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Headshunt

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Platform track and run-round loop atToyooka Station,Hyōgo, Japan, the terminus of the line fromMiyazu

Aheadshunt(orescape trackin theUnited States) is a short length oftrackprovided to releaselocomotivesatterminal platforms,or to allowshuntingto take place clear of main lines.

Terminal headshunt

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Sequence at a terminal headshunt:
1. train arrives at the station
2. locomotive is detached from the train and moves into the headshunt
3. locomotive reverses and the points are switched
4. locomotive travels along the passing loop to pass the cars
5. locomotive reverses direction and the points are switched
6. locomotive couples to the opposite end of the train
7. locomotive reverses and the train departs

A 'terminal headshunt' is a short length of track that allows a locomotive to uncouple from its train, move forward, and then run back past it on a parallel track. Such headshunts are typically installed at aterminal stationto allow the locomotive of an arriving train to move to the opposite end of (in railway parlance, 'run around') its train so that it can then haul the same train out of the station in the other direction (assuming, of course, that it is a locomotive equipped to run in either direction; for locomotives that only operate in one direction, awyeorturntableneeds to be provided to physically turn the engine around, as well as a run-around track).

Reversing headshunt

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Melbourne University tram stophas three reversing headshunts in succession, between the two running lines.

Found primarily onmetro systems,rapid transitlight railnetworks, andtramways,a 'reversing headshunt' allows certain trains or trams to change direction, even on lines with high traffic flow, whilst others continue through the station.

Shunting neck

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The term headshunt may also refer toshunting neckor 'shunt spur': a short length oftracklaid parallel to the main line to allow a train to shunt back into asidingorrail yardwithout occupying the main running-line.[citation needed]

Run round

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Diagram of a headshunt and run round loop

Arun round loop(orrun-around loop) is a track arrangement that enables a locomotive to attach to the opposite end of the train. It is commonly used to haul wagons onto a siding, or at a terminal station to prepare for a return journey.[1]This process is known as "running round a train".[2]

Although a common procedure forpassenger trainswhen the majority of them were locomotive-hauled, the maneuver is now becoming rarer on public service railways.[citation needed]Increased use ofmultiple unitandpush-pullpassenger services avoids the requirement for dedicated track and the need for railway staff to detach and reattach the locomotive at track level.[citation needed]However, onheritage railwaysrun-round loops are still usually more or less necessary at each end of the running line, partly because train services are usually locomotive-hauled, and partly because the run-round operation gives added interest to visitors. This practice is still very common on Intercity services inVictoria, Australia.

Runaround tracks are used infreight railservice in order to back cars into spurs or to change directions to keep the locomotive at the front of the train for transport. In this case the runaround track must be as long as the longest set of cars that would be pulled. The locomotive leaves the cars on the runaround track or the main line, goes around, and hooks up to the other end of the train. It can then reverse the cars into a spur.

Examples

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Stations which used to have run-rounds include:

Stations which still have run-rounds include:

No loop

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If a terminal station does not have a run-round loop trains are restricted to multiple units orTop and Tailtrains.[citation needed]

See also

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References

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  1. ^Jackson, Alan A. (2006).The Railway Dictionary(4th ed.). Sutton Publishing Ltd. p. 298.ISBN0-7509-4218-5.
  2. ^Ellis, Iain (2006).Ellis' British Railway Engineering Encyclopaedia.Lulu. p. 307.ISBN978-1-8472-8643-7.
  3. ^"View map: Edinburghshire III.8 (Edinburgh) - Ordnance Survey 25 inch 2nd and later editions, Scotland, 1892-1949".maps.nls.uk.
  4. ^Edinburgh Waverley station - NBR Co. plan - published ca. 1898-zoomed in
  5. ^Edinburgh Waverley on OS town plan (1887) showing 3-way release crossover points between platforms
  6. ^Edinburgh Waverley on OS town plan (1894) showing 3-way release crossover points between platforms 2 & 3 and 4 & 5
  7. ^Manchester Central on OS 1:500 town plan (1888) showing 3-way release crossover points between platforms 1 & 2, 3 & 4 and 5 & 6
  8. ^Manchester Central station - Ordnance Survey 25 "to the mile - published 1934
  9. ^Manchester Central station looking towards the buffer stops(Disused Stations in the UK)
  10. ^Manchester Central station from the buffer stops(Disused Stations in the UK)
  11. ^1864 - 1:500 town plan(Disused Stations)
  12. ^Liverpool Exchange on OS 1:500 town plan (1890) showing 3-way release crossover points between platforms 4 & 5
  13. ^Preston Hendry, R., Powell Hendry, R., (1982)An historical survey of selected LMS stations: layouts and illustrations. Vol. 1Oxford Publishing
  14. ^Leeds Central station from the buffer stops showing 3-way point for release crossovers
  15. ^Leeds Central on OS 1:500 town plan (1910) showing 3-way release crossover points between platforms 2 & 3
  16. ^"Moor Street Passenger Station".Warwickshirerailways.Retrieved24 March2013.
  17. ^"Moor Street Station: Ex-GWR 2-6-2T 'Prairie' No 6152 is seen standing on the traverser as it is being moved from platform 2 to platform 1 on the right".Warwickshirerailways.
  18. ^A locomotive at Moor Street being transferred to the run round loop for platform 3(Warwickshirerailways )
  19. ^"Station Name: Withernsea".Disused Stations.Subterranea Britannica. 19 April 2019.Retrieved8 March2022.
  20. ^1891 1:2,500 OS map showing the layout of Withernsea station(Disused Stations in the UK)