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68-612: The line is 7 kilometres (4.3 mi) long and was built using rail track by French manufacturer Decauville . The train can transport up to 150 passengers over 7 kilometres (4.3 mi) of track from the Visitors’ Centre to Cataratas (Waterfalls) Station and Garganta del Diablo (Devil's Gorge) Station. It carries approximately 900,000 visitors yearly. The train was built in England by Alan Keef Ltd, in Ross-on-Wye . It

136-609: A cut spike or crampon ) is a large nail with an offset head that is used to secure rails and base plates to railroad ties (sleepers) in the track. Robert Livingston Stevens is credited with the invention of the rail spike, the first recorded use of which was in 1832. The railroad spike was an invention which resulted from the state of industrialisation in the United States in the early 19th century: English mainline railways of that period used heavy and expensive cast iron chairs to secure T-shaped rails; instead, Stevens added

204-508: A slipformed (or pre-cast) concrete base (development 2000s). The 'embedded rail structure', used in the Netherlands since 1976, initially used a conventional UIC 54 rail embedded in concrete, and later developed (late 1990s) to use a 'mushroom' shaped SA42 rail profile; a version for light rail using a rail supported in an asphalt concrete –filled steel trough has also been developed (2002). Modern ladder track can be considered

272-560: A spike maul , though this manual work has been largely replaced by hydraulic tools and machines, commonly called " spikers " (a machine that removes spikes is called a "spike puller"). Splitting of the wood can be limited by pre-boring spike holes or adding steel bands around the wood. For use in the United States three basic standards are described in the ASTM A65 standard, for different carbon steel contents. A dog spike

340-440: A "clickety-clack" sound. Unless it is well-maintained, jointed track does not have the ride quality of welded rail and is less desirable for high speed trains . However, jointed track is still used in many countries on lower speed lines and sidings , and is used extensively in poorer countries due to the lower construction cost and the simpler equipment required for its installation and maintenance. A major problem of jointed track

408-430: A T shape which required a chair to hold them; the rails were held in position by iron wedges (which sometimes caused the rail to break when forced in) and later by wooden wedges, which became the standard. In the 1830s Robert L. Stevens invented the flanged 'tee' rail (actually a distorted I beam), which had a flat bottom and required no chair; a similar design was the contemporary bridge rail (of inverted U section with

476-406: A bottom flange and laid on longitudinal sleepers); these rails were initially nailed directly to the sleeper. In North American practice the flanged T rail became the standard, later being used with tie-plates. Elsewhere T rails were replaced by bull head rails of a rounded 'I' or 'figure-8' appearance which still required a supporting chair. Eventually the flanged T rail became commonplace on all

544-554: A chair (for bullhead rail), baseplate (for flat bottom rail) or to directly fasten a rail. Chair screws are screwed into a hole bored in the sleeper. The chair screw has a higher cost to manufacture than the rail spike, but has the advantage of greater fixing power—approximately twice that of a rail spike —and can be used in combination with spring washers . The chair screw was first introduced in 1860 in France (French tire-fond ) and became common in continental Europe. A dog screw

612-415: A continuous reinforced concrete slab and the use of pre-cast pre-stressed concrete units laid on a base layer. Many permutations of design have been put forward. However, ballastless track has a high initial cost, and in the case of existing railroads the upgrade to such requires closure of the route for a long period. Its whole-life cost can be lower because of the reduction in maintenance. Ballastless track

680-481: A development of baulk road. Ladder track utilizes sleepers aligned along the same direction as the rails with rung-like gauge restraining cross members. Both ballasted and ballastless types exist. Modern track typically uses hot-rolled steel with a profile of an asymmetrical rounded I-beam . Unlike some other uses of iron and steel , railway rails are subject to very high stresses and have to be made of very high-quality steel alloy. It took many decades to improve

748-431: A rail fastening system. The components of a rail fastening system may also be known collectively as other track material , or OTM for short. Various types of fastening have been used over the years. The earliest wooden rails were fixed to wooden sleepers by pegs through holes in the rail, or by nails. By the 18th century, cast iron rails had come into use, and also had holes in the rail itself to allow them to be fixed to

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816-465: A support. 18th century developments such as the flanged rail and fish bellied rail also had holes in the rail itself; when stone block sleepers were used the nails were driven into a wooden block which had been inserted into a recess in the block. The first chair for a rail is thought to have been introduced in 1797 which attached to the rail on the vertical web via bolts. By the 1820s the first shaped rolled rails had begun to be produced initially of

884-465: A supporting base to the T rail which could be fixed with a simple spike. In 1982, the spike was still the most common rail fastening in North America. Common sizes are from 9 ⁄ 16 to 10 ⁄ 16 inch (14 to 16 mm) square and 5 + 1 ⁄ 2 to 6 inches (140 to 150 mm) long. A rail spike is roughly chisel-shaped and with a flat edged point; the spike is driven with

952-465: A temperature roughly midway between the extremes experienced at that location. (This is known as the "rail neutral temperature".) This installation procedure is intended to prevent tracks from buckling in summer heat or pulling apart in the winter cold. In North America, because broken rails are typically detected by interruption of the current in the signaling system, they are seen as less of a potential hazard than undetected heat kinks. Joints are used in

1020-505: A two-stroke engine. Machines that remove spikes are called spike pullers . The earliest rail chairs , made of cast iron and introduced around 1800, were used to fix and support cast-iron rails at their ends; they were also used to join adjacent rails. In the 1830s rolled T-shaped (or single-flanged T parallel rail ) and I-shaped (or double-flanged T parallel or bullhead ) rails were introduced; both required cast-iron chairs to support them. Originally, iron keys were used to wedge

1088-592: A viewing platform built on the edge of the huge waterfall 90 metres (300 ft) high called Garganta del Diablo . 25°41′03″S 54°26′56″W  /  25.68417°S 54.44889°W  / -25.68417; -54.44889 Rail track A railway track ( British English and UIC terminology ) or railroad track ( American English ), also known as a train track or permanent way (often " perway " in Australia or " P Way " in Britain and India),

1156-570: A walkway for the people or horses that moved wagons along the track. The rails were usually about 3 feet (0.91 m) long and were not joined - instead, adjacent rails were laid on a common sleeper. The straight rails could be angled at these joints to form primitive curved track. The first iron rails laid in Britain were at the Darby Ironworks in Coalbrookdale in 1767. When steam locomotives were introduced, starting in 1804,

1224-471: Is 115 to 141 lb/yd (57 to 70 kg/m). In Europe, rail is graded in kilograms per metre and the usual range is 40 to 60 kg/m (81 to 121 lb/yd). The heaviest mass-produced rail was 155 pounds per yard (77 kg/m), rolled for the Pennsylvania Railroad . The rails used in rail transport are produced in sections of fixed length. Rail lengths are made as long as possible, as

1292-408: Is a manual process requiring a reaction crucible and form to contain the molten iron. North American practice is to weld 1 ⁄ 4 -mile-long (400 m) segments of rail at a rail facility and load it on a special train to carry it to the job site. This train is designed to carry many segments of rail which are placed so they can slide off their racks to the rear of the train and be attached to

1360-441: Is a tradename variant of the screw spike. Fang bolts or rail anchor bolts have also been used for fixing rails or chairs to sleepers. The fang bolt is a bolt inserted through a hole in the sleeper with a fanged nut that bites into the lower surface of the sleeper. For fastening flat-bottomed rails, an upper-lipped washer can be used to grip the edge of the rail. They are more resistant to loosening by vibrations and movement of

1428-519: Is a two-pronged U-shaped staple -like spike bent so that it appears M-shaped when viewed from the side. Inverted J-shaped single pointed spikes have also been used. The spike maul , also known as a spiking hammer , is a type of sledgehammer with a long thin head which was originally used to drive spikes. Manual hole drilling and spike or screw insertion and removal have been replaced by semi-automated or automated machines, which are driven electrically, by pneumatics, by hydraulics, or are powered by

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1496-494: Is cracking around the bolt holes, which can lead to breaking of the rail head (the running surface). This was the cause of the Hither Green rail crash which caused British Railways to begin converting much of its track to continuous welded rail. Where track circuits exist for signalling purposes, insulated block joints are required. These compound the weaknesses of ordinary joints. Specially-made glued joints, where all

1564-450: Is functionally equivalent to a cut spike and is also square in horizontal section and of similar dimensions, but has a pointed penetrating end, and the rail (or "plate holding") head has two lugs on either side, giving the impression of a dog's head and aiding spike removal. A chair screw (also known as coach screw ) is a large (~6 in or 152 mm length, slightly under 1 in or 25 mm diameter) metal screw used to fix

1632-466: Is graded by its linear density , that is, its mass over a standard length. Heavier rail can support greater axle loads and higher train speeds without sustaining damage than lighter rail, but at a greater cost. In North America and the United Kingdom, rail is graded in pounds per yard (usually shown as pound or lb ), so 130-pound rail would weigh 130 lb/yd (64 kg/m). The usual range

1700-490: Is painted green and the propane-fired locomotive pulls up to five opened-roofed carriages with wooden seats at the sides so that the passengers can view the forest. The tracks run along the Iguazu River and the train runs at speeds of up to 20 kilometres per hour (12 mph), stopping when animals cross the lines. The journey takes about 20 minutes. From Garganta del Diablo (Devil's Gorge) Station visitors can go to

1768-402: Is scarce and where tonnage or speeds are high. Steel is used in some applications. The track ballast is customarily crushed stone, and the purpose of this is to support the sleepers and allow some adjustment of their position, while allowing free drainage. A disadvantage of traditional track structures is the heavy demand for maintenance, particularly surfacing (tamping) and lining to restore

1836-456: Is starting to paint rails white to lower the peak temperatures reached in summer days. After new segments of rail are laid, or defective rails replaced (welded-in), the rails can be artificially stressed if the temperature of the rail during laying is cooler than what is desired. The stressing process involves either heating the rails, causing them to expand, or stretching the rails with hydraulic equipment. They are then fastened (clipped) to

1904-507: Is the Vossloh Tension Clamp. Clips are an alternative to spikes. The newer Pandrol fastclip is applied at right angles to the rail. Because the clip is captive, it has to be installed at the time of manufacture of the concrete sleeper. Rail anchors, also called anticreepers, are spring steel clips that attach to the underside of the rail baseplate and bear against the sides of the sleepers to prevent longitudinal movement of

1972-477: Is the structure on a railway or railroad consisting of the rails , fasteners , railroad ties (sleepers, British English) and ballast (or slab track ), plus the underlying subgrade . It enables trains to move by providing a dependable surface for their wheels to roll upon. Early tracks were constructed with wooden or cast iron rails, and wooden or stone sleepers; since the 1870s, rails have almost universally been made from steel. The first railway in Britain

2040-767: Is to bolt them together using metal fishplates (jointbars in the US), producing jointed track . For more modern usage, particularly where higher speeds are required, the lengths of rail may be welded together to form continuous welded rail (CWR). Jointed track is made using lengths of rail, usually around 20 m (66 ft) long (in the UK) and 39 or 78 ft (12 or 24 m) long (in North America), bolted together using perforated steel plates known as fishplates (UK) or joint bars (North America). Fishplates are usually 600 mm (2 ft) long, used in pairs either side of

2108-435: Is usually considered for new very high speed or very high loading routes, in short extensions that require additional strength (e.g. railway stations), or for localised replacement where there are exceptional maintenance difficulties, for example in tunnels. Most rapid transit lines and rubber-tyred metro systems use ballastless track. Early railways (c. 1840s) experimented with continuous bearing railtrack, in which

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2176-691: The United States. The valuable rail fastening spike represented the merge of the Central Pacific and Union Pacific railroads on May 10, 1869, at Promontory Summit, Utah Territory. The rail spike has entered American popular consciousness in this manner; the driving of the Golden Spike was a key point in the development of the western seaboard in North America and was recognized as a national achievement and demonstration of progress. Since, railroad workers have been celebrated in popular culture, including in song and verse. A rail spike (also known as

2244-400: The bolt heads on the same side of the rail. Small gaps which function as expansion joints are deliberately left between the rail ends to allow for expansion of the rails in hot weather. European practice was to have the rail joints on both rails adjacent to each other, while North American practice is to stagger them. Because of these small gaps, when trains pass over jointed tracks they make

2312-482: The canefields themselves. These tracks were narrow gauge (for example, 2 ft ( 610 mm )) and the portable track came in straights, curves, and turnouts, rather like on a model railway. Cut spike A rail fastening system is a means of fixing rails to railroad ties ( North America ) or sleepers ( British Isles , Australasia , and Africa ). The terms rail anchors , tie plates , chairs and track fasteners are used to refer to parts or all of

2380-402: The continuous welded rail when necessary, usually for signal circuit gaps. Instead of a joint that passes straight across the rail, the two rail ends are sometimes cut at an angle to give a smoother transition. In extreme cases, such as at the end of long bridges, a breather switch (referred to in North America and Britain as an expansion joint ) gives a smooth path for the wheels while allowing

2448-440: The desired track geometry and smoothness of vehicle running. Weakness of the subgrade and drainage deficiencies also lead to heavy maintenance costs. This can be overcome by using ballastless track. In its simplest form this consists of a continuous slab of concrete (like a highway structure) with the rails supported directly on its upper surface (using a resilient pad). There are a number of proprietary systems; variations include

2516-462: The edge perpendicular to the grain, which gives greater resistance to loosening. The main function is to keep the rail in gauge. When attaching tie plates the attachment is made as strong as possible, whereas when attaching a rail to tie or tie plate the spike is not normally required to provide a strong vertical force, allowing the rail some freedom of movement. On smaller scale jobs, spikes are still driven into wooden sleepers by hammering them with

2584-444: The edges of the base of the rail. The double-shoulder type is currently used. Older single-shoulder types were adaptable for various rail widths, with the single shoulder positioned on the outside (field side) of the rails. Most plates are slightly wider on the field side, without which the plates tend to cut more into the outsides of the tie, reducing cant angle. Many railways use large wood screws , also called lag screws , to fasten

2652-440: The end of one rail to expand relative to the next rail. A sleeper (tie or crosstie) is a rectangular object on which the rails are supported and fixed. The sleeper has two main roles: to transfer the loads from the rails to the track ballast and the ground underneath, and to hold the rails to the correct width apart (to maintain the rail gauge ). They are generally laid transversely to the rails. Various methods exist for fixing

2720-428: The gaps are filled with epoxy resin , increase the strength again. As an alternative to the insulated joint, audio frequency track circuits can be employed using a tuned loop formed in approximately 20 m (66 ft) of the rail as part of the blocking circuit. Some insulated joints are unavoidable within turnouts. Another alternative is an axle counter , which can reduce the number of track circuits and thus

2788-626: The intrinsic weakness in resisting vertical loading results in the ballast becoming depressed and a heavy maintenance workload is imposed to prevent unacceptable geometrical defects at the joints. The joints also needed to be lubricated, and wear at the fishplate (joint bar) mating surfaces needed to be rectified by shimming. For this reason jointed track is not financially appropriate for heavily operated railroads. Timber sleepers are of many available timbers, and are often treated with creosote , chromated copper arsenate , or other wood preservatives. Pre-stressed concrete sleepers are often used where timber

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2856-480: The iron came loose, began to curl, and intruded into the floors of the coaches. The iron strap rail coming through the floors of the coaches came to be referred to as "snake heads" by early railroaders. The Deeside Tramway in North Wales used this form of rail. It opened around 1870 and closed in 1947, with long sections still using these rails. It was one of the last uses of iron-topped wooden rails. Rail

2924-402: The joints between rails are a source of weakness. Throughout the history of rail production, lengths have increased as manufacturing processes have improved. The following are lengths of single sections produced by steel mills , without any thermite welding . Shorter rails may be welded with flashbutt welding , but the following rail lengths are unwelded. Welding of rails into longer lengths

2992-888: The mid- to late-20th century used rails 39 feet (11.9 m) long so they could be carried in gondola cars ( open wagons ), often 40 feet (12.2 m) long; as gondola sizes increased, so did rail lengths. According to the Railway Gazette International the planned-but-cancelled 150-kilometre rail line for the Baffinland Iron Mine , on Baffin Island , would have used older carbon steel alloys for its rails, instead of more modern, higher performance alloys, because modern alloy rails can become brittle at very low temperatures. Early North American railroads used iron on top of wooden rails as an economy measure but gave up this method of construction after

3060-620: The number of insulated rail joints required. Most modern railways use continuous welded rail (CWR), sometimes referred to as ribbon rails or seamless rails . In this form of track, the rails are welded together by utilising flash butt welding to form one continuous rail that may be several kilometres long. Because there are few joints, this form of track is very strong, gives a smooth ride, and needs less maintenance; trains can travel on it at higher speeds and with less friction. Welded rails are more expensive to lay than jointed tracks, but have much lower maintenance costs. The first welded track

3128-404: The outside of sharp curves compared to the rails on the inside. Rails can be supplied pre-drilled with boltholes for fishplates or without where they will be welded into place. There are usually two or three boltholes at each end. Rails are produced in fixed lengths and need to be joined end-to-end to make a continuous surface on which trains may run. The traditional method of joining the rails

3196-421: The outside. Chairs have been fixed to the sleeper using wooden spikes ( trenails ), screws, fang-bolts or spikes. In most of the world, flat-bottomed rail and baseplates became the standard. However, in Britain, bullhead rail-and-chairs remained in use until the middle of the twentieth century. A tie plate , baseplate or sole plate is a steel plate for centering and reinforcing the attachment point on

3264-423: The quality of the materials, including the change from iron to steel. The stronger the rails and the rest of the trackwork, the heavier and faster the trains the track can carry. Other profiles of rail include: bullhead rail ; grooved rail ; flat-bottomed rail (Vignoles rail or flanged T-rail); bridge rail (inverted U–shaped used in baulk road ); and Barlow rail (inverted V). North American railroads until

3332-682: The rail by special clips that resist longitudinal movement of the rail. There is no theoretical limit to how long a welded rail can be. However, if longitudinal and lateral restraint are insufficient, the track could become distorted in hot weather and cause a derailment. Distortion due to heat expansion is known in North America as sun kink , and elsewhere as buckling. In extreme hot weather special inspections are required to monitor sections of track known to be problematic. In North American practice, extreme temperature conditions will trigger slow orders to allow for crews to react to buckling or "sun kinks" if encountered. The German railway company Deutsche Bahn

3400-425: The rail ends and bolted together (usually four, but sometimes six bolts per joint). The bolts have alternating orientations so that in the event of a derailment and a wheel flange striking the joint, only some of the bolts will be sheared, reducing the likelihood of the rails misaligning with each other and exacerbating the derailment. This technique is not applied universally; European practice being to have all

3468-430: The rail into the vertical parallel jaws of the chair; these were superseded by entirely wooden keys. The wooden keys were formed from oak , steam softened and then compressed with hydraulic presses and stored in a drying house. When inserted into the chair, exposure to the wet atmosphere caused the key to expand, firmly holding the rail. The wedge may be on the inside or outside of the rail. In Britain they were usually on

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3536-500: The rail to the sleeper. Historically, spikes gave way to cast iron chairs fixed to the sleeper. More recently, springs (such as Pandrol clips ) are used to fix the rail to the sleeper chair. Sometimes rail tracks are designed to be portable and moved from one place to another as required. During construction of the Panama Canal , tracks were moved around excavation works. These track gauge were 5 ft ( 1,524 mm ) and

3604-439: The rail tracks between a flanged T rail and a railroad tie . The tie plate increases bearing area and holds the rail to correct gauge . It is fastened to wooden ties by means of spikes or bolts through holes in the plate. The part of the plate under the rail base is tapered, setting the inboard cant of the rail, typically "one in forty" (or 1.4 degrees ). The top surface of the plate has one or two shoulders that fit against

3672-655: The rail was supported along its length, with examples including Brunel's baulk road on the Great Western Railway , as well as use on the Newcastle and North Shields Railway , on the Lancashire and Yorkshire Railway to a design by John Hawkshaw , and elsewhere. Continuous-bearing designs were also promoted by other engineers. The system was tested on the Baltimore and Ohio railway in the 1840s, but

3740-401: The rail. They are thought more effective than spikes and screws and so are used in positions such as switch (point) tieplates and on sharp curves. Spring spikes or elastic rail spikes are used with flat-bottomed rail, baseplates and wooden sleepers. The spring spike holds the rail down and prevents tipping and also secures the baseplate to the sleeper. The Macbeth spike (trade name)

3808-562: The rolling stock full size. Portable tracks have often been used in open pit mines. In 1880 in New York City , sections of heavy portable track (along with much other improvised technology) helped in the move of the ancient obelisk in Central Park to its final location from the dock where it was unloaded from the cargo ship SS Dessoug . Cane railways often had permanent tracks for the main lines, with portable tracks serving

3876-426: The sleepers in their expanded form. This process ensures that the rail will not expand much further in subsequent hot weather. In cold weather the rails try to contract, but because they are firmly fastened, cannot do so. In effect, stressed rails are a bit like a piece of stretched elastic firmly fastened down. In extremely cold weather, rails are heated to prevent "pull aparts". CWR is laid (including fastening) at

3944-540: The sleepers with base plates that spread the load. When concrete sleepers are used, a plastic or rubber pad is usually placed between the rail and the tie plate. Rail is usually attached to the sleeper with resilient fastenings, although cut spikes are widely used in North America. For much of the 20th century, rail track used softwood timber sleepers and jointed rails, and a considerable amount of this track remains on secondary and tertiary routes. In North America and Australia, flat-bottomed rails were typically fastened to

4012-480: The sleepers with dog spikes through a flat tie plate. In Britain and Ireland, bullhead rails were carried in cast-iron chairs which were spiked to the sleepers. In 1936, the London, Midland and Scottish Railway pioneered the conversion to flat-bottomed rail in Britain, though earlier lines had made some use of it. Jointed rails were used at first because contemporary technology did not offer any alternative. However,

4080-468: The tie plates (or baseplates) to the railroad ties. Tie plates came into use around the year 1900, before which time flanged T rail was spiked directly to the ties. A variety of different types of heavy-duty clips are used to fasten the rails to the underlying baseplate, one common one being the Pandrol fastener (Pandrol clip), named after its maker, which is shaped like a stubby paperclip. Another one

4148-511: The ties (sleepers) in a continuous operation. If not restrained, rails would lengthen in hot weather and shrink in cold weather. To provide this restraint, the rail is prevented from moving in relation to the sleeper by use of clips or anchors. Attention needs to be paid to compacting the ballast effectively, including under, between, and at the ends of the sleepers, to prevent the sleepers from moving. Anchors are more common for wooden sleepers, whereas most concrete or steel sleepers are fastened to

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4216-406: The track then in use proved too weak to carry the additional weight. Richard Trevithick 's pioneering locomotive at Pen-y-darren broke the plateway track and had to be withdrawn. As locomotives became more widespread in the 1810s and 1820s, engineers built rigid track formations, with iron rails mounted on stone sleepers, and cast-iron chairs holding them in place. This proved to be a mistake, and

4284-490: The world's railways, though differences in the fixing system still exist. A golden tie, also known as a golden spike or the last spike, may be used to symbolize the start or the completion of an endeavor. These are less often silver or another precious material. Historically, a ceremonial Golden Spike driven by Leland Stanford connected the rails of the First Transcontinental Railroad across

4352-467: Was first introduced around 1893, making train rides quieter and safer. With the introduction of thermite welding after 1899, the process became less labour-intensive, and ubiquitous. Modern production techniques allowed the production of longer unwelded segments. Newer longer rails tend to be made as simple multiples of older shorter rails, so that old rails can be replaced without cutting. Some cutting would be needed as slightly longer rails are needed on

4420-432: Was found to be more expensive to maintain than rail with cross sleepers . This type of track still exists on some bridges on Network Rail where the timber baulks are called waybeams or longitudinal timbers. Generally the speed over such structures is low. Later applications of continuously supported track include Balfour Beatty 's 'embedded slab track', which uses a rounded rectangular rail profile (BB14072) embedded in

4488-466: Was soon replaced with flexible track structures that allowed a degree of elastic movement as trains passed over them. Traditionally, tracks are constructed using flat-bottomed steel rails laid on and spiked or screwed into timber or pre-stressed concrete sleepers (known as ties in North America), with crushed stone ballast placed beneath and around the sleepers. Most modern railroads with heavy traffic use continuously welded rails that are attached to

4556-541: Was the Wollaton Wagonway , built in 1603 between Wollaton and Strelley in Nottinghamshire. It used wooden rails and was the first of around 50 wooden-railed tramways built over the next 164 years. These early wooden tramways typically used rails of oak or beech, attached to wooden sleepers with iron or wooden nails. Gravel or small stones were packed around the sleepers to hold them in place and provide

4624-505: Was used in Germany in 1924. and has become common on main lines since the 1950s. The preferred process of flash butt welding involves an automated track-laying machine running a strong electric current through the touching ends of two unjoined rails. The ends become white hot due to electrical resistance and are then pressed together forming a strong weld. Thermite welding is used to repair or splice together existing CWR segments. This

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