Rail gauge

Rail gauge is the distance from the inside of one rail on a railroad track to the inside of the other. Most tracks use a standard gauge of 1,435 mm (4 ft, 8 1/2 in). Wider gauges are called broad gauge (1676mm), smaller gauges are called narrow gauge(762mm or 610mm). Broad gauge may be used where the track needs to have big things moving on it. Narrow gauge, such as metre gauge (1000mm), is used to build railroads for less money, because the smaller track costs less. Places where different gauges meet are called break of gauge.

Rail Gauge Media

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  Fish-belly cast-iron rails from the Cromford and High Peak Railway

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  An early Stephenson locomotive

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  Triple gauge, from left: , , and , on display at the China Railway Museum in Beijing

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  A cartoon depicting the horrors of goods transfer at the break of gauge at Gloucester in 1843

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  Cross-section of 4-rail dual-gauge track (standard and metre gauge/ narrow gauge) (click to enlarge)

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  Cross-section of Australian dual-gauge track – and gauges (click to enlarge)

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  Mixed gauge track at Sassari, Sardinia: and

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  Reconstructed mixed-gauge, / track at Didcot Railway Museum, England

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  Cross-section of triple-gauge track at Gladstone and Peterborough, South Australia, before gauge standardisation. The three gauges require the respective gaps between the outer and inner rails to be different, unlike four-rail dual gauge.