Editing Track gauge (section)

===Early track gauges===
{{See also|Permanent way (history)|Wagonway|Plateway}}

The earliest form of railway was a wooden wagonway, along which single wagons were manhandled, almost always in or from a mine or quarry. Initially the wagons were guided by human muscle power; subsequently by various mechanical methods. Timber rails wore rapidly: later, flat cast-iron plates were provided to limit the wear. In some localities, the plates were made L-shaped, with the vertical part of the L guiding the wheels; this is generally referred to as a "plateway". Flanged wheels eventually became universal, and the  spacing between the rails had to be compatible with that of the wagon wheels.<ref name="lewis">M. J. T. Lewis (1970), ''Early Wooden Railways'', Routledge Keegan Paul, London</ref>

As the guidance of the wagons was improved, short strings of wagons could be connected and pulled by teams of horses, and the track could be extended from the immediate vicinity of the mine or quarry, typically to a navigable waterway. The wagons were built to a consistent pattern and the track would be made to suit the needs of the horses and wagons: the gauge was more critical. The [[Merthyr Tramroad|Penydarren Tramroad]] of 1802 in South Wales, a plateway, spaced these at {{Track gauge|4ft4in}} over the outside of the upstands.<ref name =" cragg">R. Cragg (1997), ''Civil Engineering Heritage – Wales and West Central'', Thomas Telford Publishing, London, 2nd edition, England, {{ISBN|0 7277 2576 9}}</ref>

[[File:Chpr rail.jpg|thumb|right|Fish-belly cast-iron rails from the Cromford and High Peak Railway]]
The Penydarren Tramroad probably carried the first journey by a locomotive, in 1804, and it was successful for the locomotive, but unsuccessful for the track: the plates were not strong enough to carry its weight. A considerable progressive step was made when cast iron edge rails were first employed; these had the major axis of the rail section configured vertically, giving a much stronger section to resist bending forces, and this was further improved when fish-belly rails were introduced.<ref name="earlyrailways">Andy Guy and Jim Rees, ''Early Railways 1569–1830'', Shire Publications in association with the National Railway Museum, Oxford, 2011, {{ISBN|978 0 74780 811 4}}</ref>

Edge rails required a close match between rail spacing and the configuration of the wheelsets, and the importance of the gauge was reinforced. Railways were still seen as local concerns: there was no appreciation of a future connection to other lines, and the choice of track gauge was still a pragmatic decision based on local requirements and prejudices, and probably determined by existing local designs of (road) vehicles.

Thus, the [[Monkland and Kirkintilloch Railway]] (1826) in the West of Scotland used {{Track gauge|4ft6in}};<ref name = martin>Don Martin, ''The Monkland and Kirkintilloch and Associated Railways'', Strathkelvin Public Libraries, Kirkintilloch, 1995, {{ISBN|0 904966 41 0}}</ref> the [[Dundee and Newtyle Railway]] (1831) in the north-east of Scotland adopted {{Track gauge|4 ft 6 1/2 in}};<ref name = ferguson>N. Ferguson (1995), ''The Dundee and Newtyle Railway including the Alyth and Blairgowrie Branches'', The Oakwood Press, {{ISBN|0-85361-476-8}}.</ref> the [[Redruth and Chasewater Railway]] (1825) in Cornwall chose {{Track gauge|4ft}}.<ref>D. B. Barton (1966), ''The Redruth and Chasewater Railway, 1824–1915'', D. Bradford Barton Ltd, Truro, 2nd edition</ref>

The [[Arbroath and Forfar Railway]] opened in 1838 with a gauge of {{Track gauge|5ft6in}},<ref name = whishaw>[[Francis Whishaw]], ''The Railways of Great Britain and Ireland Practically Described and Illustrated'', 1842, reprint 1969, David & Charles (Publishers) Limited, Newton Abbot, {{ISBN|0-7153-4786-1}}</ref> and the [[Ulster Railway]] of 1839 used {{Track gauge|6ft2in}}.<ref name = whishaw/>