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Crosstree
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. In modern sailing vessels, spreaders serve the same purpose. 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-wire A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. In modern sailing vessels, spreaders serve the same purpose. 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 Beam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spar (sailing)
A spar is a pole of wood, metal or lightweight materials such as carbon fibre used in the rigging of a sailing vessel to carry or support its sail. These include yards, booms, and masts, which serve both to deploy sail and resist compressive and bending forces, as well as the bowsprit and spinnaker pole. In larger vessels during the age of sail, spare spars could be roped together to provide a temporary surface known as a "spar deck". These served as jury-rigged repairs for permanent decks, or as an additional platform under which to shelter goods or crew. The term was also informally applied to areas of the forecastle The forecastle ( ; contracted as fo'c'sle or fo'c's'le) is the upper deck (ship), deck of a sailing ship forward of the foremast, or, historically, the forward part of a ship with the sailors' living quarters. Related to the latter meaning is t ... or quarterdeck where spare spars were stored by laying them flat against the existing decking. In the moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing Ship
A sailing ship is a sea-going vessel that uses sails mounted on Mast (sailing), masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing Square rig, square-rigged or Fore-and-aft rig, 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 boat, outrigger hull configurations, which enabled the Austronesian expansion into the islands of the Indo-Pacific. This expansion originated in Ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shroud (sailing)
On a sailing ship, the shrouds are the standing rigging which holds the mast (sailing), 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 Chainplate, chain plates, which are tied into the hull. They are sometimes held outboard by Chains (nautical), 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 (nautical), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topgallant Mast
The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the median line of a ship or boat. Its purposes include carrying sails, spars, and derricks, 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 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 lower sections su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Mast
The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the median line of a ship or boat. Its purposes include carrying sails, spars, and derricks, 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 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 lower sections ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steamship
A steamship, often referred to as a steamer, is a type of steam-powered vessel, typically ocean-faring and seaworthy, that is propelled by one or more steam engines that typically move (turn) propellers or paddlewheels. The first steamships came into practical usage during the early 19th century; however, there were exceptions that came before. Steamships usually use the prefix designations of "PS" for ''paddle steamer'' or "SS" for ''screw steamer'' (using a propeller or screw). As paddle steamers became less common, "SS" is incorrectly assumed by many to stand for "steamship". Ships powered by internal combustion engines use a prefix such as "MV" for ''motor vessel'', so it is not correct to use "SS" for most modern vessels. As steamships were less dependent on wind patterns, new trade routes opened up. The steamship has been described as a "major driver of the first wave of trade globalization (1870–1913)" and contributor to "an increase in international trade that was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (radio)
In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating current, alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). It is the interface between radio waves Radio propagation, propagating through space and electric currents moving in metal Electrical conductor, conductors, used with a transmitter or receiver (radio), receiver. In transmission (telecommunications), transmission, a radio transmitter supplies an electric current to the antenna's Terminal (electronics), terminals, and the antenna radiates the energy from the current as electromagnetic radiation, electromagnetic waves (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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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" derives from the Middle English ''halier'' ("rope to haul with"), with the last syllable altered by association with the English unit of measure "yard". 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guy Rope
A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding 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 ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
