Rail gauge

Rail gauge is the distance between the inner sides of the two parallel rails that make up a railway track. Sixty percent of the world's railways use a gauge of RailGauge|1435, which is known as the standard or international gauge. Gauges wider than standard gauge are called broad gauge, those smaller are called narrow gauge. The term break-of-gauge refers to the situation at a place where different gauges meet. Some stretches of track are dual gauge, with three (or sometimes four) parallel rails in place of the usual two, to allow trains of two different gauges to share the same path. Gauge conversion can be used to reduce break-of-gauge situations.

Overview

New railways are usually built to standard gauge unless there is a compelling reason to adopt another gauge, e.g., compatibility with existing railways. The advantages of using standard gauge are:

* Facilitates inter-running with neighbouring railways
* Locomotives and rolling stock can be ordered from manufacturers' standard designs and do not need to be custom built. However, some adaptation to local conditions may still be necessary, e.g., in respect of loading gauge.

Dominant gauges

References

External links

* [http://www.trains.com/Content/Dynamic/Articles/000/000/003/011gsqfq.asp A history of track gauge] by George W. Hilton
* [http://parovoz.com/spravka/gauges-e.html Railroad Gauge Width] — A list of railway gauges used or being used worldwide, including gauges which are obsolete.
* [http://www.era.eu.int/public/Interoperability/CR%20TSI%20-%205%20-%201520%20mm%20system.aspx European Railway Agency: 1,520 mm systems] (issues having to do with the participation of 1,520/1,524 mm gauge countries in the EU rail network)
* [http://irfca.org/faq/faq-gauge.html The Indian Railways FAQ: Gauges]
* [http://southern.railfan.net/ties/1966/66-8/gauge.html The Days they Changed the Gauge in the U.S. South]
* [http://www.snopes.com/history/american/gauge.htm The United States standard railroad gauge derives from the original specification for an Imperial Roman war chariot. (Urban Legends Reference Pages)]