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Hydrostatic 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 centers of gravity, 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 one generation to the next with only min ... [...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 te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Stabilizing Gyroscopes USS Henderson 1917
A ship is a large vessel that travels the world's oceans and other navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. Ship transport is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a ship-rigged sailing ship with three or more masts, each of which is square-rigged. The earliest historical evidence of boats is found in Egypt during the 4th millennium BCE. In 2024, ships had a global cargo capacity of 2.4 billion tons, with the three largest classes being ships carrying dry bulk (43%), oil tankers (28%) and container ships (14%). Nomenclature Ships are typically larger than boats, but there is no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudder Roll Stabilisation System
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or afterend. Often rudders are shaped to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics. History of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yacht
A yacht () is a sail- or marine propulsion, motor-propelled watercraft made for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a , as opposed to a , such a pleasure vessel is likely to be at least in length and may have been judged to have good aesthetic qualities. The Commercial Yacht Code classifies yachts and over as . Such yachts typically require a hired crew and have higher construction standards. Further classifications for large yachts are : carrying no more than 12 passengers; : solely for the pleasure of the owner and guests, or by Flag#At sea, flag, the country under which it is registered. A superyacht (sometimes ) generally refers to any yacht (sail or power) longer than . Racing yachts are designed to emphasize performance over comfort. Charter yachts are run as a business for profit. As of 2020, there were more than 15,000 yachts of sufficient size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cruise Ship
Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports of call, where passengers may go on Tourism, tours known as "shore excursions". Modern cruise ships tend to have less hull strength, speed, and agility compared to ocean liners. However, they have added amenities to cater to water tourism, water tourists, with recent vessels being described as "balcony-laden floating condominiums". there were 302 cruise ships operating worldwide, with a combined capacity of 664,602 passengers. Cruising has become a major part of the tourism industry, with an estimated market of $29.4 billion per year, and over 19 million passengers carried worldwide annually . The industry's rapid growth saw nine or more newly built ships catering to a North American clientele added every year since 2001, as well as others servicing European clientele until the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around the aircraft's longitudinal axis), which normally results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called rolling or banking. Considerable controversy exists over credit for the invention of the aileron. The Wright brothers and Glenn Curtiss fought a years-long legal battle over the Wright patent of 1906, which described a method of wing-warping to achieve lateral control. The brothers prevailed in several court decisions which found that Curtiss's use of ailerons violated the Wright patent. Ultimately, the First World War compelled the U.S. Government to legislate a legal resolution. A much earlier aileron concept was patented in 1868 by British scientist Matthew Piers Watt Boul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stabilizer (ship)
Ship stabilizers (or stabilisers) are fins or rotors mounted beneath the waterline and emerging laterally from the hull (watercraft), hull to reduce a ship's ship motions#Rotational motions, roll due to wind or waves. ''Active fins'' are controlled by a gyroscope, gyroscopic control system. When the gyroscope senses the ship roll, it changes the fins' angle of attack so that the forward motion of the ship exerts force to counteract the roll. ''Fixed fins'' and bilge keels do not move; they reduce roll by hydrodynamic drag exerted when the ship rolls. Stabilizers are mostly used on ocean-going ships. Function Fins work by producing lift (force), lift or downforce when the vessel is in motion. The lift produced by the fins should work against the roll moment of the vessel. To accomplish this, two wings, each installed underwater on either side of the ship, are used. Stabilizers can be: *Retractable - All medium and large cruise and ferry ships have the ability to retract the fins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stabilizer Fin
A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, stability and trim in yaw (also known as directional or weathercock stability). It is part of the aircraft empennage, specifically of its stabilizers. The vertical tail is typically mounted on top of the rear fuselage, with the horizontal stabilizers mounted on the side of the fuselage (a configuration termed "conventional tail"). Other configurations, such as T-tail or twin tail, are sometimes used instead. Vertical stabilizers have occasionally been used in motor sports, with for example in Le Mans Prototype racing. Function Principle The vertical tail of an aircraft typically consists of a fixed vertical stabilizer or fin on which a movable rudder is mounted. A trim tab may similarly be mounted on the rudder. Together, their r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Actuators
An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate Laplace force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy. Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers, or by alternating current (AC) sources, such as a power grid, inverters or electrical generators. Electric motors may also be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed or brushless, single-phase, two-phase, or three-phase, axial or radial flux, and may be air-cooled or liquid-cooled. Standardized electric motors provide power for industrial use. The lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Pistons
Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and they cover concepts such as pipe flow, dam design, fluidics, and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue. ''Free surface hydraulics'' is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, canals, lakes, estuaries, and seas. Its sub-f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravane (water Kite)
The paravane is a towed winged (hydrofoiled) underwater object—a water kite. Paravanes have been used in sport or commercial fishing, marine exploration and industry, sports and military applications. The wings of paravanes are sometimes in a fixed position, else positioned remotely or by actions of a human pilot. Pioneer parafoil developer Domina Jalbert considered water kites hardly different from air kites. However, paravanes generally orient themselves in respect to the water surface. They may have sensors that record or transmit data or are used entirely for generating a holding force like a sea anchor does. While a sea-anchor allows a vessel to drift more slowly downwind, the paravane travels sideways to the pull at one to several times the pulling speed. Paravanes are, like air kites, often symmetrical in one axis and travel in two directions, the change being effected by gybing, shunting, or flipping over. Military applications The paravane , a form of towed underwat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
