Junction (rail)

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A junction in Baranowicze, Poland, 1934

A junction, in the context of rail transport, is a place at which two or more rail routes converge or diverge. This implies a physical connection between the tracks of the two routes (assuming they are of the same gauge), provided by 'points' (US: switches) and signalling.^[1]

Overview

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. In this latter case, the three points of the triangle may be given different names, for example using points of the compass as well as the name of the overall place.

Rail transport operations refer to stations that lie on or near a railway junction as a junction station. Frequently, trains are built up and taken apart (separated) at such stations so that the same train can split up and go to multiple destinations. For goods trains (US: freight trains), marshalling yards (US: Classification yards) serve a similar purpose.

The world's first railway junction was Newton Junction (now Earlestown station) near Newton-le-Willows, England where, in 1831, two railways merged.^{[citation needed]}

Measures to improve junction capacity

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 signalling measures, by building points suitable for higher speeds, or by turning level junctions into flying junctions. With more complicated junctions such construction can rapidly become very expensive, especially if space is restricted by tunnels, bridges or inner-city tracks.

Image gallery

Junction of a Decauville train track from the Minicomboio da Caparica line in Costa da Caparica, Portugal

References

Wikimedia Commons has media related to Rail junctions.

↑ Airey, John (2010). Railway Junction Diagrams (reprint ed.). BiblioBazaar. ISBN 9781145129566.

v t e Railway track layouts

Running lines	Single track Passing loop Double track Quadruple track Crossover

Rail sidings	Balloon loop Headshunt Refuge siding Rail yard Classification yard

Junctions	Flying junction Level junction Double junction Facing and trailing Grand union Wye Switch / turnout / points Swingnose crossing Level crossing

Stations	Railway platform Side platform Island platform Bay platform Split platform Terminal station Balloon loop Spanish solution Cross-platform interchange Interchange station

Hillclimbing	Horseshoe curve Zig Zag / Switchback Spiral

Track geometry	Track gauge Ruling gradient Minimum curve radius Cant Cant deficiency

v t e Railway infrastructure

Permanent way	Permanent way (history) Permanent way (current) Railroad tie/Sleeper Rail fastening system Track ballast Rail profile Fishplate Breather switch Datenail Axe ties Ladder track Baulk road Cant Minimum radius Track transition curve Clip and scotch

Trackwork and track structures	Junction Wye Railroad switch Gauntlet track Railway electrification system Third rail Overhead lines Guide bar Track gauge Track geometry Railway turntable Water crane Track pan Rail track Tramway track Classification yard Rail yard Siding Passing loop Balloon loop Headshunt Refuge siding Dual gauge Roll way

Signalling and safety	Derail Railway signalling Signalling control Railway signal Interlocking Level crossing Buffer stop Catch points Loading gauge Structure gauge Block post Train stop

Buildings	Railway station Station building Railway station layout Station clock Train shed Goods shed Motive power depot Roundhouse Railway platform

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Junction (rail)

Overview

Measures to improve junction capacity

Image gallery

See also

References