Single-line working

On a double track railway, single-line working refers to the practice of using one track out of two, usually when one of the tracks is out of use for maintenance or because of damage or some obstruction.


Tracks that are signalled for bi-directional operation can be operated as a single line without any special measures, since the signalling equipment is already in place to permit trains to run in either direction over the single track. However, when a section of track which is not normally bi-directional has to be used in both directions, very special safety measures are needed to ensure safe operation. On a single line the worst safety risk is a head-on collision between two trains travelling in opposite directions along the single track, but there is also the risk of a rear-end collision if two trains travel in the same direction, and the first train stops for some reason. Because the normal signalling system is not in operation, either of these two risks must be carefully guarded against by the system of operation used.

Token working

A common solution to the problem is to implement some form of token working. If the situation is a planned one, a normal token may be specially provided, complete with tickets. Alternatively, a pilotman might be provided.

A pilotman travels on trains which traverse the section of single track. Provided there is only one pilotman the system is safe — the pilotman acts as a human token authorising a driver to proceed over the single track. However, a complication arises with this system if two trains are to traverse the single track in the same direction: the pilotman can travel on the first train, but then may have to walk back along the track in order to accompany the second train.

A solution to this is to provide a locomotive for the pilotman to travel on; this locomotive can be attached to the front of any train that is to pass through the single-line section, and the locomotive can return 'light engine' in order to convey the pilotman back through the section in order to pilot a second train.

Alternatively, the pilotman authorises the driver to take his train through the section, but instead of travelling on the train, he remains where he is in order to authorise or travel on the next train to pass in the same direction (this is the same principle used for "staff and ticket" working). He then waits until he has received a message from the signalman at the far end of the section, confirming that the train has arrived complete. He can then authorise or travel on the next train to travel through the section.

Further reading

Rolt, L. T. C. (1986) "Red for Danger, a history of railway accidents and railway safety", London: Pan Books. ISBN 0-330-29189-0(4th edition revised and with additional material by Geoffrey Kichenside.) (Chapter 6: single-line collisions)

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Single track (rail) — A single track railway is one where traffic in both directions shares the same track. In the early days of railways, especially before the telegraph, operation of significant numbers of trains on a single track railway was fraught with… …   Wikipedia

  • Working Class Hero — Song infobox Name = Working Class Hero Artist = John Lennon with the Plastic Ono Band Album = John Lennon/Plastic Ono Band Released = 11 December, 1970 track no = 4 Recorded = September 26 October 9 1970 Genre = Rock Length = 3:48 Writer = John… …   Wikipedia

  • Single-wire earth return — (SWER) or single wire ground return is a single wire transmission line for supplying single phase electrical power from an electrical grid to remote areas at low cost. It is principally used for rural electrification, but also finds use for… …   Wikipedia

  • Single parent — is a term that is mostly used to suggest that one parent has most of the day to day responsibilities in the raising of the child or children, which would categorize them as the dominant caregiver. The dominant caregiver is the parent in which the …   Wikipedia

  • Working Families Party — of New York Chairman Sam Williams (co chair) Bob Master (co chair) Founded 1998 Headquarters 2 Nevins Street …   Wikipedia

  • Working tax credit — (WTC), is a component of the current tax credits scheme in the United Kingdom part of the system of means tested social security benefits. The related component of the scheme is the Child tax credit (CTC). Tax credits were introduced in their… …   Wikipedia

  • Single Audit — In the United States, the Single Audit, also known as the OMB A 133 audit, is a rigorous, organization wide audit or examination of an entity that expends $500,000 or more of Federal assistance (commonly known as Federal funds, Federal grants, or …   Wikipedia

  • Line of Delirium — infobox Book | name = Line of Delirium title orig = Linia Grez, Линия Грез (Russian) image caption = author = Sergei Lukyanenko (Сергей Лукьяненко) country = Russia language = Russian series = Line of Delirium trilogy genre = Space Opera, Science …   Wikipedia

  • Single-lens reflex camera — The single lens reflex (SLR) camera uses an automatic moving mirror system which permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to non SLR cameras where the view through the… …   Wikipedia

  • Working Group on Financial Markets — The Working Group on Financial Markets (also, President s Working Group on Financial Markets, the Working Group, and colloquially the Plunge Protection Team) was created by Executive Order 12631, [… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.