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98-418: The infrastructure consists of twin tracks, on which over 50 pieces of interlocking crossover tracks are grafted all along the subdivision. The extra length of these crossover tracks allows for high speed track interchange. Low gravity intermodal container trains are allowed to change tracks at 45 miles per hour, and Via Rail 's passenger trains, at 60, and in some areas, 90. The governing traffic control system

196-406: A spur or siding branches off. The most common type of switch consists of a pair of linked tapering rails, known as points ( switch rails or point blades ), lying between the diverging outer rails (the stock rails ). These points can be moved laterally into one of two positions to direct a train coming from the point blades toward the straight path or the diverging path. A train moving from

294-415: A train coming from the point blades toward the straight path or the diverging path. A train moving from the narrow end toward the point blades (i.e. it will be directed to one of the two paths, depending on the position of the points) is said to be executing a facing-point movement . For many types of switch, a train coming from either of the converging directions will pass through the switch regardless of

392-638: A barrier between the metal surfaces to prevent ice from forming between them (i.e. having frozen together by ice). Such approaches however, may not always be effective for extreme climates since these chemicals will be washed away over time, especially for heavily thrown switches that experience hundreds of throws daily. Heating alone may not always be enough to keep switches functioning under snowy conditions. Wet snow conditions, which generate particularly sticky snow and whiteout conditions, may occur at temperatures just below freezing, causing chunks of ice to accumulate on trains. When trains traverse over some switches,

490-638: A barrier between the metal surfaces to prevent ice from forming between them (i.e. having frozen together by ice). Such approaches however, may not always be effective for extreme climates since these chemicals will be washed away over time, especially for heavily thrown switches that experience hundreds of throws daily. Heating alone may not always be enough to keep switches functioning under snowy conditions. Wet snow conditions, which generate particularly sticky snow and whiteout conditions, may occur at temperatures just below freezing, causing chunks of ice to accumulate on trains. When trains traverse over some switches,

588-426: A connection between two or more parallel tracks, allowing a train to switch between them. In many cases, where a switch is supplied to leave a track, a second is supplied to allow the train to reenter the track some distance down the line; this allows the track to serve as a siding, allowing a train to get off the track to allow traffic to pass (this siding can either be a dedicated short length of track, or formed from

686-601: 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 use of the switch blocks multiple tracks. 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

784-601: 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 use of the switch blocks multiple tracks. 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

882-434: A lever to be moved by a human operator, and some switches are still controlled this way. However, most are now operated by a remotely controlled actuator called a point machine ; this may employ an electric motor or a pneumatic or hydraulic actuator . This both allows for remote control and monitoring and for the use of stiffer, strong switches that would be too difficult to move by hand, yet allow for higher speeds. In

980-427: A regular crossing. 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

1078-427: A regular crossing. 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

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1176-442: A section of a second, continuous, parallel line), and also allows trains coming from either direction to switch between lines; otherwise, the only way for a train coming from the opposite direction to use a switch would be to stop, and reverse through the switch onto the other line, and then continue forwards (or stop, if it is being used as a siding). A straight track is not always present; for example, both tracks may curve, one to

1274-402: A siding, allowing a train to get off the track to allow traffic to pass (this siding can either be a dedicated short length of track, or formed from a section of a second, continuous, parallel line), and also allows trains coming from either direction to switch between lines; otherwise, the only way for a train coming from the opposite direction to use a switch would be to stop, and reverse through

1372-417: A switch in this direction is known as a trailing-point movement and switches that allow this type of movement without damage to the mechanism are called trailable switches . A switch generally has a straight "through" track (such as the main-line) and a diverging route. The handedness of the installation is described by the side that the diverging track leaves. Right-hand switches have a diverging path to

1470-408: A trailing-point movement (running through the switch in the wrong direction while they are set to turn off the track), the flanges on the wheels will force the points to the proper position. This is sometimes known as running through the switch . Some switches are designed to be forced to the proper position without damage. Examples include variable switches, spring switches, and weighted switches. If

1568-483: 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, although this may cause considerable damage. This act is known as a "run through". In the United Kingdom, FPLs were common from an early date, due to laws being passed which forced

1666-426: 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, although this may cause considerable damage. This act is known as a "run through". In the United Kingdom, FPLs were common from an early date, due to laws being passed which forced

1764-403: A train to proceed over points when it was safe to do so. Purely mechanical interlockings were eventually developed into integrated systems with electric control. On some low-traffic branch lines, in self-contained marshalling yards , or on heritage railways , switches may still have the earlier type of interlocking. A railroad car 's wheels are primarily guided along the tracks by coning of

1862-581: Is CTC . Since 1995, no OCS operation clearance forms need to be filled by train conductors on the Kingston Subdivision. CTC signals thus provide both permission and authorization for train movements, as is the situation with most main line operation at CN. Just east of Newcastle , east of Toronto, the line is joined by the CP Belleville Subdivision , Canadian Pacific Railway 's similar mainline route. The two remain nearly side-by-side to

1960-417: Is a lever and accompanying linkages to align the points of a switch by hand. The lever and its accompanying hardware is usually mounted to a pair of long ties (sleepers) that extend from the switch at the points. They are often used in a place of a switch motor on less frequently 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

2058-417: Is a lever and accompanying linkages to align the points of a switch by hand. The lever and its accompanying hardware is usually mounted to a pair of long ties (sleepers) that extend from the switch at the points. They are often used in a place of a switch motor on less frequently 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

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2156-437: Is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off. The most common type of switch consists of a pair of linked tapering rails, known as points ( switch rails or point blades ), lying between the diverging outer rails (the stock rails ). These points can be moved laterally into one of two positions to direct

2254-425: Is a short piece of rail placed alongside the main (stock) rail opposite the crossing. These ensure that the wheels follow the appropriate flangeway through the frog and that the train does not derail. Check rails are often used on very sharp curves, even where there are no switches. A switch motor or switch machine (point motor or point machine) is an electric, hydraulic or pneumatic mechanism that aligns

2352-425: Is a short piece of rail placed alongside the main (stock) rail opposite the crossing. These ensure that the wheels follow the appropriate flangeway through the frog and that the train does not derail. Check rails are often used on very sharp curves, even where there are no switches. A switch motor or switch machine (point motor or point machine) is an electric, hydraulic or pneumatic mechanism that aligns

2450-410: Is better to keep these separated as much as feasible). Sometimes a switch merely divides one track into two; at others, it serves as a connection between two or more parallel tracks, allowing a train to switch between them. In many cases, where a switch is supplied to leave a track, a second is supplied to allow the train to reenter the track some distance down the line; this allows the track to serve as

2548-410: Is called a double crossover . If the crossovers in different directions overlap to form an ×, it is dubbed a scissors crossover , scissors crossing , or just scissors ; or, due to the diamond in the center, a diamond 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,

2646-410: Is called a double crossover . If the crossovers in different directions overlap to form an ×, it is dubbed a scissors crossover , scissors crossing , or just scissors ; or, due to the diamond in the center, a diamond 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,

2744-430: Is connected, the right wheel's flange will be guided along the rail of that point, and the train will continue along the straight track. Only one of the points may be connected to the facing track at any time; the two points are mechanically locked together to ensure that this is always the case. A mechanism is provided to move the points from one position to the other ( change the points ). Historically, this would require

2842-414: Is described by the side that the diverging track leaves. Right-hand switches have a diverging path to the right of the straight track, when coming from the point blades, and a left-handed switch has the diverging track leaving to the opposite side. In many cases, such as rail yards, many switches can be found in a short section of track, sometimes with switches going both to the right and left (although it

2940-433: Is measured as the number of units of length for a single unit of separation. In North America this is generally referred to as a switch's "number". For example, on a "number 12" switch, the rails are one unit apart at a distance of twelve units from the center of the frog. In the United Kingdom points and crossings using chaired bullhead rail would be referred to using a letter and number combination. The letter would define

3038-433: Is measured as the number of units of length for a single unit of separation. In North America this is generally referred to as a switch's "number". For example, on a "number 12" switch, the rails are one unit apart at a distance of twelve units from the center of the frog. In the United Kingdom points and crossings using chaired bullhead rail would be referred to using a letter and number combination. The letter would define

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3136-625: Is not uncommon to find switches where a speed of 200 km/h (124 mph) or more is allowed on the diverging branch. Switches were passed over at a speed of 560 km/h (348 mph) (straight) during the French world speed run of April 2007. The US Federal Railroad Administration has published the speed limits for higher-speed turnouts with No.  26.5 turnout that has speed limit of 60 miles per hour (97 km/h) and No.  32.7 with speed limit of 80 miles per hour (129 km/h). Under cold weather conditions, snow and ice can prevent

3234-425: Is possible to modify the simpler types of switch to allow trains to pass at high speed. More complicated switch systems, such as double slips, are restricted to low-speed operation. On European high-speed lines, it is not uncommon to find switches where a speed of 200 km/h (124 mph) or more is allowed on the diverging branch. Switches were passed over at a speed of 560 km/h (348 mph) (straight) during

3332-457: 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. Railway switch#Wye switch A railroad switch ( AE ), turnout , or [ set of ] points ( CE )

3430-442: The French world speed run of April 2007. The US Federal Railroad Administration has published the speed limits for higher-speed turnouts with No.  26.5 turnout that has speed limit of 60 miles per hour (97 km/h) and No.  32.7 with speed limit of 80 miles per hour (129 km/h). Under cold weather conditions, snow and ice can prevent the proper movement of switch or frog point rails, essentially inhibiting

3528-620: The UK and most other Commonwealth countries, the term points refers to the entire mechanism. In professional parlance, the term refers only to the movable rails and the entire mechanism is named turnout or points and crossings . Turnout and switch are terms used in North America in all contexts. 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 cross-section of

3626-519: The UK and most other Commonwealth countries, the term points refers to the entire mechanism. In professional parlance, the term refers only to the movable rails and the entire mechanism is named turnout or points and crossings . Turnout and switch are terms used in North America in all contexts. 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 cross-section of

3724-681: 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 . Likewise, it is called Engels(e) Wissel in Dutch and, occasionally, Engländer ("english one", literally "Englishman") in German. A single slip switch works on

3822-534: 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 . Likewise, it is called Engels(e) Wissel in Dutch and, occasionally, Engländer ("english one", literally "Englishman") in German. A single slip switch works on

3920-461: The case. A mechanism is provided to move the points from one position to the other ( change the points ). Historically, this would require a lever to be moved by a human operator, and some switches are still controlled this way. However, most are now operated by a remotely controlled actuator called a point machine ; this may employ an electric motor or a pneumatic or hydraulic actuator . This both allows for remote control and monitoring and for

4018-431: 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.e. approaches) where a few main lines spread out to reach any of numerous platform tracks. In North American English,

CN Kingston Subdivision - Misplaced Pages Continue

4116-431: 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.e. approaches) where a few main lines spread out to reach any of numerous platform tracks. In North American English,

4214-402: 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

4312-402: 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

4410-404: The earlier type of interlocking. A railroad car 's wheels are primarily guided along the tracks by coning of the wheels, rather than relying on the flanges on the insides of the wheels. When the wheels reach the switch, the wheels are guided along the route determined by which of the two points is connected to the track facing the switch. In the illustration, if the left point is connected,

4508-734: The east of Belleville , where the Belleville sub turns north to Smiths Falls . Sections of the Kingston Sub are no longer owned by CN. In particular, CN mainline freight traffic in the Toronto area no longer follows the Kingston Sub, and is re-directed north of the city along the York Sub . The section between Pickering Junction and Union Station in downtown Toronto has been sold to Metrolinx for GO Transit service, part of their Lakeshore East line . Via rail of Canada operates their corridor service along

4606-411: The eighteenth century, cast iron components were made to build switches with check rails. In 1797, John Curr described the system that he developed which used a single iron blade, hinged on a vertical pin that was tapered to lie against the plateway. By 1808, Curr's basic design was in common use. The use of a sprung rail, giving a smooth transition, was patented by Charles Fox in 1838. Prior to

4704-532: The entirety of the line. VIAs Toronto-Ottawa trains runs along the line to Brockville, where it splits off and heads north. The Toronto-Montreal train runs along the whole line. In fact, many say that VIA trains run along the line more than CN freight trains. The most used station on the line is Kingston, due to Montreal, and Toronto stations being on their own subdivisions. The 1850s Grand Trunk Railway mainline consisted of 34 stations, many of which have been removed from service or no longer exist. Lansdowne station

4802-481: The following corresponding radii: Switches are necessary for the operation of a railway, but they do pose a number of risks: Switch-related accidents caused by one or more of these risks have occurred, including: The switch rails or points ( point blades ) are the movable rails which guide the wheels towards either the straight or the diverging track. They are tapered, except on stub switches in industrial sidings, which have square ends. In popular parlance in

4900-481: The following corresponding radii: Switches are necessary for the operation of a railway, but they do pose a number of risks: Switch-related accidents caused by one or more of these risks have occurred, including: The switch rails or points ( point blades ) are the movable rails which guide the wheels towards either the straight or the diverging track. They are tapered, except on stub switches in industrial sidings, which have square ends. In popular parlance in

4998-418: The frequency of trains, or applying anti-icing chemicals such as ethylene glycol to the trains. The divergence and length of a switch is determined by the angle of the frog (the point in the switch where two rails cross, see below) and the angle or curvature of the switch blades. The length and placement of the other components are determined from this using established formulas and standards. This divergence

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5096-418: The frequency of trains, or applying anti-icing chemicals such as ethylene glycol to the trains. The divergence and length of a switch is determined by the angle of the frog (the point in the switch where two rails cross, see below) and the angle or curvature of the switch blades. The length and placement of the other components are determined from this using established formulas and standards. This divergence

5194-494: The left and one to the right (such as for a wye switch ), or both tracks may curve, with differing radii , while still in the same direction. Switches consume a relatively high proportion of a railway maintenance budget. Simple single-bladed switches were used on early wooden railways to move wagons between tracks. As iron-railed plateways became more common in the eighteenth century, cast iron components were made to build switches with check rails. In 1797, John Curr described

5292-408: The left wheel will be guided along the rail of that point, and the train will diverge to the right. If the right point is connected, the right wheel's flange will be guided along the rail of that point, and the train will continue along the straight track. Only one of the points may be connected to the facing track at any time; the two points are mechanically locked together to ensure that this is always

5390-462: The length (and hence the radius) of the switch blades and the number would define the angle of the crossing (frog). Thus an A7 turnout would be very short and likely only to be found in tight places like dockyards whereas an E12 would be found as a fairly high speed turnout on a mainline. On the London, Midland and Scottish Railway , switch curvatures were specified from A (sharpest) to F (shallowest), with

5488-414: The length (and hence the radius) of the switch blades and the number would define the angle of the crossing (frog). Thus an A7 turnout would be very short and likely only to be found in tight places like dockyards whereas an E12 would be found as a fairly high speed turnout on a mainline. On the London, Midland and Scottish Railway , switch curvatures were specified from A (sharpest) to F (shallowest), with

5586-407: The movable switch blades were connected to the fixed closure rails with loose joints, but since steel is somewhat flexible it is possible to obviate this looseness by thinning a short section of the rail's bottom 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

5684-407: The movable switch blades were connected to the fixed closure rails with loose joints, but since steel is somewhat flexible it is possible to obviate this looseness by thinning a short section of the rail's bottom 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

5782-407: The narrow end toward the point blades (i.e. it will be directed to one of the two paths, depending on the position of the points) is said to be executing a facing-point movement . For many types of switch, a train coming from either of the converging directions will pass through the switch regardless of the position of the points, as the vehicle's wheels will force the points to move. Passage through

5880-405: The other, alternatively to 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

5978-405: The other, alternatively to 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

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6076-575: The points are rigidly connected to the switch control mechanism, the control mechanism's linkages may be bent, requiring repair before the switch is again usable. For this reason, switches are normally set to the proper position before performing a trailing-point movement. Generally, switches are designed to be safely traversed at low speed. However, it is possible to modify the simpler types of switch to allow trains to pass at high speed. More complicated switch systems, such as double slips, are restricted to low-speed operation. On European high-speed lines, it

6174-597: 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, or for maintenance purposes. A patent by W. B. Purvis dates from 1897. A switch stand ( points lever or ground throw )

6272-552: 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, or for maintenance purposes. A patent by W. B. Purvis dates from 1897. A switch stand ( points lever or ground throw )

6370-411: The position of the points, as the vehicle's wheels will force the points to move. Passage through a switch in this direction is known as a trailing-point movement and switches that allow this type of movement without damage to the mechanism are called trailable switches . A switch generally has a straight "through" track (such as the main-line) and a diverging route. The handedness of the installation

6468-657: The proper movement of switch or frog point rails, essentially inhibiting the proper operation of railroad switches. Historically, railway companies have employees keep their railroad switches clear of snow and ice by sweeping the snow away using switch brooms (Basically wire brooms with a chisel attached onto the opposite end of the broom – quite similar to ice scrapers used today), or gas torches for melting ice and snow. Such operation are still used in some countries, especially for branch routes with only limited traffic (e.g. seasonal lines). Modern switches for heavily trafficked lines are typically equipped with switch heaters installed in

6566-581: The proper operation of railroad switches. Historically, railway companies have employees keep their railroad switches clear of snow and ice by sweeping the snow away using switch brooms (Basically wire brooms with a chisel attached onto the opposite end of the broom – quite similar to ice scrapers used today), or gas torches for melting ice and snow. Such operation are still used in some countries, especially for branch routes with only limited traffic (e.g. seasonal lines). Modern switches for heavily trafficked lines are typically equipped with switch heaters installed in

6664-476: The proper position without damage. Examples include variable switches, spring switches, and weighted switches. If the points are rigidly connected to the switch control mechanism, the control mechanism's linkages may be bent, requiring repair before the switch is again usable. For this reason, switches are normally set to the proper position before performing a trailing-point movement. Generally, switches are designed to be safely traversed at low speed. However, it

6762-410: The provision of FPLs for any routes traveled 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

6860-410: The provision of FPLs for any routes traveled 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

6958-443: The right of the straight track, when coming from the point blades, and a left-handed switch has the diverging track leaving to the opposite side. In many cases, such as rail yards, many switches can be found in a short section of track, sometimes with switches going both to the right and left (although it is better to keep these separated as much as feasible). Sometimes a switch merely divides one track into two; at others, it serves as

7056-421: 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

7154-421: 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

7252-451: The shock, vibration, possibly in combination with slight heating caused by braking or a city microclimate, may cause the chunks of ice to fall off, jamming the switches. The heaters need time to melt the ice, so if service frequency is extremely high, there may not be enough time for the ice to melt before the next train arrives, which will then result in service disruptions. Possible solutions include installing higher capacity heaters, reducing

7350-451: The shock, vibration, possibly in combination with slight heating caused by braking or a city microclimate, may cause the chunks of ice to fall off, jamming the switches. The heaters need time to melt the ice, so if service frequency is extremely high, there may not be enough time for the ice to melt before the next train arrives, which will then result in service disruptions. Possible solutions include installing higher capacity heaters, reducing

7448-460: The switch blades also influences performance. New tangential blades perform better than old-style blades. The crossing is the component that enables passage of wheels on either route through the turnout. It 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. A guard rail

7546-460: The switch blades also influences performance. New tangential blades perform better than old-style blades. The crossing is the component that enables passage of wheels on either route through the turnout. It 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. A guard rail

7644-561: The switch onto the other line, and then continue forwards (or stop, if it is being used as a siding). A straight track is not always present; for example, both tracks may curve, one to the left and one to the right (such as for a wye switch ), or both tracks may curve, with differing radii , while still in the same direction. Switches consume a relatively high proportion of a railway maintenance budget. Simple single-bladed switches were used on early wooden railways to move wagons between tracks. As iron-railed plateways became more common in

7742-423: The switch rails being about 25 mm (0.98 in) less high, and stockier in the middle. 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

7840-423: The switch rails being about 25 mm (0.98 in) less high, and stockier in the middle. 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

7938-424: The system that he developed which used a single iron blade, hinged on a vertical pin that was tapered to lie against the plateway. By 1808, Curr's basic design was in common use. The use of a sprung rail, giving a smooth transition, was patented by Charles Fox in 1838. Prior to the widespread availability of electricity , switches at heavily traveled junctions were operated from a signal box constructed near

8036-405: The tampering of switches by outside means, these switches are locked when not in use. 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 mechanically proving that they are in the correct position. The facing point part of the name refers to the fact that they prevent movement of the points during facing moves, where

8134-405: The tampering of switches by outside means, these switches are locked when not in use. 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 mechanically proving that they are in the correct position. The facing point part of the name refers to the fact that they prevent movement of the points during facing moves, where

8232-579: The tracks through an elaborate system of rods and levers . The levers were also used to control railway signals to control the movement of trains over the points. Eventually, mechanical systems known as interlockings were introduced to make sure that a signal could only be set to allow a train to proceed over points when it was safe to do so. Purely mechanical interlockings were eventually developed into integrated systems with electric control. On some low-traffic branch lines, in self-contained marshalling yards , or on heritage railways , switches may still have

8330-492: 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 1920s on the German Reichsbahn. The first step was to have different rail profile for the stock rails and switch rails, with

8428-432: 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 1920s on the German Reichsbahn. The first step was to have different rail profile for the stock rails and switch rails, with

8526-406: The use of stiffer, strong switches that would be too difficult to move by hand, yet allow for higher speeds. In a trailing-point movement (running through the switch in the wrong direction while they are set to turn off the track), the flanges on the wheels will force the points to the proper position. This is sometimes known as running through the switch . Some switches are designed to be forced to

8624-414: 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

8722-414: 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

8820-404: The usually flying junctions at each end of the local-express line. 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

8918-404: The usually flying junctions at each end of the local-express line. 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

9016-535: The vicinity of their point rails so that the point rails will not be frozen onto the stock rail and can no longer move. These heaters may take the form of electric heating elements or gas burners mounted on the rail, a lineside burner blowing hot air through ducts, or other innovative methods (e.g. geothermal heat sink, etc.) to keep the point & stock rails above freezing temperatures. Where gas or electric heaters cannot be used due to logistic or economic constraints, anti-icing chemicals can sometimes be applied to create

9114-535: The vicinity of their point rails so that the point rails will not be frozen onto the stock rail and can no longer move. These heaters may take the form of electric heating elements or gas burners mounted on the rail, a lineside burner blowing hot air through ducts, or other innovative methods (e.g. geothermal heat sink, etc.) to keep the point & stock rails above freezing temperatures. Where gas or electric heaters cannot be used due to logistic or economic constraints, anti-icing chemicals can sometimes be applied to create

9212-407: The wheels, rather than relying on the flanges on the insides of the wheels. When the wheels reach the switch, the wheels are guided along the route determined by which of the two points is connected to the track facing the switch. In the illustration, if the left point is connected, the left wheel will be guided along the rail of that point, and the train will diverge to the right. If the right point

9310-428: The widespread availability of electricity , switches at heavily traveled junctions were operated from a signal box constructed near the tracks through an elaborate system of rods and levers . The levers were also used to control railway signals to control the movement of trains over the points. Eventually, mechanical systems known as interlockings were introduced to make sure that a signal could only be set to allow

9408-485: Was torn down soon after CN abandoned service to the village in 1966; CN demolished an Iroquois station in 2002. Stations currently on the Toronto-Montréal mainline include: Crossover (rail transport) A railroad switch ( AE ), turnout , or [ set of ] points ( CE ) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where

9506-482: 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

9604-482: 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

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