1.
Cross section (geometry)
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In geometry and science, a cross section is the intersection of a body in three-dimensional space with a plane, or the analog in higher-dimensional space. Cutting an object into slices creates many parallel cross sections, conic sections – circles, ellipses, parabolas, and hyperbolas – are formed by cross-sections of a cone at various different angles, as seen in the diagram at left. Any planar cross-section passing through the center of an ellipsoid forms an ellipse on its surface, a cross-section of a cylinder is a circle if the cross-section is parallel to the cylinders base, or an ellipse with non-zero eccentricity if it is neither parallel nor perpendicular to the base. If the cross-section is perpendicular to the base it consists of two line segments unless it is just tangent to the cylinder, in which case it is a single line segment. A cross section of a polyhedron is a polygon, if instead the cross section is taken for a fixed value of the density, the result is an iso-density contour. For the normal distribution, these contours are ellipses, a cross section can be used to visualize the partial derivative of a function with respect to one of its arguments, as shown at left. In economics, a function f specifies the output that can be produced by various quantities x and y of inputs, typically labor. The production function of a firm or a society can be plotted in three-dimensional space, also in economics, a cardinal or ordinal utility function u gives the degree of satisfaction of a consumer obtained by consuming quantities w and v of two goods. Cross sections are used in anatomy to illustrate the inner structure of an organ. A cross section of a trunk, as shown at left, reveals growth rings that can be used to find the age of the tree. Cavalieris principle states that solids with corresponding sections of equal areas have equal volumes. The cross-sectional area of an object when viewed from an angle is the total area of the orthographic projection of the object from that angle. For example, a cylinder of height h and radius r has A ′ = π r 2 when viewed along its central axis, a sphere of radius r has A ′ = π r 2 when viewed from any angle. For a convex body, each ray through the object from the viewers perspective crosses just two surfaces, descriptive geometry Exploded view drawing Graphical projection Plans
2.
Hull (watercraft)
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The hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present, the line where the hull meets the water surface is called the waterline. The structure of the hull varies depending on the vessel type, the uppermost continuous deck may be called the upper deck, weather deck, spar deck, main deck, or simply deck. The particular name given depends on the type of ship or boat. In a typical wooden sailboat, the hull is constructed of wooden planking, supported by transverse frames and bulkheads, often but not always there is a centerline longitudinal member called a keel. In fiberglass or composite hulls, the structure may resemble wooden or steel vessels to some extent, in many cases, composite hulls are built by sandwiching thin fiber-reinforced skins over a lightweight but reasonably rigid core of foam, balsa wood, impregnated paper honeycomb or other material. The shape of the hull is entirely dependent upon the needs of the design, shapes range from a nearly perfect box in the case of scow barges, to a needle-sharp surface of revolution in the case of a racing multihull sailboat. Hulls come in varieties and can have composite shape, but are grouped primarily as follows. Examples are the flat-bottom, v-bottom, and multi-bottom hull and these types have at least one pronounced knuckle throughout all or most of their length. These hull shapes all have smooth curves, examples are the round bilge, semi-round bilge, and s-bottom hull. After this they can be categorized as, Displacement The hull is supported exclusively or predominantly by buoyancy, vessels that have this type of hull travel through the water at a limited rate that is defined by the waterline length. They are often, though not always, heavier than planing types, planing The planing hull form is configured to develop positive dynamic pressure so that its draft decreases with increasing speed. The dynamic lift reduces the surface and therefore also the drag. They are sometimes flat-bottomed, sometimes V-bottomed and more rarely, round-bilged, the most common form is to have at least one chine, which makes for more efficient planing and can throw spray down. Planing hulls are more efficient at speeds, although they still require more energy to achieve these speeds. An effective planing hull must be as light as possible with flat surfaces that are consistent with sea keeping. Sail boats that plane must also sail efficiently in displacement mode in light winds, semi-displacement, or semi-planing The hull form is capable of developing a moderate amount of dynamic lift, however, most of the vessels weight is still supported through buoyancy. At present, the most widely used form is the round bilge hull, in the inverted bell shape of the hull, with a smaller payload the waterline cross-section is less, hence the resistance is less and the speed is higher
3.
Smooth curve hull
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Smooth curve hulls are hulls that are rounded and dont usually have any chines or corners. They can be moulded, round-bilged or soft-chined, examples are the round bilge, semi-round bilge and s-bottom hull. The round bilge hull is the most commonly used hull form as the shape promotes planing and has good properties as well. The S-bottom hull allows relative comfort on the boat, as the shape reduces the rolling movement on the boat
4.
Plywood
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Plywood is a sheet material manufactured from thin layers or plies of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is a wood from the family of manufactured boards which includes medium-density fibreboard. All plywoods bind resin and wood fibre sheets to form a composite material, there is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite parts, the word ply derives from the French verb plier, to fold, from the Latin verb plico, from the ancient Greek verb πλέκω. In 1797 Samuel Bentham applied for patents covering several machines to produce veneers, in his patent applications, he described the concept of laminating several layers of veneer with glue to form a thicker piece – the first description of what we now call plywood. Samuel Bentham was a British naval engineer with many shipbuilding inventions to his credit. Veneers at the time of Bentham were flat sawn, rift sawn or quarter sawn, i. e. cut along or across the log manually in different angles to the grain and thus limited in width and length. One can thus presume that rotary lathe plywood manufacture was a process in France in the 1860s. Plywood was introduced into the United States in 1865 and industrial production started shortly after, in 1928, the first standard-sized 4 ft by 8 ft plywood sheets were introduced in the United States for use as a general building material. Artists use plywood as a support for paintings to replace traditional canvas or cardboard. Ready-made artist boards for oil painting in three-layered plywood were produced, in India, plywood is more commonly called Kitply after a leading brand which pioneered the concept of waterproof plywood in the early 1970s. A typical plywood panel has face veneers of a higher grade than the core veneers, the principal function of the core layers is to increase the separation between the outer layers where the bending stresses are highest, thus increasing the panels resistance to bending. As a result, thicker panels can span greater distances under the same loads, in bending, the maximum stress occurs in the outermost layers, one in tension, the other in compression. Bending stress decreases from the maximum at the layers to nearly zero at the central layer. Shear stress, by contrast, is higher in the center of the panel, the most common dimension is 1.2 by 2.4 metres or the slightly larger imperial dimension of 4 feet ×8 feet. Plies vary in thickness from 1.4 mm to 4.3 mm, the number of plies—which is always odd—depends on the thickness and grade of the sheet. Roofing can use the thinner 5/8 plywood, subfloors are at least 3/4 thick, the thickness depending on the distance between floor joists. T&G plywood is usually found in the 1/2 to 1 range, hardwood plywood is made out of wood from angiosperm trees and used for demanding end uses
5.
Fiberglass
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Fiberglass is a type of fiber-reinforced plastic where the reinforcement fiber is specifically glass fiber. The glass fiber may be arranged, flattened into a sheet. The plastic matrix may be a polymer matrix – most often based on thermosetting polymers such as epoxy, polyester resin. The glass fibers are made of various types of glass depending upon the fiberglass use and these glasses all contain silica or silicate, with varying amounts of oxides of calcium, magnesium, and sometimes boron. To be used in fiberglass, glass fibers have to be made very low levels of defects. Fiberglass is a lightweight material and is used for many products. Although it is not as strong and stiff as composites based on fiber, it is less brittle. Its bulk strength and weight are also better than many metals, other common names for fiberglass are glass-reinforced plastic, glass-fiber reinforced plastic or GFK. Because glass fiber itself is referred to as fiberglass, the composite is also called fiberglass reinforced plastic. This article will adopt the convention that fiberglass refers to the glass fiber reinforced composite material. A patent for this method of producing glass wool was first applied for in 1933, Owens joined with the Corning company in 1935 and the method was adapted by Owens Corning to produce its patented fibreglas in 1936. Originally, fibreglas was a wool with fibers entrapping a great deal of gas, making it useful as an insulator. A suitable resin for combining the fibreglass with a plastic to produce a material was developed in 1936 by du Pont. The first ancestor of modern polyester resins is Cyanamids resin of 1942, peroxide curing systems were used by then. With the combination of fiberglass and resin the gas content of the material was replaced by plastic and this reduced the insulation properties to values typical of the plastic, but now for the first time the composite showed great strength and promise as a structural and building material. Confusingly, many glass fiber composites continued to be called fiberglass, ray Greene of Owens Corning is credited with producing the first composite boat in 1937, but did not proceed further at the time due to the brittle nature of the plastic used. In 1939 Russia was reported to have constructed a boat of plastic materials. The first car to have a body was a 1946 prototype of the Stout Scarab
6.
Dugout canoe
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A dugout canoe or simply dugout is a boat made from a hollowed tree trunk. Other names for this type of boat are logboat and monoxylon, monoxylon is Greek -- mono- + ξύλον xylon -- and is mostly used in classic Greek texts. In Germany they are called einbaum, some, but not all, pirogues are also constructed in this manner. Dugouts are the oldest boats archaeologists have found, dating back about 8,000 years to the Neolithic Stone Age and this is probably because they are made of massive pieces of wood, which tend to preserve better than, e. g. bark canoes. Along with bark canoe and hide kayak, dugout boats were used by indigenous peoples of the Americas. Construction of a dugout begins with the selection of a log of suitable dimensions, sufficient wood needed to be removed to make the vessel relatively light in weight and buoyant, yet still strong enough to support the crew and cargo. Specific types of wood were often preferred based on their strength, durability, the shape of the boat is then fashioned to minimize drag, with sharp ends at the bow and stern. First the bark is removed from the exterior, before the appearance of metal tools, dugouts were hollowed out using controlled fires. The burnt wood was removed using an adze. Another method using tools is to chop out parallel notches across the span of the wood, then split out. Once hollowed out, the interior was dressed and smoothed out with a knife or adze, more primitive designs keep the trees original dimensions, with a round bottom. However, it is possible to carefully steam the sides of the hollow log until they are pliable, for travel in the rougher waters of the ocean, dugouts can be fitted with outriggers. One or two smaller logs are mounted parallel to the hull by long poles. In the case of two outriggers, one is mounted on either side of the hull, the Dufuna canoe from Nigeria is an 8000-year-old dugout, the oldest boat discovered in Africa, and the third-oldest worldwide. African Teak is the timber favoured for their construction, though this comprises a number of different species, dugouts are called pirogues in Francophone areas of Africa. A 8000-year-old dugout canoe was found by archaeologists in Kuahuqiao, Zhejiang Province and this is the earliest canoe found in Asia. The Moken, an group that lives in Myanmars Mergui Archipelago. It is now on display in front of the Municipal Town Hall, here many dugouts were made from linden wood, for several reasons
7.
Keel
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On boats and ships, keel can refer to either of two parts, a structural element that sometimes resembles a fin and protrudes below a boat along the central line, or a hydrodynamic element. As the laying down of the keel is the step in the construction of a ship, in British. Only the ships launching is considered significant in its creation. The word can also be used as a synecdoche to refer to a complete boat, a structural keel is the bottom-most structural member around which the hull of a ship is built. The keel runs along the centerline of the ship, from the bow to the stern. The keel is often the first part of a hull to be constructed. The most common type of keel is the plate keel. 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, 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 and 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, the keel surface on the bottom of the hull gives the ship greater directional control and stability. In non-sailing hulls, the helps the hull to move forward. In traditional boat building, this is provided by the structural keel, 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, 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, keels are different from centreboards and other types of foils in that keels are made of heavy materials to provide ballast 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 or slide upwards to retract, and are usually retracted with a winch due to the weight of the ballast. Since the keel provides far more stability when lowered than when retracted, types of non-fixed keels include swing keels and canting keels. Canting keels can be found on racing yachts, such as competing in the Volvo Ocean Race
8.
Canal
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Canals and navigations are human-made channels for water conveyance, or to service water transport vehicles. In the vernacular, both are referred to as canals, and in most cases, the works will have a series of dams. These areas are referred to as water levels, often just called levels. In contrast, a canal cuts across a drainage divide atop a ridge, many canals have been built at elevations towering over valleys and others water ways crossing far below. Cities need a lot of water and many canals with sources of water at a higher level can deliver water to a destination where there is a lack of water. The Roman Empires Aqueducts were such water supply canals, a navigation is a series of channels that run roughly parallel to the valley and stream bed of an unimproved river. A navigation always shares the drainage basin of the river, a vessel uses the calm parts of the river itself as well as improvements, traversing the same changes in height. A true canal is a channel that cuts across a drainage divide, most commercially important canals of the first half of the 19th century were a little of each, using rivers in long stretches, and divide crossing canals in others. This is true for many canals still in use, there are two broad types of canal, Waterways, canals and navigations used for carrying vessels transporting goods and people. These can be subdivided into two kinds, Those connecting existing lakes, rivers, other canals or seas and oceans and those connected in a city network, such as the Canal Grande and others of Venice Italy, the gracht of Amsterdam, and the waterways of Bangkok. Aqueducts, water canals that are used for the conveyance and delivery of potable water for human consumption, municipal uses, hydro power canals. Historically canals were of importance to commerce and the development, growth. In 1855 the Lehigh Canal carried over 1.2 million tons of burning anthracite coal, by the 1930s the company which built. By the early 1880s, canals which had little ability to compete with rail transport, were off the map. In the next couple of decades, coal was diminished as the heating fuel of choice by oil. Later, after World War I when motor-trucks came into their own, Canals are built in one of three ways, or a combination of the three, depending on available water and available path, Human made streams A canal can be created where no stream presently exists. Either the body of the canal is dug or the sides of the canal are created by making dykes or levees by piling dirt, stone, the water for the canal must be provided from an external source, like streams or reservoirs. Where the new waterway must change elevation engineering works like locks, lifts or elevators are constructed to raise, examples include canals that connect valleys over a higher body of land, like Canal du Midi, Canal de Briare and the Panama Canal
9.
Planing (boat)
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Planing is the mode of operation for a waterborne craft in which its weight is predominantly supported by hydrodynamic lift, rather than hydrostatic lift. The earliest documented planing sailboat was a built in 1898 by Commodore Ralph Munroe. Planing a sailing dinghy was first popularised by Uffa Fox in Britain, in 1928 Uffa Fox introduced planing to the racing world in his International 14 dinghy, Avenger. It had been designed with a shape which permitted planing. He gained 52 first places, two seconds and three third places out of 57 race starts that year and this performance was noticed by other designers who took on his ideas and developed them. Over the years many dinghies have acquired the ability to plane, advances in building materials have allowed for lighter boats which will plane faster and in lighter air. There are now many high-performance dinghies which will plane to windward, when it is at rest, a vessels weight is borne entirely by the buoyant force. At low speeds every hull acts as a displacement hull, meaning that the buoyant force is responsible for supporting the craft. As speed increases, hydrodynamic lift increases as well, in contrast, the buoyant force decreases as the hull lifts out of the water, decreasing the displaced volume. At some speed, lift becomes the predominant upward force on the hull, a simple model of this effect is a solid slab of material which is heavier than water but is shaped and oriented to have a positive angle of attack. At rest, the slab will sink because it is heavier than water, however, if the slab is kept in the same orientation and pulled horizontally through the water, it will force the incoming water downward. This results in a reactionary force upward on the slab, at a high enough speed, this reactionary force is larger than the force of gravity and the slab will stay afloat. In this way, the force is converted into a vertical force upwards. The concept of planing is often interpreted as analogous with aerodynamic lift, although any hull will plane if enough power is provided and enough speed is attained, a hull designed for operation in the planing realm is sometimes distinguished by a flat run aft. In other words, in view, the bottom is more or less a straight line towards the stern. In contrast, in a displacement, or non-planing hull, the bottom is curved in side view all the way from bow to stern, in order to minimize wave drag. All boat designs for planing benefit from minimised weight, planing powerboats are commonly made from light alloy or use other reduced-weight construction techniques- RIBs are typical examples, planing sailing boats need a good sail area and powerboats need a high-power engine. Steps and chine ridges may also be incorporated into the design to both ease of planing and stability
10.
Scow
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A scow, in the original sense, is a flat-bottomed boat with a blunt bow, often used to haul bulk freight, cf. barge. The etymology of the word is from the Dutch schouwe, meaning such a boat, Sailing scows have significant advantages over the traditional deep keel sailing vessels that were common at the time the sailing scow was popular. The cost of this shallow water advantage was the loss of the seaworthiness of flat bottomed scow boats in open water, the squared off shape and simple lines of a scow make it a popular choice for simple home-built boats made from plywood. Phil Bolger and Jim Michalak, for example, have designed a number of sailing scows, and the PD Racer. Generally these designs are created to minimize waste when using standard 4-foot by 8-foot sheets of plywood, the scow hull is also the basis for the Shantyboat or, on the Chesapeake, the Ark, a cabin houseboat once common on American rivers. The ark was used as housing by Chesapeake watermen, who followed, for example. See also the Thames sailing barge and the Norfolk wherry, two British equivalents to the scow schooner, the Thames sailing barges, while used for similar tasks, used significantly different hull shapes and rigging. The term scow is used in and around the west Solent for a class of sailing dinghy. Various towns and villages claim their own variants, they are all around 11 feet in length and share a lug sail, pivoting centre board, small foredeck and a square transom with a transom hung rudder. Originally an American design, also used widely in New Zealand, scow schooners had a broad, shallow hull, and used centreboards, bilgeboards or leeboards rather than a deep keel. The broad hull gave them stability, and the retractable foils allowed them to even heavy loads of cargo in waters far too shallow for keelboats to enter. The squared off bow and stern allowed the maximum amount of cargo to be carried in the hull, the smallest sailing scows were sloop rigged, but otherwise similar in design. The scow sloop eventually evolved into the inland lake scow, a type of fast racing boat, the American scow design was copied and modified in New Zealand by early immigrant settlers to Auckland in the 1870s. He commissioned a shipbuilder, one Septimus Meiklejohn to construct a small flat-bottomed sailing barge named the Lake Erie which was built at Omaha. The Lake Erie was 60 feet 6 inches in length, seventeen feet 3 inches in breadth and had a draught of three feet 4 inches. This one small craft spawned a fleet of sailing scows that were to become associated with the gum trade. Scows came in all manner of shape and sizes and all manner of sailing rigs and they were designed for hard work and heavy haulage and they did their job remarkably well. They took cattle north from the stockyards of Auckland and returned with a cargo of logs, sacks of kauri gum, shingle, firewood
11.
Schooner
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A schooner /ˈskuːnər/ is a type of sailing vessel with fore-and-aft sails on two or more masts, the foremast being shorter than the main and no taller than the mizzen if there is one. While the schooner was originally gaff-rigged, modern schooners typically carry a Bermuda rig, such vessels were first used by the Dutch in the 16th or 17th century. They were further developed in North America from the early 18th century, the most common type, with two masts, were popular in trades requiring speed and windward ability, such as slaving, privateering, blockade running, and offshore fishing. In the Chesapeake Bay area several distinctive schooner types evolved, including the Baltimore clipper, bugeye, schooners were also popular among pirates in the West Indies during the Golden Age of Piracy, for their speed and agility. They could also sail in shallow waters, and while being smaller than other ships of the time period. Schooners first evolved in the late 17th century from a variety of small two-masted gaff-rigged vessels used in the coast, most were working craft but some pleasure yachts with schooner rigs were built for wealthy merchants and Dutch nobility. Following the arrival of the Dutch monarch William of Orange on the British throne and this vessel, captured in a detailed Admiralty model, is the earliest fully documented schooner. Royal Transport was quickly noted for its speed and ease of handling, North American shipbuilders quickly developed a variety of schooner forms for trading, fishing and privateering. According to the language scholar Walter William Skeat, the term comes from scoon. The Dutch word schoone means nice, good looking, robinson replied, A schooner let her be. The launch is variously described as being in 1713 or 1745, naval architects such as Howard Chapelle have dismissed this invention story as a childish fable, but some language scholars feel that the legend may support a Gloucester origin of the word. Other sources state the etymology as unknown and uncertain, the first detailed definition of a schooner, describing the vessel as two-masted vessel with fore and aft gaff-rigged sails appeared in 1769 in William Falconers, Universal Dictionary of the Marine. Although a schooner may have up to four masts, the schooner has only two, with the foremast shorter than the mainmast. There may be a bowsprit to help balance the rig, the principal issue with a schooner sail plan is how to fill the space between the two masts most effectively. Traditional schooners were rigged, and the trapezoid shape of the foresail occupied the inter-mast space to good effect, with a useful sail area. A Bermuda rigged schooner typically has four sails, a mainsail, a main staysail abaft the foremast, plus a forestaysail. An advantage of the schooner is that it is easily handled and reefed by a small crew. The main staysail will not overlap the mainsail, and so little to prepare the wind for the mainsail
12.
Shipwrecking
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Warfare, piracy, mutiny, or sabotage including, guns, torpedoes, depth charges, mines, bombs and missiles. Fire Biofouling such as polychaete and other worms on wood hulls. She was too narrow, had too little ballast and her lower deck had too low free-board for good seaworthiness. Poor design allowed the ferry MS Herald of Free Enterprise to put to sea with open roll-on/roll-off bow doors, failure or leaking of the hull is a serious problem that can lead to the loss of buoyancy or the free surface effect and the subsequent sinking of the vessel. Even the hulls of modern ships have cracked in heavy storms. Leaks between the planks of wooden vessels are a particular problem. Equipment failure caused the shipwreck of cruiseferry Estonia in 1994, the stress of stormy seas on hull and bow especially caused the bow visor to break off, in turn tearing the watertight bow door open and letting seawater flow onto the car deck. Failure of pumps can lead to the loss of a potentially salvageable ship with only a minor leak or fire, failure of the means of propulsion, such as engines, sails or rigging, can lead to the loss of a ship. Loss of propulsion or steering can inhibit a ships ability to position itself in a storm. Waves attacking a ships side can overwhelm and sink it, instability is caused by the centre of mass of the ship rising above the metacenter resulting in the ship tipping on its side or capsizing, which is often referred to as foundered or foundering. This can lead to a if the openings on the upper side are not watertight at the time of the capsize. To remain buoyant, the hull of a vessel must prevent water entering the air spaces of the vessel. Large ships are designed with Compartments to help avoid foundering, on 25 October 2012, the tall ship Bounty sank in a hurricane. The vessel left New London, Connecticut, heading for St. Petersburg, Florida, on 29 October 2012 at 03,54 EDT, the ships owner called the United States Coast Guard for help during the hurricane after losing contact with the ships master. He reported she was taking on water off the coast of North Carolina, about 160 miles from the storm, there were sixteen people aboard, two of whom did not survive the sinking. Poor weather can cause problems, high winds low visibility cold weather high waves Wind causes waves which result in other difficulties. Waves make navigation difficult and dangerous near shallow water, also, waves create buoyancy stresses on the structure of a hull. The weight of breaking waves on the fabric of the force the crew to reduce speed or even travel in the same direction as the waves to prevent damage
13.
Steamboat
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A steamboat is a boat that is propelled primarily by steam power, typically driving propellers or paddlewheels. Steamboats sometimes use the prefix designation SS, S. S. or S/S or PS, the term steamboat is used to refer to smaller, insular, steam-powered boats working on lakes and rivers, particularly riverboats. As using steam became more reliable, steam power became applied to larger, Early attempts at powering a boat by steam were made by the French inventor Denis Papin and the English inventor Thomas Newcomen. Papin invented the steam digester and experimented with closed cylinders and pistons pushed in by atmospheric pressure, Papin proposed applying this steam pump to the operation of a paddlewheel boat and tried to market his idea in Britain. He was unable to convert the piston motion into rotary motion. Newcomens design did solve the first problem, but remained shackled to the inherent limitations of the engines of the time, a steamboat was described and patented by English physician John Allen in 1729. In 1736, Jonathan Hulls was granted a patent in England for a Newcomen engine-powered steamboat, William Henry of Lancaster, Pennsylvania, having learned of Watts engine on a visit to England, made his own engine. In 1763 he put it in a boat, the boat sank, and while Henry made an improved model, he did not appear to have much success, though he may have inspired others. At its first demonstration on 15 July 1783, Pyroscaphe travelled upstream on the river Saône for some fifteen minutes before the engine failed, presumably this was easily repaired as the boat is said to have made several such journeys. Following this, De Jouffroy attempted to get the government interested in his work, De Jouffroy did not have the funds for this, and, following the events of the French revolution, work on the project was discontinued after he left the country. Similar boats were made in 1785 by John Fitch in Philadelphia and William Symington in Dumfries and this boat could typically make 7 to 8 miles per hour and traveled more than 2,000 miles during its short length of service. The Fitch steamboat was not a success, as this travel route was adequately covered by relatively good wagon roads. The following year, a boat made 30-mile excursions, and in 1790. Miller sent King Gustav III of Sweden an actual version,100 feet long. Miller then engaged engineer William Symington to build his patent steam engine drove a stern-mounted paddle wheel in a boat in 1785. The boat was successfully tried out on Dalswinton Loch in 1788 and was followed by a steamboat the next year. The boat was built by Alexander Hart at Grangemouth to Symingtons design with a cylinder engine. Trials on the River Carron in June 1801 were successful and included towing sloops from the river Forth up the Carron and thence along the Forth, in 1801, Symington patented a horizontal steam engine directly linked to a crank
14.
Punt (boat)
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This article concentrates on the history and development of punts and punting in England, for other usages see Norfolk punt and the general disambiguation pages at punt and punter. A punt is a boat with a square-cut bow, designed for use in small rivers or other shallow water. Punting refers to boating in a punt, the punter generally propels the punt by pushing against the river bed with a pole. A punt should not be confused with a gondola, a shallow draft vessel that is different. Punts were originally built as boats or platforms for fowling and angling. The term punt has also used to indicate a smaller version of a regional type of long shore working boat. This derives from the usage in coastal communities of the name punt for any small clinker-built open-stem general purpose boat. In Canada, the punt can also refer to any small flat-bottomed boat with a square-cut bow, regardless of purpose, building material. In Australia, cable ferries are commonly referred to as punts, a traditional river punt differs from many other types of wooden boat in that it has no keel, stem, or sternpost. Instead, it is rather like a ladder with the main structure being two side panels connected by a series of 4 in cross planks, known as treads. The first punts are traditionally associated with the River Thames in England and were built as cargo boats or platforms for fishermen. Pleasure punts – specifically built for recreation – became popular on the Thames between 1860 and 1880, since a punt has no keel, it draws only a few inches even when fully laden, this makes it very manoeuvrable and suitable for shallow water. A punt can be punted with equal facility in either direction, the square-cut bow gives greater carrying capacity for a given length than a boat of the same beam with a narrow or pointed bow, it also makes the boat very stable, and suitable for passengers. Punts are still made in England to supply the tourist trade in Oxford, the construction material of choice for most punts is wood. Fibreglass is used for very light and narrow racing punts. The sides, the ends, and the till are normally made of such as mahogany. The treads are made from teak. The bottom is made of softwood and may be replaced several times during the life of a particular boat, a traditional punt is about 24 feet long and 3 feet wide
15.
Multihull
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A multihull is a ship, vessel, craft or boat with more than one hull. Multihull ships include multiple types, sizes and applications, hulls range from two to five, of uniform or diverse types and arrangements Catamarans are the most common type, with two symmetric hulls. They are used as racing, sailing, tourist and fishing boats, about 70% of fast passenger and car-passenger ferries are catamarans. About 300 semi-submersible drilling and auxiliary platforms operate at sea, some ships with outriggers are built, including the experimental ship Tritone and the first and second sister-ships of the series of Littoral Combat Ships. About 70 small waterplan area ships whose hulls have a cross section at the waterplane than below the surface exist. Multihull ships can be classified by the number of hulls, by their arrangement, the first multihull vessels were Austronesian canoes. They hollowed out logs to make canoes and stabilized them by attaching outriggers to prevent them from capsizing and this led to the proa, catamaran, and trimaran plus various outriggers throughout the Pacific. Individual hulls are connected by a structure called the platform or above-water bridge. The structure can be partially or fully, or can consist of separate connections. The distance between hulls is called the clearance and can be measured between center planes or between the inner boards. The distance between the design waterplane and the bottom of the platform is called the vertical clearance. The longitudinal distance between a ship is called the longitudinal clearance and can be measured between the middle of the hulls or between their fore perpendiculars. An outrigger is a small side hull attached to the main load-carrying hull by two or more struts, proas have one hull and one outrigger. Engines are commonly placed on the main hull, a ship with one hull of conventional shape and two small side hulls is called an outrigger ship. This type is identified as trimaran in English language publications, three terms from the Malay and Micronesian language group describe hull components. The terms originated as descriptions of the proa, Catamarans and trimarans share the same terminology. Ama − The ama is the outrigger hull, Aka − The aka connects the vaka to the ama. In Hawaiian, this is called the iako, Vaka − The vaka is the main canoe-like hull
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Flat-bottomed boat
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A flat-bottomed boat is a boat with a flat bottomed, two-chined hull, which allows it be used in shallow bodies of water, such as rivers, because it is less likely to ground. The flat hull makes the boat more stable in calm water. However this design less stable in choppy water. This is because it causes the boat to travel on the water, instead of through it, flat hulls are simple to construct, making them popular with boat-building hobbyists. The flat-bottoms are mentioned in the song Heart of Oak written by David Garrick during 1759, barge Bateau Dory Durham boat Flatboat Gondola Jon boat Keelboat Norfolk punt Pirogue Pram Punt Sandolo Scow Trow Horse-drawn boat Pedalo Pusher Towpath
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Barge
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A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and must be towed or pushed by towboats, Barge is attested from 1300, from Old French barge, from Vulgar Latin barga. The word originally could refer to any small boat, the modern meaning arose around 1480, bark small ship is attested from 1420, from Old French barque, from Vulgar Latin barca. The more precise meaning three-masted ship arose in the 17th century, both are probably derived from the Latin barica, from Greek, βάρις, translit. Egyptian boat, from Coptic, ⲃⲁⲁⲣⲉ bāri small boat, hieroglyphic Egyptian, by extension, the term embark literally means to board the kind of boat called a barque. The long pole used to maneuver or propel a barge has given rise to the saying I wouldnt touch that with a barge pole. On the British canal system, the barge is used to describe a boat wider than a narrowboat. In the United States, deckhands perform the labor and are supervised by a leadman or the mate, the captain and pilot steer the towboat, which pushes one or more barges held together with rigging, collectively called the tow. The crew live aboard the towboat as it travels along the river system or the intracoastal waterways. These towboats travel between ports and are also called line-haul boats, poles are used on barges to fend off the barge as it nears other vessels or a wharf. These are often called pike poles, barges are used today for low-value bulk items, as the cost of hauling goods by barge is very low. Barges are also used for heavy or bulky items, a typical American barge measures 195 by 35 feet. The most common European barge measures 76.5 by 11.4 metres, as an example, on June 26,2006, a 565-short-ton catalytic cracking unit reactor was shipped by barge from the Tulsa Port of Catoosa in Oklahoma to a refinery in Pascagoula, Mississippi. Extremely large objects are normally shipped in sections and assembled onsite, of the reactors 700-mile journey, only about 40 miles were traveled overland, from the final port to the refinery. Canal barges are made for the particular canal in which they will operate. Many barges, primarily Dutch barges, which were designed for carrying cargo along the canals of Europe, are no longer large enough to compete in this industry with larger newer vessels. Many of these barges have been renovated and are now used as hotel barges carrying holidaymakers along the same canals on which they once carried grain or coal. This holds true today, for areas of the world
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Kayak
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A kayak is a small, narrow watercraft which is propelled by means of a double-bladed paddle. The word kayak originates from the Greenlandic language, where it is the word qajaq, in the UK the term canoe is often used when referring to a kayak. The traditional kayak has a deck and one or more cockpits. Kayaks are also being sailed, as well as propelled by means of electric motors. The kayak was first used by the indigenous Aleut, Inuit, Yupik, kayaks were originally developed by the Inuit, Yupik, and Aleut. They used the boats to hunt on inland lakes, rivers and coastal waters of the Arctic Ocean, North Atlantic, Bering Sea and these first kayaks were constructed from stitched seal or other animal skins stretched over a wood or whalebone-skeleton frame. Kayaks are believed to be at least 4,000 years old, the oldest existing kayaks are exhibited in the North America department of the State Museum of Ethnology in Munich. Native people made many types of boat for different purposes, the baidarka, developed by indigenous cultures in Alaska, was also made in double or triple cockpit designs, for hunting and transporting passengers or goods. An umiak is an open sea canoe, ranging from 17 to 30 feet, made with seal skins. It is considered a kayak although it was originally paddled with single-bladed paddles, native builders designed and built their boats based on their own experience and that of the generations before them, passed on through oral tradition. A special skin jacket, Tuilik, was laced to the kayak. This enabled the eskimo roll to become the method of regaining posture after capsizing, especially as few Inuit could swim. Inuit kayak builders had specific measurements for their boats, the length was typically three times the span of his outstretched arms. The width at the cockpit was the width of the builders hips plus two fists, the typical depth was his fist plus the outstretched thumb. Thus typical dimensions were about 17 feet long by 20–22 inches wide by 7 inches deep and this measurement system confounded early European explorers who tried to duplicate the kayak, because each kayak was a little different. Most of the Aleut people in the Aleutian Islands eastward to Greenland Inuit relied on the kayak for hunting a variety of seals, though whales. Skin-on-frame kayaks are still being used for hunting by Inuit people in Greenland, because the smooth and flexible skin glides silently through the waves. In other parts of the home builders are continuing the tradition of skin on frame kayaks, usually with modern skins of canvas or synthetic fabric
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Royal Navy
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The Royal Navy is the United Kingdoms naval warfare force. Although warships were used by the English kings from the medieval period. The modern Royal Navy traces its origins to the early 16th century, from the middle decades of the 17th century and through the 18th century, the Royal Navy vied with the Dutch Navy and later with the French Navy for maritime supremacy. From the mid 18th century it was the worlds most powerful navy until surpassed by the United States Navy during the Second World War. The Royal Navy played a key part in establishing the British Empire as the world power during the 19th. Due to this historical prominence, it is common, even among non-Britons, following World War I, the Royal Navy was significantly reduced in size, although at the onset of the Second World War it was still the worlds largest. By the end of the war, however, the United States Navy had emerged as the worlds largest, during the Cold War, the Royal Navy transformed into a primarily anti-submarine force, hunting for Soviet submarines, mostly active in the GIUK gap. The Royal Navy is part of Her Majestys Naval Service, which includes the Royal Marines. The professional head of the Naval Service is the First Sea Lord, the Defence Council delegates management of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence. The strength of the fleet of the Kingdom of England was an important element in the power in the 10th century. English naval power declined as a result of the Norman conquest. Medieval fleets, in England as elsewhere, were almost entirely composed of merchant ships enlisted into service in time of war. Englands naval organisation was haphazard and the mobilisation of fleets when war broke out was slow, early in the war French plans for an invasion of England failed when Edward III of England destroyed the French fleet in the Battle of Sluys in 1340. Major fighting was confined to French soil and Englands naval capabilities sufficed to transport armies and supplies safely to their continental destinations. Such raids halted finally only with the occupation of northern France by Henry V. Henry VII deserves a large share of credit in the establishment of a standing navy and he embarked on a program of building ships larger than heretofore. He also invested in dockyards, and commissioned the oldest surviving dry dock in 1495 at Portsmouth, a standing Navy Royal, with its own secretariat, dockyards and a permanent core of purpose-built warships, emerged during the reign of Henry VIII. Under Elizabeth I England became involved in a war with Spain, the new regimes introduction of Navigation Acts, providing that all merchant shipping to and from England or her colonies should be carried out by English ships, led to war with the Dutch Republic. In the early stages of this First Anglo-Dutch War, the superiority of the large, heavily armed English ships was offset by superior Dutch tactical organisation and the fighting was inconclusive
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Motor Torpedo Boat
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Motor Torpedo Boat was the name given to fast torpedo boats by the Royal Navy and the Royal Canadian Navy. The motor in the designation, referring to the use of petrol engines, was to distinguish them from the majority of other naval craft that used steam turbines or reciprocating steam engines. The capitalised term is used for the Royal Navy boats. During the Second World War, the US Navy boats were called by their hull classification symbol of PT. German motor torpedo boats of the Second World War were called S-boote by the Kriegsmarine, Italian MTBs of this period were known as Motoscafo Armato Silurante. French MTBs were known as vedettes lance torpilles, soviet MTBs were known as торпедные катеры. After the end of the War in 1945, a number of the Royal Navys MTBs were stripped and the empty hulls sold for use as houseboats. MTBs were designed for speed, operating at night, low speed ambush and manoeuvrability on the water. With no significant armour, the boats relied upon surprise and their agility at high speed to avoid being hit by gunfire from bigger ships, the British and Italian navies started developing such vessels in the early 20th century, shortly before the beginning of the First World War. Italian MAS boats were small, at 20-30 tons displacement. MAS15 was the motor torpedo boat in history to sink a battleship. British torpedo boats of the First World War were small at only around 15 tons and were known as Coastal Motor Boats, in the Second World War, British MTBs were operated by Coastal Forces. A similar size boat with a different role in the Second World War was the BPB63 ft High Speed Launch used by the RAF, the last MTBs in the Royal Navy were the two Brave-class fast patrol boats of 1958 which were capable of 50 knots. Many boats were built with a MTB designation but varied substantially, a 55 footer capable of 40 knots was shown in 1930. The Vosper private boat was designed by Commander Peter Du Cane CBE and she was completed and launched in 1937. She was bought by the Admiralty and taken into service with the Royal Navy as MTB102. Length,68 ft Beam,19 ft 9 in Draft,3 ft 9 in, armament, Two 21 in torpedo tubes MTB102 was the fastest wartime British naval vessel in service. She was at Dunkirk for the evacuation and carried Winston Churchill and they were based on the British Power Boat rescue craft and were originally designed for the Royal Air Force but reduced to 60 ft in length
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Epoxy
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Epoxy is either any of the basic components or the cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups, Epoxy resins may be reacted either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids, phenols, alcohols and thiols. These co-reactants are often referred to as hardeners or curatives, reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with high mechanical properties, temperature and chemical resistance. Epoxy resins are low molecular weight pre-polymers or higher molecular weight polymers which contain at least two epoxide groups. The epoxide group is sometimes referred to as a glycidyl or oxirane group. A wide range of epoxy resins are produced industrially, the raw materials for epoxy resin production are today largely petroleum derived, although some plant derived sources are now becoming commercially available. Epoxy resins are polymeric or semi-polymeric materials, and as such rarely exist as pure substances, high purity grades can be produced for certain applications, e. g. using a distillation purification process. One downside of high purity liquid grades is their tendency to form crystalline solids due to their highly regular structure, an important criterion for epoxy resins is the epoxide content. Epoxies are typically cured with stoichiometric or near-stoichiometric quantities of curative to achieve maximum physical properties, use of blending, additives and fillers is often referred to as formulating. Important epoxy resins are produced from combining epichlorohydrin and bisphenol A to give bisphenol A diglycidyl ethers, as the molecular weight of the resin increases, the epoxide content reduces and the material behaves more and more like a thermoplastic. Very high molecular weight polycondensates form a class known as phenoxy resins and these resins do however contain hydroxyl groups throughout the backbone, which may also undergo other cross-linking reactions, e. g. with aminoplasts, phenoplasts and isocyanates. Bisphenol F may also undergo epoxidation in a fashion to bisphenol A. Compared to DGEBA, bisphenol F epoxy resins have lower viscosity and a higher mean epoxy content per gramme, reaction of phenols with formaldehyde and subsequent glycidylation with epichlorohydrin produces epoxidised novolacs, such as epoxy phenol novolacs and epoxy cresol novolacs. These are highly viscous to solid resins with typical mean epoxide functionality of around 2 to 6, the high epoxide functionality of these resins forms a highly crosslinked polymer network displaying high temperature and chemical resistance, but low flexibility. Aliphatic epoxy resins are typically formed by glycidylation of aliphatic alcohols or polyols, the resulting resins may be monofunctional, difunctional, or higher functionality. These resins typically display low viscosity at room temperature and are referred to as reactive diluents. They are rarely used alone, but are employed to modify the viscosity of other epoxy resins. This has led to the term ‘modified epoxy resin’ to denote those containing viscosity-lowering reactive diluents, a related class is cycloaliphatic epoxy resin, which contains one or more cycloaliphatic rings in the molecule
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Fillet (mechanics)
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In mechanical engineering, a fillet /ˈfɪlᵻt/ is a rounding of an interior or exterior corner of a part design. An interior or exterior corner, with an angle or type of bevel, is called a chamfer, fillet geometry, when on an interior corner is a line of concave function, whereas a fillet on an exterior corner is a line of convex function. Stress concentration is a problem of load-bearing mechanical parts which is reduced by employing fillets on points, the fillets distribute the stress over a broader area and effectively make the parts more durable and capable of bearing larger loads. For considerations in aerodynamics, fillets are employed to reduce interference drag where aircraft components such as wings, struts, for manufacturing, concave corners are sometimes filleted to allow the use of round-tipped end mills to cut out an area of a material. This has a cycle time benefit if the mill is simultaneously being used to mill complex curved surfaces. Radii are used to eliminate sharp edges that can be damaged or that can cause injury when the part is handled. Fillets can be quickly designed onto parts using 3D solid modeling engineering CAD software by invoking the function, smooth edges connecting two simple flat features are generally simple for a computer to create and fast for a human user to specify. Once these features are included in the CAD design of a part, different design packages use different names for the same operations. Autodesk Inventor, CATIA, FreeCAD, Solidworks and Vectorworks refer to concave and convex rounded edges as fillets, while referring to angled cuts of edges. CADKEY and Unigraphics refer to concave and convex rounded edges as blends, PTC Creo Elements/Pro refers to rounded edges simply as rounds. Other 3D solid modeling software programs outside of engineering, such as gameSpace, have similar functions
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Stitch and glue
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Stitch and glue is a simple boat building method which uses plywood panels stitched together, usually with copper wire, and glued together with epoxy resin. This type of construction can eliminate much of the need for frames or ribs, plywood panels are cut to shape and stitched together to form an accurate hull shape without the need for forms or special tools. This technique is called tack and tape, or stitch. Seams are reinforced with fiberglass tape and thickened epoxy, the technique was then popularised by the first TV DIY expert, Barry Bucknell, in about 1964. The method was adopted, substituting copper wire ties rather than fishing line as in the early Littledyke examples, the Mirror is so named because the design was sponsored by The Daily Mirror newspaper, a fact reflected by the historically red sails. The Daily Mirror apparently wanted to bring cheap sailing to the masses, as such, unlike other construction techniques of the day, which required specialist skills and tools, Stitch and Glue was supposed to put boat-building within the reach of the average public. These boats were constructed of plywood with seams filleted with fiberglass tape and could be built by DIY amateurs of modest skill, the technique consists of stitching together plywood panels with some sort of wire or other suitable device, such as cable ties or duct tape and staples. Once the epoxy sets solid in most cases the stitches or other clamping structures are removed leaving only the fused plywood panels behind, to join, the cut panels are drilled with small holes along the joining edges and stitched. Once together, the joint is glued, usually with thickened epoxy, on the outside of the hull, the wire is snipped and the joints filled and sanded over. The outside of the joint, or entire hull, may be fiberglassed and glued as well, with the wires removed, a fillet of thickened epoxy is applied over the entire length of the joint. True stitch and glue designs generally have few bulkheads, relying instead on the geometry of the panels to provide shape, Stitch and glue has become one of the dominant techniques in amateur boatbuilding. While the use of relatively few plywood panels limits the shapes possible, Stitch and glue is not inherently limited to small designs though, as demonstrated by the boats made by Sam Devlin, who has applied the technique to making boats as long as 65 feet. The Instant Boats developed by Phil Bolger use simplified framing and stitch-and-glue style plywood sheet joining, step-by-step building books about the boats and plans for many were sold by Harold Payson of Thomaston, Maine. They range from small dinghies to power and sailboats 25 to 30 feet long. They are not necessarily designed for weight, but like the original Mirror Dinghy. The plans predate CAD panel development software so the shapes are simple in some cases. The one sheet boat, or OSB, is an outgrowth of the stitch, the OSB is a boat that can be built using a single sheet of 4 foot by 8 foot plywood. Some additional wood is used, for supports, chines, or as a transom
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International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
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Wayback Machine
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The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
