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Wave Piercing
A wave-piercing boat hull has a very fine bow, with reduced buoyancy in the forward portions. When a wave is encountered, the lack of buoyancy means the hull pierces through the water rather than riding over the top, resulting in a smoother ride than traditional designs, and in diminished mechanical stress on the vessel. It also reduces a boat's wave-making resistance. Design theory calls for very long thin hulls, so in practice most are multi-hulls such as catamarans and trimarans. The main current usage areas are passenger ferries and naval ship A naval ship is a military ship (or sometimes boat, depending on classification) used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are Damage control, damage resilient a ...s. See also * * * , later renamed MY ''Ady Gil'' * * * , a pioneer of the design * * Norwegian Cruise Line -Class Cruise Ships * hull form * * * : an racing multihull * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMNZS Aotearoa
HMNZS ''Aotearoa'' (), formerly the Maritime Sustainment Capability project, is an auxiliary ship of the Royal New Zealand Navy. Builder Hyundai Heavy Industries delivered the ship to the Navy in June 2020, and she was commissioned into service on 29 July 2020. Full operational capability was expected to be achieved in 2021. The vessel will serve as a replenishment oiler, and has replaced , the Navy’s last fleet oiler, which was decommissioned in December 2017. ''Aotearoa'' is the largest ship the Royal New Zealand Navy has operated. Name HMNZS ''Aotearoa'' bears the Māori name for New Zealand. Aotearoa is commonly translated "the land of the long white cloud". The ship has been assigned the pennant number A11. Design and description The ship is ice-strengthened and winterised to facilitate operations in Antarctica's extreme weather conditions. In addition to the wave-piercing hull design, this was Rolls-Royce's first naval hybrid electrical system. Rolls-Royce designed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline. General features There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges to a needle-sharp surface of revolution in the case of a racing multihull sailboat. The shape is chosen to strike a balance between cost, hydrostatic considerations (accommodation, load carrying, and stability), hydrodynamics (speed, power requirements, and motion and behavior in a seaway) and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bow (ship)
The bow () is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. The aft end of the boat is the stern. Prow may be used as a synonym for bow or it may mean the forward-most part of the bow above the waterline. Function A ship's bow should be designed to enable the hull to pass efficiently through the water. Bow shapes vary according to the speed of the boat, the seas or waterways being navigated, and the vessel's function. Where sea conditions are likely to promote pitching, it is useful if the bow provides reserve buoyancy; a flared bow (a raked stem with flared topsides) is ideal to reduce the amount of water shipped over the bow. Ideally, the bow should reduce the resistance and should be tall enough to prevent water from regularly washing over the top of it. Large commercial barges on inland waterways rarely meet big waves and may have remarkably little freeboard at the bow, whereas fast military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid. For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress (mechanics)
In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elongation which is also known as deformation, like the stretching of an elastic band, it is called tensile stress. But, when the forces result in the compression of an object, it is called compressive stress. It results when forces like tension or compression act on a body. The greater this force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Therefore, stress is measured in newton per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave-making Resistance
Wave-making resistance is a form of drag that affects surface watercraft, such as boats and ships, and reflects the energy required to push the water out of the way of the hull. This energy goes into creating the wave. Physics For small displacement hulls, such as sailboats or rowboats, wave-making resistance is the major source of the marine vessel drag. A salient property of water waves is dispersiveness; i.e., the greater the wavelength, the faster it moves. Waves generated by a ship are affected by her geometry and speed, and most of the energy given by the ship for making waves is transferred to water through the bow and stern parts. Simply speaking, these two wave systems, i.e., bow and stern waves, interact with each other, and the resulting waves are responsible for the resistance. If the resulting wave is large, it carries much energy away from the ship, delivering it to the shore or wherever else the wave ends up or just dissipating it in the water, and that energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave-making Resistance
Wave-making resistance is a form of drag that affects surface watercraft, such as boats and ships, and reflects the energy required to push the water out of the way of the hull. This energy goes into creating the wave. Physics For small displacement hulls, such as sailboats or rowboats, wave-making resistance is the major source of the marine vessel drag. A salient property of water waves is dispersiveness; i.e., the greater the wavelength, the faster it moves. Waves generated by a ship are affected by her geometry and speed, and most of the energy given by the ship for making waves is transferred to water through the bow and stern parts. Simply speaking, these two wave systems, i.e., bow and stern waves, interact with each other, and the resulting waves are responsible for the resistance. If the resulting wave is large, it carries much energy away from the ship, delivering it to the shore or wherever else the wave ends up or just dissipating it in the water, and that energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catamaran
A Formula 16 beachable catamaran Powered catamaran passenger ferry at Salem, Massachusetts, United States A catamaran () (informally, a "cat") is a multi-hulled watercraft featuring two parallel hulls of equal size. It is a geometry-stabilized craft, deriving its stability from its wide beam, rather than from a ballasted keel as with a monohull boat. Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic 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 and wave-induced motion, as compared with a monohull, and can give reduced wakes. Catamarans were invented by the Austronesian peoples which enabled their expansion to the islands of the Indian and Pacific Oceans. Catamarans range in size from small sailing or rowing ve ... [...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 terms f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferries
A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water taxi. Ferries form a part of the public transport systems of many waterside cities and islands, allowing direct transit between points at a capital cost much lower than bridges or tunnels. Ship connections of much larger distances (such as over long distances in water bodies like the Mediterranean Sea) may also be called ferry services, and many carry vehicles. History In ancient times The profession of the ferryman is embodied in Greek mythology in Charon, the boatman who transported souls across the River Styx to the Underworld. Speculation that a pair of oxen propelled a ship having a water wheel can be found in 4th century Roman literature "''Anonymus De Rebus Bellicis''". Though impractical, there is no reason why it could not wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Ship
A naval ship is a military ship (or sometimes boat, depending on classification) used by a navy A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval warfare, naval and amphibious warfare; namely, lake-borne, riverine, littoral zone, littoral, or ocean-borne combat operations and .... Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are Damage control, damage resilient and armed with weapon systems, though armament on troop transports is light or non-existent. Naval ships designed primarily for naval warfare are termed warships, as opposed to support (auxiliary ships) or shipyard operations. Naval ship classification Naval ship classification is a field that has changed over time, and is not an area of wide international agreement, so this article currently uses the system as currently used by the United States Navy. *Aircraft carrierships that serve as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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