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A junction, in the context of rail transport, is a place at which two or more rail routes converge or diverge. The physical connection between the tracks of the two routes (assuming they are of the same gauge) is provided by turnouts (US: switches) and signalling. [1] Junctions are important for rail systems: their installation in a rail system can expand route capacity and improve on-time performance.
In a simple case where two routes with one or two tracks each meet at a junction, a fairly simple layout of tracks suffices to allow trains to transfer from one route to the other. More complicated junctions are needed to permit trains to travel in either direction after joining the new route – for example by providing a triangular track layout. [note 1]
Rail transport operations refer to stations that lie on or near a railway junction as a junction station . In the UK it is customary for the junction (and the related station) to be named after the next station on the branch, e.g. Yeovil Junction is on the mainline railway south of Yeovil, and the next destination on the branch is Yeovil Pen Mill. Frequently, trains are built up and taken apart (separated) at such stations so that the same train can be divided and proceed to multiple destinations. For goods trains (US: freight trains), marshalling yards (US: Classification yards) serve a similar purpose.
The capacity of the junctions limits the capacity of a railway network more than the capacity of individual railway lines. This applies more as the network density increases. Measures to improve junctions are often more useful than building new railway lines. The capacity of a railway junction can be increased with improved signaling measures, by building points suitable for higher speeds, or by turning level junctions into flying junctions, where tracks are grade-separated, and so one track passes over or under another. [2] With more complicated junctions such construction can rapidly become very expensive, especially if space is restricted by tunnels, bridges or inner-city tracks.
The installation of junctions into a rail system poses many challenges, including increased maintenance costs, and problems in on-time performance. Metro rail systems have a rail network design where the number of junctions is minimized. Passengers, and not trains, move from one train station to another.
Stagecoach South Western Trains Limited, trading as South West Trains (SWT), was an English train operating company owned by Stagecoach, which operated the South Western franchise between February 1996 and August 2017.
On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable. Signalling control was originally exercised via a decentralised network of control points that were known by a variety of names including signal box, interlocking tower and signal cabin. Currently these decentralised systems are being consolidated into wide scale signalling centres or dispatch offices. Whatever the form, signalling control provides an interface between the human signal operator and the lineside signalling equipment. The technical apparatus used to control switches (points), signals and block systems is called interlocking.
The East Coast Main Line (ECML) is a 393-mile long (632 km) electrified railway between its northern terminus at Edinburgh Waverley and southern terminus at London King's Cross station. The key towns and cities of Peterborough, Doncaster, York, Darlington, Durham and Newcastle are on the line. The line is a key transport artery on the eastern side of Great Britain running broadly parallel to the A1 road. The main line acts as a 'spine' for several diverging branches, serving destinations such as Cambridge, Leeds, Hull, Sunderland and Lincoln, all with direct services to London. In addition, a few ECML services extend beyond Edinburgh to serve Glasgow Central, although the principal London-Glasgow route is the West Coast Main Line (WCML).
Rail transport operations are the day-to-day operations of a railway. A railway has two major components: the infrastructure and the rolling stock
The London, Tilbury and Southend line, also known as Essex Thameside, is a commuter railway line on the British railway system. It connects Fenchurch Street station, in central London, with destinations in east London and Essex, including Barking, Upminster, Basildon, Grays, Tilbury, Southend and Shoeburyness.
In railway signalling, an interlocking is an arrangement of signal apparatus that prevents conflicting movements through an arrangement of tracks such as junctions or crossings. In North America, a set of signalling appliances and tracks interlocked together are sometimes collectively referred to as an interlocking plant or just as an interlocking. An interlocking system is designed so that it is impossible to display a signal to proceed unless the route to be used is proven safe.
The Wisbech and March line is a railway line between March and Wisbech in Cambridgeshire, England. A number of proposals are currently being investigated relating to the possible restoration of passenger services along the route.
The Cambrian Line, sometimes split into the Cambrian Main Line and Cambrian Coast Line for its branches, is a railway line that runs from Shrewsbury, England, westwards to Aberystwyth and Pwllheli in Wales. Passenger train services are operated by Transport for Wales Rail between the western terminals of Pwllheli, in Gwynedd, and Aberystwyth, in Ceredigion, and the eastern terminal at Shrewsbury, Shropshire, as part of the Wales & Borders franchise. The railway line is widely regarded as scenic, as it passes through the Cambrian Mountains in central Wales, and along the coast of Cardigan Bay in Snowdonia National Park.
Norwood Junction railway station is a National Rail station in South Norwood in the London Borough of Croydon, south London, and is in Travelcard Zone 4. It is 8 miles 55 chains down the line from London Bridge.
Gauntlet track or interlaced track, also gantlet track (AE) is an arrangement in which railway tracks run parallel on a single track bed and are interlaced in such a way that only one pair of rails can be used at any time. Since this requires only slightly more width than a single track, all rails can be carried on the same crossties/sleepers. Trains run on the pair of rails appropriate to their direction, track gauge or loading gauge.
Exeter Central railway station is the most central of the stations in the city of Exeter, Devon, United Kingdom. It is 171 miles 30 chains (275.8 km) down the line from London Waterloo. The station is smaller than Exeter St Davids on the west side of the city. Great Western Railway manages the station and operates most services, with South Western Railway providing the rest. It is the second busiest station in Devon, and the fourth busiest in South West England.
Barnetby railway station serves the village of Barnetby-le-Wold in North Lincolnshire, England. It is operated by TransPennine Express, with East Midlands Railway and Northern Trains also serving the station.
Australian railway signalling varies between the States of Australia, because the individual States are responsible for the railway systems within their own borders, with, historically, no need to co-ordinate between states except at the boundaries.
Forres railway station serves the town of Forres, Moray in Scotland. The station is managed and served by ScotRail and is on the Aberdeen–Inverness line, between Nairn and Elgin, measured 119 miles 42 chains (192.4 km) from Perth via the Dava route.
Doncaster PSB is a signalling centre on the East Coast Main Line (ECML) railway in the United Kingdom, principally covering the line from London to Edinburgh but also encompassing other lines diverging and converging to the ECML.
The application of railway signals on a rail layout is determined by various factors, principally the location of points of potential conflict, as well as the speed and frequency of trains and the movements they require to make.
France has a large network of high-speed rail lines. As of June 2021, the French high-speed rail network comprises 2,800 km (1,740 mi) of tracks, making it one of the largest in Europe and the world. As of early 2023, new lines are being constructed or planned. The first French high-speed railway, the LGV Sud-Est, linking the suburbs of Paris and Lyon, opened in 1981 and was at that time the only high-speed rail line in Europe.
The Reading–Taunton line is a major branch of the Great Western Main Line from which it diverges at Reading railway station. It runs to Cogload Junction where it joins the Bristol to Exeter and Penzance line.
Communications-based train control (CBTC) is a railway signaling system that uses telecommunications between the train and track equipment for traffic management and infrastructure control. CBTC allows a train's position to be known more accurately than with traditional signaling systems. This makes railway traffic management safer and more efficient. Rapid transit system are able to reduce headways while maintaining or even improving safety.
Route capacity is the maximum number of vehicles, people, or amount of freight than can travel a given route in a given amount of time, usually an hour. It may be limited by the worst bottleneck in the system, such as a stretch of road with fewer lanes. Air traffic route capacity is affected by weather. For a metro or a light rail system, route capacity is generally the capacity of each vehicle, times the number of vehicles per train, times the number of trains per hour (tph). In this way, route capacity is highly dependent on headway. Beyond this mathematical theory, capacity may be influenced by other factors such as slow zones, single-tracked areas, and infrastructure limitations, e.g. to useful train lengths.
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