Crosstrees
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Crosstrees
Crosstrees are the two horizontal spars at the upper ends of the topmasts of sailing ships, used to anchor the shrouds from the topgallant mast. Similarly, they may be mounted at the upper end of the topgallant to anchor the shrouds from the royal mast (if fitted). Similar transverse spars remain on steam ship and motor vessel masts to secure wire antennae or signal flag halyards. Explanation Any vertical structure like a mast is subject to dynamic swaying stress from wind, which levers immense force at the base of the mast. Such stress is countered through guy ropes which are diagonally supporting ropes from mast top to its base. These ropes share the load on the mast tops and communicate that force to the base structure. The taller the mast, the wider a base is required for the guy wires so as to form an appropriate angular support against the sway the mast is exposed to. Yet, ships are fixed in their beam (width) and hence only a limited angle is possible for the guy ...
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Crosstrees (PSF)
Crosstrees are the two horizontal spars at the upper ends of the topmasts of sailing ships that are used to anchor the shrouds from the topgallant mast. They may also be mounted at the upper end of the topgallant to anchor the shrouds from the royal mast (if fitted). Similar transverse spars remain on steamship and motor vessel masts to secure wire antennae or signal flag halyards. Explanation Any vertical structure like a mast is subject to dynamic swaying stress from wind, which levers immense force at the base of the mast. Such stress is countered through guy ropes which are diagonally supporting ropes from mast top to its base. These ropes share the load on the mast tops and communicate that force to the base structure. The taller the mast, the wider a base is required for the guy wires so as to form an appropriate angular support against the sway the mast is exposed to. Yet, ships are fixed in their beam (width) and hence only a limited angle is possible for the guy- ...
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Topmast
The masts of traditional sailing ships were not single spars, but were constructed of separate sections or masts, each with its own rigging. The topmast is one of these. The topmast is semi-permanently attached to the upper front of the lower mast, at the top. Its shrouds run to the edges of the top, rather than to the sides of the hull, though long shrouds leading well aft to the hull, more in the manner of backstays, are sometimes seen. In accordance with the standard square rig sail plan, the topmast carries the topsail. In the late 19th century, however, topsails became so big that merchant ships began to divide them into two separate sails for easier handling; since these were still on the topmast they were known as upper and lower topsails to preserve the consistency of the naming scheme. The majority of large square-riggers today carry separate upper and lower topsails. The main topmast carries the upper end of the main-topmast-staysail; a mizzen-topmast may carry the e ...
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Sailing Ship
A sailing ship is a sea-going vessel that uses sails mounted on masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing square-rigged or fore-and-aft sails. Some ships carry square sails on each mast—the brig and full-rigged ship, said to be "ship-rigged" when there are three or more masts. Others carry only fore-and-aft sails on each mast, for instance some schooners. Still others employ a combination of square and fore-and-aft sails, including the barque, barquentine, and brigantine. Early sailing ships were used for river and coastal waters in Ancient Egypt and the Mediterranean. The Austronesian peoples developed maritime technologies that included the fore-and-aft crab-claw sail and with catamaran and outrigger hull configurations, which enabled the Austronesian expansion into the islands of the Indo-Pacific. This expansion originated in Taiwan BC and propagated through Island Southeast Asia ...
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Shroud (sailing)
On a sailing boat, the shrouds are pieces of standing rigging which hold the mast up from side to side. There is frequently more than one shroud on each side of the boat. Usually a shroud will connect at the top of the mast, and additional shrouds might connect partway down the mast, depending on the design of the boat. Shrouds terminate at their bottom ends at the chain plates, which are tied into the hull. They are sometimes held outboard by channels, a ledge that keeps the shrouds clear of the gunwales.''The Lore of Ships,'' ed. by Bengt Kihlberg. Göteborg :Tre tryckare & New York: Holt, Rinehart & Winston, 1963. Shrouds are attached symmetrically on both the port and starboard sides. For those shrouds which attach high up the mast, a structure projecting from the mast must be used to increase the angle of the shroud at the attachment point, providing more support to the mast. On most sailing boats, such structures are called spreaders, and the shrouds they hold continue ...
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Topgallant Mast
The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat. Its purposes include carrying sails, spars, and derricks, and giving necessary height to a navigation light, look-out position, signal yard, control position, radio aerial or signal lamp. Large ships have several masts, with the size and configuration depending on the style of ship. Nearly all sailing masts are guyed. Until the mid-19th century, all vessels' masts were made of wood formed from a single or several pieces of timber which typically consisted of the trunk of a conifer tree. From the 16th century, vessels were often built of a size requiring masts taller and thicker than could be made from single tree trunks. On these larger vessels, to achieve the required height, the masts were built from up to four sections (also called masts). From lowest to highest, these were called: lower, top, topgallant, and royal masts. Giving the lo ...
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Royal Mast
Royal may refer to: People * Royal (name), a list of people with either the surname or given name * A member of a royal family Places United States * Royal, Arkansas, an unincorporated community * Royal, Illinois, a village * Royal, Iowa, a city * Royal, Missouri, an unincorporated community * Royal, Nebraska, a village * Royal, Franklin County, North Carolina, an unincorporated area * Royal, Utah, a ghost town * Royal, West Virginia, an unincorporated community * Royal Gorge, on the Arkansas River in Colorado * Royal Township (other) Elsewhere * Mount Royal, a hill in Montreal, Canada * Royal Canal, Dublin, Ireland * Royal National Park, New South Wales, Australia Arts, entertainment, and media * ''Royal'' (Jesse Royal album), a 2021 reggae album * ''The Royal'', a British medical drama television series * ''The Royal Magazine'', a monthly British literary magazine published between 1898 and 1939 * ''Royal'' (Indian magazine), a men's lifestyle bimonthly * Royal Te ...
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Antenna (radio)
In radio engineering, an antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic wave In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visib ...s (radio waves). In Receiver (radio), reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be Amplifier, amplified. Antennas are essential components of all radio equipment. An antenna is an array of conductor (material), conductors (Driven element, elements), elect ...
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Halyard
In sailing, a halyard or halliard is a line (rope) that is used to hoist a ladder, sail, flag or yard. The term ''halyard'' comes from the phrase "to haul yards". Halyards, like most other parts of the running rigging, were classically made of natural fibre like manila or hemp. Sail types * A square rig sail with a halyard is mounted on a lifting yard that is free to slide on a short section of the mast. The halyard is used to raise (hail or hal) the yard when setting the sail. * A gaff rigged sail has two; a throat halyard to lift the end of the gaff nearer the mast, and a peak halyard to lift the outer end. * A more modern triangular (Bermuda or "Marconi") sail has only one halyard which is attached at its uppermost point (the ''head''). Fastenings Halyards can be attached a number of ways to the head of a triangular sail. The most common methods are as follows: # A shackle through a headboard on the sail. # A bowline through a hole in the head. # A half hitch with a figure ...
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Guy Rope
A guy-wire, guy-line, guy-rope, or stay, also called simply a guy, is a tensioned cable designed to add stability to a free-standing structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and tents. A thin vertical mast supported by guy wires is called a guyed mast. Structures that support antennas are frequently of a lattice construction and are called "towers". One end of the guy is attached to the structure, and the other is anchored to the ground at some distance from the mast or tower base. The tension in the diagonal guy-wire, combined with the compression and buckling strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures. They are installed radially, usually at equal angles about the structure, in trios and quads. As the tower leans a bit due to the wind force, the increased guy tension is resolved into a compression force in the tower or mast and a later ...
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Guy-wire
A guy-wire, guy-line, guy-rope, or stay, also called simply a guy, is a tensioned cable designed to add stability to a free-standing structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and tents. A thin vertical mast supported by guy wires is called a guyed mast. Structures that support antennas are frequently of a lattice construction and are called "towers". One end of the guy is attached to the structure, and the other is anchored to the ground at some distance from the mast or tower base. The tension in the diagonal guy-wire, combined with the compression and buckling strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures. They are installed radially, usually at equal angles about the structure, in trios and quads. As the tower leans a bit due to the wind force, the increased guy tension is resolved into a compression force in the tower or mast and a later ...
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Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells designed for flatwater racing may have length to beam ratios as high as 30:1, while a cor ...
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Top (sailing Ship)
The top on a traditional square rigged ship, is the platform at the upper end of each (lower) mast. This is not the masthead "crow's nest" of the popular imagination – above the mainmast (for example) is the main-topmast, main-topgallant-mast and main-royal-mast, so that the top is actually about 1/4 to 1/3 of the way up the mast as a whole. The main purpose of the top is to anchor the shrouds of the topmast that extends above it. Shrouds down to the side of the hull would be at too acute an angle from the mast, so crosstrees running sideways out from the mast to spread the topmasts shrouds. These crosstrees rests on two trestle trees running fore and aft, which themself are placed on top of the cheeks of hounds, bolted to the sides of the mast. Placing a few timbers onto the crosstrees produces a useful platform, the top. The futtock shrouds carry the load of the upper shrouds into the mast below. At the upper end of the topmast and topgallant, there is a similar situation r ...
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