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Riding Turn
A turn is one round of rope on a pin or cleat, or one round of a coil. Turns can be made around various objects, through rings, or around the standing part of the rope itself or another rope. A turn also denotes a component of a knot. When the legs of a loop are brought together and crossed the rope has taken a turn. One distinguishes between single turn, round turn, and two round turns depending on the number of revolutions around an object. The benefit of round turns is best understood from the capstan equation. Riding turn A riding turn is a section of rope that passes on top of another section of rope, often parallel or at only a slight angle to the section below. Examples of riding turns can be seen in both the constrictor knot and the strangle knot. The second course of wrappings in some seizing knots can be referred to as riding turns. The formation of an unintentional riding turn on a sailing winch can cause it to jam. Single hitch A single hitch is a type of knot. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyes And Turns
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons (neurones). In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods. The most simple eyes, pit eyes, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine. Construction Rope may be constructed of any long, stringy, fibrous material, but generally is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are significantly stronger than their natural fibre counterparts, they have a higher tensile strength, they are more resistant to rotting than ropes created from natural fibres, and they can be made to float on water. But synthetic ropes also possess certain disadvantages, including slipperiness, and some can be damaged more easily by UV light. Common natural fibres for rope are Manila hemp, hemp, linen, cotton, coir, jute, straw, and sisal. Synthetic fibres in use for rope-making include polypropylene, nylon, polyesters (e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belaying Pin
Properly securing a line to a belaying pin starts by leading the line under and behind the base of the pin to begin the figure-8 pattern left, Lines coiled and secured by belaying pins A belaying pin is a solid metal or wooden device used on traditionally rigged sailing vessels to secure lines of running rigging. Largely replaced on most modern vessels by cleats, they are still used, particularly on square rigged ships. A belaying pin is composed of a round handle and cylindrical shaft. The shaft is inserted into a hole in various strategically located wooden ''pinrails'' (lining the inside of the bulwarks, surrounding the base of masts, or free-standing, called fife rails) up to the base of the handle. A line is then led under and behind the base of the pin then round the top in a Figure-8 pattern till at least four turns are complete. Excess line is coiled and stored neatly by taking a bight The word is derived from Old English ''byht'' (“bend, angle, corner; bay, bigh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleat (nautical)
In nautical contexts, a cleat is a device for securing a rope. Types Types of cleat designs include the following: * A horn cleat is the traditional design, featuring two “horns” extending parallel to the deck or the axis of the spar, attached to a flat surface or a spar, and resembling an anvil. * A cam cleat in which one or two spring-loaded cams pinch the rope, allowing the rope to be adjusted easily, and quickly released when under load. * A jam cleat in which the line is pinched in a v-shaped slot. * A clam cleat (or jam cleat) in which the rope is held between two fluted stationary pieces. Such a cleat vaguely resembles two halves of a clam shell held back to back. It is more compact than a cam cleat, but the rope is less easily released under load. A cleat hitch is a knot used to secure a rope to a cleat. Tied cleat.jpg, A line tied with a cleat hitch to a horn cleatAshley 1993, p. 286. on a dock. The line comes from a boat off the top of the picture, around the ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torus
In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not touch the circle, the surface has a ring shape and is called a torus of revolution. If the axis of revolution is tangent to the circle, the surface is a horn torus. If the axis of revolution passes twice through the circle, the surface is a spindle torus. If the axis of revolution passes through the center of the circle, the surface is a degenerate torus, a double-covered sphere. If the revolved curve is not a circle, the surface is called a ''toroid'', as in a square toroid. Real-world objects that approximate a torus of revolution include swim rings, inner tubes and ringette rings. Eyeglass lenses that combine spherical and cylindrical correction are toric lenses. A torus should not be confused with a '' solid torus'', which is formed by r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standing Part
A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ''bend'' fastens two ends of a rope to each another; a ''loop knot'' is any knot creating a loop; and ''splice'' denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory. History Knots and knotting have been used and studied throughout history. For example, Chinese knotting is a decorative handicraft art that began as a form of Chinese folk art in the Tang and Song Dynasty (960–1279 AD) in China, later popularized in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot
A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ''bend'' fastens two ends of a rope to each another; a ''loop knot'' is any knot creating a loop; and ''splice'' denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory. History Knots and knotting have been used and studied throughout history. For example, Chinese knotting is a decorative handicraft art that began as a form of Chinese folk art in the Tang and Song Dynasty (960–1279 AD) in China, later popularized in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capstan Equation
The capstan equation or belt friction equation, also known as Euler-Eytelwein's formula (after Leonhard Euler and Johann Albert Eytelwein), relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a capstan). Because of the interaction of frictional forces and tension, the tension on a line wrapped around a capstan may be different on either side of the capstan. A small ''holding'' force exerted on one side can carry a much larger ''loading'' force on the other side; this is the principle by which a capstan-type device operates. A holding capstan is a ratchet device that can turn only in one direction; once a load is pulled into place in that direction, it can be held with a much smaller force. A powered capstan, also called a winch, rotates so that the applied tension is multiplied by the friction between rope and capstan. On a tall ship a holding capstan and a powered capstan are used in tandem so that a small force c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constrictor Knot
The constrictor knot is one of the most effective binding knots.Clifford W. Ashley, ''The Ashley Book of Knots'' (New York: Doubleday, 1944), 224-225.Brion Toss, ''The Complete Rigger's Apprentice'' (Camden, Maine: International Marine, 1998), 10-13.Geoffrey Budworth, ''The Complete Book of Knots'' (London: Octopus, 1997), 136-139. Simple and secure, it is a harsh knot that can be difficult or impossible to untie once tightened. It is made similarly to a clove hitch but with one end passed under the other, forming an overhand knot under a riding turn. The double constrictor knot is an even more robust variation that features two riding turns. History First called "constrictor knot" in Clifford Ashley's 1944 work ''The Ashley Book of Knots'', this knot likely dates back much further.Cyrus Lawrence Day, ''The Art of Knotting and Splicing, 4th ed.'' (Annapolis: Naval Institute Press, 1986), 112. Although Ashley seemed to imply that he had invented the constrictor knot over 25 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strangle Knot
The strangle knot is a simple binding knot. Similar to the constrictor knot, it also features an overhand knot under a riding turn. A visible difference is that the ends emerge at the outside edges, rather than between the turns as for a constrictor. This knot is a rearranged double overhand knot and makes up each half of the double fisherman's knot. See also *List of binding knots *List of knots *Clove hitch The clove hitch is a type of knot. Along with the bowline and the sheet bend, it is often considered one of the most important knots. A clove hitch is two successive half-hitches around an object. It is most effectively used as a crossing kno ... in comparison * Transom knot References {{knot-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizing (knot)
Seizings are a class of stopping knots used to semi-permanently bind together two ropes, two parts of the same rope, or rope and another object. Akin to lashings, they use string or small-stuff to produce friction and leverage to immobilize larger ropes. Seizings are not recommended for heavy loads for critical use as strain reduces the diameter of the main rope and can permit slippage even with proper construction. According to ''The Ashley Book of Knots'', "A ''seizing'' holds several objects together."Ashley (1944), p.546. The other type of stopping knots are whipping knots. See also * Ropework Ropework or marlinespike seamanship are traditional umbrella terms for a skillset spanning the use, maintenance, and repair of rope. Included are tying knots, splicing, making lashings, whippings, and proper use and storage of rope. While th ... References Knots {{Knot-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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