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Weather Helm
Weather helm is the tendency of sailing vessels to turn towards the source of wind, creating an unbalanced helm that requires pulling the tiller to windward (i.e. 'to weather') in order to counteract the effect. Weather helm is the opposite of lee helm. It is generally less troublesome than lee helm. Overview Weather helm is the result of a leeward and aft shift of a vessel's vector center of effort (the direction to which the force generated by the sails is pushing). This shift is caused by excess pressure on the mainsail, which overpowers the windward lateral resistance generated by the jib (or other head sail) and keel or centerboard. This results in an imbalance of force at the stern from windward, and the craft pivots about the center of drag (often near the center of the keel or centerboard), causing the bow to drive windward. Weather helm does not only result from an overpowered main; when a vessel is heeling to leeward, the aft component of keel drag is moved to windwar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailboat
A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminology has varied across history, many terms have specific meanings in the context of modern yachting. A great number of sailboat-types may be distinguished by size, hull configuration, keel type, purpose, number and configuration of masts, and sail plan. Popular monohull designs include: Cutter The cutter is similar to a sloop with a single mast and mainsail, but generally carries the mast further aft to allow for a jib and staysail to be attached to the head stay and inner forestay, respectively. Once a common racing configuration, today it gives versatility to cruising boats, especially in allowing a small staysail to be flown from the inner stay in high winds. Catboat A catboat has a single mast mounted far forward and does not carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sloop
A sloop is a sailboat with a single mast typically having only one headsail in front of the mast and one mainsail aft of (behind) the mast. Such an arrangement is called a fore-and-aft rig, and can be rigged as a Bermuda rig with triangular sails fore and aft, or as a gaff-rig with triangular foresail(s) and a gaff rigged mainsail. Sailboats can be classified according to type of rig, and so a sailboat may be a sloop, catboat, cutter, ketch, yawl, or schooner. A sloop usually has only one headsail, although an exception is the Friendship sloop, which is usually gaff-rigged with a bowsprit and multiple headsails. If the vessel has two or more headsails, the term cutter may be used, especially if the mast is stepped further towards the back of the boat. When going before the wind, a sloop may carry a square-rigged topsail which will be hung from a topsail yard and be supported from below by a crossjack. This sail often has a large hollow foot, and this foot is sometimes fil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sail Plan
A sail plan is a description of the specific ways that a sailing craft is rigged. Also, the term "sail plan" is a graphic depiction of the arrangement of the sails for a given sailing craft.> In the English language, ships were usually described, until the end of the eighteenth century, in terms of their type of hull design. Using the type of rig as the main type identifer for a vessel only became common in the nineteenth century. This is illustrated by the terminology for ships in the large fleet of colliers that traded to London from the coal ports of the Northeast of England (of which was a well-known example). Many of these full-rigged ships (square rigged on all of three masts) had the hull type "bark"another common classification was "cat". In the second half of the eighteenth century, the square sails on the mizzen were often eliminated. The resulting rig acquired the name of the hull type: initially as "bark" and soon as "barque". This explains the Royal Navy's descripti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Rig
Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called ''yards'' and their tips, outside the lifts, are called the ''yardarms.'' A ship mainly rigged so is called a square-rigger. The square rig is aerodynamically the most efficient running rig (i.e., sailing downwind), and stayed popular on ocean-going sailing ships until the end of the Age of Sail. The last commercial sailing ships, windjammers, were usually square-rigged four-masted barques. History The oldest archaeological evidence of use of a square-rig on a vessel is an image on a clay disk from Mesopotamia from 5000 BC. Single sail square rigs were used by the ancient Egyptians, the Phoenicians, the Greeks, the Romans, and the Celts. Later the Scandinavians, the Germanic peoples, and the Slavs adopted the single square-rigged sail, with it be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trade Wind
The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere, strengthening during the winter and when the Arctic oscillation is in its warm phase. Trade winds have been used by captains of sailing ships to cross the world's oceans for centuries. They enabled colonial expansion into the Americas, and trade routes to become established across the Atlantic Ocean and the Pacific Ocean. In meteorology, they act as the steering flow for tropical storms that form over the Atlantic, Pacific, and southern Indian oceans and make landfall in North America, Southeast Asia, and Madagascar and East Africa. Shallow cumulus clouds are seen within trade wind regimes and are capped from becoming taller by a trade wind inversion, which is caused by descending air aloft from within the subtropical ridge. The weak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whisker Pole
A spinnaker pole is a spar used in sailboats (both dinghys and yachts) to help support and control a variety of headsails, particularly the spinnaker. However, it is also used with other sails, such as genoas and jibs, when sailing downwind with no spinnaker hoisted. (Since the load on a spinnaker pole is very light on this point of sailing, sometimes a special light spinnaker pole called a whisker pole is used in these circumstances.) The spinnaker pole is rigged to run from the base of the mast, where there is a special fitting for attaching one end of the pole, out to windward over the side of the boat. There, one of the control lines of whichever sail it is to be used with is run through a fitting on the other end of the spinnaker pole. This allows for more precise control of the corner of the sail to which the line is attached. For a spinnaker, the line attached to the pole is the guy, or brace, and the corner is the tack. For other headsails, such as a jib, the line would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinnaker
A spinnaker is a sail designed specifically for sailing off the wind on courses between a reach (wind at 90° to the course) to downwind (course in the same direction as the wind). Spinnakers are constructed of lightweight fabric, usually nylon, and are often brightly colored. They may be designed to perform best as either a reaching or a running spinnaker, by the shaping of the panels and seams. They are attached at only three points and said to be ''flown''. Nomenclature Informal names for a spinnaker are ''kite'' or ''chute'' (owing to their resemblance to a parachute in both construction and appearance). Boats may have more than one spinnaker, differentiated by a letter to indicate symmetric (S) or asymmetric (A) and a number to indicate size (with higher numbers indicating smaller size), e.g. ''A1'' would be a large asymmetric sail and ''S3'' would be a smaller symmetric sail. Operation A spinnaker is used for sailing with the direction of the wind. Symmetrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staysail
A staysail ("stays'l") is a fore-and-aft rigged sail whose Sail components#Edges, luff can be affixed to a stays (nautical), stay running forward (and most often but not always downwards) from a mast (sailing), mast to the deck (ship), deck, the bowsprit, or to another mast. Description Most staysails are triangular; however, some are four-cornered, notably some fisherman's staysails. Triangular staysails set forward of the foremost mast are called jibs, headsails, or foresails. The innermost such sail on a Cutter (ship), cutter, schooner, and many other rigs having two or more foresails is referred to simply as ''the staysail'', while the others are referred to as jibs, flying jibs, etc. Types of staysail include the tallboy staysail (a narrow staysail carried between the spinnaker and the mainsail on racing yachts), the Genoa (sail), genoa staysail (a larger one carried inside the spinnaker when broad reaching), and the bigboy staysail (another name for the shooter or bloo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutter (boat)
A cutter is a type of watercraft. The term has several meanings. It can apply to the rig (or sailplan) of a sailing vessel (but with regional differences in definition), to a governmental enforcement agency vessel (such as a coast guard or border force cutter), to a type of ship's boat which can be used under sail or oars, or, historically, to a type of fast-sailing vessel introduced in the 18th century, some of which were used as small warships. As a sailing rig, a cutter is a single-masted boat, with two or more headsails. On the eastern side of the Atlantic, the two headsails on a single mast is the fullest extent of the modern definition. In U.S. waters, a greater level of complexity applies, with the placement of the mast and the rigging details of the bowsprit taken into account so a boat with two headsails may be classed as a sloop. Government agencies use the term "cutter" for vessels employed in patrolling their territorial waters and other enforcement activities. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Over-canvassed Sailing
A sailing boat that is carrying too much sail for the current wind conditions is said to be over-canvassed. An over-canvassed boat, whether a dinghy, a yacht or a sailing ship, is difficult to steer and control and tends to heel or roll too much. If the wind continues to rise, an over-canvassed sailing boat will become dangerous and ultimately gear may break or it may round-up into the wind, broach or capsize. Any of these eventualities puts the safety of the crew and the vessel in danger. To over-canvass a sailing boat is considered unseamanlike and imprudent. In order to reduce sail, individual sails may be lowered or furled and existing sails may be reefed. Counter-intuitively, many boats will sail faster, and certainly more smoothly, comfortably and safely, when carrying the correct amount of sail in a strong wind than they would if over-canvassed and excessively rolling, heeling, carrying too much weather helm Weather helm is the tendency of sailing vessels to turn towar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steering
Steering is a system of components, linkages, and other parts that allows a driver to control the direction of the vehicle. Introduction The most conventional steering arrangement allows a driver to turn the front wheels of a vehicle using a hand–operated steering wheel positioned in front of the driver. The steering wheel is attached to a steering column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ..., which is linked to rods, pivots and gears that allow the driver to change the direction of the front wheels. Other arrangements are sometimes found on different types of vehicles; for example, a tiller or rear-wheel steering. Tracked vehicles such as bulldozers and tanks usually employ differential steering, where the tracks are made to move at different speeds or even in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
