Welded rails are more expensive to lay than jointed tracks, but have much lower maintenance costs. The first welded track was used in Germany in and the US in  and has become common on main lines since the s. 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 is a manual process requiring a reaction crucible and form to contain the molten iron. Thermite-bonded joints are seen as less reliable and more prone to fracture or break. 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 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 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. 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 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. CWR is laid including fastening at 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 winter cold.
In North America, because broken rails known as a pull-apart 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 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 the end of one rail to expand relative to the next rail.
A sleeper tie is a rectangular object on which the rails are supported and fixed. The sleeper has two main roles: They are generally laid transversely to the rails. Various methods exist for fixing 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. Portable tracks have often been used in open pit mines. In in New York City , sections of heavy portable track along with much other improvised technology helped in the epic 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 the canefields themselves. Decauville was a source of many portable light rail tracks, also used for military purposes.
The permanent way is so called because temporary way tracks were often used in the construction of that permanent way. The geometry of the tracks is three-dimensional by nature, but the standards that express the speed limits and other regulations in the areas of track gauge, alignment, elevation, curvature and track surface are usually expressed in two separate layouts for horizontal and vertical. Horizontal layout is the track layout on the horizontal plane. This involves the layout of three main track types: Vertical layout is the track layout on the vertical plane including the concepts such as crosslevel, cant and gradient.
A sidetrack is a railroad track other than siding that is auxiliary to the main track.
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The word is also used as a verb without object to refer to the movement of trains and railcars from the main track to a siding, and in common parlance to refer to giving in to distractions apart from a main subject. During the early days of rail, there was considerable variation in the gauge used by different systems. 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 use the same track. Gauge can safely vary over a range. Track needs regular maintenance to remain in good order, especially when high-speed trains are involved.
Inadequate maintenance may lead to a "slow order" North American terminology, or Temporary speed restriction in the United Kingdom being imposed to avoid accidents see Slow zone. Track maintenance was at one time hard manual labour , requiring teams of labourers, or trackmen US: Currently, maintenance is facilitated by a variety of specialised machines. The surface of the head of each of the two rails can be maintained by using a railgrinder.
Common maintenance jobs include changing sleepers, lubricating and adjusting switches , tightening loose track components, and surfacing and lining track to keep straight sections straight and curves within maintenance limits. The process of sleeper and rail replacement can be automated by using a track renewal train. Spraying ballast with herbicide to prevent weeds growing through and redistributing the ballast is typically done with a special weed killing train.
Over time, ballast is crushed or moved by the weight of trains passing over it, periodically requiring relevelling "tamping" and eventually to be cleaned or replaced. If this is not done, the tracks may become uneven causing swaying, rough riding and possibly derailments. An alternative to tamping is to lift the rails and sleepers and reinsert the ballast beneath. Conventional high-speed rail technology would be used as opposed to Maglev. A second phase of the project is planned to reach further north to Manchester, Sheffield and Leeds, as well as linking into the Midland Main Line.
In the fastest timetabled start-to-stop run by a UK domestic train service was the Hull Trains This is operated by a Class diesel unit running "under the wires" on this East Coast route. This was matched by several Leeds to London Class 91 -operated East Coast trains if their two-minute recovery allowance for this section is excluded from the public timetable. A number of towns and cities have rapid transit systems. Heavy rail underground technology is used in the London and Glasgow Underground systems while the Merseyrail system in Liverpool shares some characteristics.
Blackpool has the one remaining traditional tram system. Monorails, heritage tramways, miniature railways and funiculars also exist in several places. In addition, there are a number of heritage mainly steam standard and narrow gauge railways, and a few industrial railways and tramways. Some lines which appear to be heritage operations sometimes claim to be part of the public transport network; the Romney, Hythe and Dymchurch Railway in Kent regularly transports schoolchildren.
Most major cities have some form of commuter rail network. There are also several smaller independent operators including Mendip Rail. Types of freight carried include intermodal — in essence containerised freight — and coal, metals, oil, and construction material. The Beeching Cuts, in contrast to passenger services, greatly modernised the goods sector, replacing inefficient wagons with containerised regional hubs. Statistics on freight are specified in terms of the weight of freight lifted, and the net tonne kilometre , being freight weight multiplied by distance carried.
A symbolic loss to the rail freight industry in Great Britain was the custom of the Royal Mail , which from discontinued use of its train fleet, and switching to road haulage after a near year-preference for trains. Mail trains had long been part of the tradition of the railways in Great Britain, famously celebrated in the film Night Mail , for which W.
Auden wrote the poem of the same name. Although Royal Mail suspended the Mail train in January , this decision was reversed in December of the same year, and Class s are now used on some routes including between London, Warrington and Scotland.
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At the time of privatisation, the rolling stock of British Rail was sold to the new operators, as in the case of the freight companies, or to the three ROSCOs rolling stock operating companies which lease or hire stock to passenger and freight train operators. Leasing is relatively commonplace in transport, since it enables operating companies to avoid the complication associated with raising sufficient capital to purchase assets; instead, assets are leased and paid for from ongoing revenue.
Since there has been a growth in smaller spot-hire companies that provide rolling stock on short-term contracts. Many of these have grown thanks to the major selling-off of locomotives by the large freight operators, especially EWS. Unlike other major players in the privatised railway system of Great Britain, the ROSCOs are not subject to close regulation by the economic regulatory authority.
They were expected to compete with one another, and they do, although not in all respects. Since privatisation in , the ROSCOs have faced criticism from several quarters - including passenger train operating companies such as GNER, Arriva and FirstGroup - on the basis they are acting as an oligopoly to keep lease prices higher than they would be in a competitive market.
Many believed Prescott favoured much closer regulation of the ROSCOs, perhaps bringing them into the net of contract-specific regulation, i. Swift's report did not find major problems with the operation of what was then an infant market, and instead recommended the ROSCOs sign up to voluntary, non-binding codes of practice in relation to their future behaviour. Prescott did not like this, but he did not have the legislative time allocation to do much about it. Swift's successor as Rail Regulator, Tom Winsor , agreed with Swift and the ROSCOs were happy to go along with codes of practice, coupled with the Rail Regulator's new powers to deal with abuse of dominance and anti-competitive behaviour under the Competition Act The codes of practice were duly put in place and for the next five years the Rail Regulator received no complaints about ROSCO behaviour.
In July , the Department for Transport's White Paper on the future of the railways contained a statement it was dissatisfied with the operation of the rolling stock leasing market and believed there may have been excessive pricing on the part of the ROSCOs. While the TOCs are negotiating for a franchise they have some freedom to propose different rolling stock options. However, Wolmar considers it a mistake to blame the ROSCOs who are simply behaving as commercial companies always behave.
Ultimately the problem for Wolmar is the system — and that is down to the government, who he believes are not prepared to seek a more workable solution. On 29 November , following a June complaint by the Department for Transport alleging excessive pricing by the ROSCOs, the Office of Rail Regulation as it was then called announced it was minded to refer the operation of the market for passenger rolling stock to the Competition Commission , citing, amongst other factors, problems in the DfT's own franchising policy as responsible for what may be regarded as a dysfunctional market.
ORR said it will consult the industry and the public on what to do, and will publish its decision in April If the ORR does refer the market to the Competition Commission, there may well be a hiatus in investment in new rolling stock whilst the ROSCOs and their parent companies wait to hear what return they will be allowed to make on their train fleets.
This could have the unintended consequence of intensifying the problem of overcrowding on some routes because TOCs will be unable to lengthen their trains or acquire new ones if they need the ROSCOs to co-operate in their acquisition or financing. Some commentators have suggested that such an outcome would be detrimental to the public interest. This is especially striking since the National Audit Office , in its November report on the renewal and upgrade of the West Coast main line , said that the capacity of the trains and the network will be full in the next few years and advocated train lengthening as an important measure to cope with sharply higher passenger numbers.
The Competition Commission conducted an investigation and published provisional findings  on 7 August The report was published on 7 April Three companies took over British Rail 's rolling stock on privatisation:. Railways in Great Britain are in the private sector, but they are subject to control by central government, and to economic and safety regulation by arms of government. In , using powers in the Railways Act , the Department for Transport took over most of the functions of the now wound up Strategic Rail Authority.
The DfT now itself runs competitions for the award of passenger rail franchises, and, once awarded, monitors and enforces the contracts with the private sector franchisees. Franchises specify the passenger rail services which are to be run and the quality and other conditions for example, the cleanliness of trains, station facilities and opening hours, the punctuality and reliability of trains which the operators have to meet. Some franchises receive a subsidy from the DfT for doing so, and some are cash-positive, which means the franchisee pays the DfT for the contract.
Some franchises start life as subsidised and, over their life, move to being cash-positive. The other regulatory authority for the privatised railway is the Office of Rail and Road previously the Office of Rail Regulation , which, following the Railways Act , is the combined economic and safety regulator.
It replaced the Rail Regulator on 5 July The Rail Safety and Standards Board still exists, however; established in on the recommendations of a public inquiry, it leads the industry's progress in health and safety matters. See Passenger transport executive. See List of companies operating trains in the United Kingdom. This is only the earliest of the main line openings: Many lines closed by British Railways, including many closed during the Beeching cuts , have been restored and reopened as heritage railways. A few have been relaid as narrow-gauge but the majority are standard-gauge.
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Rail transport in Great Britain - Wikipedia
Most heritage railways are operated as tourist attractions and do not provide regular year-round train services. Several pressure groups are campaigning for the re-opening of closed railway lines in Great Britain. From until , 27 new lines totalling track miles and 68 stations were opened, with 65 further new station sites identified by Network Rail or government for possible construction. Expanding Access to the Rail Network , detailing schemes around England where it believed there was a commercial business case for passenger network expansion.
The published proposals involved the re-opening or new construction of 40 stations, serving communities with populations of over 15,, including 14 schemes involving the re-opening or reconstruction of rail lines for passenger services. These would be short-lead-time local projects, to be completed in timescales ranging from 2 years 9 months to 6 years, once approved by local and regional governments, Network Rail and the Department for Transport , complementing existing long-term national projects.
From Wikipedia, the free encyclopedia. For transport in Northern Ireland, see Rail transport in Ireland. History of rail transport in Great Britain. History of rail transport in Great Britain - Timeline of future rail network upgrades in Great Britain. List of railway lines in Great Britain. On some low-traffic branch lines, in self-contained marshalling yards , or on heritage railways , switches may still have the earlier type of interlocking. The points switch rails or point blades are the movable rails which guide the wheels towards either the straight or the diverging track.
They are tapered on most switches, but on stub switches they have square ends. In the UK and Commonwealth countries, the term points refers to the entire mechanism, whereas in North America the term refers only to the movable rails. In some cases the switch blades can be heat treated for improvement of their service life. There are different kinds of heat treatment processes such as edge hardening or complete hardening.
The frog, also known as the common crossing or V-rail in Australian terminology , is the crossing point of two rails. This can be assembled out of several appropriately cut and bent pieces of rail or can be a single casting of manganese steel. On lines with heavy use the casting may be treated with explosive shock hardening to increase service life. On lines with heavy or high-speed traffic, a swingnose crossing movable-point frog may be used. As the name implies, there is a second mechanism located at the frog.
This moves a small portion of rail, to eliminate the gap in the rail that normally occurs at the frog. A separate switch machine is required to operate the movable-point frog switch. This term frog is taken from the part of a horse's hoof it most closely resembles. Certain types of overhead electrification systems that makes use of trolley poles have similar devices referred to as wire frogs.
On dual-gauge switches, a special frog is used where the third rail crosses the common rail. Denver and Rio Grande crews called this a "toad". A recent development on North American freight railroads is the flange-bearing frog , in which the wheel flange supports the weight of the vehicle as opposed to the tread. This design reduces impact loading and extends the life of the frog.
A guard rail check rail is a short piece of rail placed alongside the main stock rail opposite the frog. These ensure that the wheels follow the appropriate flangeway through the frog and that the train does not derail. Generally, there are two of these for each frog, one by each outer rail. Guard rails are not required with a "self-guarding cast manganese" frog, as the raised parts of the casting serve the same purpose.
These frogs are for low-speed use and are common in yards.
Rail transport in Great Britain
Check rails are often used on very sharp curves, even where there are no switches. A switch motor also known as a switch machine, point motor or point machine is an electric , hydraulic or pneumatic mechanism that aligns the points with one of the possible routes. The motor is usually controlled remotely by the dispatcher signaller in the UK. The switch motor also includes electrical contacts to detect that the switch has completely set and locked. If the switch fails to do this, the governing signal is kept at red stop.
There is also usually some kind of manual handle for operating the switch in emergencies, such as power failures. A patent by W. Purvis dates from A points lever , ground throw , or switchstand is a lever and accompanying linkages that are used to align the points of a switch manually. This lever and its accompanying hardware is usually mounted to a pair of long sleepers that extend from the switch at the points. They are often used in a place of a switch motor on infrequently used switches. In some places, the lever may be some distance from the points, as part of a lever frame or ground frame.
To prevent the tampering of switches by outside means, these switches are locked up when not in use. A point machine conversion system consist in a remotely controlled device attached to an existing manually operated point that allows the shunter or driver to remotely operate hand points with a radio handset. Each converter can be used as a stand-alone or multiple units can be installed operating together with routing. A facing point lock FPL , or point lock , is a device which, as the name implies, locks a set of points in position, as well as proving that they are in the correct position.
The facing point part of the name refers to the fact that they are to prevent movement of the points during facing moves, where a train could potentially split the points end up going down both tracks if the points were to move underneath the train — during trailing moves, the wheels of a train will force the points into the correct position if they attempt to move. In the United Kingdom, FPLs were common from an early date, due to laws being passed which forced the provision of FPLs for any routes travelled by passenger trains — it was, and still is, illegal for a passenger train to make a facing move over points without them being locked, either by a point lock, or temporarily clamped in one position or another.
Joints are used where the moving points meet the fixed rails of the switch. They allow the points to hinge easily between their positions. Originally the movable switch blades were connected to the fixed closure rails with loose joints, but since steel rails are somewhat flexible it is possible to make this join by thinning a short section of the rail itself. This can be called a heelless switch. Turnouts were originally built with straight switch blades, which ended at the pointed end with a sharp angle. These switches cause a bump when the train traverses in the turnout direction.
The switch blades could be made with a curved point which meets the stockrail at a tangent, causing less of a bump, but the disadvantage is that the metal at the point is thin and necessarily weak. A solution to these conflicting requirements was found in the s on the German Reichsbahn.
As it is difficult to see the lie of a switch from a distance, especially at night, European railways and their subsidiaries provide point indicators which are often illuminated. Apart from the standard right-hand and left-hand switches, switches commonly come in various combinations of configurations. A double slip switch double slip is a narrow-angled diagonal flat crossing of two lines combined with four pairs of points in such a way as to allow vehicles to change from one straight track to the other, as well as going straight across.
A train approaching the arrangement may leave by either of the two tracks on the opposite side of the crossing. To reach the third possible exit, the train must change tracks on the slip and then reverse. The arrangement gives the possibility of setting four routes, but because only one route can be traversed at a time, the four blades at each end of the crossing are often connected to move in unison, so the crossing can be worked by just two levers or point motors.
This gives the same functionality of two points placed end to end. These compact albeit complex switches usually are found only in locations where space is limited, such as station throats i. In North American English, the arrangement may also be called a double switch , or more colloquially, a puzzle switch. The Great Western Railway in the United Kingdom used the term double compound points , and the switch is also known as a double compound in Victoria Australia.
In Italian, the term for a double switch is deviatoio inglese , which means English switch. A single slip switch works on the same principle as a double slip, but provides for only one switching possibility. Trains approaching on one of the two crossing tracks can either continue over the crossing, or switch tracks to the other line. However, trains from the other track can only continue over the crossing, and cannot switch tracks. This is normally used to allow access to sidings and improve safety by avoiding having switch blades facing the usual direction of traffic.
To reach the sidings from what would be a facing direction, trains must continue over the crossing, then reverse along the curved route usually onto the other line of a double track and can then move forward over the crossing into the siding. An outside slip switch is similar to the double or single slip switches described above, except that the switch blades are outside of the diamond instead of inside. An advantage over an inside slip switch is that trains can pass the slips with higher speeds. A disadvantage over an inside slip switch is that they are longer and need more space.
An outside slip switch can be so long that its slips do not overlap at all, as in the example pictured. In such a case a single, outside slip switch is the same as two regular switches and a regular crossing. An outside, double slip switch is about the same as a scissors crossover see below , but with the disadvantages:. Due to the disadvantages over both the double inside slip switch and the scissors crossover , double outside slip switches are only used in rare, specific cases. A crossover is a pair of switches that connects two parallel rail tracks , allowing a train on one track to cross over to the other.
Like the switches themselves, crossovers can be described as either facing or trailing. When two crossovers are present in opposite directions, one after the other, the four-switch configuration is called a double crossover. This makes for a very compact track layout at the expense of using a level junction. In a setup where each of the two tracks normally carries trains of only one direction, a crossover can be used either to detour "wrong-rail" around an obstruction or to reverse direction.
A crossover can also join two tracks of the same direction, possibly a pair of local and express tracks, and allow trains to switch from one to the other. On a crowded system, routine use of crossovers or switches in general will reduce throughput, as the switches must be changed for each train. For this reason, on some high-capacity rapid transit systems, crossovers between local and express tracks are not used during normal rush hour service, and service patterns are planned around use of the usually flying junctions at each end of the local-express line.
Depending on the safety equipment provided, trains may run this other track either by exception or routinely against the normal direction of traffic. On double tracked routes, single and double crossovers are common, each one consisting of two turnouts and an intermediate section. Previous to that there were already operating control points at which trains could just transfer from one track to another on the same route, but they were considered as junctions Abzweigstelle.
The latter are still used to refer to those places in stations which enable trains to cross from one route to another.
A stub switch lacks the tapered points point blades of a typical switch. Instead, both the movable rails and the ends of the rails of the diverging routes have their ends cut off square. The switch mechanism aligns the movable rails with the rails of one of the diverging routes. In 19th century US railroad use, the stub switch was typically used in conjunction with a harp switch stand.
The rails leading up to a stub switch are not secured to the sleepers for several feet, and rail alignment across the gap is not positively enforced. Stub switches also require some flexibility in the rails meaning lighter rails , or an extra joint at which they hinge.
Therefore, these switches cannot be traversed at high speed or by heavy traffic and so are not suitable for main line use. A further disadvantage is that a stub switch being approached from the diverging route that is not connected by the points would result in a derailment. Yet another disadvantage is that in very hot weather, expansion of the steel in the rails can cause the movable rails to stick to the stock rails, making switching impossible until the rails have cooled and contracted.
One advantage to stub switches is that they work better in the snow.
The sideways action of the point rails pushes snow to the side, instead of packing the snow between the points and the rail in a more modern design. Stub switches were more common in the very early days of railways and their tramway predecessors. Now, because of their disadvantages, stub switches are used primarily on narrow gauge lines and branch lines.
Some modern monorail switches use the same principle. A plate switch incorporates the tapered points of a typical switch into a self-contained plate. Each point blade is moved separately by hand. Plate switches are only used for double-flanged wheels, with wheels running through the plates on their flanges, guided by the edges of the plate and the moveable blade. Because plate switches can only be used by double-flanged wheels and at extremely low speeds, they are typically only found on hand-worked narrow gauge lines.
A three-way switch is used to split a railroad track into three divergent paths rather than the more usual two. There are two types of three-way switches. In a symmetrical three-way switch , the left and right branches diverge at the same place. In an asymmetrical three-way switch , the branches diverge in a staggered way. Both types of three-way switches require three frogs. The complexity of symmetrical switches usually results in speed restrictions, therefore three-way switches are most often used in stations or depots where space is restricted and low speeds are normal.
Symmetrical switches were used quite often on Swiss narrow-gauge railways. Asymmetrical three-way switches are more common, because they do not have speed restrictions compared to standard switches. However, because of their higher maintenance cost due to special parts as well as asymmetric wear, both types of three-way switches are replaced with two standard switches wherever possible. In areas with very low speeds, like depots, and on railroads that had to be built very cheaply, like logging railroads, three-way switches were sometimes built as stub switches.