A watercraft or waterborne vessel is any vehicle designed for travel across or through water bodies , such as a boat , ship , hovercraft , submersible or submarine .
31-481: A merchant ship , merchant vessel , trading vessel , or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft , which are used for personal recreation, and naval ships , which are used for military purposes. They come in myriad sizes and shapes, from six-metre (20 ft) inflatable dive boats in Hawaii, to 5,000-passenger casino vessels on
62-628: A common means of commercial intermodal freight transport . A tanker is a ship designed to transport liquids in bulk. Tankers can range in size from several hundred tons , designed to serve small harbours and coastal settlements, to several hundred thousand tons, with these being designed for long-range haulage. A wide range of products are carried by tankers, including: Different products require different handling and transport, thus special types of tankers have been built, such as chemical tankers , oil tankers , and gas carriers . Among oil tankers, supertankers were designed for carrying oil around
93-525: A formula based on the vessel's length and beam. Historically in England , tunnage was the medieval import duty on tuns of wine. A tun was a large size of casks used for wine ), used in the wine trade. The number of tuns that a ship could carry was used as a measure of the size of the ship. The wine trade to England originated in France, which is where the tuns were made. A French standard tun cask size
124-441: A good position in a tidal stream while drifting with the tide in or out of a river. In a modern yacht , motor-sailing – travelling under the power of both sails and engine – is a common method of making progress, if only in and out of harbour. Tonnage Tonnage is a measure of the capacity of a ship , and is commonly used to assess fees on commercial shipping . The term derives from
155-809: A number of modifications from the former net register tonnage of the Moorsom System and was established by the International Commission of Constantinople in its Protocol of 18 December 1873. It is still in use, as amended by the Rules of Navigation of the Suez Canal Authority and is registered in the Suez Canal Tonnage Certificate. Thames measurement tonnage (TM) is another volumetric system, generally used for small vessels such as yachts ; it uses
186-540: A smaller size of standard barrel. This was the barrique bordelaise , measuring a quarter of the size of the tun (in English, this barrel was termed a hogshead ). For instance, Basque ships engaged in 16th century whaling in Labrador used this size of barrel (with the name barrica ). The French tonneau de mer was legally defined, in 1681, as the cubic space into which four barrique bordelaise fitted, with
217-507: A variety of subcategories and are used for different needs and applications. The design of watercraft requires a tradeoff among internal capacity ( tonnage ), speed and seaworthiness . Tonnage is important for transport of goods, speed is important for warships and racing vessels, and the degree of seaworthiness varies according to the bodies of water on which a watercraft is used. Regulations apply to larger watercraft, to avoid foundering at sea and other problems. Design technologies include
248-407: A volume that, if filled with fresh water, would weigh around 2.83 tonnes . The definition and calculation of the internal volume is complex; for instance, a ship's hold may be assessed for bulk grain (accounting for all the air space in the hold) or for bales (omitting the spaces into which bulk, but not baled cargo, would spill). Gross register tonnage was replaced by gross tonnage in 1982 under
279-399: Is a function of the moulded volume of all cargo spaces of the ship. The Panama Canal/Universal Measurement System (PC/UMS) is based on net tonnage modified for Panama Canal purposes. PC/UMS is based on a mathematical formula to calculate a vessel's total volume; one PC/UMS net ton is equivalent to 100 cubic feet (2.83 m ) of capacity. The Suez Canal Net Tonnage (SCNT) is derived with
310-731: Is any sort of ship or vessel that carries cargo , goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year; they handle 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. A bulk carrier is a ship used to transport bulk cargo items such as iron ore , bauxite, coal, cement, grain and similar cargo. Bulk carriers can be recognized by large box-like hatches on deck, designed to slide outboard or fold fore-and-aft to enable access for loading or discharging cargo. The dimensions of bulk carriers are often determined by
341-1221: Is defined by the United States Coast Guard as any vessel (i.e. boat or ship) engaged in commercial trade or that carries passengers for hire. In English, the term "Merchant Navy" without further clarification is used to refer to the British Merchant Navy ; the United States merchant fleet is known as the United States Merchant Marine . Merchant ships' names have a prefix to indicate which kind of vessel they are: 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". A cargo ship or freighter
SECTION 10
#1732786751857372-443: Is important, since a ship's registration fee, harbour dues, safety and manning rules, and the like may be based on its gross tonnage (GT) or net tonnage (NT). Gross tonnage (GT) is a function of the volume of all of a ship's enclosed spaces (from keel to funnel ) measured to the outside of the hull framing. The numerical value for a ship's GT is always smaller than the numerical values of gross register tonnage (GRT). Gross tonnage
403-600: Is just over 40 cubic feet (1.1 m ). British practice by the 19th century was for a ton of cargo volume to be 50 cubic feet (1.4 m ). This is derived from an estimate of the hull space needed to fit the roughly cylindrical tun and is broadly consistent with the much earlier French definition given below. The Bordeaux tun was used as a measurement elsewhere in Europe. By the 16th century, multi-decked ships which were loaded through hatchways (as opposed to earlier undecked or single decked ships) found it more convenient to use
434-483: Is the largest in the world. Today, the Greek fleet accounts for some 16 per cent of the world's tonnage ; this makes it currently the largest single international merchant fleet in the world, albeit not the largest in history. During wars, merchant ships may be used as auxiliaries to the navies of their respective countries, and are called upon to deliver military personnel and materiel . The term "commercial vessel"
465-413: Is therefore a kind of capacity-derived index that is used to rank a ship for purposes of determining manning, safety, and other statutory requirements and is expressed simply as GT, which is a unitless entity, even though it derives from the volumetric capacity in cubic metres. Net tonnage (NT) is based on a calculation of the volume of all cargo spaces of the ship. It indicates a vessel's earning space and
496-735: The Horn of Africa from the Middle East ; the FSO Knock Nevis being the largest vessel in the world, a ULCC supertanker formerly known as Jahre Viking (Seawise Giant). It has a deadweight of 565,000 metric tons and length of about 458 meters (1,500 ft). The use of such large ships is in fact very unprofitable, due to the inability to operate them at full cargo capacity; hence, the production of supertankers has currently ceased. Today's largest oil tankers in comparison by gross tonnage are TI Europe , TI Asia , TI Oceania , which are
527-468: The Middle Ages , ships were often impressed by the crown for military use. To do this in an efficient and speedy manner, a measurement of size was needed. The payment to the owner of the requisitioned ship was based on the tonnage. Port dues and various licences were based on tonnage, and it was a useful measure for a ship builder who needed to build a vessel that met the new owner's requirements. In
558-478: The Tudor period a bounty per ton was paid for the construction of larger ships, so the threshold for that payment had to be determined, as well as the amount paid for those qualifying. In the middle ages, the normal way of discovering the tonnage of a ship was to load her with wine and see how many tuns could be fitted in. There is an instance of the owner of a new ship, in 1459, being challenged that his safe-conduct
589-564: The Mississippi River, to tugboats plying New York Harbor , to 300-metre (1,000 ft) oil tankers and container ships at major ports, to passenger-carrying submarines in the Caribbean . Many merchant ships operate under a " flag of convenience " from a country other than the home of the vessel's owners, such as Liberia and Panama , which have more favorable maritime laws than other countries. The Greek merchant marine
620-581: The Tonnage Measurement convention of 1969, with all ships measured in GRT either scrapped or re-measured in GT by 1994. Net register tonnage (NRT) is the volume of cargo the vessel can carry—that is, the gross register tonnage less the volume of spaces that do not hold cargo (e.g., engine compartment, helm station, and crew spaces, again with differences depending on which port or country does
651-474: The casks aligned two directly above the two below (so not optimising the layout). This redefined ton worked out as 42 cubic pieds de roi (1.44 cubic metres (51 cu ft). The difference between this measure and, for instance, the Spanish toneladas was calculated by recognised adjustment factors. Tonnage measurement was important for an increasing number of reasons through history. In England in
SECTION 20
#1732786751857682-599: The formerly ubiquitous twelve-passenger freighters in which the transport of passengers is secondary to the carriage of freight. The type does however include many classes of ships which are designed to transport substantial numbers of passengers as well as freight. Indeed, until recently virtually all ocean liners were able to transport mail, package freight and express, and other cargo in addition to passenger luggage, and were equipped with cargo holds and derricks, kingposts, or other cargo-handling gear for that purpose. Modern cruiseferries have car decks for lorries as well as
713-750: The largest sailing vessels today. But even with their deadweight of 441,585 metric tons, sailing as VLCC most of the time, they do not use more than 70% of their total capacity. Apart from pipeline transport , tankers are the only method for transporting large quantities of oil, although such tankers have caused large environmental disasters when sinking close to coastal regions, causing oil spills . See Braer , Erika , Exxon Valdez , Prestige and Torrey Canyon for examples of tankers that have been involved in oil spills. Coastal trading vessels are smaller ships that carry any category of cargo along coastal, rather than trans-oceanic, routes. Coasters are shallow-hulled ships used for trade between locations on
744-995: The passengers' cars. Only in more recent ocean liners and in virtually all cruise ships has this cargo capacity been removed. A ferry is a boat or ship carrying passengers and sometimes their vehicles. Ferries are also used to transport freight (in lorries and sometimes unpowered freight containers ) and even railroad cars (in the case of a train ferry ). Watercraft Historically, watercraft have been divided into two main categories. Watercraft can be grouped into surface vessels , which include ships, yachts , boats, hydroplanes , wingships , unmanned surface vehicles , sailboards and human-powered craft such as rafts , canoes , kayaks and paddleboards ; underwater vessels , which include submarines, submersibles, unmanned underwater vehicles (UUVs), wet subs and diver propulsion vehicles ; and amphibious vehicles , which include hovercraft, car boats , amphibious ATVs and seaplanes . Many of these watercraft have
775-553: The ports and sea routes that they need to serve, and by the maximum width of the Panama Canal. Most lakes are too small to accommodate bulk carriers, but a large fleet of lake freighters has been plying the Great Lakes and St. Lawrence Seaway of North America for over a century. A container ship is a cargo ship that carries its cargo in standardized containers, in a technique called containerization . These ships are
806-412: The same island or continent. Their shallow hulls allow them to sail over reefs and other submerged navigation hazards, whereas ships designed for blue-water trade usually have much deeper hulls for better seakeeping . A passenger ship is a ship whose primary function is to carry passengers. The category does not include cargo vessels which have accommodations for limited numbers of passengers, such as
837-664: The taxation paid on tuns or casks of wine. In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Although tonnage (volume) should not be confused with displacement (the actual mass of the vessel), the long ton (or imperial ton) of 2,240 lb is derived from the fact that a " tun " of wine typically weighed that much. Tonnage measurements are governed by an IMO Convention (International Convention on Tonnage Measurement of Ships, 1969 (London-Rules)), which initially applied to all ships built after July 1982, and to older ships from July 1994. A commonly defined measurement system
868-438: The use of computer modeling and ship model basin testing before construction. Watercraft propulsion can be divided into five categories. Any one watercraft might use more than one of these methods at different times or in conjunction with each other. For instance, early steamships often set sails to work alongside the engine power. Before steam tugs became common, sailing vessels would back and fill their sails to maintain
899-411: Was apparently paid without any measurement system to confirm the actual size. The presumption is that it was taken from the amount of cargo unloaded after the first voyage (which would be recorded in the customs records of the relevant port). Gross register tonnage (GRT) represents the total internal volume of a vessel, where one register ton is equal to a volume of 100 cubic feet (2.83 m );
930-431: Was established about 1450. The 15th century Bordeaux wine tun was between 240 and 252 imperial gallons (1,090 and 1,150 L; 288 and 303 US gal). When measuring the tonnage of a ship, the approximately cylindrical cask would have air space around it when stowed in a ship. Therefore the volume of hold space required for several tuns was greater than the total of the capacity of those tuns. 252 imperial gallons
961-403: Was for a 400 ton vessel, whilst he had already loaded more than 600 tons. The excuse was accepted that he had no idea of her tonnage until she was loaded. In another case, in 1456, a dispute over the actual tonnage of a ship had to be resolved by having coopers part load her with (presumably empty) barrels to estimate what she could carry. The Tudor bounty paid for the construction of larger ship