Information about Leeboard
A leeboard is a lifting foil used by a sailboat, much like a centerboard, but located on the leeward side of the boat. The leeward side is used so that the leeboard isn't lifted from the water when the boat heels, or leans under the force of the wind.
According to traditional design principles, a boat utilizing a leeboard either needs to have two retractable leeboards, one on each side, or a method of removing the leeboard and attaching it to either side while under way, because nearly all sailboats tack to work their way upwind (with the exception of the proa). However, some small sailboat designers claim to have created seaworthy vessels with only a single, fixed leeboard[1][2][3]. On a traditional two-leeboard (or non-fixed leeboard) design, they are designed so that the windward board can be retracted when it isn't needed to reduce drag. Unlike centerboards, which are symmetric along the boat's axis, leeboards are often asymmetric, so they more efficiently provide lift in one direction only. Some fast racing scows use bilgeboards, which are mounted between the centerline of the hull and the sides, specifically so that they can use a pair of asymmetric foils for maximum lift and minimum drag.
Leeboards are not common in commercially built boats, because many people consider them inelegant and awkward (thus preventing them from being used in commercial boats, and perpetuating the cycle). They are far more common in home-built boats, especially stitch and glue sailboats. Leeboards simplify construction of the hull, as they are attached to the outside and do not require holes in the hull, which can leak. Since centerboards are retractable, they require a large, watertight trunk to hold them in place when retracted, and this occupies what otherwise might be useful space in the cabin or cockpit of the boat. Use of leeboards, while it adds complexity to the process of tacking, leaves the floor of the boat unobstructed.
In the past, leeboards were used by relatively large inshore sailing vessels used for transport, such as Dutch barges and Thames barges. For these boats, leeboards provided the advantages of shallow draught for working close inshore and an unobstructed hold for cargo. They were also easier to build than a large centreboard would have been.
According to traditional design principles, a boat utilizing a leeboard either needs to have two retractable leeboards, one on each side, or a method of removing the leeboard and attaching it to either side while under way, because nearly all sailboats tack to work their way upwind (with the exception of the proa). However, some small sailboat designers claim to have created seaworthy vessels with only a single, fixed leeboard[1][2][3]. On a traditional two-leeboard (or non-fixed leeboard) design, they are designed so that the windward board can be retracted when it isn't needed to reduce drag. Unlike centerboards, which are symmetric along the boat's axis, leeboards are often asymmetric, so they more efficiently provide lift in one direction only. Some fast racing scows use bilgeboards, which are mounted between the centerline of the hull and the sides, specifically so that they can use a pair of asymmetric foils for maximum lift and minimum drag.
Leeboards are not common in commercially built boats, because many people consider them inelegant and awkward (thus preventing them from being used in commercial boats, and perpetuating the cycle). They are far more common in home-built boats, especially stitch and glue sailboats. Leeboards simplify construction of the hull, as they are attached to the outside and do not require holes in the hull, which can leak. Since centerboards are retractable, they require a large, watertight trunk to hold them in place when retracted, and this occupies what otherwise might be useful space in the cabin or cockpit of the boat. Use of leeboards, while it adds complexity to the process of tacking, leaves the floor of the boat unobstructed.
In the past, leeboards were used by relatively large inshore sailing vessels used for transport, such as Dutch barges and Thames barges. For these boats, leeboards provided the advantages of shallow draught for working close inshore and an unobstructed hold for cargo. They were also easier to build than a large centreboard would have been.
The lift force, lifting force or simply lift is a mechanical force generated by solid objects as they move through a fluid.[1]
While many types of objects can generate lift, the most common and familiar object in this category is the airfoil, a
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While many types of objects can generate lift, the most common and familiar object in this category is the airfoil, a
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A foil is a surface designed to maximize lift (force generated perpendicular to the fluid flow) while minimizing drag (force generated in the direction of the fluid flow) in a given range of conditions. Foils may be designed to operate in any fluid, such as air or water.
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A centreboard is a retractable keel which pivots out of a slot in the hull of a sailboat, known as a centerboard trunk (US) or case. The pivoting ability allows the centreboard to be raised to operate in shallow waters, to reduce drag when the full area of the centreboard isn't
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Windward is the direction from which the wind is blowing at the time in question. The side of a ship which is towards the windward is the weather side. If the vessel is heeling under the pressure of the wind, this will be the "higher side"
Leeward
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Leeward
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Tack is a term used in sailing that has different meanings in different contexts.
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Sail
The tack is the lower corner of the sail's leading edge. On a sloop rigged sailboat, the mainsail tack is connected to the mast and the boom at the gooseneck...... Click the link for more information.
Proa is a multihull vessel consisting of two (usually) unequal parallel hulls, superficially similar to an outrigger canoe. Found in many configurations and forms, it was developed as a sailing vessel in Micronesia (Pacific Ocean), and forms of it may be found as far as Madagascar
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Windward is the direction from which the wind is blowing at the time in question. The side of a ship which is towards the windward is the weather side. If the vessel is heeling under the pressure of the wind, this will be the "higher side"
Leeward
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Leeward
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drag (sometimes called resistance) is the force that resists the movement of a solid object through a fluid (a liquid or gas). Drag is made up of friction forces, which act in a direction parallel to the object's surface (primarily along its sides, as friction forces at the
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A scow, in the original sense, is a flat bottomed boat with a blunt bow, often used to haul garbage or similar bulk freight; cf. barge. The etymology of the word is from Dutch schouwe, meaning such a boat.
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A bilgeboard is a lifting foil used in a sailboat, which resembles a cross between a centerboard and a leeboard. Bilgeboards are mounted between the centerline of the boat and the sides, and are almost always asymmetric foils mounted at an angle to maximize lateral lift while
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The terms stitch and glue, tack and tape, and stitch and tape all refer to a construction method used by many amateur boat builders.
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History
The stitch and glue method was developed by woodwork teacher Ken Littledyke for the manufacture of canoes, using..... Click the link for more information.
A hull is the body of a ship or boat. It is a central concept in floating vessels as it provides the buoyancy that keeps the vessel from sinking.
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General features
Nearly all watercraft, from small boats to the largest ships, adhere to a general form that serve the needs of..... Click the link for more information.
A cabin is an enclosed room generally on a ship or an aircraft.
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Sailing ships
In sailing ships, the officers and paying passengers would have an individual or shared cabin...... Click the link for more information.
cockpit originally referred to the area where the coxswain was stationed. This led to the word being used to refer to the area towards the stern of a small decked vessel that houses the rudder controls, also the common location of the ship's surgeon during a naval battle.
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Sailing ship is now used to refer to any large, wind-powered, vessel. In technical terms, a ship was a sailing vessel with a specific rig of at least three masts, square rigged on all of them, making the sailing adjective redundant.
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anchor is a heavy object, often made out of metal, that is used to attach a ship to the bottom of a body of water at a specific point. There are two primary classes of anchors—temporary and permanent.
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anchor windlass is a machine that restrains and manipulates the anchor chain and/or rope on a boat, allowing the anchor to be raised and lowered. A notched wheel engages the links of the chain or the rope.
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beakhead is the protruding part of the foremost section of a sailing ship. It was fitted on sailing vessels from the 16th to the 18th century and served as a working platform by sailors working the sails of the bowsprit, the forward-pointing mast that carries the spritsails.
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A bilgeboard is a lifting foil used in a sailboat, which resembles a cross between a centerboard and a leeboard. Bilgeboards are mounted between the centerline of the boat and the sides, and are almost always asymmetric foils mounted at an angle to maximize lateral lift while
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boom brake is a device designed to control the swing of the boom on a sailboat. The boom brake acts as a preventer when sailing downwind, and can also be used to jibe the mainsail in a slow measured action.
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bow (pronounced to rhyme with how) is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow.
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capstan is a rotating machine used to apply force to another element, notably used on board ship and on dock walls, for heaving-in or veering ropes, cables, and hawsers.
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A centreboard is a retractable keel which pivots out of a slot in the hull of a sailboat, known as a centerboard trunk (US) or case. The pivoting ability allows the centreboard to be raised to operate in shallow waters, to reduce drag when the full area of the centreboard isn't
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A daggerboard is a retractable keel used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail.
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A deck is a permanent covering over a compartment or a hull[1] of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface.
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figurehead is a carved wooden decoration, often female or bestial, found at the prow of ships of the 16th to the 19th century. The practice was introduced with the galleons of the 16th century, as although earlier ships had often had some form of bow ornamentation, the figurehead
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Forecastle", also spelled fo'c's'le (pronounced /'fəʊksəl/), originally meant the upper deck of a sailing ship, forward of the foremast.
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The gunwale, (IPA /gʌnəl/ ) pronounced "gunnel" to rhyme with "tunnel", is a nautical term describing the top edge of the side of a boat.
Wale is the same word as the skin injury, a weal, which, too, forms a ridge.
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Wale is the same word as the skin injury, a weal, which, too, forms a ridge.
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A hull is the body of a ship or boat. It is a central concept in floating vessels as it provides the buoyancy that keeps the vessel from sinking.
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General features
Nearly all watercraft, from small boats to the largest ships, adhere to a general form that serve the needs of..... Click the link for more information.
jackline is a rope or wire strung from a ship's bow to stern to which a safety harness can be clipped, allowing a crewmember to move about the deck safely when there is risk of falling or being swept overboard.
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