support the entire weight of the boat, and maintain stability even with often unevenly distributed weight. Hydrodynamic constraints include the ability to withstand shock waves, weather collisions and groundings.
Older ships and pleasure craft often have or had wooden hulls. Steel is used for most commercial vessels. Aluminium is frequently used for fast vessels, and composite materials are often found in sailboats and pleasure craft. Some ships have been made with concrete hulls.
Propulsion systems for ships fall into three categories: human propulsion, sailing, and mechanical propulsion. Human propulsion includes rowing, which was used even on large galleys. Propulsion by sail generally consists of a sail hoisted on an erect mast, supported by stays and spars and controlled by ropes. Sail systems were the dominant form of propulsion until the 19th century. They are now generally used for recreation and competition, although experimental sail systems, such as the turbosails, rotorsails, and wingsails have been used on larger modern vessels for fuel savings.
Mechanical propulsion systems generally consist of a motor or engine turning a propeller, or less frequently, an impeller or wave propulsion fins. Steam engines were first used for this purpose, but have mostly been replaced by two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines on faster ships. Nuclear reactors producing steam are used to propel warships and icebreakers, and there have been attempts to utilize them to power commercial vessels (see NS Savannah).
In addition to traditional fixed and controllable pitch propellers there are many specialized variations, such as contra-rotating and nozzle-style propellers. Most vessels have a single propeller, but some large vessels may have up to four propellers supplemented with transverse thrusters for maneuvring at ports. The propeller is connected to the main engine via a propeller shaft and, in case of medium- and high-speed engines, a reduction gearbox. Some modern vessels have a diesel-electric powertrain in which the propeller is turned by an electric motor powered by the ship's generators.
For ships with independent propulsion systems for each side, such as manual oars or some paddles, steering systems may not be necessary. In most designs, such as boats propelled by engines or sails, a steering system becomes necessary. The most common is a rudder, a submerged plane located at the rear of the hull. Rudders are rotated to generate a lateral force which turns the boat. Rudders can be rotated by a tiller, manual wheels, or electro-hydraulic systems. Autopilot systems combine mechanical rudders with navigation systems. Ducted propellers are sometimes used for steering.
Larger boats and ships generally have multiple decks and compartments. Separate berthings and heads are found on sailboats over about 25 feet (7.6 m). Fishing boats and cargo ships typically have one or more cargo holds. Most larger vessels have an engine room, a galley, and various compartments for work. Tanks are used to store fuel, engine oil, and fresh water. Ballast tanks are equipped to change a ship's trim and modify its stability.
Superstructures are found above the main deck. On sailboats, these are usually very low. On modern cargo ships, they are almost always located near the ship's stern. On passenger ships and warships, the superstructure generally extends far forward.
Shipboard equipment varies from ship to ship depending on such factors as the ship's era, design, area of operation, and purpose. Some types of equipment that are widely found include:
Ships float in the water at a level where mass of the displaced water equals the mass of the vessel, such that the downwards force of gravity equals the upward force of buoyancy. As a vessel is lowered into the water its weight remains constant but the corresponding weight of water displaced by its hull increases. If the vessel's mass is evenly distributed throughout, it floats evenly along its length and across its beam (width). A vessel's stability is considered in both this hydrostatic sense as well as a hydrodynamic sense, when subjected to movement, rolling and pitching, and the action of waves and wind. Stability problems can lead to excessive pitching and rolling, and eventually capsizing and sinking.
The advance of a vessel through water is resisted by the water. This resistance can be broken down into several components, the main ones being the friction of the water on the hull and wave making resistance. To reduce resistance and therefore increase the speed for a given power, it is necessary to reduce the wetted surface and use submerged hull shapes that produce low amplitude waves. To do so, high-speed vessels are often more slender, with fewer or smaller appendages. The friction of the water is also reduced by regular maintenance of the hull to remove the sea creatures and algae that accumulate there. Antifouling paint is commonly used to assist in this. Advanced designs such as the bulbous bow assist in decreasing wave resistance.
A simple way of considering wave-making resistance is to look at the hull in relation to its wake. At speeds lower than the wave propagation speed, the wave rapidly dissipates to the sides. As the hull approaches the wave propagation speed, however, the wake at the bow begins to build up faster than it can dissipate, and so it grows in amplitude. Since the water is not able to "get out of the way of the hull fast enough", the hull, in essence, has to climb over or push through the bow wave. This results in an exponential increase in resistance with increasing speed.
This hull speed is found by the formula:
or, in metric units:
where L is the length of the waterline in feet or meters.
When the vessel exceeds a speed/length ratio of 0.94, it starts to outrun most of its bow wave, and the hull actually settles slightly in the water as it is now only supported by two wave peaks. As the vessel exceeds a speed/length ratio of 1.34, the hull speed, the wavelength is now longer than the hull, and the stern is no longer supported by the wake, causing the stern to squat, and the bow rise. The hull is now starting to climb its own bow wave, and resistance begins to increase at a very high rate. While it is possible to drive a displacement hull faster than a speed/length ratio of 1.34, it is prohibitively expensive to do so. Most large vessels operate at speed/length ratios well below that level, at speed/length ratios of under 1.0.
For large projects with adequate funding, hydrodynamic resistance can be tested experimentally in a hull testing pool or using tools of computational fluid dynamics.
Vessels are also subject to ocean surface waves and sea swell as well as effects of wind and weather. These movements can be stressful for passengers and equipment, and must be controlled if possible. The rolling movement can be controlled, to an extent, by ballasting or by devices such as fin stabilizers. Pitching movement is more difficult to limit and can be dangerous if the bow submerges in the waves, a phenomenon called pounding. Sometimes, ships must change course or speed to stop violent rolling or pitching.
How it has been convincingly shown in scientific studies of the 21st century, controllability of some vessels decreases dramatically in some cases that are conditioned by effects of the bifurcation memory. This class of vessels includes ships with high manoeuvring capabilities, aircraft and controlled underwater vehicles designed to be unstable in steady-state motion that are interesting in terms of applications. These features must be considered in designing ships and in their control in critical situations.
A ship will pass through several stages during its career. The first is usually an initial contract to build the ship, the details of which can vary widely based on relationships between the shipowners, operators, designers and the shipyard. Then, the design phase carried out by a naval architect. Then the ship is constructed in a shipyard. After construction, the vessel is launched and goes into service. Ships end their careers in a number of ways, ranging from shipwrecks to service as a museum ship to the scrapyard.
A vessel's design starts with a specification, which a naval architect uses to create a project outline, assess required dimensions, and create a basic layout of spaces and a rough displacement. After this initial rough draft, the architect can create an initial hull design, a general profile and an initial overview of the ship's propulsion. At this stage, the designer can iterate on the ship's design, adding detail and refining the design at each stage.
The designer will typically produce an overall plan, a general specification describing the peculiarities of the vessel, and construction blueprints to be used at the building site. Designs for larger or more complex vessels may also include sail plans, electrical schematics, and plumbing and ventilation plans.
As environmental laws are becoming more strict, ship designers need to create their design in such a way that the ship, when it nears its end-of-term, can be disassembled or disposed easily and that waste is reduced to a minimum.
Ship construction takes place in a shipyard, and can last from a few months for a unit produced in series, to several years to reconstruct a wooden boat like the frigate Hermione, to more than 10 years for an aircraft carrier. During World War II, the need for cargo ships was so urgent that construction time for Liberty Ships went from initially eight months or longer, down to weeks or even days. Builders employed production line and prefabrication techniques such as those used in shipyards today.
Hull materials and vessel size play a large part in determining the method of construction. The hull of a mass-produced fiberglass sailboat is constructed from a mold, while the steel hull of a cargo ship is made from large sections welded together as they are built.
Generally, construction starts with the hull, and on vessels over about 30 meters (98 ft), by the laying of the keel. This is done in a drydock or on land. Once the hull is assembled and painted, it is launched. The last stages, such as raising the superstructure and adding equipment and accommodation, can be done after the vessel is afloat.
Once completed, the vessel is delivered to the customer. Ship launching is often a ceremony of some significance, and is usually when the vessel is formally named. A typical small rowboat can cost under US$100, $1,000 for a small speedboat, tens of thousands of dollars for a cruising sailboat, and about $2,000,000 for a Vendée Globe class sailboat. A 25 meters (82 ft) trawler may cost $2.5 million, and a 1,000-person-capacity high-speed passenger ferry can cost in the neighborhood of $50 million. A ship's cost partly depends on its complexity: a small, general cargo ship will cost $20 million, a Panamax-sized bulk carrier around $35 million, a supertanker around $105 million and a large LNG carrier nearly $200 million. The most expensive ships generally are so because of the cost of embedded electronics: a Seawolf-class submarine costs around $2 billion, and an aircraft carrier goes for about $3.5 billion.
Ships undergo nearly constant maintenance during their career, whether they be underway, pierside, or in some cases, in periods of reduced operating status between charters or shipping seasons.
Most ships, however, require trips to special facilities such as a drydock at regular intervals. Tasks often done at drydock include removing biological growths on the hull, sandblasting and repainting the hull, and replacing sacrificial anodes used to protect submerged equipment from corrosion. Major repairs to the propulsion and steering systems as well as major electrical systems are also often performed at dry dock.
Some vessels that sustain major damage at sea may be repaired at a facility equipped for major repairs, such as a shipyard. Ships may also be converted for a new purpose: oil tankers are often converted into floating production storage and offloading units.
Most ocean-going cargo ships have a life expectancy of between 20 and 30 years. A sailboat made of plywood or fiberglass can last between 30 and 40 years. Solid wooden ships can last much longer but require regular maintenance. Carefully maintained steel-hulled yachts can have a lifespan of over 100 years.
As ships age, forces such as corrosion, osmosis, and rotting compromise hull strength, and a vessel becomes too dangerous to sail. At this point, it can be scuttled at sea or scrapped by shipbreakers. Ships can also be used as museum ships, or expended to construct breakwaters or artificial reefs.
One can measure ships in terms of overall length, length between perpendiculars, length of the ship at the waterline, beam (breadth), depth (distance between the crown of the weather deck and the top of the keelson), draft (distance between the highest waterline and the bottom of the ship) and tonnage. A number of different tonnage definitions exist and are used when describing merchant ships for the purpose of tolls, taxation, etc.
In Britain until Samuel Plimsoll's Merchant Shipping Act of 1876, ship-owners could load their vessels until their decks were almost awash, resulting in a dangerously unstable condition. Anyone who signed on to such a ship for a voyage and, upon realizing the danger, chose to leave the ship, could end up in jail. Plimsoll, a Member of Parliament, realised the problem and engaged some engineers to derive a fairly simple formula to determine the position of a line on the side of any specific ship's hull which, when it reached the surface of the water during loading of cargo, meant the ship had reached its maximum safe loading level. To this day, that mark, called the "Plimsoll Line", exists on ships' sides, and consists of a circle with a horizontal line through the centre. On the Great Lakes of North America the circle is replaced with a diamond. Because different types of water (summer, fresh, tropical fresh, winter north Atlantic) have different densities, subsequent regulations required painting a group of lines forward of the Plimsoll mark to indicate the safe depth (or freeboard above the surface) to which a specific ship could load in water of various densities. Hence the "ladder" of lines seen forward of the Plimsoll mark to this day. This is called the "freeboard mark" or "load line mark" in the marine industry.
Ship pollution is the pollution of air and water by shipping. It is a problem that has been accelerating as trade has become increasingly globalized, posing an increasing threat to the world’s oceans and waterways as globalization continues. It is expected that "shipping traffic to and from the United States is projected to double by 2020." Because of increased traffic in ocean ports, pollution from ships also directly affects coastal areas. The pollution produced affects biodiversity, climate, food, and human health. However, the degree to which humans are polluting and how it affects the world is highly debated and has been a hot international topic for the past 30 years.
Oil spills have devastating effects on the environment. Crude oil contains polycyclic aromatic hydrocarbons (PAHs) which are very difficult to clean up, and last for years in the sediment and marine environment. Marine species constantly exposed to PAHs can exhibit developmental problems, susceptibility to disease, and abnormal reproductive cycles.
By the sheer amount of oil carried, modern oil tankers must be considered something of a threat to the environment. An oil tanker can carry 2 million barrels (318,000 m3) of crude oil, or 84,000,000 US gallons (69,940,000 imp gal; 318,000,000 L). This is more than six times the amount spilled in the widely known Exxon Valdez incident. In this spill, the ship ran aground and dumped 10,800,000 US gallons (8,993,000 imp gal; 40,880,000 L) of oil into the ocean in March 1989. Despite efforts of scientists, managers, and volunteers, over 400,000 seabirds, about 1,000 sea otters, and immense numbers of fish were killed.
The International Tanker Owners Pollution Federation has researched 9,351 accidental spills since 1974. According to this study, most spills result from routine operations such as loading cargo, discharging cargo, and taking on fuel oil. 91% of the operational oil spills were small, resulting in less than 7 tons per spill. Spills resulting from accidents like collisions, groundings, hull failures, and explosions are much larger, with 84% of these involving losses of over 700 tons.
Following the Exxon Valdez spill, the United States passed the Oil Pollution Act of 1990 (OPA-90), which included a stipulation that all tankers entering its waters be double-hulled by 2015. Following the sinkings of Erika (1999) and Prestige (2002), the European Union passed its own stringent anti-pollution packages (known as Erika I, II, and III), which require all tankers entering its waters to be double-hulled by 2010. The Erika packages are controversial because they introduced the new legal concept of "serious negligence".
When a large vessel such as a container ship or an oil tanker unloads cargo, seawater is pumped into other compartments in the hull to help stabilize and balance the ship. During loading, this ballast water is pumped out from these compartments.
One of the problems with ballast water transfer is the transport of harmful organisms. Meinesz believes that one of the worst cases of a single invasive species causing harm to an ecosystem can be attributed to a seemingly harmless jellyfish. Mnemiopsis leidyi, a species of comb jellyfish that inhabits estuaries from the United States to the Valdés peninsula in Argentina along the Atlantic coast, has caused notable damage in the Black Sea. It was first introduced in 1982, and thought to have been transported to the Black Sea in a ship's ballast water. The population of the jellyfish shot up exponentially and, by 1988, it was wreaking havoc upon the local fishing industry. "The anchovy catch fell from 204,000 tonnes (225,000 short tons; 201,000 long tons) in 1984 to 200 tonnes (220 short tons; 197 long tons) in 1993; sprat from 24,600 tonnes (27,100 short tons; 24,200 long tons) in 1984 to 12,000 tonnes (13,200 short tons; 11,800 long tons) in 1993; horse mackerel from 4,000 tonnes (4,410 short tons; 3,940 long tons) in 1984 to zero in 1993." Now that the jellyfish have exhausted the zooplankton, including fish larvae, their numbers have fallen dramatically, yet they continue to maintain a stranglehold on the ecosystem. Recently the jellyfish have been discovered in the Caspian Sea. Invasive species can take over once occupied areas, facilitate the spread of new diseases, introduce new genetic material, alter landscapes and jeopardize the ability of native species to obtain food. "On land and in the sea, invasive species are responsible for about 137 billion dollars in lost revenue and management costs in the U.S. each year."
Ballast and bilge discharge from ships can also spread human pathogens and other harmful diseases and toxins potentially causing health issues for humans and marine life alike. Discharges into coastal waters, along with other sources of marine pollution, have the potential to be toxic to marine plants, animals, and microorganisms, causing alterations such as changes in growth, disruption of hormone cycles, birth defects, suppression of the immune system, and disorders resulting in cancer, tumors, and genetic abnormalities or even death.
Exhaust emissions from ships are considered to be a significant source of air pollution. "Seagoing vessels are responsible for an estimated 14 percent of emissions of nitrogen from fossil fuels and 16 percent of the emissions of sulfur from petroleum uses into the atmosphere." In Europe ships make up a large percentage of the sulfur introduced to the air, "as much sulfur as all the cars, lorries and factories in Europe put together". "By 2010, up to 40% of air pollution over land could come from ships." Sulfur in the air creates acid rain which damages crops and buildings. When inhaled, sulfur is known to cause respiratory problems and increase the risk of a heart attack.
Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling, with the hulls being discarded in ship graveyards. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially steel, to be reused.
In addition to steel and other useful materials, however, ships (particularly older vessels) can contain many substances that are banned or considered dangerous in developed countries. Asbestos and polychlorinated biphenyls (PCBs) are typical examples. Asbestos was used heavily in ship construction until it was finally banned in most of the developed world in the mid 1980s. Currently, the costs associated with removing asbestos, along with the potentially expensive insurance and health risks, have meant that ship-breaking in most developed countries is no longer economically viable. Removing the metal for scrap can potentially cost more than the scrap value of the metal itself. In most of the developing world, however, shipyards can operate without the risk of personal injury lawsuits or workers' health claims, meaning many of these shipyards may operate with high health risks. Furthermore, workers are paid very low rates with no overtime or other allowances. Protective equipment is sometimes absent or inadequate. Dangerous vapors and fumes from burning materials can be inhaled, and dusty asbestos-laden areas around such breakdown locations are commonplace.
Aside from the health of the yard workers, in recent years, ship breaking has also become an issue of major environmental concern. Many developing nations, in which ship breaking yards are located, have lax or no environmental law, enabling large quantities of highly toxic materials to escape into the environment and causing serious health problems among ship breakers, the local population and wildlife. Environmental campaign groups such as Greenpeace have made the issue a high priority for their campaigns.
'Ship' means any vessel used for the carriage of goods by sea.
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Carriers have evolved since their inception in the early twentieth century from wooden vessels used to deploy balloons to nuclear-powered warships that carry numerous fighters, strike aircraft, helicopters, and other types of aircraft. While heavier aircraft such as fixed-wing gunships and bombers have been launched from aircraft carriers, it is currently not possible to land them. By its diplomatic and tactical power, its mobility, its autonomy and the variety of its means, the aircraft carrier is often the centerpiece of modern combat fleets. Tactically or even strategically, it replaced the battleship in the role of flagship of a fleet. One of its great advantages is that, by sailing in international waters, it does not interfere with any territorial sovereignty and thus obviates the need for overflight authorizations from third party countries, reduce the times and transit distances of aircraft and therefore significantly increase the time of availability on the combat zone.
There is no single definition of an "aircraft carrier", and modern navies use several variants of the type. These variants are sometimes categorized as sub-types of aircraft carriers, and sometimes as distinct types of naval aviation-capable ships. Aircraft carriers may be classified according to the type of aircraft they carry and their operational assignments. Admiral Sir Mark Stanhope, RN, former First Sea Lord (head) of the Royal Navy, has said, "To put it simply, countries that aspire to strategic international influence have aircraft carriers." Henry Kissinger, while United States Secretary of State, also said: "An aircraft carrier is 100,000 tons of diplomacy".As of May 2019, there are 41 active aircraft carriers in the world operated by thirteen navies. The United States Navy has 11 large nuclear-powered fleet carriers—carrying around 80 fighter jets each—the largest carriers in the world; the total combined deckspace is over twice that of all other nations combined. As well as the aircraft carrier fleet, the U.S. Navy has nine amphibious assault ships used primarily for helicopters, although these also carry up to 20 vertical or short take-off and landing (V/STOL) fighter jets and are similar in size to medium-sized fleet carriers. China, France, India, Russia, and the UK each operate a single large/medium-size carrier, with capacity from 30 to 60 fighter jets. Italy operates two light fleet carriers and Spain operates one. Helicopter carriers are operated by Japan (4), France (3), Australia (2), Egypt (2), Brazil (1), South Korea (1), and Thailand (1). Future aircraft carriers are under construction or in planning by Brazil, China, India, Russia, the United Kingdom, and the United States.Battleship
A battleship is a large armored warship with a main battery consisting of large caliber guns. During the late 19th and early 20th centuries the battleship was the most powerful type of warship, and a fleet of battleships was considered vital for any nation that desired to maintain command of the sea.
The term battleship came into formal use in the late 1880s to describe a type of ironclad warship, now referred to by historians as pre-dreadnought battleships. In 1906, the commissioning of HMS Dreadnought into the United Kingdom's Royal Navy heralded a revolution in battleship design. Subsequent battleship designs, influenced by HMS Dreadnought, were referred to as "dreadnoughts", though the term eventually became obsolete as they became the only type of battleship in common use.
Battleships were a symbol of naval dominance and national might, and for decades the battleship was a major factor in both diplomacy and military strategy. A global arms race in battleship construction began in Europe in the 1890s and culminated at the decisive Battle of Tsushima in 1905, the outcome of which significantly influenced the design of HMS Dreadnought. The launch of Dreadnought in 1906 commenced a new naval arms race. Three major fleet actions between steel battleships took place: the long range gunnery duel at the Battle of the Yellow Sea in 1904, the decisive Battle of Tsushima in 1905, both, during the Russo-Japanese War, and the inconclusive Battle of Jutland (1916) during the First World War. Jutland was the largest naval battle and the only full-scale clash of dreadnaughts of the war, it was the last major battle in naval history fought primarily by battleships.The Naval Treaties of the 1920s and 1930s limited the number of battleships, though technical innovation in battleship design continued. Both the Allied and Axis powers built battleships during World War II, though the increasing importance of the aircraft carrier meant that the battleship played a less important role than had been expected.
The value of the battleship has been questioned, even during their heyday. There were few of the decisive fleet battles that battleship proponents expected, and used to justify the vast resources spent on building battlefleets. Even in spite of their huge firepower and protection, battleships were increasingly vulnerable to much smaller and relatively inexpensive weapons: initially the torpedo and the naval mine, and later aircraft and the guided missile. The growing range of naval engagements led to the aircraft carrier replacing the battleship as the leading capital ship during World War II, with the last battleship to be launched being HMS Vanguard in 1944. Four battleships were retained by the United States Navy until the end of the Cold War for fire support purposes and were last used in combat during the Gulf War in 1991. The last battleships were stricken from the U.S. Naval Vessel Register in the 2000s.Boston Tea Party
The Boston Tea Party was a political and mercantile protest by the Sons of Liberty in Boston, Massachusetts, on December 16, 1773. The target was the Tea Act of May 10, 1773, which allowed the British East India company to sell tea from China in American colonies without paying taxes apart from those imposed by the Townshend Acts. American Patriots strongly opposed the taxes in the Townshend Act as a violation of their rights. Demonstrators, some disguised as Native Americans, destroyed an entire shipment of tea sent by the East India Company.
They boarded the ships and threw the chests of tea into the Boston Harbor. The British government responded harshly and the episode escalated into the American Revolution. The Tea Party became an iconic event of American history, and since then other political protests such as the Tea Party movement have referred to themselves as historical successors to the Boston protest of 1773.
The Tea Party was the culmination of a resistance movement throughout British America against the Tea Act, which had been passed by the British Parliament in 1773. Colonists objected to the Tea Act because they believed that it violated their rights as Englishmen to "no taxation without representation", that is, to be taxed only by their own elected representatives and not by a British parliament in which they were not represented. In addition, the well-connected East India Company had been granted competitive advantages over colonial tea importers, who resented the move and feared additional infringement on their business. Protesters had successfully prevented the unloading of tea in three other colonies, but in Boston, embattled Royal Governor Thomas Hutchinson refused to allow the tea to be returned to Britain.The Boston Tea Party was a significant event in the growth of the American Revolution. Parliament responded in 1774 with the Intolerable Acts, or Coercive Acts, which, among other provisions, ended local self-government in Massachusetts and closed Boston's commerce. Colonists up and down the Thirteen Colonies in turn responded to the Intolerable Acts with additional acts of protest, and by convening the First Continental Congress, which petitioned the British monarch for repeal of the acts and coordinated colonial resistance to them. The crisis escalated, and the American Revolutionary War began near Boston in 1775.Cargo ship
A cargo ship or freighter ship is a merchant ship that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year, handling the bulk of international trade. Cargo ships are usually specially designed for the task, often being equipped with cranes and other mechanisms to load and unload, and come in all sizes. Today, they are almost always built by welded steel, and with some exceptions generally have a life expectancy of 25 to 30 years before being scrapped.Corvette
A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper (or "rated") warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloop-of-war. The modern types of ship below a corvette are coastal patrol craft, missile boat and fast attack craft. In modern terms, a corvette is typically between 500 tons and 2,000 tons although recent designs may approach 3,000 tons, which might instead be considered a small frigate.
The word "corvette" is first found in Middle French, a diminutive of the Dutch word corf, meaning a small ship, from the Latin corbis, meaning "basket".The rank "corvette captain", equivalent in many navies to "lieutenant commander", derives from the name of this type of ship. The rank is the most junior of three "captain" ranks in several European (e.g., France, Spain, Italy, Croatia) and South American (e.g., Argentina, Chile) navies, because a corvette, as the smallest class of rated warship, was traditionally the smallest class of vessel entitled to a commander of a "captain" rank.Cruise ship
A cruise ship is a passenger ship used for pleasure voyages when the voyage itself, the ship's amenities, and sometimes the different destinations along the way (i.e., ports of call), form part of the passengers' experience. Transportation is not the only purpose of cruising, particularly on cruises that return passengers to their originating port (known as "closed-loop cruises"). On "cruises to nowhere" or "nowhere voyages", cruise ships make 2-to-3 night round trips without any ports of call.In contrast, dedicated transport-oriented ocean liners do "line voyages" and typically transport passengers from one point to another, rather than on round trips. Traditionally, shipping lines build liners for the transoceanic trade to a higher standard than that of a typical cruise ship, including higher freeboard and stronger plating to withstand rough seas and adverse conditions encountered in the open ocean, such as the North Atlantic. Ocean liners also usually have larger capacities for fuel, food, and other stores for consumption on long voyages, compared to dedicated cruise-ships, but few ocean liners remain in existence—note the preserved liners and Queen Mary 2, which make scheduled North Atlantic voyages.
Although often luxurious, ocean liners had characteristics that made them unsuitable for cruising, such as high fuel-consumption, deep draughts that prevented their entering shallow ports, enclosed weatherproof decks inappropriate for tropical weather, and cabins designed to maximize passenger numbers rather than comfort (such as a high proportion of windowless suites). The gradual evolution of passenger-ship design from ocean liners to cruise ships has seen passenger cabins shifted from inside the hull to the superstructure and provided with private verandas. Modern cruise ships, while sacrificing some qualities of seaworthiness, have added amenities to cater to water tourists, and recent vessels have been described as "balcony-laden floating condominiums".
The distinction between ocean liners and cruise ships has blurred, particularly with respect to deployment, although differences in construction remain. Larger cruise ships have also engaged in longer trips, such as transoceanic voyages which may not return to the same port for months (longer round-trips). Some former ocean liners operate as cruise ships, such as Marco Polo, although this number is diminishing. The only dedicated transatlantic ocean liner in operation as a liner as of December 2013 is Queen Mary 2 of the Cunard Line. She also has the amenities of contemporary cruise ships and sees significant service on cruisesCruising has become a major part of the tourism industry, accounting for U.S.$29.4 billion, with over 19 million passengers carried worldwide as of 2011. The industry's rapid growth has seen nine or more newly built ships catering to a North American clientele added every year since 2001, as well as others servicing European clientele. Smaller markets, such as the Asia-Pacific region, are generally serviced by older ships. These are displaced by new ships in the high-growth areas.As of 2019 the world's largest cruise-ship was Royal Caribbean International's Symphony of the Seas along with its three sister ships Harmony of the Seas, Allure of the Seas, and Oasis of the Seas which round out the top 4 largest cruise liners in the world.Destroyer
In naval terminology, a destroyer is a fast, maneuverable long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller powerful short-range attackers. They were originally developed in the late 19th century by Fernando Villaamil for the Spanish Navy as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War.Before World War II, destroyers were light vessels with little endurance for unattended ocean operations; typically a number of destroyers and a single destroyer tender operated together. After the war, the advent of the guided missile allowed destroyers to take on the surface combatant roles previously filled by battleships and cruisers. This resulted in larger and more powerful guided missile destroyers more capable of independent operation.
At the start of the 21st century, destroyers are the global standard for surface combatant ships, with only two nations (United States and Russia) operating the heavier class cruisers, with no battleships or true battlecruisers remaining. Modern guided missile destroyers are equivalent in tonnage but vastly superior in firepower to cruisers of the World War II era, and are capable of carrying nuclear tipped cruise missiles. At 510 feet (160 m) long, a displacement of 9,200 tons, and with armament of more than 90 missiles, guided missile destroyers such as the Arleigh Burke-class are actually larger and more heavily armed than most previous ships classified as guided missile cruisers.
Some European navies, such as the French, Spanish, or German, use the term "frigate" for their destroyers, which leads to some confusion.Draft (hull)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel), with the thickness of the hull included; in the case of not being included the draft outline would be obtained. Draft determines the minimum depth of water a ship or boat can safely navigate. The draft can also be used to determine the weight of the cargo on board by calculating the total displacement of water and then using Archimedes' principle. A table made by the shipyard shows the water displacement for each draft. The density of the water (salt or fresh) and the content of the ship's bunkers has to be taken into account. The closely related term "trim" is defined as the difference between the forward and aft drafts.Frigate
A frigate () is a type of warship, having various sizes and roles over the last few centuries.
In the 17th century, a frigate was any warship built for speed and maneuverability, the description often used being "frigate-built". These could be warships carrying their principal batteries of carriage-mounted guns on a single deck or on two decks (with further smaller carriage-mounted guns usually carried on the forecastle and quarterdeck of the vessel). The term was generally used for ships too small to stand in the line of battle, although early line-of-battle ships were frequently referred to as frigates when they were built for speed.
In the 18th century, frigates were full-rigged ships, that is square-rigged on all three masts, they were built for speed and handiness, had a lighter armament than a ship of the line, and were used for patrolling and escort. In the definition adopted by the British Admiralty, they were rated ships of at least 28 guns, carrying their principal armaments upon a single continuous deck – the upper deck – while ships of the line possessed two or more continuous decks bearing batteries of guns.
In the late 19th century (beginning about 1858 with the construction of prototypes by the British and French navies), the armoured frigate was a type of ironclad warship that for a time was the most powerful type of vessel afloat. The term "frigate" was used because such ships still mounted their principal armaments on a single continuous upper deck.
In modern navies, frigates are used to protect other warships and merchant-marine ships, especially as anti-submarine warfare (ASW) combatants for amphibious expeditionary forces, underway replenishment groups, and merchant convoys. Ship classes dubbed "frigates" have also more closely resembled corvettes, destroyers, cruisers and even battleships. Some European navies such as the French, German or Spanish ones use the term "frigate" for both their destroyers and frigates. The rank "frigate captain" derives from the name of this type of ship.German battleship Bismarck
Bismarck was the first of two Bismarck-class battleships built for Nazi Germany's Kriegsmarine. Named after Chancellor Otto von Bismarck, the ship was laid down at the Blohm & Voss shipyard in Hamburg in July 1936 and launched in February 1939. Work was completed in August 1940, when she was commissioned into the German fleet. Bismarck and her sister ship Tirpitz were the largest battleships ever built by Germany, and two of the largest built by any European power.
In the course of the warship's eight-month career under its sole commanding officer, Captain Ernst Lindemann, Bismarck conducted only one offensive operation, lasting 8 days in May 1941, codenamed Rheinübung. The ship, along with the heavy cruiser Prinz Eugen, was to break into the Atlantic Ocean and raid Allied shipping from North America to Great Britain. The two ships were detected several times off Scandinavia, and British naval units were deployed to block their route. At the Battle of the Denmark Strait, the battlecruiser HMS Hood initially engaged Prinz Eugen, probably by mistake, while HMS Prince of Wales engaged Bismarck. In the ensuing battle Hood was destroyed by the combined fire of Bismarck and Prinz Eugen, which then damaged Prince of Wales and forced her retreat. Bismarck suffered sufficient damage from three hits to force an end to the raiding mission.
The destruction of Hood spurred a relentless pursuit by the Royal Navy involving dozens of warships. Two days later, heading for occupied France to effect repairs, Bismarck was attacked by 16 obsolescent Fairey Swordfish biplane torpedo bombers from the aircraft carrier HMS Ark Royal; one scored a hit that rendered the battleship's steering gear inoperable. In her final battle the following morning, the already-crippled Bismarck was severely damaged during a sustained engagement with two British battleships and two heavy cruisers, was scuttled by her crew, and sank with heavy loss of life. Most experts agree that the battle damage would have caused her to sink eventually. The wreck was located in June 1989 by Robert Ballard, and has since been further surveyed by several other expeditions.Glossary of nautical terms
This is a partial glossary of nautical terms; some remain current, while many date from the 17th to 19th centuries. See also Wiktionary's nautical terms, Category:Nautical terms, and Nautical metaphors in English. See the Further reading section for additional words and references.List of current ships of the United States Navy
The United States Navy has approximately 490 ships in both active service and the reserve fleet, with approximately 90 more in either the planning and ordering stages or under construction, according to the Naval Vessel Register and published reports. This list includes ships that are owned and leased by the U.S. Navy; ships that are formally commissioned, by way of ceremony, and non-commissioned. Ships denoted with the prefix "USS" are commissioned ships. Prior to commissioning, ships may be described as a "pre-commissioning unit" or PCU, but are officially referred to by name with no prefix. US Navy support ships are often non-commissioned ships organized and operated by Military Sealift Command. Among these support ships, those denoted "USNS" are owned by the US Navy. Those denoted by "MV" or "SS" are chartered.
Current ships include commissioned warships that are in active service, as well as ships that are part of Military Sealift Command, the support component and the Ready Reserve Force, that while non-commissioned, are still part of the effective force of the U.S. Navy. Future ships listed are those that are in the planning stages, or are currently under construction, from having its keel laid to fitting out and final sea trials.
There exist a number of former US Navy ships which are museum ships (not listed here), some of which may be US government-owned. One of these, USS Constitution, a three-masted tall ship, is one of the original six frigates of the United States Navy. It is the oldest naval vessel afloat, and still retains its commission (and hence is listed here), as a special commemoration for that ship alone.RMS Titanic
RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean in 1912 after the ship struck an iceberg during her maiden voyage from Southampton to New York City. Of the estimated 2,224 passengers and crew aboard, more than 1,500 died, making it one of modern history's deadliest peacetime commercial marine disasters. RMS Titanic was the largest ship afloat at the time she entered service and was the second of three Olympic-class ocean liners operated by the White Star Line. She was built by the Harland and Wolff shipyard in Belfast. Thomas Andrews, chief naval architect of the shipyard at the time, died in the disaster.Titanic was under the command of Capt. Edward Smith, who also went down with the ship. The ocean liner carried some of the wealthiest people in the world, as well as hundreds of emigrants from Great Britain and Ireland, Scandinavia and elsewhere throughout Europe who were seeking a new life in the United States. The first-class accommodation was designed to be the pinnacle of comfort and luxury, with an on-board gymnasium, swimming pool, libraries, high-class restaurants and opulent cabins. A high-powered radiotelegraph transmitter was available for sending passenger "marconigrams" and for the ship's operational use. Although Titanic had advanced safety features such as watertight compartments and remotely activated watertight doors, it only carried enough lifeboats for 1,178 people—about half the number on board, and one third of her total capacity—due to outdated maritime safety regulations. The ship carried 16 lifeboat davits which could lower three lifeboats each, for a total of 48 boats. However, Titanic carried only a total of 20 lifeboats, four of which were collapsible and proved hard to launch during the sinking.After leaving Southampton on 10 April 1912, Titanic called at Cherbourg in France and Queenstown (now Cobh) in Ireland before heading west to New York. On 14 April, four days into the crossing and about 375 miles (600 km) south of Newfoundland, she hit an iceberg at 11:40 p.m. ship's time. The collision caused the hull plates to buckle inwards along her starboard (right) side and opened five of her sixteen watertight compartments to the sea; she could only survive four flooding. Meanwhile, passengers and some crew members were evacuated in lifeboats, many of which were launched only partially loaded. A disproportionate number of men were left aboard because of a "women and children first" protocol for loading lifeboats. At 2:20 a.m., she broke apart and foundered with well over one thousand people still aboard. Just under two hours after Titanic sank, the Cunard liner RMS Carpathia arrived and brought aboard an estimated 705 survivors.
The disaster was met with worldwide shock and outrage at the huge loss of life and the regulatory and operational failures that led to it. Public inquiries in Britain and the United States led to major improvements in maritime safety. One of their most important legacies was the establishment in 1914 of the International Convention for the Safety of Life at Sea (SOLAS), which still governs maritime safety. Additionally, several new wireless regulations were passed around the world in an effort to learn from the many missteps in wireless communications—which could have saved many more passengers.The wreck of Titanic was discovered in 1985 (more than 70 years after the disaster) during a US military mission, and it remains on the seabed. The ship was split in two and is gradually disintegrating at a depth of 12,415 feet (3,784 m). Thousands of artefacts have been recovered and displayed at museums around the world. Titanic has become one of the most famous ships in history; her memory is kept alive by numerous works of popular culture, including books, folk songs, films, exhibits, and memorials. Titanic is the second largest ocean liner wreck in the world, only beaten by her sister HMHS Britannic, the largest ever sunk, although she holds the record as the largest sunk while actually in service as a liner due to Britannic being used as a hospital ship at the time of her sinking. The final survivor of the sinking, Millvina Dean, aged two months at the time, died in 2009 at the age of 97.Ship breaking
Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap. It may also be known as ship dismantling, ship cracking, or ship recycling. Modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to run. Ship breaking allows the materials from the ship, especially steel, to be recycled and made into new products. This lowers the demand for mined iron ore and reduces energy use in the steelmaking process. Equipment on board the vessel can also be reused. While ship breaking is sustainable, there are concerns about the use of poorer countries without stringent environmental legislation. It is also considered one of the world's most dangerous industries and very labour-intensive.In 2012, roughly 1,250 ocean ships were broken down, and their average age was 26 years. In 2013, the world total of demolished ships amounted to 29,052,000 tonnes, 92% of which were demolished in Asia. India, Bangladesh, China and Pakistan have the highest market share and are global centres of ship breaking, with Chittagong Ship Breaking Yard in Bangladesh, Alang in India and Gadani in Pakistan being the largest ships' graveyards in the world. The largest sources of ships are states of China, Greece and Germany respectively, although there is a greater variation in the source of carriers versus their disposal. The ship breaking yards of India, Bangladesh, China and Pakistan employ 225,000 workers as well as providing a large number of indirect jobs. In Bangladesh, the recycled steel covers 20% of the country's needs and in India it is almost 10%.As an alternative to ship breaking, ships may be sunk to create artificial reefs after legally-mandated removal of hazardous materials, or sunk in deep ocean waters. Storage is a viable temporary option, whether on land or afloat, though all ships will be eventually scrapped, sunk, or preserved for museums.Ship commissioning
Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military forces. The ceremonies involved are often rooted in centuries old naval tradition.
Ship naming and launching endow a ship hull with her identity, but many milestones remain before she is completed and considered ready to be designated a commissioned ship. The engineering plant, weapon and electronic systems, galley, and multitudinous other equipment required to transform the new hull into an operating and habitable warship are installed and tested. The prospective commanding officer, ship's officers, the petty officers, and seamen who will form the crew report for training and intensive familiarization with their new ship.
Prior to commissioning, the new ship undergoes sea trials to identify any deficiencies needing correction. The preparation and readiness time between christening-launching and commissioning may be as much as three years for a nuclear powered aircraft carrier to as brief as twenty days for a World War II landing ship. USS Monitor, of American Civil War fame, was commissioned less than three weeks after launch.Ship of the line
A ship of the line was a type of naval warship constructed from the 17th through to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which depended on the two columns of opposing warships maneuvering to fire with the cannons along their broadsides. In conflicts where opposing ships were both able to fire from their broadsides, the side with more cannons, and therefore more firepower typically had an advantage. Since these engagements were almost invariably won by the heaviest ships carrying the most powerful guns, the natural progression was to build sailing vessels that were the largest and most powerful of their time.From the end of the 1840s, the introduction of steam power brought less dependence on the wind in battle and led to the construction of screw-driven, wooden-hulled, ships of the line; a number of pure sail-driven ships were converted to this propulsion mechanism. However, the introduction of the ironclad frigate in about 1859 led swiftly to the decline of the steam-assisted ships of the line. The ironclad warship became the ancestor of the 20th-century battleship, whose very designation is itself a contraction of the phrase "ship of the line of battle" or, more colloquially, "line-of-battle ship".
The term "ship of the line" has fallen into disuse except in historical contexts, after warships and naval tactics evolved and changed from the mid 19th century.Shipwreck
A shipwreck is the remains of a ship that has wrecked, which are found either beached on land or sunken to the bottom of a body of water. Shipwrecking may be deliberate or accidental. In January 1999, Angela Croome estimated that there have been about three million shipwrecks worldwide (an estimate rapidly endorsed by UNESCO and other organizations).Sinking of the RMS Titanic
The RMS Titanic sank in the early morning of 15 April 1912 in the North Atlantic Ocean, four days into the ship's maiden voyage from Southampton to New York City. The largest ocean liner in service at the time, Titanic had an estimated 2,224 people on board when she struck an iceberg at around 23:40 (ship's time) on Sunday, 14 April 1912. Her sinking two hours and forty minutes later at 02:20 (ship's time; 05:18 GMT) on Monday, 15 April, resulted in the deaths of more than 1,500 people, making it one of history's deadliest marine disasters during peacetime.
Titanic received six warnings of sea ice on 14 April but was travelling near her maximum speed when her lookouts sighted the iceberg. Unable to turn quickly enough, the ship suffered a glancing blow that buckled her starboard side and opened six of her sixteen compartments to the sea (the forepeak, all three holds, and boiler rooms 5 and 6). Titanic had been designed to stay afloat with four of her forward compartments flooded but no more, and the crew soon realised that the ship would sink. They used distress flares and radio (wireless) messages to attract help as the passengers were put into lifeboats. In accordance with existing practice, Titanic's lifeboat system was designed to ferry passengers to nearby rescue vessels, not to hold everyone on board simultaneously; therefore, with the ship sinking rapidly and help still hours away, there was no safe refuge for many of the passengers and crew. Compounding this, poor management of the evacuation meant many boats were launched before they were completely full.
As a result, when Titanic sank, over a thousand passengers and crew were still on board. Almost all those who jumped or fell into the water either drowned or died within minutes due to the effects of cold shock and incapacitation. RMS Carpathia arrived on the scene about an hour and a half after the sinking and rescued the last of the survivors by 09:15 on 15 April, some nine and a half hours after the collision. The disaster shocked the world and caused widespread outrage over the lack of lifeboats, lax regulations, and the unequal treatment of the three passenger classes during the evacuation. Subsequent inquiries recommended sweeping changes to maritime regulations, leading to the establishment in 1914 of the International Convention for the Safety of Life at Sea (SOLAS).
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