Rail gauge
Broad gauge
Standard gauge
Scotch gauge
Narrow gauge
Minimum gauge
List of rail gauges
Dual gauge
Gauge conversion
Break-of-gauge
Rail tracks
Tramway track
[edit]

Rail tracks are used on railways (or railroads), which, together with railroad switches (or points), guide trains without the need for steering. "Railroad" and "Railway" both redirect here For other uses see Railroad (disambiguation. This article primarily uses North American terminology British and Commonwealth terms are given in parentheses A train is a connected series of vehicles that move along a track ( Permanent way) to transport freight or passengers from one place to another Tracks consist of two parallel steel rails, which are laid upon sleepers (or cross ties) that are embedded in ballast to form the railroad track. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for Railroad tracks. Track ballast forms the trackbed upon which Railroad ties (US or railway sleepers (UK are laid The rail is fastened to the ties with rail spikes, lag screws or clips such as Pandrol clips. A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed In Rail terminology, a spike is a large nail with an offset head that is used to secure rails or Fishplates (or baseplates to ties in the track A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw Pandrol is a British company which manufactures clips used on Rail tracks Overview It was first developed in 1959 by a Norwegian

The type of fastener depends partly on the type of sleeper, with spikes being used on wooden sleepers, and clips being used more on concrete sleepers. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag

Usually, a baseplate tie plate is used between the rail and wooden sleepers, to spread the load of the rail over a larger area of the sleeper. A tie plate (US or baseplate (UK in Railroading is a Steel plate used between Flanged T rail and the crossties The tie plate increases Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs Sometimes spikes are driven through a hole in the baseplate to hold the rail, while at other times the baseplates are spiked or screwed to the sleeper and the rails clipped to the baseplate.

Steel rails can carry heavier loads than any other material. Railroad ties spread the load from the rails over the ground and also serve to hold the rails a fixed distance apart (called the gauge. Rail gauge is the distance between the inner sides of the two parallel rails that make up a railway track. )

Rail tracks are normally laid on a bed of coarse stone chippings known as ballast, which combines resilience, some amount of flexibility, and good drainage. Track ballast forms the trackbed upon which Railroad ties (US or railway sleepers (UK are laid Drainage is the natural or artificial removal of surface and sub-surface water from a given area Steel rails can also be laid onto a concrete slab (a slab track). Across bridges, track is often laid on ties across longitudinal timbers or longitudinal steel girders. Lumber or timber is Wood in any of its stages from felling through readiness for use as structural Material for Construction, or Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 A girder is a support beam used in Construction. Girders often have an I beam cross section for strength but may also have a box shape Z shape

Contents 1 Rail 2 Rail support 3 Rail classification (weight) 4 Joining rails 4.1 Jointed track 4.2 Insulated joints 4.3 Continuous welded rail 5 Fixing rail to ties 5.1 Spikes 5.2 Chairs 5.3 Clips 5.4 Sleeperless track 6 Track maintenance 7 Gauge 8 U.S. track classes 9 Other types 10 References 11 Further reading 12 See also 13 External links

Rail

Main article: Rail profile

Hot rolled steel in the profile of an asymmetrical I-beam is usually used as the surface on which railway wheels run. A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed Hot rolling is a Metalworking process where large pieces of Metal, such as slabs or billets are heated above their Recrystallization temperature and Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 I-beams (also known as W-beams or double-T esp in Polish and German) are beams with an I- or H-shaped 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. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 It took many decades to improve the quality of the materials, including the change from iron to steel. For example, minor flaws in the steel that pose no problems in reinforcing rods for buildings, can, however, lead to broken rails and dangerous derailments when used on railway tracks. A derailment is an accident on a railway in which a Train leaves the rails which can result in damage injury and death The heavier the rails and the rest of the trackwork, the heavier and faster the trains these tracks can carry.

Profiles of rail include:

• Bullhead rail
• Grooved rail
• Vignoles rail (flat-bottomed rail)
• Flanged T rail

Rail support

Main article: Railroad tie

A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for railroad tracks. A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed Tramway track is used on tramways or Light rail operations Grooved rails (or girder rails are often used in order to make street running feasible A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for Railroad tracks. Sleepers are members generally laid transverse to the rails, on which the rails are supported and fixed, to transfer the loads from rails to the track ballast and sub grade below, and to hold the rails to the correct gauge. Track ballast forms the trackbed upon which Railroad ties (US or railway sleepers (UK are laid Rail gauge is the distance between the inner sides of the two parallel rails that make up a railway track.

Rail classification (weight)

Main article: Rail profile

Rail is graded by weight over a standard length. A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed Heavier rail can support greater axle loads and higher train speeds without sustaining damage, compared to lighter rail, but at a greater cost. In North America and the UK, rail is graded in units of pounds per yard (usually just shown as 'lb'), so "130-pound rail" would weigh 130 lb per linear yard (about 59 kg). The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass The usual range is 115 to 141 lbs (about 52 to about 64 kg). In Europe rail is graded in kg/m and the usual range is 40 to 60 kg/m (81 to 126 pounds). The heaviest rail ever mass-produced was 155 pounds (about 70 kg) and was rolled for the Pennsylvania Railroad. The Pennsylvania Railroad was an American Railroad, founded in 1846

Joining rails

Rails are produced in fixed lengths and need to be joined into continuous lengths for trains to run upon.

Jointed track

There are different ways of joining rails together to form tracks. The traditional method was to bolt rails together in what is known as jointed track. In this form of track, lengths of rail, usually around 20 metres (60 ft) long, are laid and fixed to sleepers (UK) (crossties, or simply ties in North American parlance), and are joined to other lengths of rail with steel plates known as fishplates (UK) or joint bars (N. A. ).

Historically, North American railroads until the mid to late 20th century used sections of rail that measured 39 feet (11. 9 m) long so they could be carried to and from a worksite in conventional gondolas, which often measured 40 feet (12. In Railroad terminology, a gondola is an open-top type of Rolling stock that is used for carrying loose bulk materials 2 m) long; as car sizes increased, so did rail lengths.

Fishplates or joint bars are usually 60 centimetres (2 ft) long, and are bolted through each side of the rail ends with bolts (usually four, but sometimes up to six. This article relates to the connection bar used in railways For the type of Greek pottery see Fish plate. ) Small gaps known as expansion joints are deliberately left between the rails to allow for expansion of the rails in hot weather. expansion joint is an assembly designed to safely absorb the heat-induced expansion and contraction of various construction materials The holes through which the fishplate bolts pass are oval to allow for expansion.

British practice was always to have the rail joints on both rails adjacent to each other, while North American practice is to stagger them.

Because of the small gaps left between the rails, when trains pass over jointed tracks, they make a "clickety clack" sound. Unless it is well maintained, jointed track doesn't have the ride quality of welded rail, and is unsuitable for high speed trains. A major problem is cracking around the bolt holes, which can lead to the rail head breaking. 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. The Hither Green rail crash was an accident on the British railway system that occurred on 5 November 1967 opposite Hither Green Traction Maintenance See also Rail transport in Great Britain, National Rail, Network Rail This article is about the defunct entity "British Railways" However, it is still used in many countries on lower speed lines and sidings. A siding, in Rail terminology, is a track section distinct from a through route such as a main line or Branch line or spur Jointed track is still extensively used in poorer countries due to the lower construction cost and lack of modernization of their railway systems.

Insulated joints

Where track circuits exist for signalling purposes, insulated block joints are required. A track circuit is a simple electrical device used to detect the presence or absence of a Train on Rail tracks, used to inform signallers and control relevant signals Railway signalling is a system used to control Railway traffic safely essentially to prevent Trains from colliding. These compound the weakness of ordinary block joints. Specially made glued joints, where all the gaps filled with epoxy resin increases the strength again. In Chemistry, epoxy or polyepoxide is a Thermosetting Epoxide Polymer that cures (polymerizes and crosslinks when mixed with a Audio frequency track circuits replace the conventional block joint with a tuned loop which uses approximately 20 m of the rail as part of the blocking circuit. An audio frequency (abbreviation AF) or audible frequency is characterized as a periodic vibration whose Frequency is audible to the average human A track circuit is a simple electrical device used to detect the presence or absence of a Train on Rail tracks, used to inform signallers and control relevant signals Axle counters can also reduce the number of track circuits and thus the number of insulated rail joints. An axle counter is a device on a Railway that detects the passing of a Train in lieu of the more common Track circuit.

Continuous welded rail

Most modern railways use continuous welded rail (CWR), sometimes referred to as ribbon 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, or thermite welding to repair or splice together existing CWR segments. Welding is a fabrication process that joins materials usually Metals or Thermoplastics by causing coalescence. Flash Welding is a form of resistance welding that involves pressing two ends together while simultaneously running a current between them Thermite is a Pyrotechnic composition of Aluminium powder and a metal oxide which produces an Aluminothermic reaction known as a Because there are few joints, this form of track is very strong, gives a smooth ride, and needs less maintenance. The first welded track was used in the 1920s and 30s^[1] and has become common on main lines since the 1950s.

Flash butt welding is the preferred process which involves an automated track laying machine running a strong electrical current through the touching ends of two unjoined pieces of rail. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The ends become white hot due to electrical resistance and are then pressed together forming a strong weld. Thermite welding is a manual process requiring a reaction crucible and form to contain the molten iron. Thermite-bonded joints are also seen as less reliable and more prone to fracture or break.

Because of the increased strength of welded track, 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.

Rails expand in hot weather and shrink in cold weather. Because welded track has very few expansion joints, if no special measures are taken it could become distorted in hot weather and cause a derailment (a condition known in America as heat kink, and in Britain as buckling). A derailment is an accident on a railway in which a Train leaves the rails which can result in damage injury and death Sun kink refers to a condition that can occur on hot days in Rail tracks. In Engineering, buckling is a failure mode characterized by a sudden failure of a structural member subjected to high Compressive stresses where In North America a rail broken due to cold-related contraction is known as a pull-apart.

To avoid this, welded rails are laid on concrete or steel sleepers, which are so heavy they hold the rails firmly in place. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for Railroad tracks. Great attention is paid to compacting the ballast effectively, particularly the shoulder over the ends of the sleepers, to prevent them from moving. Even so, in extreme weather, foot patrols monitor sections of track known to be problematic. See also List of extreme weather events Extreme weather includes Weather phenomena that are at the extremes of the historical distribution especially

After new segments of rail are laid, or defective rails replaced (welded in), the rails are artificially stressed. The stressing process involves either heating the rails causing them to expand,^[2] or stretching the rails with hydraulic equipment. Stressing is a technique developed in the 1960's to avert rail track problems that can occur when installing Continuous Welded Rail (CWR For the mechanical technology see Hydraulic machinery and Hydraulic cylinder Hydraulics is a topic of science and Engineering They are then fastened (clipped) to 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. An elastomer is a Polymer with the property of Elasticity. The term which is derived from elastic polymer, is often used interchangeably with the term

Engineers try to heat the rail to a temperature roughly midway between the average extremes of hot and cold (this is known as the 'rail neutral temperature'). If temperatures reach outside normal ranges however, welded rail can buckle in a hotter than usual summer or can actually break in a colder than anticipated winter. In North America, because broken rails are typically detected by the signaling system they are seen as less of a problem than heat kinks which are not. For this reason, and because it is harder to break a rail than displace the trackbed, CWR is usually installed at a temperature of 90 °F (32 °C), to cope with rail temperature extremes of nearly 120 °F (49 °C) in the summer sun.

Joints are used in continuously welded rail when necessary; instead of a joint that passes straight across the rail, producing a loud noise and shock when the wheels pass over it, two sections of rail are sometimes cut at a steep angle and put together with a gap between them - a breather switch (referred to in Britain as an expansion joint). A Breather Switch (or Adjustment Switch) is a long diagonal gap in Rail tracks created to allow for the transition between two segments of continuously welded This gives a much smoother transition yet still provides some expansion room.

Fixing rail to ties

There are several methods used to fasten rail to wooden ties. The worldwide standard type of rail used today is flat-bottomed rail (Vignoles rail), which has a flat base and can stand upright without support. A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed A flat-bottomed rail has a cross-section like that of an upside-down 'T' and is usually held to the sleeper with a tie plate (baseplate), a metal plate attached to the sleeper; although for lower cost construction flat bottom rails can be laid directly onto the sleepers. A tie plate (US or baseplate (UK in Railroading is a Steel plate used between Flanged T rail and the crossties The tie plate increases

Modern sleepers can be made of reinforced concrete and pressed steel, with rubber pads inserted between the sleeper and rail. Reinforced concrete is Concrete in which reinforcement bars (" Rebars quot or fibers have been incorporated to strengthen a material that would otherwise be This is done for two reasons: to give a smoother ride and to prevent the sleeper from shorting the track circuit, a low voltage passed through the rails for signalling purposes. A track circuit is a simple electrical device used to detect the presence or absence of a Train on Rail tracks, used to inform signallers and control relevant signals This is different from a "traction current," which powers electric trains.

Spikes

A rail spike is a large nail with an offset head that is used to secure rails or fishplates (or baseplates) to ties in the track. In Rail terminology, a spike is a large nail with an offset head that is used to secure rails or Fishplates (or baseplates to ties in the track In Engineering, Woodworking and Construction, a nail is a pin -shaped sharp object of hard Metal, typically Steel, This article relates to the connection bar used in railways For the type of Greek pottery see Fish plate. Spikes are driven into wooden ties either by hammering them with a spike hammer by hand, or in an automated fashion with a spiker. A railroad tie, cross tie, or railway sleeper is a rectangular object used as a base for Railroad tracks. A spiker is a piece of Rail transport Maintenance of way equipment

Spikes are cheaper and simpler to install than other methods but can loosen if the tie rots, much more easily than the British chair (a type of baseplate) does. An alternate method is the use of large wood screws, also called lag screws. A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw

Chairs

In traditional British practice, cast metal chairs were screwed to the sleepers, which took a style of rail known as bullhead that was somewhat figure-8 in cross-section — wider at top and bottom (known as the head and foot respectively) and smaller in the middle (the web). A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw Keys (wedges of wood or sprung steel) were then driven in between chair and rail to hold it in place. This was common practice on British railways until the 1950s, but is now largely obsolete^[3].

The idea behind bullhead rails was that because both the top and bottom of the rails were the same shape, when one side of the rail became worn, the rail could be turned over to the unused side, thus extending the rail's lifespan. However the bottom head turned out to get dented, rendering the original idea useless. Since the turnover requirement was no longer needed, bullhead rails came to have a flat base (narrower than flat-bottomed rail), and the top part has curved edges that fit the profile of the train wheels.

Clips

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 sturdy, stubby paperclip. [1], [2] and [3]. Another one is the Vossloh Tension Clamp. [4]

Sleeperless track

In recent years, methods have been developed to put tracks on concrete without using conventional sleepers or track ballast. While this method's construction cost is high, this system is expected to have significantly lower maintenance cost than conventional tracks. It is mainly used on high-speed lines and in tunnels, where maintenance access is difficult and where the track is subject to fewer climatic stresses (such as rain and temperature fluctuation).

See Tubular Modular Track. Tubular Modular Track is a form of track construction for railways where the concrete sleepers are parallel to the rails (with cross pieces at intervals rather than at right angles to

Track maintenance

See also: Maintenance of way

Track needs frequent maintenance to remain in good order; the frequency increases with higher-speed or heavier trains. MOW redirects here For other meanings see MOW (disambiguation. Without frequent maintenance, a Slow Order in American terminology, a "slack" or speed restriction in the United Kingdom, may have to be imposed due to damage on the tracks. (see Slow zone). A slow zone, in America, is an area where a train is forced to slow down for either structural construction power signal or track problems Track maintenance was formerly hard manual labour, requiring teams of labourers (US: gandy dancers, GB: platelayers or navvies), who used levers to force rails back into place on steep turns, correcting the gradual shifting caused by the centripetal force of passing trains. Manual labour (or manual labor) is physical work done with the hands especially in an unskilled job such as fruit and vegetable picking road building or any Gandy dancer is a Slang term for workers who maintained Railroads in North America The centripetal force is the external force required to make a body follow a curved path Currently, maintenance is facilitated by a variety of specialised machines.

The profile of the track is maintained by using a railgrinder. A railgrinder (or rail grinder is a Maintenance of way vehicle or train used to restore the profile and remove irregularities from worn Rail track to extend its life

Common maintenance jobs include spraying ballast with weedkiller to prevent weeds growing through and disrupting the ballast. A herbicide is used to kill unwanted Plants Selective herbicides kill specific targets while leaving the desired Crop relatively unharmed This is typically done with a special weedkilling train.

Over time, ballast is crushed or moved by the weight of trains passing over it, and periodically it needs to be levelled (tamped) and eventually cleaned or replaced. If this is not done, the tracks may become uneven causing swaying, rough riding and eventually the risk for derailment.

Rail Inspections utilize nondestructive testing methods to detect internal flaws in the rails. Rail inspection is the practice of examining Rail tracks for flaws that could lead to catastrophic failures Nondestructive testing ( NDT) also called nondestructive examination ( NDE) and nondestructive inspection ( NDI) is testing that does This is done by using specially equipped HiRail trucks, inspection cars, or in some cases handheld inspection devices. A Road-rail vehicle is a Self-propelled Vehicle that can be legally used on both Roads and rails.

Broken or worn-out rails also need replacing periodically. Mainline rails that get worn out usually have life left in branch line or rail siding use and are "cascaded" to those branch lines. A branch line is a secondary railway line which branches off a more important through route usually a main line. A siding, in Rail terminology, is a track section distinct from a through route such as a main line or Branch line or spur

The environmental conditions along railroad tracks create a unique ecosystem. Railroad ecology is a term used to refer to the study of the ecological community growing along railroad tracks This is particularly so in the United Kingdom where steam locomotives are no longer used and vegetation has not been trimmed back so thoroughly. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located This, however, creates a problem for steam-hauled "heritage" trains in prolonged dry weather.

Gauge

Main article: Rail gauge

During the early days of rail there was considerable variation in the gauge used by different systems. Rail gauge is the distance between the inner sides of the two parallel rails that make up a railway track. Today, sixty percent of the world's railways use a gauge of 4 ft 8½ in (1,435 mm), which is known as the standard or international gauge. The standard gauge (also named the Stephenson gauge after George Stephenson, or Normal gauge) is a widely-used Rail gauge. The standard gauge (also named the Stephenson gauge after George Stephenson, or Normal gauge) is a widely-used Rail gauge. Gauges wider than standard gauge are called broad gauge, those smaller than standard narrow gauge. Broad gauge Railways use a Rail gauge (distance between the rails greater than the Standard gauge of. A narrow gauge railway (or narrow gauge railroad) is a Railway that has a Track gauge narrower than the of Standard gauge railways Some stretches of track are dual gauge, with three (or sometimes four) parallel rails in place of the usual two, to allow trains of two different gauges to share the same track. Dual-gauge or mixed-gauge Railway is a special configuration of railway track, allowing trains of different gauges to use the same track ^[4]

U. S. track classes

In the United States, the Federal Railroad Administration has developed a system of classification for track quality. The United States of America —commonly referred to as the The Federal Railroad Administration (FRA is an administration in the United States Department of Transportation. ^{[5] [6]} The class a track is placed in determines speed limits and the ability to run passenger trains.

• Excepted track. Only freight trains are allowed to operate on this type of trackage, and they may run at speeds up to 10 mph (16 km/h). Also, no more than five cars loaded with hazardous material may be operated within any single train. A dangerous good is any Solid, Liquid, or Gas that can harm people other living Organisms property or the environment Passenger trains of any kind are prohibited, including chartered excursions and fantrips.
• Class 1 track is the lowest class allowing the operation of passenger trains. Freight train speeds are still limited to 10 mph (16 km/h), and passenger trains are restricted to 15 mph (24 km/h).
• Class 2 track limits freight trains to 25 mph (40 km/h) and passenger trains to 30 mph (48 km/h).
• Class 3 track limits freight trains to 40 mph (64 km/h) and passenger trains to 60 mph (97 km/h).
• Class 4 track limits freight trains to 60 mph (97 km/h) and passenger trains to 80 mph (130 km/h).
  • Most track, especially that owned by major railroads the Union Pacific, BNSF, CSX, and Norfolk Southern is class 4 track. The BNSF Railway headquartered in Fort Worth, Texas, is one of the four remaining Transcontinental railroads and one of the largest railroad networks in This article is about the present railroad formed in 1990 For the former regional railroad in Virginia and North Carolina a small part of the new one see Norfolk Southern Due to a poorly worded regulation, passenger trains are technically limited to 79 mph ("less than 80") (126 km/h) on this track, unless cab signaling or automatic train stop are in service. Cab signalling is a Railroad safety system that communicates track status information to the train cab (driving position where the engineer or driver can see the information An automatic train stop is a system on a train that will automatically stop a train if certain situations happened (unresponsive train operator earthquake disconnected rail train running
• Class 5 track limits freight trains to 80 mph (130 km/h) and passenger trains to 90 mph (140 km/h).
  • The only Class 5 track operated by a freight railroad are parts of the BNSF Railway Chicago–Los Angeles mainline, the old Santa Fe main, upon which ATS equipped passenger trains such as Amtrak's Southwest Chief can operate at up to 90 mph (140 km/h). The BNSF Railway headquartered in Fort Worth, Texas, is one of the four remaining Transcontinental railroads and one of the largest railroad networks in The Southwest Chief (formerly the Southwest Limited) is a Passenger train operated by Amtrak along a 2256-mile (3631-km route through This is gradually being reduced to Class 4 as the train stop system is retired.
• Class 6 limits freight trains and passenger trains to 110 mph (180 km/h).
• Class 7 limits all trains to 125 mph (201 km/h).
  • Most of Amtrak's Northeast Corridor is Class 7 trackage. The Northeast Corridor ( NEC) is the busiest passenger rail line in the United States by ridership and service frequency
• Class 8 limits all trains to 160 mph (260 km/h).
  • Portions of the Northeast Corridor are the only Class 8 trackage in North America allowing for 135 mph (217 km/h) and 150 mph (240 km/h) operation.
• Class 9 trackage limits all trains to 200 mph (320 km/h).
  • There is currently no Class 9 trackage.

In addition to class, maximum track speed is also subject to specific regulatory restrictions known as rules. The rule governing the maximum permissible speed of a train operating on curved track is determined by the following formula:

where E_a is the amount in inches that the outside rail is superelevated above the inside rail on a curve and d is the degree of curvature in degrees per 100 feet (30 m). The cant of a Road (sometimes referred to as Camber or Cross slope) or Railway (also referred to as superelevation) is the difference Degree of curve or degree of curvature is a measure of Curvature used in Civil engineering for its easy use in layout Surveying. V_max is given in miles per hour.

Track unbalanced superelevation in the U. S. is restricted to 3 inches (76 mm), though 4 inches (100 mm) is permissible by waiver. There is no hard maximum set for European railways, some of which have curves with over 11 inches (280 mm) of unbalanced superelevation to permit high-speed transportation. ^[7]

Generally the aim is for trains to run without flange contact, which also depends on the tyre profile of the wheels. Allowance has to be made for the different speeds of trains. Slower trains will tend to make flange contact with the inner rail on curves, while faster trains will tend to ride outwards and make contact with the outer rail. Either creates wear and may lead to derailment. Many high speed lines do not permit the use of slower freight trains, particularly with heavier axle loads. On Railways the axle load is the maximum weight of a Train per pair of wheels allowable for a given section of track. In some cases, problems are alleviated by the use of flange lubrication.

Other types

See also: Wagonway and Plateway

In the early years of railways, there was much experimentation with rails and sleepers and fixtures, before the better designs emerged. Wagonways are the horses equipment and tracks used for hauling wagons which preceded steam powered railways There are two styles of waggonway and two spellings A plateway is an early kind of railway or tramway or Wagonway, with a Cast iron rail.

Wooden rails with a metal strap on top was tried to save costs, but the straps had a tendency to come loose and penetrate the carriages going over them. These were commonly known as "snakeheads".

"Pole Roads" were used in past American logging operations in place of the more expensive standard railroad. Logging is the process in which Trees are cut down for Forest management and Timber. They consisted of wooden poles laid end to end and parallel to each other in place of the steel rails. Locomotives and rolling stock on pole roads used concave wheels (double flanged) as opposed to the single flange used on most railway lines. Fordson tractors were often converted into pole road locomotives. The Fordson model F tractor by the Ford Motor Company was the first agricultural Tractor to be mass produced. The major setback to these lines was that the primitive (often home-made) locomotives tended to derail on curves.

The "flangeway" was an early type of railway, the rails of which were equipped with a flange, while the locomotives and rolling stock that ran on it had wheels with plain rims. However switches/turnouts were very primitive, and high speeds could not be achieved, thus leading to the demise of the flangeway and the rise of today's "edgeway".

Barlow rail had a wide cross section to spread the load, but the rail itself tended to spread and go out of gauge. Barlow rail was a kind of rail used on early railways It has a top-hat or saddle-back kind of cross-section ^[8] There are some examples in the Powerhouse Museum in Sydney. The Powerhouse Museum is the major branch of the Museum of Applied Arts and Sciences in Sydney, the other being the historic Sydney Observatory. Sydney (ˈsɪdniː is the most populous city in Australia, with a Metropolitan area population of approximately 4 ^{[9] [10]}

Brunel's Great Western Railway used longitudinal sleepers, with piles to hold the track down, but as the earthworks settled, the piles came to hold the track up. Isambard Kingdom Brunel, FRS (9 April 1806 &ndash 15 September 1859 (ˈɪzəmbɑrd ˈkɪŋdəm brʊˈnɛl was a British Engineer. The Great Western Railway ( GWR) was a British railway company and a notable example of Civil engineering, linking London with the West "Bridge Rail" was originally used; this is somewhat similar to Barlow rail mentioned above, only squarer and perhaps thicker. Barlow rail was a kind of rail used on early railways It has a top-hat or saddle-back kind of cross-section ^[11]

References

Further reading

• Pike, J. Light Railways is a Magazine produced by the Light Railway Research Society of Australia (LRRSA , (2001), Track, Sutton Publishing, ISBN 0-7509-2692-9
• Firuziaan, M. and Estorff, O. , (2002), Simulation of the Dynamic Behavior of Bedding-Foundation-Soil in the Time Domain, Springer Verlag.

See also

Railroad switch (points) Rail terminology (including US/UK and other regional/national differences) Rail transport Railroad ecology Grand union Third rail Rack railway Monorail LGV construction TGV tracks Main line (railway) Double track

Grooved rail Single track Rail siding Passing loop Track transition curve Vignoles rail Wagonway Wye Railway station layout Flanged T rail Permanent way nl:Verschil tussen trein- en tramspoor

External links

• Table of North American tee rail (flat bottom) sections
• ThyssenKrupp handbook, Vignoles rail
• ThyssenKrupp handbook, Light Vignoles rail
• Track Details in photographs

This article primarily uses North American terminology British and Commonwealth terms are given in parentheses 0-9 Note for 4-4-0 2-6-4T 0-4-4-0 etc See Whyte notation or UIC classification A B "Railroad" and "Railway" both redirect here For other uses see Railroad (disambiguation. Railroad ecology is a term used to refer to the study of the ecological community growing along railroad tracks This article is about a type of tram/railway junction For the canal see Grand Union Canal, for the supermarket see Grand Union (stores, for the rail operator A third rail is a method of providing Electricity to power a railway through a continuous rigid conductor alongside the railway track or between the rails A cog railway, rack-and-pinion railway or rack railway is a Railway with a toothed rack rail, usually between the running rails. A monorail is a transportation system based on a single beam The term is also used variously to describe the beam of the system or the vehicles travelling on such a beam or LGV construction is the process by which the land on which TGV trains are to run is prepared for their use involving carving the trackbed and laying the The TGV ( t rain à g rande v itesse, French for "high-speed train" is France 's High-speed rail service The Mainline or Main line of a Railway is a track that is used for through trains or is the principal artery of the system from which Branch lines, A double track railway usually involves running one track in each direction compared to a single track railway where trains in both directions share the same track Tramway track is used on tramways or Light rail operations Grooved rails (or girder rails are often used in order to make street running feasible A single track Railway is one where traffic in both directions shares the same track A siding, in Rail terminology, is a track section distinct from a through route such as a main line or Branch line or spur A passing loop (or "crossing loop" is a place on a single line railway/tramway where trains/trams in opposing directions can pass each other A Track transition curve, or spiral easement, is a mathematically calculated curve on a section of highway or railroad track where a straight section changes into a curve A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed Wagonways are the horses equipment and tracks used for hauling wagons which preceded steam powered railways There are two styles of waggonway and two spellings A railway station is a place where trains make scheduled stops A Rail profile is a Hot rolled Steel profile of a specific Shape or cross section (an asymmetrical I-beam) designed The permanent way means the physical elements of the railway line itself generally the pairs of rails typically laid on sleepers embedded in ballast intended to carry the ordinary

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