Editing Standard-gauge railway (section)

==Early railways by gauge==
=== Non-standard gauge ===
{|class="wikitable sortable"
!Name !!Authorised !!Opened !!Gauge
|-
|[[Monkland and Kirkintilloch Railway]]||1824||1825||{{Track gauge|4ft6in}}
|-
|[[Dundee and Newtyle Railway]]||1829||1831||{{Track gauge|54.5in}}
|-
|[[Eastern Counties Railway]]||1836, 4 July||1839, 20 June||{{Track gauge|5ft|lk=on}}<ref name="Whishaw, 91" >{{harvp|Whishaw|1842|p=91}}.</ref>
|-
|[[London and Blackwall Railway]]||1838, 28 July|| 1840 ||{{Track gauge|60.5in}}<ref>{{cite web |url=http://www.stgite.org.uk/media/publictransport.html |title=Public transport in and about the parish |at=London and Blackwall Railway; London, Tilbury & Southend Railway |website=St George-in-the-East Church |location=London}}</ref><ref>{{cite web |url=http://www.mernick.org.uk/dlr/documents/09.pdf|title=Docklands Light Railway: Tower Gateway to West India Quay |website=Mernick |access-date=1 June 2016}}</ref><ref name="Whishaw, 260">{{harvp |Whishaw|1842|p=260}}.</ref>
|-
|[[Dundee and Arbroath Railway]] ||1836, 19 May<br><small>incorporated</small>||1838, October||{{Track gauge|5ft6in|lk=on}}<br><small>Until [[Track gauge conversion|standardised]] in 1847</small>
|-
|[[Arbroath and Forfar Railway]] ||1836, 19 May<br><small>incorporated</small>||1838, November||{{Track gauge|5ft6in}}
|-
|[[Northern and Eastern Railway]] ||1836, 4 July||1840, 15 September|| {{Track gauge|5ft}}<ref name="Whishaw, 363" >{{harvp |Whishaw|1842|p=363}}.</ref>
|-
|[[Aberdeen Railway]]       || 1845 || 1848 || {{Track gauge|5ft6in}}<br><small>Until [[Track gauge conversion|standardised]]</small>
|-
| [[Great Western Railway]] || 1835 || 1838 || {{Track gauge|7ft 0.25in}}<br><small>Until [[Track gauge conversion|standardised]]</small>
|-
| [[Ulster Railway]]        || 1836 || 1839 || {{Track gauge|6ft 2in}} <br><small>Until [[Track gauge conversion|5ft 3in]]</small>
|}

===Almost standard gauge===
{{main|4 ft 8 in gauge railways}}
* The [[Huddersfield Corporation Tramways]], used {{Track gauge |4ft7.75in}}
* The [[Portsdown and Horndean Light Railway]], used {{Track gauge |4ft7.75in}}
* The [[Portsmouth Corporation Transport]], used {{Track gauge |4ft7.75in}}
* The [[Killingworth Colliery railway|Killingworth colliery railway]], used {{Track gauge |4ft8in}}.<ref name="The Rocket Men p33">{{harvp|Jones|2013|p=33}}.</ref>
* The [[Hetton colliery railway]], opened 1822, used {{Track gauge|4ft8in}}.<ref name="The Rocket Men p33" />
* The [[Stockton and Darlington Railway]], authorised 1821, opened 1825, used {{Track gauge |4ft8in}}.
* The [[New Orleans and Carrollton Railroad]] used {{Track gauge |4ft8in}}
* The [[Pontchartrain Railroad]] used {{Track gauge |4ft8in}}
* The [[trams in Nuremberg]] nominally used {{Track gauge|1432mm}} during much of their existence, but have since been [[Track gauge conversion|converted]] to standard gauge in name as well as fact.
<!-- Please add info on modern railways in the Modern section, not here. -->

===Standard gauge===
{|class="wikitable sortable"
!Name!!Authorised!!Opened!!Remarks
|-
|[[Baltimore and Ohio Railroad]]||1827||1830||A 13 mile section, between [[Baltimore]] and [[Ellicott City, Maryland|Elliot's Mill]] started revenue operation, with horse-drawn cars, on 24 May 1830.<ref>{{Cite web |last=Bak |first=Luca |date=1830-05-24 |title=First passenger rail service in US (Baltimore and Elliots Mill, Maryland). |url=https://www.todaysflashback.com/first-passenger-rail-service-in-us-baltimore-and-elliots-mill-maryland/ |access-date=2025-05-14 |website=Today's Flashback |language=en-US}}</ref>
|-
|[[Liverpool and Manchester Railway]]||1824||1830||
|-
|[[Saint-Étienne–Lyon railway]]||1826||1833||All the early French railways (including Saint-Etienne Andrezieux, authorised 1823, opened 1827) had a French Gauge of {{Track gauge|1500mm}} from rail axis to rail axis, compatible with early standard gauge [[Engineering tolerance|tolerances]])
|-
|[[Dublin and Kingstown Railway]]||1831||1834<br><small>For passenger traffic</small>|| converted to 5&nbsp;ft 3in
|-
|[[Newcastle & Carlisle Railway]]||1829||1834||Isolated from LMR
|-
|[[Grand Junction Railway]]||1833||1837||Connected to LMR
|-
|[[London and Birmingham Railway]]||1833||1838||Connected to LMR
|-
|[[Manchester and Birmingham Railway]]               ||1837||1840||Connected to LMR
|-
|[[Birmingham and Gloucester Railway]]               ||1836||1840||Connected to LMR
|-
|[[London and Southampton Railway]]                  ||1834||1840||
|-
|[[London and Brighton Railway]]                     ||1837||1841||
|-
|[[South Eastern Railway (UK)|South Eastern Railway]]||1836||1844||
|}

===Small deviations from standard gauge===
* The [[Manchester and Leeds Railway]], authorised on 4 July 1836, used {{Track gauge|4ft9in}}.<ref name="Whishaw, 319" >{{harvp |Whishaw|1842|p=319}}.</ref>
** The {{Track gauge|4ft9in}} railways were intended to take {{Track gauge|ussg}} gauge vehicles and allow a (second) running [[Engineering tolerance|tolerance]].
* The [[Chester and Birkenhead Railway]], authorised on 12 July 1837, used {{Track gauge|4ft9in}}.<ref name="Whishaw, 54" >{{harvp |Whishaw|1842|p=54}}.</ref>
* The [[London and Brighton Railway]], authorised on 15 July 1837, used {{Track gauge|4ft9in}}.<ref name="Whishaw, 273" >{{harvp |Whishaw|1842|p=273}}.</ref>
* The [[Manchester and Birmingham Railway]], authorised on 30 June 1837, used {{Track gauge|4ft9in}}.<ref name="Whishaw, 303" >{{harvp |Whishaw|1842|p=303}}.</ref>
* The [[Pennsylvania Railroad]] originally used {{Track gauge|4ft9in}}
* The [[trams in Dresden]], authorised in 1872 as [[horsecar]]s, used {{Track gauge|1440mm}} gauge vehicles. Converted to 600 V DC electric trams in 1893, they now use {{Track gauge|1450mm}}; both gauges are within the [[Engineering tolerance|tolerance]] for standard gauge.
* The [[Track gauge in the United States#Gauge war|Ohio gauge]] of {{Track gauge|4ft10in|lk=on}}

=== Dual gauge ===
{{main|Dual gauge}}
* [[Cheltenham and Great Western Union Railway]], authorised 1836, opened 1840, dual gauge 1843 {{Track gauge|uksg|allk=on}} and {{Track gauge|7ft0.25in|lk=on}}.

=== Initially standard gauge ===
Several lines were initially built as standard gauge but were later converted to another gauge for cost or for compatibility reasons.{{Citation needed|date=December 2023}}
* [[South Africa]] became {{railgauge|1067mm}}
* [[State Railway of Thailand#History|Thailand]] became {{railgauge|1000mm}}
* [[Indonesia]] became {{railgauge|1067mm}}
* [[Ireland]] became {{railgauge|1600mm}} – [[Dublin and Kingstown Railway]]
* [[Australia]] became {{railgauge|1600mm}} – [[Victoria (Australia)|Victoria]] & [[South Australia]] – partly converted to {{railgauge|1435mm}}
* [[India]] became {{railgauge|1676mm}} – initial freight lines <!-- [[5 ft 6 in gauge railway]] -->
* some private [[Japan]]ese railways