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Angle Of List
The angle of list is the degree to which a vessel heels (leans or tilts) to either port or starboard at equilibrium—with no external forces acting upon it. If a listing ship goes beyond the point where a righting moment will keep it afloat, it will capsize and potentially sink. Listing is caused by the off-centerline distribution of weight aboard due to uneven loading or to flooding. By contrast, ''roll'' is the dynamic movement from side to side caused by waves. See also * Angle of loll *Heeling (sailing) * Capsizing * Metacentric height *Ship stability Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on center of mass#center of gravity, centers of ... * Ship motions References Engineering concepts Naval architecture Ship measurements Angle {{navy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivory Tirupati With Heavy List 3
Ivory is a hard, white material from the tusks (traditionally from elephants) and Tooth, teeth of animals, that consists mainly of dentine, one of the physical structures of teeth and tusks. The chemical structure of the teeth and tusks of mammals is the same, regardless of the species of origin, but ivory contains structures of mineralised collagen. The trade in certain teeth and tusks other than elephant is well established and widespread; therefore, "ivory" can correctly be used to describe any mammalian teeth or tusks of commercial interest which are large enough to be carved or scrimshawed. Besides natural ivory, ivory can also be produced synthetically, hence (unlike natural ivory) not requiring the retrieval of the material from animals. Tagua nuts can also be carved like ivory. The trade of finished goods of ivory products has its origins in the Indus Valley. Ivory is a main product that is seen in abundance and was used for trading in Harappan civilization. Finished iv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watercraft
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. Types Historically, watercraft have been divided into two main categories. *Rafts, which gain their buoyancy from the fastening together of components that are each buoyant in their own right. Generally, a raft is a "flow through" structure, whose users would have difficulty keeping dry as it passes through waves. Consequently, apart from short journeys (such as a river crossing), their use is confined to warmer regions (roughly 40° N to 40° S). Outside this area, use of rafts at sea is impracticable due to the risks of exposure to the crew. *Boats and ships, which float by having the submergeable part of their structure exclude water with a waterproof surface, so creating a space that contains air, as well as cargo, passengers, crew, etc. In total, this structure weighs less than the water that would occupy the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port And Starboard
Port and starboard are Glossary of nautical terms (M-Z), nautical terms for watercraft and spacecraft, referring respectively to the left and right sides of the vessel, when aboard and facing the Bow (watercraft), bow (front). Vessels with bilateral Symmetry (geometry), symmetry have left and right halves which are mirror images of each other. One asymmetric feature is where access to a boat, ship, or aircraft is at the side; it is usually only on the port side (hence the name). Side Port side and starboard side respectively refer to the left and right sides of the vessel, when aboard and facing the bow. The port and starboard sides of the vessel always refer to the same portion of the vessel's structure, and do not depend on the position of someone aboard the vessel. The port side is the side to the left of an observer aboard the vessel and , towards the direction the vessel is heading when underway in the forward direction. The starboard side is to the right of such an obser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metacentric Height
The metacentric height (GM) is a measurement of the initial static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its '' metacentre''. A larger metacentric height implies greater initial stability against overturning. The metacentric height also influences the natural period of rolling of a hull, with very large metacentric heights being associated with shorter periods of roll which are uncomfortable for passengers. Hence, a sufficiently, but not excessively, high metacentric height is considered ideal for passenger ships. Different centres The ''centre of buoyancy'' is at the centre of mass of the volume of water that the hull displaces. This point is referred to as B in naval architecture. The '' centre of gravity'' of the ship is commonly denoted as point G or CG. When a ship is at equilibrium, the centre of buoyancy is vertically in line with the centre of gravity of the ship. The metacentre is the point where th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsize
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is Turtling (sailing), upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broach (nautical), broaching, , loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast. If a capsized vessel has enough flotation to prevent sinking, it may recover on its own in changing conditions or through mechanical work if it is not Ship stability, stable while inverted. Vessels of this design are called #Self-righting, self-righting. Small vessels In dinghy sailing, a practical distinction can be made between being knocked down (to 90 degrees; on its wiktionary:beam-ends, beam-ends, figuratively) which is called a capsize, and being inverted, which is called being Turtling (sailing), turtled. Small dinghies frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roll (ship)
Ship motions are the six degrees of freedom that a ship, boat, or other watercraft can experience. Reference axes The '' vertical/Z axis'', or ''yaw axis'', is an imaginary line running vertically through the ship and through its centre of mass. A yaw motion is a side-to side movement of the bow and stern of the ship. The '' transverse/Y axis'', ''lateral axis'', or ''pitch axis'' is an imaginary line running horizontally across the ship and through the centre of mass. A pitch motion is an up-or-down movement of the bow and stern of the ship. The '' longitudinal/X axis'', or ''roll axis'', is an imaginary line running horizontally through the length of the ship, through its centre of mass, and parallel to the ''waterline''. A roll motion is a side-to-side or port-starboard tilting motion of the superstructure around this axis. Rotational There are three special axes in any ship, called longitudinal, transverse and vertical axes. The angular movements around them—af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Wave
In fluid dynamics, a wind wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result of the wind blowing over the water's surface. The contact distance in the direction of the wind is known as the '' fetch''. Waves in the oceans can travel thousands of kilometers before reaching land. Wind waves on Earth range in size from small ripples to waves over high, being limited by wind speed, duration, fetch, and water depth. When directly generated and affected by local wind, a wind wave system is called a wind sea. Wind waves will travel in a great circle route after being generated – curving slightly left in the southern hemisphere and slightly right in the northern hemisphere. After moving out of the area of fetch and no longer being affected by the local wind, wind waves are called '' swells'' and can travel thousands of kilometers. A noteworthy example of this is waves generated south of Tasmania during heavy wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Loll
Angle of loll is the state of a ship that is unstable when upright (i.e. has a negative metacentric height) and therefore takes on an angle of heel to either port or starboard. When a vessel has negative metacentric height (GM) ''i.e.'', is in unstable equilibrium, any external force applied to the vessel will cause it to start heeling. As it heels, the moment of inertia of the vessel's waterplane (a plane intersecting the hull at the water's surface) increases, which increases the vessel's BM (distance from the centre of ''B''uoyancy to the ''M''etacenter). Since there is relatively little change in KB (distance from the ''K''eel to the centre of ''B''uoyancy) of the vessel, the KM (distance from ''K''eel to the ''M''etacentre) of the vessel increases. At some angle of heel (say 10°), KM will increase sufficiently equal to KG (distance from the keel to the centre of gravity), thus making GM of vessel equal to zero. When this occurs, the vessel goes to neutral equilibrium, and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heeling Moment
Forces on sails result from movement of air that interacts with sails and gives them motive power for sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and sail-powered land vehicles. Similar principles in a rotating frame of reference apply to windmill sails and wind turbine blades, which are also wind-driven. They are differentiated from forces on wings, and propeller blades, the actions of which are not adjusted to the wind. Kites also power certain sailing craft, but do not employ a mast to support the airfoil and are beyond the scope of this article. Forces on sails depend on wind speed and direction and the speed and direction of the craft. The direction that the craft is traveling with respect to the "true wind" (the wind direction and speed over the surface) is called the point of sail. The speed of the craft at a given point of sail contributes to the "apparent wind"—the wind speed and direction as measured on the moving craft. The apparent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsizing
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broaching, , loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast. If a capsized vessel has enough flotation to prevent sinking, it may recover on its own in changing conditions or through mechanical work if it is not stable while inverted. Vessels of this design are called self-righting. Small vessels In dinghy sailing, a practical distinction can be made between being knocked down (to 90 degrees; on its beam-ends, figuratively) which is called a capsize, and being inverted, which is called being turtled. Small dinghies frequently capsize in the normal course of use and can usually be recovered by the crew. Some types of dinghy ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Stability
Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on center of mass#center of gravity, centers of gravity, buoyancy, centers of buoyancy, the metacenters of vessels, and on how these interact. History Ship stability, as it pertains to naval architecture, has been taken into account for hundreds of years. Historically, ship stability calculations relied on rule of thumb calculations, often tied to a specific system of measurement. Some of these very old equations continue to be used in naval architecture books today. However, the advent of calculus-based methods of determining stability, particularly Pierre Bouguer's introduction of the concept of the metacenter in the 1740s ship model basin, allow much more complex analysis. Master shipbuilders of the past used a system of adaptive and variant design. Ships were often copied from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
