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Catamarans
file:Bladef16-1up.jpg, A Formula 16 (sailing), Formula 16 beachable catamaran file:Salem Ferry.JPG, Powered catamaran passenger ferry at Salem, Massachusetts, Salem, Massachusetts, United States A catamaran () (informally, a "cat") is a multihull, multi-hulled watercraft featuring two parallel hull (watercraft), hulls of equal size. It is a geometry-stabilized craft, deriving its stability from its wide beam (nautical), beam, rather than from a ballasted keel as with a monohull boat. Catamarans typically have less hull volume, smaller Displacement (ship), displacement, and shallower draft (hull), draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic drag (physics), resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran's wider stance on the water can reduce both Heeling (sailing)#Heeling, heeling and wave-induced motion, as compared with a monohull, and can give ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multihull
A multihull is a boat or ship with more than one hull, whereas a vessel with a single hull is a monohull. The most common multihulls are catamarans (with two hulls), and trimarans (with three hulls). There are other types, with four or more hulls, but such examples are very rare and tend to be specialised for particular functions. Sailing multihulls Counter-intuitively, it is unhelpful to think of the design progression to be "1-2-3", namely monohull - catamaran - trimaran; rather, it is "1-3-2". A sailing trimaran is, in effect, a modified monohull with lightweight outrigger hulls (or "amas") for stability instead of a heavy deep keel; so it follows that a sailing trimaran will be lighter and faster than a sailing monohull. A sailing trimaran will have a centre hull that may comprise up to 90% of total hull volume, and 95% of total deadweight. A sailing trimaran at rest will have both amas out of the water and, when heeled, will only ever have one of the amas immersed. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outrigger Canoe
Outrigger boats are various watercraft featuring one or more lateral support floats known as outriggers, which are fastened to one or both sides of the main hull. They can range from small dugout canoes to large plank-built vessels. Outrigger boats can also vary in their configuration, from the ancestral double-hull configuration ( catamarans), to single-outrigger vessels prevalent in the Pacific Islands and Madagascar, to the double-outrigger vessels ( trimarans) prevalent in Island Southeast Asia. They are traditionally fitted with Austronesian sails, like the crab claw sails and tanja sails, but in modern times are often fitted with petrol engines. Unlike a single-hulled vessel, an outrigger or double-hull vessel generates stability as a result of the distance between its hulls rather than due to the shape of each individual hull. As such, the hulls of outrigger or double-hull boats are typically longer, narrower and more hydrodynamically efficient than those of single-h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimaran
A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreation or racing; others are ferries or warships. They originated from the traditional double-outrigger hulls of the Austronesian cultures of Maritime Southeast Asia; particularly in the Philippines and Eastern Indonesia, where it remains the dominant hull design of traditional fishing boats. Double-outriggers are derived from the older catamaran and single-outrigger boat designs. Terminology The word "trimaran" is a portmanteau of "tri" and "(cata)maran", a term that is thought to have been coined by Victor Tchetchet, a pioneering, Ukrainian-born modern multihull designer. Trimarans consist of a main hull connected to outrigger floats on either side by a crossbeam, wing, or other form of superstructure—the traditional Polynesian t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heeling (sailing)
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen course, which is often part of a larger plan of navigation. From prehistory until the second half of the 19th century, sailing craft were the primary means of maritime trade and transportation; exploration across the seas and oceans was reliant on sail for anything other than the shortest distances. Naval power in this period used sail to varying degrees depending on the current technology, culminating in the gun-armed sailing warships of the Age of Sail. Sail was slowly replaced by steam as the method of propulsion for ships over the latter part of the 19th century – seeing a gradual improvement in the technology of steam through a number of stepwise developments. Steam allowed scheduled services that ran at higher average speeds than saili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' ( sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' ( iceboat) or on ''land'' ( land yacht) over a chosen course, which is often part of a larger plan of navigation. From prehistory until the second half of the 19th century, sailing craft were the primary means of maritime trade and transportation; exploration across the seas and oceans was reliant on sail for anything other than the shortest distances. Naval power in this period used sail to varying degrees depending on the current technology, culminating in the gun-armed sailing warships of the Age of Sail. Sail was slowly replaced by steam as the method of propulsion for ships over the latter part of the 19th century – seeing a gradual improvement in the technology of steam through a number of stepwise developments. Steam allowed scheduled services that ran at higher average speeds tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austronesian Peoples
The Austronesian peoples, sometimes referred to as Austronesian-speaking peoples, are a large group of peoples in Taiwan, Maritime Southeast Asia, Micronesia, coastal New Guinea, Island Melanesia, Polynesia, and Madagascar that speak Austronesian languages. They also include indigenous ethnic minorities in Vietnam, Cambodia, Myanmar, Thailand, Hainan, the Comoros, and the Torres Strait Islands. The nations and territories predominantly populated by Austronesian-speaking peoples are sometimes known collectively as Austronesia. Based on the current scientific consensus, they originated from a prehistoric seaborne migration, known as the Austronesian expansion, from pre- Han Taiwan, at around 1500 to 1000 BCE. Austronesians reached the northernmost Philippines, specifically the Batanes Islands, by around 2200 BCE. Austronesians used sails some time before 2000 BCE. In conjunction with their use of other maritime technologies (notably catamarans, outrigger boats, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells In watercraft, a racing shell (also referred to as just a ''fine boat'' (UK) or just ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kattumaram
Kattumaram (கட்டுமரம்) is a traditional Tamil watercraft used in the Coast of Southern India, Sri Lanka, and Bangladesh,. They are characterized by being made from three to seven tree trunks tied together with fiber lashings and/or treenails. The lashings are not permanent and the individual tree trunks are commonly separated to dry under the sun when kattumaram are beached. Most kattumaram are rafts because they are not watertight and rely on the buoyancy of the individual logs. However, some types of kattumaram known as teppa are watertight due to the addition polystyrene fillings on the hull and thus are true boats. They are propelled by oars, paddles, or lateen or lug sails. Modern versions of the kattumaram made from fibreglass are known as "fibre-teppa". The name "''kattumaram''" is Tamil for "tied wood," from ''kattu'' "binding" + ''maram'' "wood". Small kattumaram are called ''chinnamaram'', while larger kattumaram are called ''periamaram''. The term "'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Succession Of Forms In The Development Of The Austronesian Boat
Succession is the act or process of following in order or sequence. Governance and politics *Order of succession, in politics, the ascension to power by one ruler, official, or monarch after the death, resignation, or removal from office of another, usually in a clearly defined order *Succession of states, in international relations, is the process of recognition and acceptance of a newly created state by other states, based on a perceived historical relationship the new state has with a prior state *Succession planning, in organizations, identifying and developing individuals to succeed to senior positions in government, business, organizations, etc. *Successor company / Successor corporation / Successor in Business Inheritance * Apostolic succession, the doctrine, held by some Christian denominations, that bishops are the successors of the original Twelve Apostles, inheriting their spiritual, ecclesiastical and sacramental authority, power, and responsibility *Succession ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outrigger
An outrigger is a projecting structure on a boat, with specific meaning depending on types of vessel. Outriggers may also refer to legs on a wheeled vehicle that are folded out when it needs stabilization, for example on a crane that lifts heavy loads. Powered vessels and sailboats An outrigger describes any contraposing float rigging beyond the side ( gunwale) of a boat to improve the vessel's stability. If a single outrigger is used it is usually but not always windward. The technology was originally developed by the Austronesian people. There are two main types of boats with outriggers: double outriggers (prevalent in maritime Southeast Asia) and single outriggers (prevalent in Madagascar, Melanesia, Micronesia and Polynesia). Multihull ships are also derived from outrigger boats. In an outrigger canoe and in sailboats such as the proa, an outrigger is a thin, long, solid, hull used to stabilise an inherently unstable main hull. The outrigger is positioned rigi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
