5 ft and 1520 mm gauge railways

Railways with a railway track gauge of 5 ft/​1,524 mm were first constructed in the United Kingdom and the United States. This gauge is also commonly called Russian gauge because this gauge was later chosen as the common track gauge for the Russian Empire and its neighbouring countries. The gauge was redefined by Russian Railways to be 1520 mm (4 ft 11 ²⁷⁄₃₂ in).

The primary region where Russian gauge is used is the former Soviet Union (CIS states, Baltic states and Georgia), Mongolia and Finland, with about 225,000 km (140,000 mi) of track. Russian gauge is the second most common gauge in the world, after 1,435 mm (4 ft 8 ¹⁄₂ in) standard gauge.

In 1748, the Wylam waggonway was built to a 5 ft (1,524 mm) gauge for the shipment of coal from Wylam to Lemington down the River Tyne. In 1839, the Eastern Counties Railway was constructed; and in 1840, the Northern and Eastern Railway was built. In 1844, both lines were converted to 1,435 mm (4 ft 8 ¹⁄₂ in) standard gauge. In 1903, the East Hill Cliff Railway, a funicular, was opened.

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