4 ft 6 in gauge railway

The 4 ft 6 in (1,372 mm) track gauge, also called the Scotch gauge, was adopted by early 19th century railways mainly in the Lanarkshire area of Scotland. It differed from the gauge of 4 ft 8 in (1,422 mm) that was used on some early lines in England. Early railways chose their own gauge, but later in the century interchange of equipment was facilitated by establishing a uniform rail gauge across railways: a so-called 'standard gauge' of 4 ft 8 ¹⁄₂ in (1,435 mm). In the early 1840s standard gauge lines began to be constructed in Scotland, and all the Scotch Gauge lines were eventually converted to standard gauge. The gauge was outlawed in Great Britain by law in 1846. From 1903, tram lines of Tokyo adopted this gauge.

A small number of early to mid-19th century passenger railways were built to 4 ft 6 in (1,372 mm) Scotch gauge including:

Interestingly Robert Stephenson and Company built a Scotch gauge locomotive, the St. Rollox, for the Garnkirk and Glasgow Railway; which was later sold to the Paisley and Renfrew Railway.

All the lines were later relaid in standard gauge.

In addition to the above lines, there were three railways, authorised between 1822 and 1835, that were built in the Dundee area, to a gauge of 4 ft 6 ¹⁄₂ in (1,384 mm). They were:

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