Editing Track gauge (section)

===Minimum gauge===
{{Main||Minimum-gauge railway}}

[[Minimum-gauge railway|Very narrow gauges]] of under {{convert|2|ft|mm}} were used for some [[industrial railway]]s in space-restricted environments such as [[mining|mines]] or farms. The French company [[Decauville]] developed {{Track gauge|500mm}} and {{Track gauge|400mm}} tracks, mainly for mines; [[Arthur Percival Heywood|Heywood]] developed {{Track gauge|15in}} gauge for [[British narrow-gauge railways#Estate railways|estate railways]]. The most common minimum gauges were {{RailGauge|15in}},<ref name="Heywood, Minimum Gauge Railways" >{{cite book
  |last=Heywood |first=A.P.
  |author-link=Sir Arthur Heywood
  |title=Minimum Gauge Railways
  |url=https://www.gutenberg.org/ebooks/44341
  |orig-year=1881, Derby: Bemrose
  |year=1974
  |publisher=Turntable Enterprises
  |isbn=0-902844-26-1
  |ref=Heywood, Minimum Gauge Railways
}}</ref> {{RailGauge|400mm}}, {{RailGauge|16in}}, {{RailGauge|18in}}, {{RailGauge|500mm}} or {{RailGauge|20in}}.