View source for Dual gauge

{{Short description|Railway track with more than two rails }}
{{distinguish|Third rail|Guard rail (rail transport)}}
{{Use dmy dates|date=November 2022}}
{{Use Australian English|date=November 2022}} 
{{train topics}}

'''Dual gauge''' [[railroad track]] has three or four rails, allowing vehicles of two [[track gauge]]s to run on it.

Signalling and sidings are more expensive to install on dual gauge tracks than on two single gauge tracks. Dual gauge is used when there is not enough room for two single tracks or when tracks of two different gauges meet in [[marshalling yard]]s or [[train station]]s.

==Background==
{{Hatnote|A comprehensive list of rail gauges around the world is in the article about [[Track gauge]].}}

The rail gauge is the most fundamental specification of a railway. [[Rail tracks]] and [[Wheelset (rail transport)|wheelsets]] are built within [[engineering tolerance]]s that allow optimum lateral movement of the wheelsets between the rails. Pairs of rails that become too wide or narrow in gauge will cause derailments, especially if in excess of normal gauge-widening on curves.<ref name=Tratman>{{cite book |last=Tratman |first=E.E. Russell |date=1908 |url= https://archive.org/details/railwaytracktrac01trat/page/n9/mode/2up |title=Railway track and track work |publisher=The Engineering News Publishing Co. |edition=3 |location=New York|access-date=8 November 2022 |page=402}}</ref>{{refn|group=note|Two-rail track on curves is re-gauged when the gauge is 20 mm over (16 mm on narrow gauge). It is sometimes done by relocating the low (inner) rail to save "spike-killing" the sleeper at the outer end, where lateral loads are greater.  In other cases, the sleeper may be slid through by about 70 mm to provide "new" timber for spiking.<ref>{{cite book |date=1988 |title=Track Maintenance Guide |publisher=Australian National Railways Commission |location=Adelaide |page=section 12.2}}</ref> On dual-gauge turnouts, tolerances are small: only {{convert|8|mm|in|abbr=off}} over gauge and {{convert|2|mm|in|abbr=off}} under.<ref>{{cite web |url=https://extranet.artc.com.au/docs/eng/track-civil/workinstruct/pc/ETN-03-01.pdf |title=50kg dual gauge turnouts and gauge separations – construction and maintenance manual |author=<!--Not stated-->|date=2008 |website=Australian Rail Track Corporation |access-date=7 November 2022 }}</ref>}}

Given the requirement for gauge to be within very tight limits, when the designed distance between the pair of wheels on a wheelset differs even slightly from that of others on a railway, track must be built to two specific gauges. That is achieved in a variety of ways: most commonly by adding a third rail, more rarely by adding another pair of rails; and rarer still, when three gauges are present, by four rails.

==Configurations==
[[File:Rail baseplate on dual gauge (1435 and 1600 mm) track, South Australian Railways.jpg|thumb|200px|[[Rail fastening system#Tieplates|Baseplate]] on dual-gauge track showing the minimum practicable gap between the bases of two rails – about 40&nbsp;mm (1<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;in) – which determines the minimum difference in gauges possible in a three-rail configuration]]

{{Quote box
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{{big|An interactive 3D view of&nbsp;dual-gauge&nbsp;track&nbsp;components is<br />[https://inlandrail.com.au/what-is-dual-gauge-track/ here]}} 
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Dual-gauge track can consist of three rails, sharing one "common" rail; or four rails, with the rails of the narrower gauge lying between those of the broader gauge. In the three-rail configuration, wear and tear of the common rail is greater than with the two other outer rails. In dual gauge lines, turnouts ([[railroad switch]]es) are more complex than in single-gauge track, and trains must be safely signalled on both of the gauges. [[Track circuit]]s and mechanical interlocking must also operate on both gauges.<ref>{{cite book|title=Farewell narrow gauge |last=Rogers |first=K.C. |date=1969 |location=Adelaide |publisher=Australian Railway Historical Society (SA Division Inc.) |pages=19–22 }}</ref>

Multi-gauge track is very often associated with a break-of-gauge station, where rail vehicles or vehicle contents are transferred from one gauge to another. A break of gauge causes delay and increases congestion, especially on single-track lines. Essentially, two trains are required to do what a single train would normally accomplish. When traffic passes mainly in one direction, full wagons taken to the border have to be returned as empties, and a train of empty wagons has to be brought to the break of gauge from the other side to fetch the cargo. Congestion is also caused by unloading and reloading.<ref>{{cite book |last=Pratt |first=Edwin A. |date=1912 |title=The state railway muddle in Australia |publisher=John Murray |location=London |via=Internet Archive |page=68 |url=https://archive.org/details/staterailwaymudd00pratrich/page/68/mode/1up |access-date=2022-11-28}}</ref><ref name=haul>{{cite book |last1=Donovan|first1=Peter Francis|last2=O'Neil|first2=Bernard|last3=Jay|first3=Christopher|date=1991 |title=The long haul: Australian National 1978–1988 |edition=Revised |publisher= Australian National Railways Commission |location=Adelaide |isbn=1875359087}}</ref>{{rp|74–75}} The problem is worsened when there is a disparity between the capacity of locomotives and vehicles on the two gauges: typically, one broad-gauge trainload needs three narrow-gauge trains to carry.<ref>{{cite journal |last=Chambers |first=T.F. |date=February 1971 |title=The railways and Terowie – their early history and change of pattern over nearly a century |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |volume=XXII |issue=400 |page=34 |issn=0005-0105 }}</ref>

===Three rails===
[[File:Cross-section of Australian dual-gauge railway track.tif|thumb|left|Configuration of dual-gauge (1600 mm and 1435 mm) track.]]

Constructing dual-gauge track with three rails is possible when the two adjacent rails can be separated at the base by at least the space required by rail fastening hardware such as spikes and or rail clips – typically {{convert|40|mm|in|abbr=off|comma=off}}. If the two gauges are closer than that, four rails must be used. Depending on the rail fasteners used and the weight of rails (heavy rails are bigger), the practicable difference between the two gauges is in the range {{convert|145|mm|in|abbr=off|comma=off}} to {{convert|200|mm|in|abbr=off|comma=off}}.<ref>{{cite book |date=1988 |title=Track Maintenance Guide |publisher=Australian National Railways Commission |location=Adelaide |page=section 9.1}}</ref>

{| class="wikitable floatleft mw-collapsible mw-collapsed" border= "1" style= "width:60%; font-size: 86%; float:left; margin-left:2em; margin-right:2em; margin-bottom:2em"
! colspan="2"| {{larger|''' Gallery: Dual gauge (3 rails)'''}}
|-align="center"
|<br />[[Image: Dual-gauge tracks (1600 mm and 1000 mm) at Belo Horizonte, Brazil(cropped).jpg|border|400x130px|none]]
|<br />[[Image: Wallaroo-dual-gauge-railway-0855.jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1600&nbsp;/ 1000&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 3&nbsp;ft 3<span style="vertical-align:super;font-size:x-small">3</span>/<span style="vertical-align:sub;font-size:x-small">8</span>&nbsp;in)<br />{{efn-la|Commuter lines near Estação Central, City of [[Belo Horizonte]], Brazil, 2007.}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;mm<br /> (5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;in).<br />{{efn-la| Secondary main line, [[Wallaroo, South Australia]], 2008. Such close spacing of two rails is at the limit of possibilities for three-rail dual gauge; if closer, a four-rail configuration must be built.}}
|-align="center"
|<br /> [[Image: Dual-gauge (1435 and 891 mm) track and turnout at Jenny, Sweden.jpg|border|400x130px|none]]
|<br />[[Image:Liberec, Tatranská, výhybka u vozovny.jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1435&nbsp;/ 891&nbsp;mm<br />(4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 2&nbsp;ft 11<span style="vertical-align:super;font-size:x-small">3</span>/<span style="vertical-align:sub;font-size:x-small">32</span>&nbsp;in)<br />{{efn-la|Jenny, Sweden, 2006.}}
|style="vertical-align: top; width=100"|1435&nbsp;/ 1000&nbsp;mm<br />(4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 3<span style="vertical-align:super;font-size:x-small">3</span>/<span style="vertical-align:sub;font-size:x-small">8</span>&nbsp;in)<br />{{efn-la|Street [[tramway track]] in [[Liberec#Transport|Liberec]], Czech Republic, 2007.}}
|-align="center"
|<br />[[Image: Dual gauge track (1435mm and 1000 mm), Hakone Tozan Line, Japan (cropped).jpg|border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1435&nbsp;/ 1067&nbsp;mm<br />(4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in)<br />{{efn-la| Odawara on the [[Hakone Tozan Railway]], Japan, 2005.}}
|}
{{clear}}

===Four rails===
[[File: Cross-section of 4-rail dual-gauge track (standard and metre gauge).png |thumb|left|Four-rail arrangement of standard and metre gauge on the [[Chemin de Fer de la Baie de Somme]]. A 435&nbsp;mm difference in gauge can also be accommodated in a three-rail configuration.]]

In some places, the dimensions of two gauges needing to be collocated are too close to allow a three-rail configuration – for example:
* {{Track gauge|1000mm|lk=on|comma=off}} and {{Track gauge|1067mm|lk=on|comma=off}} (common in Africa, a legacy respectively of French/Belgian and British railway practice)
* {{Track gauge|1000mm|lk=on|comma=off}} and {{Track gauge|914mm|lk=on|comma=off}} (common in South America)
* {{Track gauge|1435mm|lk=on|comma=off}} and {{Track gauge|1524mm|lk=on|comma=off}} (common where [[broad-gauge railway]]s of former [[satellite states]] of the [[Soviet Union]] meet European or Chinese standard gauge).
In such cases, four rails are needed to provide the dual gauge.

Four rails might also be installed because of other engineering or operational factors, even though three rails would suffice: an example is on the [[Chemin de Fer de la Baie de Somme]] (Somme Bay railway), which combines standard and metre gauge – {{convert|435|mm|in|abbr=off|comma=off}} different, well within the parameters for three rails.

Four rails are necessary where the centre-line of rail vehicles on both tracks must be closely aligned with the centre-line of the track in tunnels or other constricted locations. Such configurations, when they revert  back to standard parallel lines as soon as room is available, are termed "[[Gauntlet track|gauntlet track" (US: "gantlet track")]].<ref>{{cite web|url=https://www.trains.com/trn/train-basics/ask-trains/gantlet-gauntlet/ |title=Gantlet vs. gauntlet |author=<!--Not stated--> |date=1 February 2011 |website=[[Trains (magazine)|Trains]] |publisher=[[Kalmbach Media]]|access-date=1 September 2023 }}</ref><ref name=Tratman/>

Four rails must be placed identically on either side of the central axis of dual-gauge [[Railway turntable|turntables]] (and six rails on triple-gauge turntables) so that they match the configuration of the fixed rails leading to and from the turntable, regardless of the direction in which the turntable is facing.

{|class="wikitable floatleft mw-collapsible mw-collapsed" border= "1" style= "width:60%; font-size: 86%; float:left; margin-left:2em; margin-right:2em; margin-bottom:2em"
!colspan="2"| {{larger|''' Gallery: Dual gauge (4 rails)'''}}

|-align="center"
|<br />[[Image: Double écartement CFBS.jpg |border|400x130px|none]]
|<br />[[Image: Rail Baltica Lietuva.jpg |border|400x130px|none]]

|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1435&nbsp;/ 1000&nbsp;mm<br />(4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 3<span style="vertical-align:super;font-size:x-small">3</span><span style="vertical-align:sub;font-size:x-small">8</span>&nbsp;in).<br />In the foreground, the narrow gauge diverges via a fixed-rail configuration.{{hair space}}{{efn-la|[[Chemin de Fer de la Baie de Somme]], France, 2007.}}
|style="vertical-align: top; width=100"|1520&nbsp;/ 1435&nbsp;mm<br /> (4&nbsp;ft 11<span style="vertical-align:super;font-size:x-small">27</span>/<span style="vertical-align:sub;font-size:x-small">32</span>&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;in).<br />The gauges of this track are as follows (numbering the rails from left to right). [[5 ft and 1520 mm gauge railways|1520 mm]] gauge: rails 1 and 3; [[standard gauge|1435 mm gauge]]: rails 2 and 4.{{hair space}}{{efn-la| Newly laid track between [[Mockava]] and [[Šeštokai]], Lithuania, 2013 or earlier.}}
|-align="center"
|<br />[[Image: Haparanda-Tornio rail bridge across the Torne River, looking towards Sweden, 2008.jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1524&nbsp;/ 1435&nbsp;mm<br />(5&nbsp;ft 0&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;in).<br />A line comprising European standard gauge and "Russian" gauge, a legacy of the former [[satellite state]]s of the [[Soviet Union]]. The 89&nbsp;mm difference between the two gauges is too small to allow a three-rail configuration.{{hair space}}{{efn-la|Torne River  rail bridge between Tornio (Finland) and Haparanda (Sweden, ahead), 2008.}}
|-align="center"
|}
{{clear}}

===Triple gauge===
[[File:Cross-section of Australian triple-gauge track.png|thumb|left|Cross-section of triple-gauge track at [[Gladstone railway station, South Australia|Gladstone]] and [[Peterborough railway station, South Australia|Peterborough]], [[South Australia]], before [[Sydney–Perth rail corridor|gauge standardisation]]. The three gauges require the respective gaps between the outer and inner rails to be different, unlike four-rail dual gauge.]]

In rare situations, three different gauges may converge on to a rail yard and triple-gauge track is needed to meet the operational needs of the break-of-gauge station – most commonly where there is insufficient space to do otherwise. Construction and operation of triple-gauge track and its signalling, however, involves immense cost and disruption, and is undertaken when no other alternative is available.<ref>{{cite book|title=Making tracks: 46 years in Australian railways  |last=Fitch |first=Ronald J. |date=1989 |location= Kenthurst NSW |publisher=Kangaroo Press |page=141 |isbn=0864172702 }}</ref>

{|class="wikitable floatleft mw-collapsible mw-collapsed" border= "1" style= "width:60%; font-size: 86%; float:left; margin-left:2em; margin-right:2em; margin-bottom:2em"
!colspan="2"| {{larger|''' Gallery: Triple gauge (4 rails)'''}}

|-align="center"
|<br />[[Image: South Australian Railways triple-gauge turnout, Gladstone (KNorgrove).jpg|border|400x130px|none]] 
|<br />[[Image: Four-rail triple-gauge turnout, Gladstone South Australia (HSWilliams).jpg|border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />Turnout, 4-rail triple-gauge both ways, from the points end.{{hair space}}{{efn-la|Gladstone, South Australia, early 1970s.}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />Turnout, 4-rail triple-gauge both ways, from the crossing end.{{hair space}}{{efn-la|Gladstone, South Australia, early 1970s.}}

|-align="center"
|<br />[[Image: Gladstone Railyard March 1986 002.jpg |border|400x130px|none]]
|<br />[[Image: South Australian Railways standard gauge car on 4-rail track, Gladstone (KNorgrove).jpg|border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"| 1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in). Three-rail dual-gauge track is joined by four-rail triple-gauge.{{hair space}}{{efn-la| Gladstone, South Australia, early 1970s.}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span> in&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />Standard-gauge car on 4-rail triple-gauge track. Narrow gauge track is two central rails; broad gauge is far left rail and second from right.{{hair space}}{{efn-la|Gladstone, South Australia, early 1970s.}}

|-align="center"
|<br /> [[Image:Triple-gauge track on turntable, Gladstone, South Australia (HSWilliams).jpg|400x130px|none]]
|<br />[[Image:Triple-gauge railway yard looking south, Gladstone, SA, 1976 (HSWilliams).jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />A six-rail triple-gauge turntable. It must always present the same positioning of rails at both ends, so all four rails must be symmetrical to the central axis. This is made possible only by reducing the profile of the middle rail on either side.{{hair space}}{{efn-la|Locomotive depot, Peterborough, South Australia, 2010 (turntable was made triple-gauge in 1969 to accommodate new standard gauge).}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />When the Sydney–Perth rail corridor was [[track gauge conversion|converted to standard gauge]] in the late 1960s, dual-gauge track in the [[Gladstone railway station, South Australia|Gladstone yard]] had to be replaced by all-new triple-gauge track. The result was an inordinately complex marshalling yard.{{hair space}}{{efn-la|[[Gladstone railway station, South Australia|Gladstone railway station]], 1976.}}
|}
{{clear}}

The following table shows localities where triple gauge has been necessary. 
{| class="wikitable sortable floatleft mw-collapsible mw-collapsed" border= "1" style= "width:95%; font-size: 87%; float:left; margin-left:2em; margin-right:2em; margin-bottom:2em"
! colspan="5"|{{larger|Occurrences of triple gauge}} 
|-
! Place
! Narrowest<br />gauge
! Middle<br />gauge
! Broadest<br />gauge
! Notes
|-
| [[Volos#Railway|Volos]], Greece
| {{Track gauge|600mm}} || rowspan="4" | {{Track gauge|1000mm|comma=off}} || rowspan="5" | {{Track gauge|1435mm|comma=off}}
| {{Track gauge|600mm}} gauge closed in the 1970s, {{Track gauge|1000mm|comma=off}} gauge closed in 1998
|-
| [[Jenbach]], Austria
| {{Track gauge|760mm}} 
| rowspan="2" | Still in use{{When|date=November 2022}}
|-
| [[Montreux]], Switzerland
| rowspan="2" | {{Track gauge|800mm}} 
|-
| [[Capolago]], Switzerland
| Metre gauge line closed in 1950
|-
| [[Växjö]], Sweden
| {{Track gauge|891mm}} || {{Track gauge|1067mm|comma=off}} 
| Until 1974 or later<ref>[http://www.vmjs.se/ Triple gauge at Växjö, ''click on Treskensspår at the left'']</ref>
|-
| [[Latour-de-Carol]], France
| rowspan="3" | {{Track gauge|1000mm|comma=off}} || rowspan="6" | {{Track gauge|1435mm|comma=off}} || rowspan="3" | {{Track gauge|1668mm|comma=off}}
| Three gauges since 1928; still in use in 2024.
|-
| [[Hendaye]], France
| Still in use
|-
| [[Barcelona]], Spain  
| Approach to [[Port of Barcelona]], still in use as of September 2024
|-
| [[Gladstone railway station, South Australia|Gladstone, South Australia]]{{refn|group=note|[[Port Pirie Junction railway station|Port Pirie Junction]] was a triple-gauge station from 1937 to 1983 but, unlike Gladstone, did not have any triple-gauge track. For the most part the gauges were separate; dual-gauge tracks served a few trans-shipment sidings and another [[Port Pirie railway station (Ellen Street)|passenger station]] in the town's main street.<ref>{{cite journal |last1=Bakewell |first1=Guy  |last2=Wilson |first2=John |date=September 1968 |title=Farewell to Ellen Street |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |volume=XIX |issue=371 |page=211 |issn=0005-0105}}</ref><ref>{{Cite web |url=http://natrailmuseum.org.au/downloads/documents/Multi_Gauge_Muddle.compressed.pdf |title=South Australia's mixed gauge muddle |access-date=8 November 2022 |archive-date=28 February 2016 |archive-url=https://web.archive.org/web/20160228020700/http://natrailmuseum.org.au/downloads/documents/Multi_Gauge_Muddle.compressed.pdf |url-status=dead }}</ref>}} 
| rowspan="3" | {{Track gauge|1067mm|comma=off}} || rowspan="2" | {{Track gauge|1600mm|comma=off}}
| 1968–1983<br />(Some has been reconstructed at the [[National Railway Museum, Port Adelaide]].)<ref>{{cite magazine|title=NRM report |author=<!--Not stated-->|date= January 2022 |magazine=[[Catch Point (periodical)|Catch Point Magazine]] |location=Port Adelaide |publisher=National Railway Museum |page=45 }}</ref>
|-
| [[Peterborough railway station, South Australia|Peterborough, South Australia]]
| 1968–1983. (Some has been preserved at the [[Steamtown Heritage Rail Centre]] in Peterborough.)<ref>{{cite web |url=https://www.steamtown.com.au/gallery-links/ |title=About Steamtown |author=<!--Not stated-->|date=2022 |website=Steamtown Peterborough |publisher=Steamtown Heritage Rail Centre |access-date=5 November 2022 }}</ref> 
|-
| [[Toronto]], Canada
|| {{Track gauge|1676mm|comma=off}}
| Reported as impending in 1872.<ref>{{cite news |title=The railway gauges |newspaper=[[The Mercury (Hobart)]] |url=https://trove.nla.gov.au/newspaper/article/8920889# |volume= XXI |issue=3577 |location=(Original, Hobart. Digital reproduction, Canberra|publisher=National Library of Australia – [[Trove]] digital newspaper archive) |date= 14 June 1872 |page=3 |accessdate=31 October 2022}}</ref> Subsequently [[Track gauge conversion|converted]] to {{Track gauge|1435mm|comma=off}} gauge.
|}

{| class="wikitable floatleft mw-collapsible mw-collapsed" border= "1" style= "width:60%; font-size: 86%; float:left; margin-left:2em; margin-right:2em; margin-bottom:2em"
! colspan="2"| {{larger|'''Gallery: Multi-gauge devices'''}}
|-align="center"
|<br />[[Image:South Australian Railways dual-gauge centraliser, Gladstone (KNorgrove).jpg |border|400x130px|none]]
|<br />[[Image:Dual gauge -- common rail change-over device, Southern Cross station, Melbourne.jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1600&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 3&nbsp;ft 6&nbsp;in). <br />A dual-gauge '''centraliser''' that directs narrow-gauge livestock cars to the centre of the broad gauge so that they can be shunted without snagging the platforms.{{hair space}}{{efn-la|Gladstone, South Australia, 1970s.}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;mm<br /> (5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;in).<br />A simple dual-gauge common-rail '''change-over''' device. It directs standard-gauge rolling stock from the common rail in the left foreground to the right-hand rail in readiness for the turnout in the distance.{{hair space}}{{efn-la|[[Southern Cross station]], Melbourne, Australia, 2010.}}
|-align="center"
|<br /> [[Image:South Australian Railways triple-gauge change-over trackwork -- from one common rail to NG in middle.jpg|border|400x130px|none]] 
|<br />[[Image: Three gauges with one common rail on the right hand side, plus change-over, Gladstone, South Australia (HSWilliams) (cropped).jpg |border|400x130px|none]]
|-align="left" vertical-align="top"
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />Triple-gauge common-rail '''change-over''' device: from one common rail (right foreground) to narrow gauge in the middle (in the distance).{{hair space}}{{efn-la|[[National Railway Museum, Port Adelaide]], 2022. Rebuilt with components from [[Gladstone, South Australia|Gladstone]].}}
|style="vertical-align: top; width=100"|1600&nbsp;/ 1435&nbsp;/ 1067&nbsp;mm<br />(5&nbsp;ft 3&nbsp;/ 4&nbsp;ft 8<span style="vertical-align:super;font-size:x-small">1</span>/<span style="vertical-align:sub;font-size:x-small">2</span>&nbsp;/ 3&nbsp;ft 6&nbsp;in).<br />A four-rail triple-gauge track that joins a three-rail dual-gauge track. The '''change-over''' device in the foreground directs standard-gauge rolling stock into a four-rail configuration.{{hair space}}{{efn-la|[[Gladstone railway station, South Australia|Gladstone station, South Australia]], 1976. The four rails in the foreground include one rail that is common to all three gauges (the rail on the right) and the gauges are as follows (numbering rails from left to right): broad gauge, 1&nbsp;and&nbsp;4; standard gauge, 2&nbsp;and&nbsp;4; narrow gauge, 3&nbsp;and&nbsp;4.}}
|}
{{clear}}

===More than three gauges===
[[File: Beyer, Peacock and Co Gorton Foundry in 1870.jpg|thumb|The Gorton Foundry of [[Beyer, Peacock & Company]] was typical of locomotive and rolling stock manufacturers that exported to many countries. This track of four gauges traversed two turntables, requiring the rails to be centralised.]]

Three gauges are the maximum found on operating railway lines and in railway yards, but some rolling stock manufacturers collocate more than three lines in their works, depending on the particular gauges of their customers.

==Alternatives==
[[File:Schema rollbocks trucks.PNG|thumb|[[Rollbock]]s compared to [[transporter wagon]]s]]

[[File: Australian National Railways 5-pack freight cars and container loader, Islington freight terminal, 1985.jpg |thumb|250px|Standardised [[Intermodal container|containers]] have revolutionised rail, road and sea [[freight transport]]. Although mechanisation has sped up handling, moving containers from one train to another because of different rail gauges is costly and inefficient.]]

Transfer of freight and passengers between different gauges does not necessarily involve dual-gauge track: there may simply be two tracks that approach either side of a platform without overlapping. In Australia, 13 break-of-gauge stations existed by 1945 as a result of longstanding interstate rivalries: three different gauges had persisted since the 1850s and the five mainland state capitals were not linked by standard gauge until 1995.<ref>{{cite book|title=Australian Railwayman: from cadet engineer to railways commissioner |last=Fitch |first=Ronald J. |date=2006 |location=Dural, New South Wales |publisher=Rosenberg Publishing Pty Ltd |page=168 |isbn=1877058483 }}</ref> Huge costs and long delays were imposed by [[Transshipment|trans-shipment]] of freight at break-of-gauge stations, whether manually, by gantry crane or by wheelset or bogie exchange.<ref name=haul/>{{rp|67}} During [[World War II]], breaks of gauge in Australia added immense difficulty to the war effort by needing extra locomotives and rolling stock, and more than 1600 service personnel and a large pool of civilians, at transfer points for an annual average transfer of about 1.8&nbsp;million tonnes of freight.<ref>{{cite book |last=Laird |first=Philip |date=2001 |title=Back on track: re-thinking transport policy in Australia and New Zealand |publisher=University of New South Wales Press |location=Sydney |isbn=086840411X |page=187}}</ref>

To cost and inefficiency was added, in the case of passengers, considerable inconvenience. In 1896, at [[Albury railway station|Albury station]] on the [[Sydney–Melbourne railway]], famed American writer Samuel Clemens ([[Mark Twain]]) had to change trains in the middle of a "biting-cold" night in 1896 and there formed his pungent view of "the paralysis of intellect that gave that idea birth".<ref>{{cite web |url= http://www.online-literature.com/twain/following-the-equator/14/ |title=  Following the Equator |first= Mark |last= Twain |date= 2020 |website= The Literature Network|access-date= 27 May 2020 }}</ref>

In some locations, an alternative to building long lengths of dual-gauge track has been to change the wheels on [[railroad car|rolling stock]], either by dropping and changing wheelsets from [[Train wheel|four-wheeled]] vehicles or exchanging bogies (US: trucks) under eight-wheeled vehicles. With this arrangement, a short length of dual-gauge track is only needed within the facility. A benefit is that the contents of fully loaded cars are not disturbed. The scheme was first adopted on the French–Spanish border and in Poland. It introduces delay into transit times compared with dual-gauge operation, but is much quicker than trans-shipping: when introduced in 1962 in Melbourne, Australia, on the route between Sydney and Adelaide, the freight handling time per train dropped from five days to less than two. The process involved disconnecting the [[Railway brake|brake rigging]] and [[bogie]] [[List of railroad truck parts#Center pin|centre pins]] have to be disconnected before the vehicle is lifted and new bogies are wheeled underneath.<ref name=buckland>{{cite journal | last=Buckland |first=J.L.  |date=October 1962 |title=Bogie changing extends the benefits of standard-gauge |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |volume=XIII |issue=300 |pages=161–162 |issn=0005-0105 }}</ref>{{refn|group=note|At that time, each transfer took 20 minutes; inspection and marshalling took up the remaining time.<ref name=buckland/> In 1982, each of two shifts of 18 men exchanged an average of 66 bogies per day; in comparison, 100 men would have been needed to transfer the same amount of freight wagon to wagon.<ref>{{cite book |author=Lee, Robert |title=The Railways of Victoria 1854–2004 |publisher=Melbourne University Publishing Ltd |year=2007 |isbn= 978-0-522-85134-2 |page=224}}</ref>}}

In Europe, a similar principle embodies low-profile, small-wheeled [[transporter wagon]]s, which carry vehicles built for one gauge on a line with a different gauge. A variant is the [[rollbock]] (Rollböcke in German), used under two-axle standard-gauge vehicles: each wheelset is carried on a small four-wheeled narrow-gauge trolley.<ref>{{cite AV media|date=2015 |title=Harzquerbahn 2015 – Güterverkehr zwischen Unterberg und Nordhausen |trans-title=Freight traffic between Unterberg and Nordhausen |language=|url=https://www.youtube.com/watch?v=6CBdZdcGpmI |access-date=3 November 2022 |publisher=Schmalspurbahn-Fans }}</ref> The entire train is converted in minutes at a slow walking pace, each rollbock being automatically matched to its wheelset from underneath.{{refn|group=note|The [[Ramsey car-transfer apparatus|principle]] of attaching narrow-gauge bogies from underneath in this manner had been patented by Robert Henry Ramsey in 1872, in the United States.<ref>{{cite web|url=https://www.midcontinent.org/rollingstock/builders/ramseys_cartruck.htm |title=Ramsey's car truck shifting apparatus |author=<!--Not stated-->|date=2007 |website=Mid-Continent Railway Museum |access-date=3 November 2022}}</ref>}}

A further variant is "[[Train on Train|train on train]]", in which an entire narrow-gauge train is carried on standard-gauge [[flatcar]]s on which continuous rail has been fitted.<ref>{{cite book| title=Uniform railway gauge| first=Eric| last=Harding| publisher=Lothian Publishing| year=1958| page=14}}</ref><ref>{{cite book| title=Tales from a Railway Odyssey| authorlink=Keith Smith (engineer)| first=Keith A.| last=Smith| page=114}}</ref><ref>{{cite journal |last=Buckland |first=J.L. |date=December 1955 |title=The "pick-a-back" train |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |volume=VI |issue=218 |pages=157–162 |issn=0005-0105 }}</ref>

Differences in gauge are also accommodated by [[variable gauge|gauge-adjustable wheelsets]], which {{As of|2022|lc=yes}} were installed under some passenger vehicles on international links between Spain and France, Sweden and Finland, Poland and Lithuania, and Poland and Ukraine. In Spain, change-over facilities are extensive, since although {{Track gauge|1668mm|comma=off}} track predominates, and high-speed lines are laid to {{Track gauge|1435mm|comma=off}} [[Standard-gauge railway|standard gauge]], there are many lines with narrower gauges ({{Track gauge|1000mm|comma=off}} [[Metre-gauge railway|metre gauge]] and others).<ref>{{cite book|url=https://www.vialibre-ffe.com/pdf/Track_gauge_changeover.pdf|title=Automatic track gauge changeover for trains in Spain|first=Alberto García|last=Álvarez|publisher=Fundación de los Ferrocarriles Españoles|edition=4|date=2010|isbn=978-84-89649-56-9|page=7}}</ref>

==Dual-gauge railways by nation==
{{More citations needed section|date=November 2022}}
;Australia{{anchor|Australia}}
In [[Victoria (Australia)|Victoria]], there are sections of {{Track gauge|1600mm|lk=on|comma=off}} and {{Track gauge|1435mm|lk=on|comma=off}} dual-gauge track between [[Southern Cross railway station|Southern Cross station]] and [[West Footscray railway station|West Footscray]], [[Sunshine railway station, Melbourne|Sunshine]] and [[Newport railway station, Melbourne|Newport]], [[Albion railway station, Melbourne|Albion]] and [[Jacana railway station|Jacana]], [[North Geelong railway station|North Geelong]] and [[Gheringhap, Victoria|Gheringhap]], [[Maryborough railway station, Victoria|Maryborough]] and [[Dunolly railway station|Dunolly]], and in various goods yards and industrial sidings. Until 2008, there was a dual-gauge line between [[Wodonga railway station|Wodonga]] and [[Bandiana railway station|Bandiana]].

At [[Albury railway station]], [[New South Wales]], a {{Track gauge|1600mm |comma=off}} and {{Track gauge|1435mm |comma=off}} dual-gauge line was in place until 2011. A dual-gauge line was within [[Tocumwal railway station]] until 1988, when the standard gauge component was put out of use.

In 1900, in [[South Australia]], a three-rail dual-gauge system was proposed in order to avoid a break of gauge. However, designing turnouts was considered to be difficult due to the difference of only {{convert|165|mm|in|abbr=off}} between the {{Track gauge|1435mm |comma=off}} and the {{Track gauge|1600mm |comma=off}}  broad gauge. After twenty years, the proposal was abandoned.<ref>{{cite news |url=http://nla.gov.au/nla.news-article45890361 |title=Personal. |newspaper=[[The Barrier Miner]] |location=Broken Hill, NSW |date=3 July 1924 |access-date=1 September 2012 |page=2 |publisher=National Library of Australia}}</ref><ref>{{cite news |url=http://nla.gov.au/nla.news-article3739201 |title=Great Western Railway. |newspaper=[[The Argus (Melbourne)|The Argus]] |location=Melbourne |date=11 March 1926 |access-date=27 August 2011 |page=7 |publisher=National Library of Australia}}</ref><ref>{{cite news |url=http://nla.gov.au/nla.news-article14617972 |title=Unification of gauges. |newspaper=[[The Sydney Morning Herald]] |date=6 May 1904 |access-date=10 March 2014 |page=5 |publisher=National Library of Australia}}</ref> Much later, the [[South Australian Railways]] successfully adopted [[Railroad switch#Dual gauge switches|dual-gauge turnouts]].<ref>[http://extranet.artc.com.au/docs/eng/track-civil/workinstruct/pc/ETN-03-01.pdf Civil track engineering] ARTC pdf.</ref>

In [[Western Australia]], {{Track gauge|1067mm|lk=on|comma=off}} and {{Track gauge|1435mm |comma=off}} of double-track dual-gauge extends for {{Convert|120|km|mi|abbr=on}} of the [[Eastern Railway (Western Australia)#Third Route|main line]] from [[East Perth railway station|East Perth]] to [[Northam railway station, Western Australia|Northam]]. Dual-gauge track is also used from the triangle at [[Woodbridge, Western Australia|Woodbridge]] to [[Cockburn, Western Australia|Cockburn Junction]], then to [[Kwinana Beach|Kwinana]] on one branch and [[North Fremantle]] on the other. The signalling system detects the gauge of the approaching train and puts the signals to stop if the route is set for the wrong gauge.

In [[Queensland]], there is a section of {{Track gauge|1067mm |comma=off}} and {{Track gauge|1435mm |comma=off}} dual-gauge track between the rail freight [[Classification yard|yards]] at [[Acacia Ridge]] and [[Park Road railway station|Park Road station]], which is utilised by both passenger and freight trains. Freight trains to the Port of Brisbane utilise the dual gauge [[Fisherman Islands railway line|Fisherman Islands line]] that runs parallel to the [[Cleveland railway line]] from Park Road to [[Lindum railway station|Lindum]]. Passenger trains use the dual-gauge section of the [[Beenleigh railway line]] running parallel to the electric suburban narrow gauge of the Queensland Rail city network over the [[Merivale Bridge]] into platforms 2 and 3 at [[Roma Street railway station|Roma Street Station]]. This is used by standard gauge interstate [[NSW TrainLink|New South Wales TrainLink]] [[New South Wales XPT|XPT]] services to [[Central railway station, Sydney|Sydney]]. In 2012, a dual-gauge line was installed between Acacia Ridge and [[Bromelton, Queensland|Bromelton]] to serve a new freight hub at Bromelton.

The {{convert|1700|km|mi|abbr=off|comma=off}} long [[Inland Railway]], under construction in 2022, will have about {{convert|300|km|mi|abbr=off|comma=off}} of dual gauge.

;Bangladesh
The [[Bangladesh Railway]] uses three rails to avoid breaks of gauge between its broad-gauge and metre-gauge lines. The [[Jamuna Bridge]] and [[Padma Bridge]], which link the east–west and north–south rail systems respectively, have [[#Dual gauge (four rails)|four-rail]] dual-gauge tracks. Of the {{convert|2875|km|mi}} Bangladesh Railway system, about {{convert|1600|km|mi}} has [[#Dual gauge (four rails)|four-rail]] dual-gauge.{{Citation needed|date=March 2023}}{{Dubious|date=March 2023}}

;Belgium
[[Trams in Brussels|Tram tracks in Brussels]] once combined {{Track gauge|1000mm|allk=on|comma=off}} lines for [[Vicinal tramway|inter-urban trams]] and {{Track gauge|1435mm |comma=off}} lines for urban trams in a three-rail layout. In 1991, the interurban trams went out of service and then the network used only standard-gauge track.

;Bulgaria
The [[Trams in Sofia|Sofia tramway]] uses a mixture of narrow and standard gauge. A {{cvt|2.6|km|mi}} section of track between Krasna polyana depot and Pirotska street is dual-gauge shared by {{Track gauge|1435mm |comma=off}} route 22 and {{Track gauge|1009mm|lk=on|comma=off }} route 11.

;Cameroon
The new port of [[Kribi]] may serve 1000mm gauge bauxite traffic as well as 1435mm gauge iron ore traffic.

;Czech Republic
In the [[Czech Republic]], there is 2&nbsp;km of dual gauge {{Track gauge|1435mm |comma=off}} and {{Track gauge|760mm }} track near [[Jindřichův Hradec]]. In 1985, its original four rails were converted to three rails. In 2004, in Jindřichův Hradec at a switch where a dual gauge railway bifurcates, a Junák express from [[Plzeň]] to [[Brno]] derailed due to a signalling error. The standard gauge train had been switched on to the narrow gauge track.

;France
The [[Chemin de Fer de la Baie de Somme]] in France is dual gauge between [[Noyelles-sur-Mer]] and [[Saint-Valery-sur-Somme]]. The line has four rails with metre gauge laid within standard gauge. There are some dual-gauge (standard and Iberian) sidings at Cerbère on the Spanish border.

;Germany
In the 1970s, the [[Stuttgarter Straßenbahnen]] tram lines underwent a gauge conversion from {{Track gauge|1000mm |comma=off}} gauge to standard gauge. This was part of an upgrade to the [[Stuttgart Stadtbahn]]. In 1981, {{Track gauge|1435mm |comma=off}} and {{Track gauge|1000mm |comma=off}} dual-gauge track was constructed so that new DT-8 Stadtbahn cars and old trams could share the network. In 2008, a further gauge conversion was completed. The Stuttgart Straßenbahn Museum operates {{Track gauge|1000mm |comma=off}} gauge trams on weekends and special occasions.

In [[Krefeld]] on Ostwall, tram lines are dual gauge so that standard {{Track gauge|1435mm |comma=off}} [[Rheinbahn]] U76 [[Stadtbahn]] cars and {{Track gauge|1000mm |comma=off}} gauge trams may share the lines. At the north end of the route, at the junction with Rheinstraße, the trams reverse. There, the standard gauge line ends, while the metre gauge lines continue. At the Hauptbahnhof, on Oppumer Straße, dual gauge track continues. At the ends of Oppumer Straße, the two tracks diverge.

In [[Mülheim]] there is a similar situation. The [[Trams in Duisburg|Duisburg tram line 901]] meets the [[Trams in Mülheim/Oberhausen|local line 102]]. The tram system in Duisburg uses {{Track gauge|1435mm |comma=off}} gauge track while the tram route from [[Witten]] to Mülheim uses {{Track gauge|1000mm |comma=off}} gauge tracks. Two lines share a tunnel section between the [[Mülheim (Ruhr) Hauptbahnhof]] and Schloss Broich then diverge at street level.

The tram network between [[Werne]] to [[Bad Honnef]] is large with various operators and gauges. The trams in [[Wuppertal]] used {{Track gauge|1435mm |comma=off}} gauge track on east{{ndash}}west lines and {{Track gauge|1000mm |comma=off}} gauge track on north{{ndash}}south lines. [[Trams in Duisburg]] used {{Track gauge|1435mm |comma=off}} gauge track on lines south of the [[Ruhr]] and {{Track gauge|1000mm |comma=off}} gauge tracks on lines north of the Ruhr. The north lines closed in the 1960s and 1970s. Duisburg's three routes were converted to {{Track gauge|1435mm |comma=off}} gauge track.

;Ghana
Ghana is converting its narrow gauge to standard gauge, and is installing dual-gauge sleepers as an intermediate stage.

;Greece
In Greece, the line between [[Athens]] and [[Elefsis]] (now closed) was dual gauge in order to allow the {{Track gauge|1000mm |comma=off}} gauge trains of the [[Peloponnese]] rail network to pass. It also allowed standard gauge trains to reach the Elefsis shipyards. In [[Volos]], a short section of track between the main station and the harbour used an unusual triple gauge, to accommodate standard gauge trains from [[Larissa]], metre gauge trains from [[Kalabaka|Kalambaka]], and the {{Track gauge|600mm |comma=off}} gauge trains of the [[Pelion railway]].

;Indonesia
In 1899, in the [[Dutch East Indies]], dual gauge track was installed between [[Yogyakarta (city)|Yogyakarta]] and [[Surakarta|Solo]]. The track was owned by the [[Nederlandsch-Indische Spoorweg Maatschappij]], a private company, which in 1867 had built the {{Track gauge|1435mm |comma=off}} gauge line. The third rail was installed to allow passengers and goods travelling over the {{Track gauge|1067mm|comma=off}}   gauge ''Staatsspoorweg'' (state railway) a direct connection. At a later date, the government constructed new tracks to allow greater capacity and higher speeds. In 1940, a third rail was installed between Solo and Gundih on the line to [[Semarang]], allowing {{Track gauge|1067mm|comma=off}} gauge trains to travel between Semarang, Solo and Yogyakarta via Gambringan, on the line to [[Surabaya]] instead of on the original line via Kedungjati.

In 1942 and 1943 in [[Java]], under [[Japan|Japanese military occupation]], conversion took place from {{Track gauge|ussg}} to {{Track gauge|1067mm |comma=off}} on the [[Rail transport in Indonesia|Brumbung]]{{ndash}}Kedungjati{{ndash}}Gundih main line and the Kedungjati{{ndash}}[[Ambarawa]] branch line.

Until the 1970s, a short section of dual gauge {{Track gauge|1067mm| comma=off}} and {{Track gauge|750mm}} line existed in [[North Sumatra]] on a joint line of the [[Deli Railway]] and the [[Atjeh Tram]].

Some sugar mill railways in [[Java (island)|Java]] have dual-gauge sections.

;Ireland
Ireland's [[Ulster Railway]] underwent a gauge conversion from 1880mm to the new Irish standard of {{Track gauge|1600mm|comma=off}}. The [[Dublin & Drogheda Railway]] underwent a gauge conversion because the gauges were too close to allow a dual-gauge line.

;Italy
The Potenza {{ndash}} Avigliano Lucania line in Italy is a dual gauge rail with {{Track gauge|1435mm |comma=off}} and {{Track gauge|950mm }} tracks.

;Japan
In Japan, the national standard is {{Track gauge|1067mm |comma=off}} narrow gauge. Dual gauge is used where the {{Track gauge|1435mm |comma=off}} [[Shinkansen]] (bullet train) lines join the main network. For example, part of the [[Ōu Main Line]] became part of the [[Akita Shinkansen]] and was converted to dual gauge in a limited section. The longest ({{convert|82.1|km|mi|abbr=on}}) dual gauge section in Japan is near, and in, the [[Seikan Tunnel]]. Sections of the [[Hakone Tozan Line]] are among a number of other dual-gauge lines.

;Mexico
[[Rail transport in Mexico|Mexico]] previously had {{Track gauge|1435mm|comma=off}} and {{Track gauge|914mm}} dual gauge track.

;Netherlands
The first railway lines in the [[Netherlands]] were constructed with a track gauge of {{Track gauge|1945mm|lk=on|comma=off}}. For the 1939 centennial celebration, an exact replica of the country's first locomotive [[De Arend (locomotive)|"De Arend"]] was built using the original blueprints. Since 1953, the locomotive is housed at the Dutch [[Railway Museum (Netherlands)|National Railway Museum]], where in recent years, a dual-gauge track has been constructed in the rail yard, allowing for the locomotive to drive back and forth on special occasions.<ref>{{cite web |url=https://www.spoorwegmuseum.nl/ontdek/nu-in-het-museum/arend-onder-stoom/ |title=Arend onder Stoom – Het Spoorwegmuseum |website=www.spoorwegmuseum.nl |url-status=dead |archive-url=https://web.archive.org/web/20200926190317/https://www.spoorwegmuseum.nl/ontdek/nu-in-het-museum/arend-onder-stoom/ |archive-date=2020-09-26}}</ref>

;Poland
In Poland, there is {{convert|3|km|mi|abbr=off|1}} of {{Track gauge|1435mm |comma=off}} and {{Track gauge|750mm}} dual-gauge track in the [[Greater Poland Voivodeship]], linking [[Pleszew]] with a nearby mainline station. It is served by narrow-gauge passenger trains and standard-gauge freight trains.

;Portugal
In Portugal there were sections of dual gauge railways <ref>{{cite thesis |last= Nunes Costa |first= Pedro |date= 2016|title= Via algaliada versus mudança de bitola dos eixos do material circulante |url= https://repositorio.ipl.pt/entities/publication/b2d7af6f-78cc-48bc-923f-5d855e17f438|trans-title= |work= |degree= Master|language= pt|location= Lisbon|publisher= Polytechnical University of Lisbon|access-date=}}</ref>

In [[Linha do Douro|Douro Line]] with [[Corgo Line]], between [[Régua railway station]] and Corgo bifurcation, over a length of 1,100 m. The Corgo Line is currently closed for operation. 

In [[Linha do Minho|Minho Line]] between  [[Trofa]] and [[Vila Nova de Famalicão Municipality|Famalicão]] the [[meter gauge]] [[Guimarães line]]  run inside the 1,668 m [[iberian gauge]] in an extension of 10 km. This section has been dismantled in 2004 with the regauging of Guimarães Line and duplication and electrification of the Minho line between [[Ermesinde]] and [[Braga]]. 

;Russia
Between 2008 and 2012, a {{convert|2|km|mi|abbr=on}} dual-gauge cross-border track was rebuilt between [[Khasan (urban-type settlement)|Khasan]], Russia, and [[Rajin-guyok|Rajin]], North Korea; its gauges were the Russian {{Track gauge|1520mm|lk=on|comma=off}} and Korean {{Track gauge|1435mm|comma=off}}.<ref>[http://eng.rzd.ru/newse/public/rzdeng?STRUCTURE_ID=15&layer_id=4839&id=105789 Russian Railways : Demonstration train makes run between Rajin and Khasan] RZD news</ref>
Similar arrangements exist on the approach to [[Kaliningrad]], where {{Track gauge|1435mm |comma=off}} track extends from the Polish border with some sections of dual gauge.

;Spain
In Spain, there is {{Convert|21.7|km|abbr=on}} of dual gauge in the [[AVE]] line from [[Zaragoza]] to [[Huesca]], usable for both {{Track gauge|1435mm |comma=off}} standard-gauge high-speed trains and {{Track gauge|1668mm|lk=on|comma=off}} Spanish network trains. Some dual-gauge  sidings are at Port Bou on the French border. In 2009, [[Administrador de Infraestructuras Ferroviarias|Adif]] called for tenders for the installation of a third rail for standard-gauge trains on the {{convert|22|km|abbr=on}} between [[Castellbisbal]] and the Can Tunis freight terminal in [[Barcelona]].<ref>{{cite news | url=http://www.railwaygazette.com/nc/news/single-view/view/world-infrastructure-market-march-2009.html | archive-url=https://archive.today/20130131232359/http://www.railwaygazette.com/nc/news/single-view/view/world-infrastructure-market-march-2009.html | url-status=dead | archive-date=31 January 2013 | title=World infrastructure market March 2009 | date=14 March 2009 | work=[[Railway Gazette International]] }}</ref>

;Sweden
The bridges at the borders of [[Rail transport in Sweden|Sweden]] and [[Rail transport in Finland|Finland]], between [[Haparanda]] and [[Tornio]] have {{convert|2|km|mi|abbr=on}} of dual gauge, {{Track gauge|1435mm |comma=off}} and {{Track gauge|1524mm |comma=off}} track. At each end of the dual-gauge section are yards with standard and Finnish gauge areas to allow for [[transshipment|trans-shipment]]. [[#Dual gauge (four rails)|Four rails]] are used because the gauges are close and the [[Structure gauge|bridge structure]] is wider than normal to allow for the offset from the centreline of each gauge. A Rafil [[variable gauge|gauge changer]] is at the Tornio yard. 
Between [[Västervik]] and [[:sv:Jenny, Västervik|Jenny]], Sweden, there is a {{Track gauge|891mm}} and {{Track gauge|1435mm |comma=off}} dual-gauge line and dual-gauge track in the Västervik station area.

;Switzerland
In Switzerland, dual-gauge {{Track gauge|1435mm |comma=off}} track and {{Track gauge|1000mm |comma=off}} track exists between [[Lucerne]] and [[Horw]] of the [[Zentralbahn]], between [[Niederbipp]] and [[Oberbipp]] of the [[Oberaargau-Jura Railways]] and between [[Chur]] and [[Domat/Ems]] of [[RhB]]. All three allow narrow-gauge passenger trains and standard-gauge freight trains to operate. A ″non-stop″ scheme (albeit with a pause to change locomotives) on the [[Montreux]]-[[Interlaken]] route was inaugurated in December 2022.<ref>{{cite magazine|last=Fender|first=Keith|title=Swiss introduce gauge-changing train on Montreaux Interlaken route|date=April 2023|magazine=[[Trains (magazine)|Trains]]|publisher=[[Kalmbach Media]]|pages=41–42}}</ref> The former [[Zollikofen]]-[[Worblaufen]]-[[Stettlen|Deisswil]] dual gauge was cut back to Papiermühle when the factory in Deisswil closed.{{when|date=November 2022}}

;Ukraine
The railway tracks between the border with [[Slovakia]] at [[Solomonovo]] and the border with [[Romania]] at [[Nevetlenfolu]] are dual-gauge, {{Track gauge|1520mm|lk=on|comma=off}} and {{Track gauge|1435mm|lk=on|comma=off}}. This is in part due to the Austro-Hungarian heritage of the [[Zakarpattia Oblast]], but also has military and political importance, as it allows standard-gauge trains to run between Romania and Slovakia by bypassing [[Hungary]], otherwise impossible due to the break-of -gauge between the Russian-gauge network of Ukraine and standard-gauge networks of Romania and Slovakia.

;United Kingdom
The [[Great Western Railway]] in Britain was originally built to a broad gauge of 2134&nbsp;mm (7&nbsp;ft 0 in), subsequently widened to 2140&nbsp;mm (7&nbsp;ft 0{{frac|1|2}} in). After a [[Great Western Railway#Brunel's 7-foot gauge and the "gauge war"|"gauge war"]], the gauge was [[track gauge conversion|converted]] to {{Track gauge|1435mm |comma=off}}. A dual-gauge system was easily installed as the gauges were well separated and the line had wooden [[railroad tie|sleepers]]. A short section of broad and standard gauge is at the [[Great Western Society]] site at [[Didcot]].

The port authority in [[Derry]], [[Northern Ireland]], used a dual-gauge line in a street-level network to transfer freight. Two of the city's stations were on a narrow {{Track gauge|914mm|lk=on|comma=off}} gauge. The other two city stations were on broad {{Track gauge|1600mm|lk=on|comma=off}} gauge.

The [[Fairbourne Railway]] in [[Gwynedd]], [[Wales]], has a section of dual gauge track from Fairbourne station to Car Park crossing installed in the late 2010s to allow visiting {{Track gauge|15in|lk=on}} gauge trains to run on part of the line, which was converted to {{Track gauge|12.25in|lk=on}} gauge in 1986, usually as part of special events.
;United States
In Los Angeles, the {{Track gauge|1067mm|lk=on|comma=off}} [[Los Angeles Railway]] and {{Track gauge|1435mm |comma=off}} [[Pacific Electric Railway]] ran on dual gauge track on some [[Downtown Los Angeles|downtown]] streets.{{when|date=November 2022}}

From 1880 to 1902, the [[Burlington, Cedar Rapids and Northern Railway]] (standard gauge) and the [[Burlington and Northwestern Railway]] (narrow gauge) shared a dual-gauge mainline from [[Burlington, Iowa]], to [[Mediapolis, Iowa|Mediapolis]], {{convert|23|km|mi|abbr=off}} to the north.

The early operational years of the [[State Belt Railroad]] in [[San Francisco]] featured dual-gauge tracks to accommodate regional railroads of the time, which [[Ferries of San Francisco Bay|interchanged via ferry]].

Until 1941, the [[Colorado and Southern Railway]] used both standard-gauge and narrow-gauge tracks, and had a dual-gauge line between [[Denver]] and [[Golden, Colorado]].

Until the 1960s, the [[Denver and Rio Grande Western Railroad]]'s [[Alamosa–Durango Line]] from [[Alamosa, Colorado]], to [[Antonito, Colorado|Antonito]] was dual-gauge ({{Track gauge|914mm }} and {{Track gauge|1435mm |comma=off}}).

Previously, in its yard at [[Mount Union, Pennsylvania]], the [[East Broad Top Railroad and Coal Company]] used dual-gauge tracks.

;Vietnam
In Vietnam, near the border with China, there is {{Track gauge|1000mm |comma=off}} and {{Track gauge|1435mm |comma=off}} dual-gauge track between [[Hanoi]] and [[Đồng Đăng]]. Other smaller dual-gauge sections exist elsewhere in the north-east of the country.<ref>[http://www.vr.com.vn/english/hientaihoatdong.html The length of Vietnam railway network] {{webarchive |url=https://web.archive.org/web/20060910185049/http://www.vr.com.vn/english/hientaihoatdong.html |date=September 10, 2006 }}</ref>

==See also==
{{Portal|Trains}}

{{div col|colwidth=22em}}
* [[Glossary of rail transport terms]]
* [[History of rail transport]]
* [[Rail transport]]
* [[Rail transport by country]]
* [[Tamping machine#Tamping and track layouts|Tamping machine]]
* [[Track gauge conversion]]

{{div col end}}

==Notes==
{{Reflist|group=note}}
 
===Notes to gallery photos===
{{notelist-la}}

==References==
{{ Reflist}}

==Further reading==
* {{cite book |last=Fairlie |first=Robert F. |date=1872 |title=Railways or no railways: narrow gauge v broad gauge |publisher=Effingham Wilson |location=Royal Exchange, London}}
* {{cite book |last=Tratman |first=E.E. Russell |date=1908 |url= https://archive.org/details/railwaytracktrac01trat/page/n9/mode/2up |title=Railway track and track work |publisher=The Engineering News Publishing Co. |edition=3rd |location=New York|access-date=8 November 2022}}

==External links==
* [https://inlandrail.com.au/what-is-dual-gauge-track/ Interactive 3D model of dual-gauge track]
* [https://web.archive.org/web/20061205185702/http://jwr.janes.com/public/jwr/index.shtml Jane's World Railways] (hard copy)
* [http://www.columbusrailroads.com/track%20gauge.htm Dual-gauge streetcar track]
* [http://nla.gov.au/nla.news-article100575593 Diagram of mixed gauge turnouts]<ref>{{cite news |url=http://nla.gov.au/nla.news-article100575593 |title=Diagram of mixed gauge turnouts |newspaper=The Globe and Sunday Times War Pictorial |issue=272 |location=New South Wales, Australia |date=17 June 1916 |page=19 |via=National Library of Australia}}</ref>

{{Navbox track gauge}}
{{Rail tracks}}
{{Authority control}}

{{DEFAULTSORT:Dual Gauge}}
[[Category:Dual gauge railways| ]]

[[de:Gleis#Mehrschienengleise]]