In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event. Only the ship's launching There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely used is the end-on launch, in which the vessel slides, usually stern first, down an inclined slipway. The side launch, whereby the ship enters the water broadside, is considered more significant in its creation.

Contents

Structural keels

Keel laid for the USS United States in drydock A drydock is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Drydocks are used for the construction, maintenance, and repair of ships, boats, and other watercraft

A structural keel is a large beam around which the hull A hull is the watertight body of a ship or boat. Above the hull comes the superstructure and deckhouse. The line where the hull meets the water surface is called the waterline of a ship A ship ( Audio (help·info)) is a large vessel that floats on water. Ships are generally distinguished from boats based on size and cargo or passenger capacity. In traditional terms, ships were considered to be vessels which had at least one continuous water-tight deck extending from bow to stern. However, some modern designs for ships, and boats, is built. The keel runs in the middle of the ship, from the bow The bow 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. The other end of the boat is called the stern to the stern The stern is the rear or aft part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. The stern side of a vessel is indicated with a white navigation light at night, and serves as the foundation A foundation is a structure that transfers loads to the earth. Foundations are generally broken into two categories: shallow foundations and deep foundations or spine of the structure, providing the major source of structural strength of the hull. The keel is generally the first part of a ship's hull to be constructed, and laying the keel, or placing the keel in the cradle in which the ship will be built, is often a momentous event in a ship's construction — so much so that the event is often marked with a ceremony, and the term lay the keel has entered the language as a phrase meaning the beginning of any significant undertaking. Modern ships are now largely built in a series of pre-fabricated, complete hull sections rather than being built around a single keel, so the start of the shipbuilding process is now considered to be when the first sheet of steel Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten. Carbon and other elements act as a hardening agent, preventing is cut.

The keel converts sideways force into a forward force.

The keel contributes substantially to the longitudinal strength and effectively local loading caused when docking the ship. The most common type of keel is the "flat plate keel", and this is fitted in the majority of ocean-going ships and other vessels. A form of keel found on smaller vessels is the "bar keel", which may be fitted in trawlers, tugs, and smaller ferries. Where grounding is possible, this type of keel is suitable with its massive scantlings In shipbuilding, the scantling refers to the collective dimensions of the various parts, particularly the framing and structural supports. The word is most often used in the plural to describe how much structural strength in the form of girders, I-beams, etc. is in a given section. The Scantling length refers to the structural length of a ship, but there is always a problem of the increased draft with no additional cargo capacity. If a double bottom is fitted, the keel is almost inevitably of the flat plate type, bar keels often being associated with open floors, where the plate keel may also be fitted.

Duct keels are provided in the bottom of some vessels. These run from the forward engine room bulkhead to the collision bulkhead and are utilized to carry the double bottom piping. The piping is then accessible when cargo is loaded.

If a ship suffers severe structural stress — classically during a shipwreck A shipwreck is the remains of a ship that has wrecked, either sunk or beached. A shipwreck can refer to a wrecked ship or to the event that caused the wreck, such as the striking of something that causes the ship to sink, the stranding of the ship on rocks, land or shoal, or the destruction of the ship at sea by violent weather. Whatever the cause, when running aground in a heavy sea — it is possible for the keel to break or be strained to the extent that it loses structural integrity. In this case the ship is commonly said to have "broken its back". Such a failure means that the entire structure of the ship and its machinery has been compromised and repairing such damage would require virtually re-building the ship from the ground up. A ship that has broken its back is almost certainly unsalvagable Marine salvage is the process of rescuing a ship, its cargo, or other property from peril. Salvage encompasses rescue towing, refloating a sunken or grounded vessel, or patching or repairing a ship. Today the protection of the environment from cargoes such as oil or other contaminants is often considered a high priority and subsequently written off The term write-off describes a reduction in recognized value. In accounting terminology, it refers to recognition of the reduced or zero value of an asset. In income tax statements, it refers to a reduction of taxable income as recognition of certain expenses required to produce the income. Write-off is also used in vehicle insurance to describe a by its insurers.

Hydrodynamic keels

Keels provide extra stability by providing a weight low enough to significantly lower the centre of gravity The centre of mass of a system of particles is the point at which the system's whole mass can be considered to be concentrated for the purpose of calculations. The center of mass is a function only of the positions and masses of the particles that compose the system. In the case of a rigid body, the position of its center of mass is fixed in.

Non-sailing keels

The keel surface on the bottom of the hull gives the ship greater directional control and stability. In non-sailing A sailboat or sailing boat is a boat propelled partly or entirely by sails. The term covers a variety of boats, larger than small vessels such as sailboards and smaller than sailing ships, but distinctions in size are not strictly defined and what constitutes a sailing ship, sailboat, or a smaller vessel varies by region and culture hulls, the keel helps the hull to move forward, rather than slipping to the side. In traditional boat building, this is provided by the structural keel, which projects from the bottom of the hull along most or all of its length. In modern construction the bar keel or flat-plate keel performs the same function. There are many types of fixed keels, including full keels, long keels, fin keels, winged keels, bulb keels, and bilge keels among other designs. Deep draft ships will typically have a flat bottom and employ only bilge keels, both to aid directional control and to damp rolling motions

Sailboat keels

In sailboats A sailboat or sailing boat is a boat propelled partly or entirely by sails. The term covers a variety of boats, larger than small vessels such as sailboards and smaller than sailing ships, but distinctions in size are not strictly defined and what constitutes a sailing ship, sailboat, or a smaller vessel varies by region and culture, keels use the forward motion of the boat to generate lift A fluid flowing past the surface of a body exerts a surface force on it. Lift is defined to be the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is defined to be the component of the surface force parallel to the flow direction to counter act the leeward force of the wind. The rudimentary purpose of the keel is to convert the sideways motion of the wind when it is abeam into forward motion. A secondary purpose of the keel is to provide ballast.

Capsizing effect of a sailing keel

Keels are different from centreboards A centerboard is a retractable keel which pivots out of a slot in the hull of a sailboat, known as a centerboard trunk or case. The pivoting ability allows the centerboard to be raised to operate in shallow waters, to move the center of lateral resistance to offset changes to the sailplan that move the center of effort aft and to reduce drag when and other types of foils in that keels are made of heavy materials to provide ballast Ballast is used in sailboats to provide moment to resist the lateral forces on the sail. Insufficiently ballasted boats will tend to tip, or heel, excessively in high winds. Too much heel may result in the boat capsizing. When sailing vessels carried cargo, it was at times necessary to sail to a port with no cargo. In order to do this enough to stabilize the boat. Keels may be fixed, or non-movable, or they may retract to allow sailing in shallower waters. Retracting keels may pivot (a swing keel) or slide upwards to retract, and are usually retracted with a winch A winch is a mechanical device that is used to pull in or let out (wind out) or otherwise adjust the "tension" of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form it consists of a spool and attached hand crank. In larger forms, winches stand at the heart of machines as diverse as tow due to the weight of the ballast. Since the keel provides far more stability when lowered than when retracted (due to the greater moment arm involved), the amount of sail carried is generally reduced when sailing with the keel retracted.

Types of non-fixed keels include swing keels and canting keels A canting keel is a form of sailing ballast, suspended from a rigid canting strut beneath the boat, which can be swung to windward of a boat under sail, in order to counteract the heeling force of the sail. The canting keel must be able to pivot to either port or starboard, depending on the current tack. Canting keels can be found on racing yachts, such as those competing in the Volvo Ocean Race The Volvo Ocean Race is a yacht race around the world, held every three years. It is named after its current owner, Volvo. They provide considerably more righting moment as the keel moves out to the windward-side of the boat while using less weight. The horizontal distance from the weight to the pivot is increased, which generates a larger righting moment.

Etymology

The word "keel" comes from Old English Old English or Anglo-Saxon is an early form of the English language that was spoken and written in parts of what are now England and south-eastern Scotland between at least the mid-5th century and the mid-12th century. What survives through writing represents primarily the literary register of Anglo-Saxon cēol, Old Norse Old Norse is a North Germanic language that was spoken by inhabitants of Scandinavia and inhabitants of their overseas settlements during the Viking Age, until about 1300 kjóll, = "ship A ship ( Audio (help·info)) is a large vessel that floats on water. Ships are generally distinguished from boats based on size and cargo or passenger capacity. In traditional terms, ships were considered to be vessels which had at least one continuous water-tight deck extending from bow to stern. However, some modern designs for ships, and boats," or "keel". It has the distinction of being regarded by some scholars as the very first word in the English language recorded in writing, having been recorded by Gildas Saint Gildas was a 6th-century British cleric. He is one of the best-documented figures of the Christian church in the British Isles during this period. His renowned learning and literary style earned him the designation Gildas Sapiens (Gildas the Wise). His work De Excidio et Conquestu Britanniae, which contains narratives of the post-Roman in his 6th century Latin Latin or sometimes Roman is an Italic language originally spoken in Latium and Ancient Rome. Although often considered a dead language, in view of the fact that it has no native, fluent speakers, Latin continues to be taught in schools and has been, and currently is, used in the process of new word production in modern languages from many work De Excidio et Conquestu Britanniae, under the spelling cyulae (he was referring to the three ships that the Saxons The Saxons were a confederation of Old Germanic tribes. Their modern-day descendants in Lower Saxony and Westphalia and other German states are considered ethnic Germans (the state of Sachsen is not inhabited by ethnic Saxons; the state of Sachsen-Anhalt is, though, in its northern and western parts); those in the eastern Netherlands are first arrived in).[1][2]

Carina is the Latin Latin or sometimes Roman is an Italic language originally spoken in Latium and Ancient Rome. Although often considered a dead language, in view of the fact that it has no native, fluent speakers, Latin continues to be taught in schools and has been, and currently is, used in the process of new word production in modern languages from many word for "keel" and is the origin of the term careen (to clean a keel and the hull in general, often by rolling the ship on its side). An example of this use is Careening Cove, a suburb of Sydney, Australia Sydney is the largest city in Australia and Oceania, and the state capital of New South Wales. Sydney has a metropolitan area population of approximately 4.5 million and an area of approximately 12,000 square kilometres (4,633 sq mi). Its inhabitants are called Sydneysiders, and Sydney is often called "the Harbour City". It is one of the, where careening was carried out in early colonial days.

See also

Notes

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  1. ^ "Gildas, The Ruin of Britain &c. (1899). pp. 4-252. The Ruin of Britain.". http://www.tertullian.org/fathers/gildas_02_ruin_of_britain.htm.
  2. ^ G. W. Whittaker (1970). Collected Essays. Ayer Publishing. p. 44. ISBN The International Standard Book Number is a unique numeric commercial book identifier based upon the 9-digit Standard Book Numbering (SBN) code created by Gordon Foster, now Emeritus Professor of Statistics at Trinity College, Dublin, for the booksellers and stationers W.H. Smith and others in 1966 0836916360. http://books.google.com/books?id=P94dqHC91DMC.

Bibliography

Parts of a sailing ship 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. In popular usage "ship" became associated with all large sailing vessels and when steam power came along the
Aftcastle An aftcastle is the upper deck of a sailing ship positioned behind the Mizzenmast. It was used in medieval shipping such as galleys or galleasses to provide a heightened platform from which to fire upon other ships; it was also a place of defense in the event of boarding. More common, but much smaller, is the forecastle · Anchor An 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 to act as a weight to keep the ship from moving. There are two primary classes of anchors—temporary and permanent. A permanent anchor is often called a mooring, and is rarely moved; it is quite possible the · Anchor windlass An 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. A brake is provided for control and the windlass is usually powered by an electric or hydraulic motor operating via a gear train · Beakhead A 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. The beakhead would be one of the most ornate sections of a ship, · Bilgeboard 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 minimizing drag. They are most often found on racing scows · Boom brake A 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 or gybe(UK) the mainsail in a slow measured action · Bow The bow 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. The other end of the boat is called the stern · Capstan The word, connected with the Old French capestan or cabestan, from Old Provençal cabestan, from capestre "pulley cord,", from Latin capistrum, -a halter, from capere, to take hold of, seems to have come into English (14th century) from Portuguese or Spanish shipmen at the time of the Crusades. Both device and word are considered Spanish · Centreboard A centerboard is a retractable keel which pivots out of a slot in the hull of a sailboat, known as a centerboard trunk or case. The pivoting ability allows the centerboard to be raised to operate in shallow waters, to move the center of lateral resistance to offset changes to the sailplan that move the center of effort aft and to reduce drag when · Cockpit In the Royal Navy, the term 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 · Crow's nest In early ships it was simply a barrel or a basket lashed to the tallest mast. Later it became a specially designed platform with protective railing · Daggerboard 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 · Deck A deck is a permanent covering over a compartment or a hull 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. Vessels often have more than one level both within the hull and in the superstructure above the · Figurehead Although earlier ships had often had some form of bow ornamentation , the general practice was introduced with the galleons of the 16th century, as the figurehead as such could not come to be until ships had an actual head structure on which to place it · Forecastle · Gunwale · Head · Hull · Jackline · Keel · Keel (Canting) · Leeboard · Mast · Orlop deck · Poop deck · Quarter gallery · Rudder · Steering wheel · Skeg · Stern · Tiller · Top · Winch

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is pre weighed and melted in a large vat with a hood to collect the fumes The pour was made from buckets which were supported from a hoist arm Each bucket contained about 300 lbs of lead Removing the keel from mold was an anxious moment for me three days later After the pour several people had asked was I really sure it wouldn t stick in the mold I wasn t and woke in the

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A team of Australian researchers have just published this paper in PLoS ONE, the free to access journal for the communication of all peer-reviewed scientific and medical research. The paper describes an experimental delivery system ...

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How many think that Teddy Long should have waited until AFTER he got married to keel over?
Q. How many think that Teddy Long should have waited until AFTER he got married to keel over?
Asked by Rex - Fri Sep 21 22:37:00 2007 - - 14 Answers - 0 Comments

A. the wedding was a disaster from start to finish from Kristal taking a dive on the steps to H'swoggle diving under her dress.~It made better tv having Teddy do his thing on TV in-ring, He's asked for time off in real-life & this was a good way of letting him go for a while.Kristal is going to Raw & Vicki is getting a run as new GM.The wedding fiasco allows all of this in a funny interesting way.
Answered by Simenon - Fri Sep 21 23:35:44 2007

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