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Backstay
A backstay is a piece of standing rigging on a sailing vessel that runs from the mast to either its transom or rear quarter, counteracting the forestay and jib. It is an important sail trim control and has a direct effect on the shape of the mainsail and the headsail. Backstays are generally adjusted by block and tackle, hydraulic adjusters, or lines leading to winches. Types Backstays may be ''permanent'' or ''running''. Permanent backstay A permanent backstay is attached to the top of the mast. Running backstays appear in pairs attached about two-thirds of the way up the mast (sometimes at multiple locations along the length of the mast). In general, most modern sailboats have a permanent backstay and some have a permanent backstay combined with running backstays. Backstays are not always found on all vessels, especially smaller ones. A permanent backstay is attached at the top of the mast and may or may not be readily adjustable. In a masthead rig, tensioning the perma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fractional Rig
A fractional rig on a sailing vessel consists of a foresail, such as a jib or genoa sail, that does not reach all the way to the top of the mast. The forestay is a wire that secures the mast to the front of the boat. With a fractional rig, the forestay is attached between about 1/8 and 1/4 of the length of the mast lower down, rather than being attached to the top of the mast as in a masthead rig. The foresail (jib or genoa) is then rigged to this stay. The mast is farther forward on the boat than on a masthead rig and so it has a larger mainsail. Masthead rigs are most common on larger keelboats or cruisers. A fractional rig is typically used on sailing dinghies and racing oriented keelboats, such as the J/24. Fractional rigs were introduced on race boats in order to allow more controllability of the surface of the mainsail and also less drag when sailing upwind. According to one manufacturer, "a key to making fast boats easier to sail than slow boats is the 'fraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standing Rigging
Standing rigging comprises the fixed lines, wires, or rods, which support each mast or bowsprit on a sailing vessel and reinforce those spars against wind loads transferred from the sails. This term is used in contrast to running rigging, which represents the moveable elements of rigging which adjust the position and shape of the sails. Historical development Early sailing vessels used rope of hemp or other fibers, which gave way to wire ropes of various types. Galvanized steel was common for the first half of the 20th century, continuing as an inexpensive option to its 1960s successor material—stainless steel cables and rods. In the late 20th Century, racing yachts adopted composite fiber lines for standing rigging, with the goal of reducing weight and windage aloft. Materials On modern yachts, standing rigging is often stainless steel wire, Nitronic-50 stainless steel rod or synthetic fiber Synthetic fibers or synthetic fibres (in British English; see spelling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaff Rig
Gaff rig is a sailing rig (configuration of sails, mast and stays) in which the sail is four-cornered, fore-and-aft rigged, controlled at its peak and, usually, its entire head by a spar (pole) called the ''gaff''. Because of the size and shape of the sail, a gaff rig will have running backstays rather than permanent backstays. The gaff enables a fore-and-aft sail to be four sided, rather than triangular. A gaff rig typically carries 25 percent more sail than an equivalent Bermuda rig for a given hull design. A sail hoisted from a gaff is called a gaff-rigged sail. Description Gaff rig remains the most popular fore-aft rig for schooner and barquentine mainsails and other course sails, and spanker sails on a square rigged vessel are always gaff rigged. On other rigs, particularly the sloop, ketch and yawl, gaff rigged sails were once common but have now been largely replaced by the Bermuda rig sail, which, in addition to being simpler than the gaff rig, usually all ... [...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, Windsurfing, windsurfer, or Kitesurfing, kitesurfer), on ''ice'' (iceboat) or on ''land'' (Land sailing, land yacht) over a chosen Course (navigation), 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 developmental steps. Steam allowed schedul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masthead Rig
A masthead rig on a sailing vessel consists of a forestay and backstay both attached at the top of the mast. The Bermuda rig can be split into two groups: the masthead rig and the fractional rig. The masthead rig has larger and more headsails, and a smaller mainsail, compared to the fractional rig. The major advantage a masthead sloop has over a fractional one, is that the jib is larger. Since the jib has no mast in front of it to cause turbulent airflow over it, it is considered much more efficient than the main, especially for sailing up wind. Also, since the fore stay is attached to the top of the mast, it pulls directly against the back stay. Tightening the back stay, then, increases the tension on the fore stay. This is useful because the jib needs considerable fore stay tension to set well. This need increases in direct proportion to the wind speed and jib size. Increasing the tension on the back stay does not tend to bend the mast, as it would on a fractional sloop. It put ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transom (nautical)
In some boats and ships, a transom is the aft transverse surface of the hull that forms the stern of a vessel. Historically, they are a development from the canoe stern (or "double-ender") wherein which both bow and stern are pointed. Transoms add both strength and width to the stern. They may be flat or curved and they may be vertical, raked forward (known as retroussé), or raked aft. In small boats and yachts, this flat termination of the stern is typically above the waterline, but large commercial vessels often exhibit vertical transoms that dip slightly beneath the water. On cruising boats, a counter stern may be truncated to form a "truncated counter stern", in which there is a part of the stern that approximates a transom. Although that standard stern transom is typically vertical, they may be raked such that there is an overhang above the water, as at the bow. A reverse transom is angled from the waterline forwards. On smaller boats such as dinghies, transoms may be ... [...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] |
McGraw Hill
McGraw Hill is an American education science company that provides educational content, software, and services for students and educators across various levels—from K-12 to higher education and professional settings. They produce textbooks, digital learning tools, and adaptive technology to enhance learning experiences and outcomes. It is one of the "big three" educational publishers along with Houghton Mifflin Harcourt and Pearson Education. McGraw Hill also publishes reference and trade publications for the medical, business, and engineering professions. Formerly a division of The McGraw Hill Companies (later renamed McGraw Hill Financial, now S&P Global), McGraw Hill Education was divested and acquired by Apollo Global Management in March 2013 for $2.4 billion in cash. McGraw Hill was sold in 2021 to Platinum Equity for $4.5 billion. History McGraw Hill was founded in 1888, when James H. McGraw, co-founder of McGraw Hill, purchased the ''American Journal of Railwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Current
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge carriers, which may be one of several types of particles, depending on the Electrical conductor, conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or Electron hole, holes. In an Electrolyte#Electrochemistry, electrolyte the charge carriers are ions, while in Plasma (physics), plasma, an Ionization, ionized gas, they are ions and electrons. In the International System of Units (SI), electric current is expressed in Unit of measurement, units of ampere (sometimes called an "amp", symbol A), which is equivalent to one coulomb per second. The ampere is an SI base unit and electric current is a ISQ base quantity, base quantity in the International System of Qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator (electricity)
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and electrical conductor, conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are Nonmetal (chemistry), non-metals. A perfect insulator does not exist because even the materials used as insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as electrical breakdown, and the voltage at which it occurs is called the breakdown voltage of an insulator. Some materials such as glass, Electrical insulation paper, paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightning Strike
A lightning strike or lightning bolt is a lightning event in which an electric discharge takes place between the atmosphere and the ground. Most originate in a cumulonimbus cloud and terminate on the ground, called cloud-to-ground (CG) lightning. A less common type of strike, ground-to-cloud (GC) lightning, is upward-propagating lightning initiated from a tall grounded object and reaching into the clouds. About 25% of all lightning events worldwide are strikes between the atmosphere and earth-bound objects. Most are intracloud (IC) lightning and cloud-to-cloud (CC), where discharges only occur high in the atmosphere.Cooray, Vernon. (2014). Lightning Flash (2nd Edition) - 1. Charge Structure and Geographical Variation of Thunderclouds. Page 4. Institution of Engineering and Technology. Lightning strikes the average commercial aircraft at least once a year, but modern engineering and design means this is rarely a problem. The movement of aircraft through clouds can even cause lightn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Google Books
Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google that searches the full text of books and magazines that Google has scanned, converted to text using optical character recognition (OCR), and stored in its digital database.The basic Google book link is found at: https://books.google.com/ . The "advanced" interface allowing more specific searches is found at: https://books.google.com/advanced_book_search Books are provided either by publishers and authors through the Google Books Partner Program, or by Google's library partners through the Library Project. Additionally, Google has partnered with a number of magazine publishers to digitize their archives. The Publisher Program was first known as Google Print when it was introduced at the Frankfurt Book Fair in October 2004. The Google Books Library Project, which scans works in the collections of library partners and adds them to the digital inventory, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
