these configurations will be saved for each time you visit this page using this browser
full-rigged ship Amerigo Vespucci in New York Harbor, 1976]] A ship () is a large vessel that floats on water. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships may be found on lakes, seas, and rivers and they allow for a variety of activities, such as the transport of people or goods, fishing, entertainment, public safety, and warfare. Historically, a ship referred to a vessel with sails rigged in a specific manner.
Ships and boats have developed alongside mankind. In major wars, and in day to day life, they have become an integral part of modern commercial and military systems. Fishing boats are used by millions of fishermen throughout the world. Military forces operate highly sophisticated vessels to transport and support forces ashore. Commercial vessels, nearly 35,000 in number, carried 7.4 billion tons of cargo in 2007.
These vessels were also key in history's great explorations and scientific and technological development. Navigators such as Zheng He spread such inventions as the compass and gunpowder. Ships have been used for such purposes as colonization and the slave trade, and have served scientific, cultural, and humanitarian needs. New crops that had come from the Americas via the European seafarers in the 16th century significantly contributed to the world's population growth.
As Thor Heyerdahl demonstrated with his tiny craft the Kon-Tiki, it is possible to navigate long distances upon a simple log raft. From Mesolithic canoes to today's powerful nuclear-powered aircraft carriers, ships tell the history of human technological development.
A number of large vessels are traditionally referred to as boats. Submarines are a prime example. Other types of large vessels which are traditionally called boats are the Great Lakes freighter, the riverboat, and the ferryboat. Though large enough to carry their own boats and heavy cargoes, these vessels are designed for operation on inland or protected coastal waters.
In most maritime traditions, ships have an individual name, and modern ships may belong to a ship class often named after its first ship. In English, a ship is traditionally referred to as "she", even if named after a man, but as of the 2000s this figure of speech is in decline and journalistic style guides advise to use "it".
The history of boats parallels the human adventure. The first known boats date back to the Neolithic Period, about 10,000 years ago. These early vessels had limited function: they could move on water, but that was it. They were used mainly for hunting and fishing. The oldest dugout canoes found by archaeologists were often cut from coniferous tree logs, using simple stone tools.
By around 3000 BC, Ancient Egyptians already knew how to assemble wooden planks into a hull. They used woven straps to lash the planks together, 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 B. C., 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 BCE) to a ship being referred to by name.
In East Asia, by the time of the Zhou Dynasty ship technologies such as stern mounted rudders were developed, and by the Han Dynasty, a well kept naval fleet was an integral part of the military. Ship technology advanced to the point where by the medieval period, water tight compartments were developed. During the 15th century in the Ming Dynasty, one of the largest and most powerful naval fleet in the world was assembled for the diplomatic and power projection voyages of Zheng He. Elsewhere in Korea in the 15th century, one of the world's first iron-clads, the turtle ship, was also developed.
By about 2000 BC, Minoan civilization in Crete had evolved into a naval power exercising effective control of the sea in the eastern Mediterranean. 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.
mosaic from Carthage, Bardo Museum, Tunis.]] The Swahili people had various extensive trading ports dotting the cost 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.
At about the same time, people living near Kongens Lyngby in Denmark invented the segregated hull, which allowed the size of boats to gradually be increased. Boats soon developed into keel boats similar to today's wooden pleasure craft.
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 example the settlement of Oceania about 3,000 years ago.
The ancient Egyptians were perfectly at ease building sailboats. A remarkable example of their shipbuilding skills was the Khufu ship, a vessel in length entombed at the foot of the Great Pyramid of Giza around 2500 BC and found intact in 1954. According to Herodotus, the Egyptians made the first circumnavigation of Africa around 600 BC.
The Phoenicians 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. With 300 Greek ships a year sailing between Roman Empire and India, the annual trade may have reached 300,000 tons. , 1571, naval engagement between allied Christian forces and the Ottoman Turks.]] 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 invented in Europe no later than 1300.
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. 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.
of a medieval Mogadishan ship.]] During the Age of the Ajuuraan, 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 islands 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 CE 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. . Ferdinand Magellan led the first expedition that circumnavigated the globe in 1519-1522.]] 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 long and had a beam of . His fleet carried 30,000 men aboard 70 vessels, with the goal of bringing glory to the Chinese emperor.
The carrack and then the caravel were developed in Iberia. 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. A major sea power, the Dutch in 1650 owned 16,000 merchant ships. In the 17th century Dutch explorers such as Abel Tasman explored the coasts of Australia, while in the 18th century it was British explorer James Cook who mapped much of Polynesia.
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 long and their construction required 2,800 oak trees and of rope; they carried a crew of about 800 sailors and soldiers.
departs from Southampton. Her sinking would tighten safety regulations]] 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 route fell into commercial disuse with the introduction of steam ships, 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.
Other classification systems exist that use criteria such as:
* The number of hulls, giving categories like monohull, catamaran, trimaran.
Another way to categorize ships and boats is based on their use, as described by Paulet and Presles. This system includes military ships, commercial vessels, fishing boats, pleasure craft and competitive boats. In this section, ships are classified using the first four of those categories, and adding a section for lake and river boats, and one for vessels which fall outside these categories.
Passenger ships range in size from small river ferries to giant cruise ships. This type of vessel includes ferries, which move passengers and vehicles on short trips; ocean liners, which carry passengers on one-way trips; and cruise ships, which typically transport passengers on round-trip voyages promoting leisure activities aboard and in the ports they visit.
Special-purpose vessels are not used for transport but are designed to perform other specific tasks. Examples include tugboats, pilot boats, rescue boats, cable ships, research vessels, survey vessels, and ice breakers.
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 captain, with deck officers and marine engineers on larger vessels. Special-purpose vessels often have specialized crew if necessary, for example scientists aboard research vessels. Commercial vessels are typically powered by a single propeller driven by a diesel engine. Vessels which operate at the higher end of the speed spectrum may use pump-jet engines or sometimes gas turbine engines.
Modern warships are generally divided into seven main categories, which are: aircraft carriers, cruisers, destroyers, frigates, corvettes, submarines and amphibious assault ships. Battleships encompass an eighth category, but are not in current service with any navy in the world.
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 missiles and submarine-launched 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 bombs to nuclear weapons.
Most navies also include many types of support and auxiliary vessels, such as minesweepers, patrol boats, offshore patrol vessels, replenishment ships, and hospital ships which are designated medical treatment facilities.
Combat vessels like cruisers and destroyers usually have fine hulls to maximize speed and maneuverability. They also usually have advanced electronics and communication systems, as well as weapons.
Fishing boats are generally small, often little more than but up to 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, of fish were caught in the marine capture fishery. Anchoveta represented the largest single catch at .
The St. Mary's Challenger, built in 1906 as the William P Snyder, is the oldest laker still working on the Lakes. Similarly, the E.M. Ford, built in 1898 as the Presque Isle, was sailing the lakes 98 years later in 1996. As of 2007 the Ford was still afloat as a stationary transfer vessel at a riverside cement silo in Saginaw, Michigan.
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.
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).
There are many variations of propeller systems, including twin, contra-rotating, controllable-pitch, and nozzle-style propellers. Smaller vessels tend to have a single propeller. Large vessels use multiple propellers, supplemented with bow- and stern-thrusters. Power is transmitted from the engine to the propeller by way of a propeller shaft, which may or may not be connected to a gearbox. Some modern vessels use electric motors connected directly to the propeller shaft, usually powered by generators. These electric systems are often more energy efficient than other systems where the engine is mechanically connected to the propeller.
Some propulsion systems are inherently steering systems. Examples include the outboard motor, the bow thruster, and the Z-drive. Some sails, such as jibs and the mizzen sail on a ketch rig, are used more for steering than propulsion.
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.
* Masts can be the home of antennas, navigation lights, radar transponders, fog signals, and similar devices often required by law.
* For most vessels, known as displacement vessels, the vessel's weight is offset by that of the water displaced by the hull.
A vessel is in equilibrium when the upwards and downwards forces are of equal magnitude. As a vessel is lowered into the water its weight remains constant but the corresponding weight of water displaced by its hull increases. When the two forces are equal, the boat floats. If weight is evenly distributed throughout the vessel, it floats without trim or heel.
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.
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.
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 strictening, ship designers need to create their design in such a way that the ship -when it nears its end-of-term- can be disassmbled or disposed easily and that waste is reduced to a minimum.
under construction in a shipyard in Turku.]]
at the Northern Shipyard in Gdansk, Poland]] , Southern India ]] Generally, construction starts with the hull, and on vessels over about , 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 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 costs around $2 billion, and an aircraft carrier goes for about $3.5 billion.
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.
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.
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.
Many ships do not make it to the scrapyard, and are lost in fires, collisions, grounding, or sinking at sea. There are more than 3 million shipwrecks on the ocean floor, the United Nations estimates. The Allies lost some 5,150 ships during World War II.
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.
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 in 1984 to in 1993; sprat from in 1984 to in 1993; horse mackerel from in 1984 to zero in 1993."
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. “By 2010, up to 40% of air pollution over land could come from ships.”
A floating boat displaces its weight in water. The material of the boat hull may be denser than water, but if this is the case then it forms only the outer layer. If the boat floats, the mass of the boat (plus contents) as a whole divided by the volume below the waterline is equal to the density of water (1 kg/l). If weight is added to the boat, the volume below the waterline will increase to keep the weight balance equal, and so the boat sinks a little to compensate.
Model ships
Lists
*
This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
![The Material - Before This Ship Goes Down [Lyrics]](http://web.archive.org./web/20110208152249im_/http://i.ytimg.com/vi/LW0NgVTiDlI/0.jpg "The Material - Before This Ship Goes Down [Lyrics]")
