View source for Loading gauge

{{Short description|Maximum dimensions for railway vehicles and their loads}}
{{Use dmy dates|date=January 2020}}
{{train topics}}

[[File:Why London Underground is nicknamed The Tube.jpg|thumb|right|The [[Engineering tolerance|clearance space]] between a train and the tunnel is often small. Pictured is a [[London Underground]] [[Northern line]] [[London Underground 1995 Stock|1995 Stock]] train emerging from the tunnel north of [[Hendon Central tube station|Hendon Central station]].]]

A '''loading gauge''' is a diagram or physical structure that defines the maximum height and width of [[rail transport|railway]] [[rolling stock|vehicles]] and their loads. The loading gauge is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and other structures.<ref>{{Cite web |work= NetworkRail.co uk |url= http://www.networkrail.co.uk/aspx/2232.aspx |title= Glossary |publisher= Network Rail |access-date= 15 May 2009 |url-status=live |archive-url= https://web.archive.org/web/20090506214752/http://www.networkrail.co.uk/aspx/2232.aspx |archive-date=6 May 2009 }}</ref> Classification systems vary between different countries, and loading gauges may vary across a network, even if the [[track gauge]] is uniform.

The term loading gauge can also be applied to the maximum size of road [[vehicle]]s in relation to [[tunnel]]s, [[overpass]]es and [[bridge]]s, and [[garage door|doors]] into [[automobile repair shop]]s, [[bus garage]]s, [[filling station]]s, [[Garage (residential)|residential garages]], [[multi-storey car park]]s and [[warehouse]]s.

A related but separate gauge is the [[structure gauge]], which sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. The difference between these two gauges is called the [[Engineering tolerance#Clearance (civil engineering)|clearance]]. The specified amount of clearance makes allowance for the [[envelope (motion)|oscillation]] of rail vehicles at speed.

==Overview==
[[File:At Eastcote tube station 2023 03.jpg|thumb|The [[London Underground]] utilises differing loading gauges: a [[Metropolitan line]] [[S Stock]] sub-surface train ''(left)'' passes a [[Piccadilly line]] [[London Underground 1973 Stock|1973 Stock]] tube train ''(right)''.]]
The loading gauge governs the size of passenger carriages, goods wagons (freight cars) and [[intermodal container|shipping containers]] that can travel on the relevant section of railway track. It varies between rail systems around the world and can even vary within a single railway system.

Over time, there has been a trend towards less restrictive loading gauges and greater standardization of them. Some older systems and lines have had their [[structure gauge]]s expanded by raising bridges, increasing the height and width of tunnels and making other necessary alterations. [[Containerisation]], and a trend towards larger [[intermodal container|shipping containers]], has led rail operators to increase loading and structure gauges to compete with road haulage.

The term "loading gauge" can also refer to a physical structure, sometimes using electronic detectors using [[electric eye|light beams]] on an arm or gantry placed over the exit lines of goods yards or at the entry point to a restricted part of a network. The devices ensure that loads stacked on open or flat wagons stay within the height/shape limits of the line's bridges and tunnels, and prevent out-of-gauge rolling stock entering a stretch of line with a smaller loading gauge. Compliance with a loading gauge can be checked using a [[clearance car]]. In the past, they were simple wooden frames or physical feelers mounted on rolling stock. More recently, [[laser]] beams have been used.

The loading gauge is the maximum size of rolling stock. It is distinct from the [[structure gauge|minimum structure gauge]], which sets limits to the size of bridges and tunnels on a rail line, allowing for [[engineering tolerance]]s and the motion of rail vehicles. The difference between the two is called the [[engineering tolerance|clearance]]. The terms "dynamic [[envelope (motion)|envelope]]" or "kinematic envelope", which include factors such as suspension travel, overhang on curves (at both ends and middle) and lateral motion on the track, are sometimes used in place of loading gauge.{{Citation needed|date=May 2009}}

[[Railway platform height]] is also a consideration for the loading gauge of passenger trains. Where the two are not directly compatible, stairs may be required, which will increase [[dwell time (transportation)|loading times]]. Where long carriages are used at a curved platform, there will be [[platform gap|gaps between the platform and the carriage door]], causing risk. Problems increase where trains of several different loading gauges and vehicle floor heights use (or even must pass through) the same platform.

The size of load that can be carried on a railway of a particular gauge is also influenced by the design of the rolling stock. Low-deck rolling stock can sometimes be used to carry taller {{convert|9|ft|6|in|m|1|abbr=on}} shipping containers on lower gauge lines although their low-deck rolling stock cannot then carry as many containers.

[[Rapid transit]] (metro) railways generally have a smaller loading gauge, which reduces the cost of tunnel construction. Those systems have to use their own specialised rolling stock.

=== Out of gauge ===
Larger ''out-of-gauge'' loads can also sometimes be conveyed by taking one or more of the following measures:
* Operate at low speed, especially in places with limited clearance, such as platforms.
* Cross over from a track with inadequate clearance to another track with greater clearance, even if there is no signalling to allow this.
* Prevent operation of other trains on adjacent tracks.
* Use refuge loops to allow trains to operate on other tracks.
* Use of [[Schnabel car]]s (special rolling stock) that manipulate the load up and down or left and right to clear obstacles.
* Remove (and later replace) obstacles.
* Use [[gauntlet track]] to shift the train to side or center.
* For locomotives that are too heavy, ensure that fuel tanks are nearly empty.
* Turn off power in overhead wiring or in the third rail (use diesel locomotive)
* Permanently adapt a certain route to larger gauge if there is repeated need for such trains.

==History==
The loading gauge on the main lines of Great Britain, most of which were built before 1900, is generally smaller than in other countries. In mainland Europe, the slightly larger [[Berne gauge]] (Gabarit passe-partout international, PPI) was agreed to in 1913 and came into force in 1914.<ref>{{cite web|url=http://www.crowsnest.co.uk/gauge.htm|title=European Loading Gauges|website=www.crowsnest.co.uk|url-status=live|archive-url=https://web.archive.org/web/20100213091359/http://www.crowsnest.co.uk/gauge.htm|archive-date=13 February 2010}}</ref><ref>{{cite web
  |author=Douglas Self 
  |author-link=Douglas Self 
  |url=http://www.douglas-self.com/MUSEUM/LOCOLOCO/loadgauge/loadgauge.htm|title=A Word on Loading Gauges
  |url-status=live|archive-url=https://web.archive.org/web/20160303201424/http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/loadgauge/loadgauge.htm|archive-date=3 March 2016}}</ref> As a result, British trains have noticeably and considerably smaller loading gauges and, for passenger trains, smaller interiors, despite the track being [[standard gauge]], which is in line with much of the world.

This often results in increased costs for purchasing new trainsets or locomotives as they must be specifically designed for the existing British network, rather than being purchased "off-the-shelf". For example, the new trains for [[HS2]] have a 50% premium applied to the "classic compatible" sets that will be "compatible" with the current (or "classic") rail network loading gauge as well as the HS2 line. The "classic compatible" trainsets will cost £40{{nbsp}}million per trainset whereas the HS2-only stock (built to European loading gauge and only suitable to operate on HS2 lines) will cost £27M per trainset despite the HS2-only stock being physically larger.<ref>{{cite web |url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69741/hs2-cost-and-risk-model-report.pdf |page=15 |title=HS2 Cost and Risk Model Report |url-status=live |archive-url=https://web.archive.org/web/20131020074728/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69741/hs2-cost-and-risk-model-report.pdf |archive-date=20 October 2013 }}</ref>

It was recognized even during the nineteenth century that this would pose problems and countries whose railroads had been built or upgraded to a more generous loading gauge pressed for neighboring countries to upgrade their own standards. This was particularly true in continental Europe where the Nordic countries and Germany with their relatively generous loading gauge wanted their cars and locomotives to be able to run throughout the [[Standard-gauge railway|standard gauge]] network without being limited to a small size. France, which at the time had the most restrictive loading gauge ultimately compromised giving rise to [[Berne gauge]] which came into effect just before World War I.

[[Military railways]] were often built to particularly high standards, especially after the [[American Civil War]] and the [[Franco-Prussian War]] showed the importance of railroads in [[military deployment]] as well as [[mobilization]]. The [[German Empire]] was particularly active in the construction of military railways which were often built with great expense to be as flat, straight and permissive in loading gauge as possible while bypassing major urban areas, making those lines of little use to civilian traffic, particularly civilian passenger traffic. However, all those aforementioned factors have in some cases led to the subsequent abandoning of those railroads.

==Standard loading gauges for standard track gauge lines==

===International Union of Railways (UIC) Gauge===
[[File:Railway Loading gauge UIC and containers profile -ISO.png|thumb|UIC loading gauges]]
The [[International Union of Railways]] (UIC) has developed a standard series of loading gauges named A, B, B+ and C.
* PPI – the predecessor of the UIC gauges had the maximum dimensions {{convert|3.15|by|4.28|m|ftin|abbr=on}} with an almost round roof top.
* UIC A: The smallest (slightly larger than PPI gauge).<ref name=crow>{{Cite web|url=http://www.crowsnest.co.uk/gauge.htm|title=European Loading Gauges|publisher=Modern Railways|date=April 1992|url-status=live|archive-url=https://web.archive.org/web/20100213091359/http://www.crowsnest.co.uk/gauge.htm|archive-date=13 February 2010}} Images do not load</ref> Maximum dimensions {{convert|3.15|by|4.32|m|ftin|abbr=on}}.<ref name=UICgauge/>
* UIC B: Slightly larger than the UIC on the roof level.<ref name=crow/> Maximum dimensions {{convert|3.15|by|4.32|m|ftin|abbr=on}}.<ref name=UICgauge>{{cite journal
 |url=http://www.rgsonline.co.uk/Railway_Group_Standards/Infrastructure/Guidance%20Notes/GEGN8573%20Iss%203.pdf
 |page=20
 |publisher=[[Rail Safety and Standards Board]]
 |title=GE/GN8573 Guidance on Gauging, Issue 3
 |date=October 2009
 |location=London
 |access-date=2 July 2013
 |url-status=dead
 |archive-url=https://web.archive.org/web/20120907121105/http://www.rgsonline.co.uk/Railway_Group_Standards/Infrastructure/Guidance%20Notes/GEGN8573%20Iss%203.pdf
 |archive-date=7 September 2012
}}</ref>
* UIC B+: New structures in France are being built to UIC B+.<ref name=crow/> Up to {{convert|4.28|m|ftin|abbr=on}} has a shape to accommodate tractor-trailers loaded with [[ISO 668|ISO container]]s.
* UIC C: The Central European gauge. In Germany and other central European countries, the railway systems are built to UIC C gauges, sometimes with an increment in the width, allowing Scandinavian trains to reach German stations directly, originally built for Soviet freight cars. Maximum dimensions {{convert|3.15|by|4.65|m|ftin|abbr=on}}.<ref name=UICgauge/>
<!--GB+ means Garbarit B+, so it's the same as above // * UIC GB+: Is being used for some new European routes, including the [[Channel tunnel]].<ref name=DfTlong>{{cite web|url=http://www.dft.gov.uk/pgr/rail/strategyfinance/strategy/freightnetwork/|title=Strategic Freight Network: The Longer-Term Vision|publisher=Department for Transport|access-date=17 May 2009}}</ref>-->

===Europe===

====European standards====
[[File:Lademass EBO.png|thumb|Railway clearance G1 and G2 (Germany)]]
In the [[European Union]], the UIC directives were supplanted by [[ERA Technical Specifications for Interoperability]] (TSI) of European Union in 2002, which has defined a number of recommendations to harmonize the train systems. The TSI Rolling Stock (2002/735/EC) has taken over the UIC Gauges definitions defining Kinematic Gauges with a reference profile such that Gauges GA and GB have a height of {{convert|4.35|m|ftin|abbr=on}} (they differ in shape) with Gauge GC rising to {{convert|4.70|m|ftin|abbr=on}} allowing for a width of {{convert|3.08|m|ftin|abbr=on}} of the flat roof.<ref>{{Cite web|url=http://data.europa.eu/eli/dec/2002/735/oj/eng|archive-url=https://web.archive.org/web/20151019001730/http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32002D0735|url-status=dead|title=EUR-Lex - 32002D0735 - EN - EUR-Lex|archive-date=19 October 2015}}</ref> All cars must fall within an envelope of {{convert|3.15|m|ftin|abbr=on}} wide on a {{convert|250|m|ch ft|sigfig=3|lk=on|abbr=on}} radius curve. The [[TGV]]s, which are {{convert|2.9|m|ftin|abbr=on}} wide, fall within this limit.

The designation of a GB+ loading gauge refers to the plan to create a pan-European freight network for [[Intermodal container|ISO containers]] and trailers with loaded ISO containers. These container trains (''[[Piggyback (transportation)#Rail|piggy-back]] trains'') fit into the B envelope with a flat top so that only minor changes are required for the widespread structures built to loading gauge B on continental Europe. A few structures on the British Isles were extended to fit with GB+ as well, where the first lines to be rebuilt start at the [[Channel Tunnel]].<ref name=MS>{{Cite web |url=http://myweb.tiscali.co.uk/gansg/2-track/02track3.htm |title=Track Gauge & Loading Gauge |author=Mike Smith |year=2003 |url-status=dead |archive-url=https://web.archive.org/web/20090812052709/http://myweb.tiscali.co.uk/gansg/2-track/02track3.htm |archive-date=12 August 2009 |access-date=18 May 2009 }}</ref>

Owing to their historical legacies, many member states' railways do not conform to the TSI specification. For example, [[#Great Britain|Britain]]'s role at the forefront of railway development in the 19th century has condemned it to the small [[Structure gauge|infrastructure dimensions]] of that era. Conversely, the {{nobold|loading gauge}}s of countries that were satellites of the former Soviet Union are much larger than the TSI specification. Other than for GB+, they are not likely to be retrofitted, given the enormous cost and disruption that would be entailed.{{Citation needed|date=May 2022}}

{| class="wikitable"
! colspan="2" | Loading gauge
! colspan="2" | Static reference profile
! colspan="2" | Kinematic reference profile
! rowspan="2" | Comments
|-
! UIC and/or TSI<ref name='note506'>{{Cite web|url=http://www.uic.org/etf/codex/codex-detail.php?langue_fiche=E&codeFiche=506|title=Leaflet 506 – Rules governing application of the enlarged GA, GB, GB1, GB2, GC and GI3 gauges|access-date=27 May 2009|url-status=dead|archive-url=https://web.archive.org/web/20111007123000/http://www.uic.org/etf/codex/codex-detail.php?langue_fiche=E&codeFiche=506|archive-date=7 October 2011}}</ref><ref>{{Cite web | url = http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:02006D0861-20130124 | title = TSI CR WAG; 02006D0861-20130124; Annex C: Track interaction and gauging | access-date = 7 October 2015 | author = EUR-Lex | date = 28 July 2006| url-status = live | archive-url = https://web.archive.org/web/20151019001730/http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:02006D0861-20130124 | archive-date = 19 October 2015}}</ref>
! [[International Wagon Regulations|RIV]]<ref>{{Cite web | url = http://www.rail.dbschenker.de/rail-deutschland-de/products_services/additional_services/ladungssicherung/loading_guidelines_of_ss/loading_guidelines.html | title = Verladerichtlinien der DB Schenker Rail AG (UIC – Verladerichtlinien); Tafel 1 Sammlung der Lademasse | access-date = 6 October 2015 | date = 1 July 2014 | language = de | url-status = live | archive-url = https://web.archive.org/web/20151019001730/http://www.rail.dbschenker.de/rail-deutschland-de/products_services/additional_services/ladungssicherung/loading_guidelines_of_ss/loading_guidelines.html | archive-date = 19 October 2015}}</ref>
! Width
! Height
! Width
! Height
|-
| G1 / UIC&nbsp;505-1 || T&nbsp;1<sub>1</sub>
| rowspan="6" align="center" | 3.150&nbsp;m || align="center" | 4.280&nbsp;m || rowspan="8" align="center" | 3.290&nbsp;m || align="center" | 4.310&nbsp;m
| Static profile also known as [[Berne gauge]], PPI or OSJD&nbsp;03-WM.
|-
| GA || T&nbsp;1<sub>2</sub>
| rowspan="4" align="center" | 4.320&nbsp;m || rowspan="4" align="center" | 4.350&nbsp;m
|
|-
| GB || T 1<sub>3</sub>
|
|-
| GB1 / GB+<ref>{{Cite web | url = http://www.gir-maralpin.org/TransptsDeplacemts/FerTransptCombine2S.pdf | title = Transport combiné et infrastructures ferroviaires; Compléments 1 – Terminologie – Chargements – Gabarits – Institutions | access-date = 29 September 2015 | author = Jacques Molinari | date = April 1999 | language = fr | url-status = dead | archive-url = https://web.archive.org/web/20160306163748/http://www.gir-maralpin.org/TransptsDeplacemts/FerTransptCombine2S.pdf | archive-date = 6 March 2016 }}</ref> ||
|
|-
| GB2 ||
|
|-
| G2 || T&nbsp;1<sub>4</sub>
| align="center" | 4.650&nbsp;m || rowspan="2" align="center" | 4.680&nbsp;m
| Formerly UIC&nbsp;C; Static profile also known as OSJD&nbsp;02-WM.
|-
| DE3 ||
| colspan="2" align="center" | not defined
| Expansion for G2, part of [[Trans-European Rail network|TEN-T]] regulations.
|-
| GC ||
| align="center" | 3.150&nbsp;m || align="center" | 4.650&nbsp;m || align="center" | 4.700&nbsp;m
| Formerly UIC&nbsp;C1.
|-
| SE-A ||
| align="center" | 3.400&nbsp;m || align="center" | 4.650&nbsp;m || align="center" | 3.600&nbsp;m || align="center" | 4.790&nbsp;m
|-
| SE-C ||
| align="center" | 3.600&nbsp;m || align="center" | 4.830&nbsp;m || align="center" | 3.960&nbsp;m || align="center" | 4.990&nbsp;m
| High-capacity rail corridor standard for  [[Øresund Bridge]] and [[Fehmarn Belt Tunnel]]<ref>{{cite journal |last1=Boysen |first1=Hans E. |title=Øresund and Fehmarnbelt high-capacity rail corridor standards updated |journal=Journal of Rail Transport Planning & Management |date=December 2014 |volume=4 |issue=3 |pages=44–58 |doi=10.1016/j.jrtpm.2014.09.001 |doi-access=free }}</ref>
|}

====Double-decker carriages====
[[File:IC2000 Zürich - Luzern.jpg|thumb|Zürich – Lucerne [[IC 2000]] double-decker Intercity train]]
[[File:TGVDuplex Centre.JPG|thumb|Double-decker carriage as used on French [[TGV]] railways]]
A specific example of the value of these loading gauges is that they permit [[Bilevel rail car|double decker]] passenger carriages. Although mainly used for suburban commuter lines, France is notable for using them on its high speed TGV services: the [[SNCF]] [[TGV Duplex]] carriages are {{convert|4303|mm|ftin|frac=8}} high,<ref>{{cite conference
| title = Rollmaterial
| first = Matthias
| last = Handschin
| date = 2003-09-22
| conference = BTS Bahn Technik - Seminar 2003
| conference-url =
| institution = SBB
| location = Bern
| pages = 51–52
| language = German
| trans-title = rolling stock 
}}</ref> the Netherlands, Belgium and Switzerland feature large numbers of double decker intercity trains as well. In Germany the [[Bombardier Twindexx]] was introduced in InterCity service in December 2015.

====Great Britain====
Great Britain has (in general) the most restrictive loading gauge (relative to track gauge) in the world. That is a legacy of the British railway network being the world's oldest, and of having been built by a large number of different private companies, each with different standards for the width and height of trains. After nationalisation, a standard static gauge W5 was defined in 1951 that would virtually fit everywhere in the network. The W6 gauge is a refinement of W5, and the W6a changed the lower body to accommodate third-rail electrification. While the upper body is rounded for W6a with a static curve, there is an additional small rectangular notch for W7 to accommodate the transport of {{convert|2.44|m|ftin|abbr=on}} ISO containers, and the W8 loading gauge has an even larger notch spanning outside of the curve to accommodate the transport of {{convert|2.6|m|ftin|abbr=on}} ISO containers. While W5 to W9 are based on a rounded roof structure, those for W10 to W12 define a flat line at the top and, instead of a strict static gauge for the wagons, their sizes are derived from dynamic gauge computations for rectangular freight containers.<ref name="britishgauging">{{cite web|url=http://www.rssb.co.uk/Library/groups-and-committees/2013-guide-vehicle-structure-sic-guide-to-british-gauging-t926.pdf|publisher=[[Rail Safety and Standards Board]] (RSSB)|date=January 2013|access-date=3 August 2015|url-status=dead|archive-url=https://web.archive.org/web/20151019001730/http://www.rssb.co.uk/Library/groups-and-committees/2013-guide-vehicle-structure-sic-guide-to-british-gauging-t926.pdf|archive-date=19 October 2015|title=Gauging - The V/S SIC Guide to British gauging practice}}</ref>

[[Network Rail]] uses a ''W'' loading gauge classification system of freight transport ranging from W6A (smallest) through W7, W8, W9, W9Plus, W10, W11 to W12 (largest). The definitions assume a common "lower sector structure gauge" with a common freight platform at {{convert|1100|mm|in|2|abbr=on}} above rail.<ref>{{cite web|url=http://www.rssb.co.uk/SiteCollectionDocuments/pdf/reports/research/T727_rpt_final_part3.pdf|title=Freight Opportunities Stage 2 Part 3 – Available Space Assessment – ISO Container Routes|at=7481- LR- 009 issue 1|publisher=Rail and Safety Standards Board|date=September 2007|quote=(2 Definitions)'W' Gauge. A set of static gauges that defines the physical size of freight vehicles. [...] (3 Methodology) It was assumed that the container / wagon combinations under consideration already conform to the dimensions set out in the lower sector structure gauge. Therefore, only structural clearances above {{convert|1100|mm|in|2|abbr=on}} above rail level were assessed.|url-status=dead|archive-url=https://web.archive.org/web/20110927012222/http://www.rssb.co.uk/SiteCollectionDocuments/pdf/reports/research/T727_rpt_final_part3.pdf|archive-date=27 September 2011}}</ref>

In addition, gauge C1 provides a specification for standard coach stock, gauge C3 for longer [[British Rail Mark 3|Mark 3]] coaching stock, gauge C4 for [[British Rail Class 390|Pendolino]] stock<ref>{{Cite web|url=https://www.rssb.co.uk/Library/groups-and-committees/2013-guide-vehicle-structure-sic-guide-to-british-gauging-t926.pdf|title=The V/S SIC Guide to British gauging practice|access-date=19 February 2018|publisher=Rail and Safety Standards Board|date=January 2013|quote=Mark 3 coaches are labeled C3 restriction and Class (Pendolino) trains are labeled C4. These do not refer to any standard gauge.|url-status=dead|archive-url=https://web.archive.org/web/20161019113126/http://www.rssb.co.uk/Library/groups-and-committees/2013-guide-vehicle-structure-sic-guide-to-british-gauging-t926.pdf|archive-date=19 October 2016}}</ref> and gauge UK1 for high-speed rail. There is also a gauge for locomotives. The size of container that can be conveyed depends both upon the size of the load that can be conveyed and the design of the rolling stock.<ref>{{Cite web|url=http://www.rgsonline.co.uk/Railway_Group_Standards/Infrastructure/Guidance%20Notes/GEGN8573%20Iss%202.pdf|title=GE/GN8573|access-date=15 May 2009|url-status=dead|archive-url=https://web.archive.org/web/20110929163219/http://www.rgsonline.co.uk/Railway_Group_Standards/Infrastructure/Guidance%20Notes/GEGN8573%20Iss%202.pdf|archive-date=29 September 2011}}</ref>

* W6A: Available over the majority of the British rail network.<ref>{{Cite web|url=http://www.networkrail.co.uk/documents/3150_2004BusinessPlanNetworkCapability.pdf|title=Business Plan 2004 – Network Capability|publisher=Network Rail|access-date=15 May 2009|url-status=dead|archive-url=https://web.archive.org/web/20120929221932/http://www.networkrail.co.uk/documents/3150_2004BusinessPlanNetworkCapability.pdf|archive-date=29 September 2012}}</ref>
* W8: Allows standard {{convert|2.6|m|ftin|abbr=on}} high [[shipping container]]s to be carried on standard wagons.<ref name=Felix>{{Cite web|url=http://www.dft.gov.uk/pgr/shippingports/ports/ir/felixstowesouth/felixstowesouthreconfigurati4953?page=34|title=Felixstowe South reconfiguration inspector's report, Strategic Rail Authority submission|publisher=Department for Transport|access-date=21 July 2017|url-status=bot: unknown|archive-url=http://webarchive.nationalarchives.gov.uk/20100210092126/http://www.dft.gov.uk/pgr/shippingports/ports/ir/felixstowesouth/felixstowesouthreconfigurati4953?page=34|archive-date=10 February 2010}}</ref>
* W9: Allows {{convert|2.9|m|ftin|abbr=on}} high [[Intermodal container|''Hi-Cube'']] shipping containers to be carried on "[[Megafret]]"<ref>{{cite web|url=http://www.ersrail.com/files/file/SFFGGMRRSS-ME-PB.pdf|title=Megafret|website=ersrail.com|url-status=dead|archive-url=https://web.archive.org/web/20150705172157/http://www.ersrail.com/files/file/SFFGGMRRSS-ME-PB.pdf|archive-date=5 July 2015|access-date=22 November 2012}}</ref> wagons that have lower deck height with reduced capacity.<ref name=Felix/> At {{convert|2.6|m|ftin|abbr=on}} wide, it allows for {{convert|2.5|m|ftin|abbr=on}} wide ''Euro'' shipping containers,<ref name=For>{{Cite web|url=http://www.freightonrail.org.uk/HotTopicsTenProposedEnhancementsScotland.htm|title=TEN PROPOSED ENHANCEMENT SCHEMES IN SCOTLAND|publisher=Freight on rail|access-date=17 May 2009|url-status=dead|archive-url=https://web.archive.org/web/20081118194205/http://www.freightonrail.org.uk/HotTopicsTenProposedEnhancementsScotland.htm|archive-date=18 November 2008}}</ref> which are designed to carry Euro-[[pallet]]s efficiently<ref name=MS/><ref>{{Cite web|url=http://www.containercontainer.com/about_containers.aspx|title=Standard Shipping Containers|publisher=Container container|access-date=18 May 2009|url-status=live|archive-url=https://web.archive.org/web/20090707132234/http://www.containercontainer.com/about_containers.aspx|archive-date=7 July 2009}}</ref>
* W10: Allows {{convert|2.9|m|ftin|abbr=on}} high ''Hi-Cube'' shipping containers to be carried on standard wagons<ref name=Felix/> and also allows {{convert|2.5|m|ftin|abbr=on}} wide ''Euro'' shipping containers.<ref name=For/> Larger than UIC A.<ref name=MS/>
* W11: Little used but larger than UIC B.{{Citation needed|date=November 2021}}
* W12: Slightly wider than W10 at {{convert|2.6|m|ftin|abbr=on}} to accommodate refrigerated containers.<ref>{{Cite web|url=http://www.central-railway.co.uk/resources/cr_FreightConsultation2006.pdf|title=24 November 2006 Freight RUS Consultation Response National RUS|publisher=Central Railways|access-date=17 May 2009|url-status=dead|archive-url=https://web.archive.org/web/20080807135513/http://www.central-railway.co.uk/resources/cr_FreightConsultation2006.pdf|archive-date=7 August 2008}}</ref> Recommended clearance for new structures, such as bridges and tunnels.<ref name=RUS>{{Cite web|url=http://www.networkrail.co.uk/browse%20documents/rus%20documents/route%20utilisation%20strategies/freight/freight%20rus.pdf|title=Freight RUS|url-status=dead|archive-url=https://web.archive.org/web/20120302212305/http://www.networkrail.co.uk/browse%20documents/rus%20documents/route%20utilisation%20strategies/freight/freight%20rus.pdf|archive-date=2 March 2012|access-date=16 May 2009}}</ref>
* UIC GC: [[Channel Tunnel]] and [[Channel Tunnel Rail Link]] to London; with proposals to upgrade the [[Midland Main Line]] northwards from London to GB+ standards.<ref name=DfTlong>{{Cite web|url=http://www.dft.gov.uk/pgr/rail/strategyfinance/strategy/freightnetwork/|title=Strategic Freight Network: The Longer-Term Vision|publisher=Department for Transport|access-date=17 May 2009 |url-status=dead |archive-url=http://webarchive.nationalarchives.gov.uk/20110504024713/http://www.dft.gov.uk/pgr/rail/strategyfinance/strategy/freightnetwork/ |archive-date=4 May 2011 }}</ref>

A strategy was adopted in 2004 to guide enhancements of loading gauges<ref>{{Cite web|url=http://www.dft.gov.uk/press/releases/sra/2004/2004b/ragaugingpolicyaimstomak1394.pdf|archive-url=https://web.archive.org/web/20090512055126/http://www.dft.gov.uk/press/releases/sra/2004/2004b/ragaugingpolicyaimstomak1394.pdf|url-status=dead|archive-date=12 May 2009|title=New SRA Gauging Policy Aims to Make Best Use of Network Capability|publisher=Department for Transport|access-date=15 May 2009}}</ref> and in 2007 the [[freight route utilisation strategy]] was published. That identified a number of key routes where the loading gauge should be cleared to W10 standard and, where structures are being renewed, that W12 is the preferred standard.<ref name="RUS" />

Height and width of containers that can be carried on GB gauges (height by width). Units as per source material.
* W9: {{convert|9|ft|0|in|m|abbr=on}} by {{convert|2.6|m|ftin|abbr=on|order=flip}}
* W10: {{convert|9|ft|6|in|m|abbr=on}} by {{convert|2.5|m|ftin|abbr=on|order=flip}}
* W11: {{convert|9|ft|6|in|m|abbr=on}} by {{convert|2.55|m|ftin|abbr=on|order=flip}}
* W12: {{convert|9|ft|6|in|m|abbr=on}} by {{convert|2.6|m|ftin|abbr=on|order=flip}}<ref name="For" />

=====Tube lines=====
* The [[City and South London Railway]] was built with tunnels of only {{convert|10|ft|6|in|m|2|abbr=on}} diameter. Enlarged for [[Northern line]] to {{convert|12|ft|m|2|abbr=on}}
* The [[Central line (London Underground)|Central line]] has tunnels of {{convert|11|ft|8+1/4|in|m|2|abbr=on}}, increasing on curves and narrowing to {{convert|11|ft|6|in|m|2|abbr=on}} near stations. This makes Central line trains unique on the [[London Underground]] because although the rolling stock's loading gauge is the same as the other Tube lines, the smaller tunnels require the positive [[Fourth rail|conductor]] rail is {{convert|1.6|in|abbr=on}} higher than on all other lines.

A Parliamentary committee headed by [[James Stansfeld]] then reported on 23 May 1892, "The evidence submitted to the Committee on the question of the diameter of the underground tubes containing the railways has been distinctly in favour of a minimum diameter of {{convert|11|ft|6|in|abbr=on}}". After that, all tube lines were at least that size.<ref>{{cite magazine |magazine=Railway Magazine |date=February 1959 |pages=94–96 |first1=Michael |last1=Robbins |title=The Size of the Tube }}</ref>

* [[Piccadilly line]] with tunnels of {{convert|12|ft|m|2|abbr=on}}
* [[Victoria line]] with tunnels of {{convert|12|ft|6|in|m|2|abbr=on}}; enlarged to reduce air friction.
* [[Glasgow Subway]] with tunnels of {{convert|11|ft|m|2|abbr=on}} and a unique track gauge of only {{Track gauge|4ft|lk=on}}.
* [[Tyne and Wear Metro]] with tunnels of {{convert|15|ft|6|in|m|2|abbr=on}}; built to mainline rail network standards.

====Sweden====
The Swedish Transport Administration (Trafikverket) has largely replaced static reference profiles with kinematic reference profiles. The two main standards are SE-A and SE-C. The SE-B profile has been withdrawn, as all track has been upgraded to at least SE-A. SE-C is required for all new construction and, when economically viable, during upgrades. Some SE-A track has been partially upgraded to SE-C and accommodates profiles such as P/C 450 (P/C 447) and GC or loads such as SECU containers. 

Both SE-A and SE-C are defined for straight track, with the corresponding structure gauge. On curved track, the structure gauge is widened to allow the 24-metre reference vehicle to pass. By European standards, SE-C is unusually large, permitting vehicles up to 24 metres long and almost 4 metres wide. However, vehicles with softer suspension that allows greater lateral movement must be narrower to remain within the kinematic reference profile.<ref>{{cite web |title="[TRVINFRA-00398 Krav Version 2.0]" |url=https://puben.trafikverket.se/dpub/visa-dokument/cf62ea9d-f551-404f-92f2-6f28a8980c81 |publisher=Trafikverket |accessdate=2025-10-02}}</ref>

<div style="max-width:100%; margin:0 auto; text-align:center;">

<div style="display:inline-block; max-width:100%;">

{{multiple image
| total_width = 900
| image1 = SE-A.png
| image2 = SE-C.png
| image3 = REF-V.png
| caption1 = Kinematic reference profile SE-A on straight track. Conductive materials are not permitted in Area 2, and Area 3 must be kept empty if the vehicle is to use the loading docks.
| caption2 = Kinematic reference profile SE-C on straight track.
| caption3 = Reference vehicle for Sweden. Values in mm.
}}

</div>
</div>

<div style="clear:both;"></div>
====Netherlands====
In the Netherlands, a similar shape to the UIC C is used that rises to {{convert|4.70|m|ftin|abbr=on}} in height. The trains are wider allowing for {{convert|3.40|m|ftin|abbr=on}} width similar to Sweden. About one third of the Dutch passenger trains use [[bilevel rail car]]s. However, Dutch platforms are much higher than Swedish ones.

===== Betuweroute =====
* [[Betuweroute]]: {{convert|4.10|by|6.15|m|ftin|frac=8|abbr=on}} to allow [[double stacked container trains]] in the future. The present [[overhead line]] does not allow this height, as it has to follow standards.

==== Channel Tunnel====
* [[Channel Tunnel]]: {{convert|4.10|by|5.60|m|ftin|frac=8|abbr=on}}

===North America===

====Freight====
{{Further|Boxcar#Loading gauges}}
{{Further|Double-stack rail transport#Sizes and clearances}}

The American loading gauge for [[Railroad car#Freight cars|freight cars]] on the [[North American rail network]] is generally based on standards set by the [[Association of American Railroads]] (AAR) Mechanical Division.<ref name="gauge">{{cite book |title=Car and Locomotive Cyclopedia of American Practice |edition=1970 |publisher=Association of American Railroads Mechanical Division |date=1970 |oclc=5245643 |pages=71–74 }}</ref> The most widespread standards are '''''AAR Plate B''''' and '''''AAR Plate C''''',<ref name="gauge2">[https://my.aar.org/OTLR/Documents/Section%201/Section1AppendixA_20200826.pdf Preload Inspection Checklist and Equipment Plate Diagrams] {{webarchive|url=https://web.archive.org/web/20210224215901/https://my.aar.org/OTLR/Documents/Section%201/Section1AppendixA_20200826.pdf|date=February 24, 2021}}</ref> but higher loading gauges have been introduced on major routes outside urban centers to accommodate rolling stock that makes better economic use of the network, such as [[Auto rack|auto carriers]], [[Boxcar#Hicube boxcar|hi-cube boxcars]], and [[Double-stack rail transport|double-stack container loads]].<ref>{{Cite web|url=http://www.csx.com/index.cfm/customers/other-services-partners/dimensionalclearance/clearance-maps/|archive-url=https://web.archive.org/web/20121210165904/http://www.csx.com/index.cfm/customers/other-services-partners/dimensionalclearance/clearance-maps/|url-status=dead|title=Clearance maps for CSX, a typical major carrier|archive-date=10 December 2012}}</ref> The maximum width of {{cvt|10|ft|8|in}} on {{cvt|41|ft|3|in}} ('''AAR Plate B'''), {{cvt|46|ft|3|in}} ('''AAR Plate C''') and all other [[Bogie|truck]] centers (of all other '''AAR Plates''') are on a {{cvt|441|ft|8+3/8|in|m|2}} radius or [[Degree of curvature#Length selection|13°]] curve.<ref name="gauge" /><ref name="gauge2" /> In all cases of the increase of truck centers, the decrease of width is covered by '''AAR Plates D1 and D2'''.<ref name="gauge" /><ref name="gauge2" />

Listed here are the maximum heights and widths for cars. However, the specification in each AAR plate shows a car cross section that is chamfered at the top and bottom, meaning that a compliant car is not permitted to fill an entire rectangle of the maximum height and width.<ref name="gauge2" />

{| class="wikitable"
! rowspan="2" | AAR<br>Plate !! colspan="2"| Width !! colspan="2" | Height !! colspan="2" | Truck centers !!rowspan="2" width=350| Comments !! rowspan="2" | Image
|- 
! width=50|ft in !!width=40|m !! width=50|ft in !!width=40| m !!width=50| ft in !!width=40| m  
|-
| '''B''' || {{convert|10|ft|8|in|m|2|disp=table}} || {{convert|15|ft|1|in|m|2|disp=table}} || {{convert|41|ft|3|in|m|2|disp=table}} || For longer truck centers, the width is decreased according to [[Graph of a function|graph]] '''AAR Plate B-1''' on a {{cvt|441|ft|8+3/8|in|m|2}} radius curve<ref name="gauge" /> or '''AAR Plate D1'''<ref name="gauge2" /> || [[File:Gabarit AAR Plate-B.png|100px|center]]
|-
| '''C''' || {{convert|10|ft|8|in|m|2|disp=table}} || {{convert|15|ft|6|in|m|2|disp=table}} || with {{convert|46|ft|3|in|m|2|disp=table}} || For longer truck centers, the width is decreased according to graph '''AAR Plate C-1''' on a {{cvt|441|ft|8+3/8|in|m|2}} radius curve<ref name="gauge" /> or '''AAR Plate D1'''<ref name="gauge2" /> || [[File:Gabarit AAR Plate-C.png|100px|center]]
|-
| '''E''' || {{convert|10|ft|8|in|m|2|disp=table}} || {{convert|15|ft|9|in|m|2|disp=table}} || with {{convert|46|ft|3|in|m|2|disp=table}}
|| However the top of rail clearance is {{convert|2+3/4|in|mm|0|abbr=on}} instead of {{convert|2+1/2|in|mm|0|abbr=on}}.<ref name="gauge2" /><ref name="gauge3">{{cite book |title=Car and Locomotive Cyclopedia of American Practice |edition=1984 |publisher=Association of American Railroads Mechanical Division |date=1984 |oclc=5245643 |pages=91, 92 }}</ref> || [[File:Gabarit AAR Plate E.png|100px|center]]
|-
| '''F''' || {{convert|10|ft|8|in|m|2|disp=table}} || {{convert|17|ft|0|in|m|2|disp=table}} ||with {{convert|46|ft|3|in|m|2|disp=table}} || As with '''AAR Plate C''' but {{convert|18|in|mm|0|abbr=on}} taller than '''AAR Plate C''' and {{convert|15|in|mm|0|abbr=on}} taller than '''AAR Plate E''', and the car cross section is larger at the top than '''AAR Plate E'''.<ref name="gauge2" /> || [[File:Gabarit AAR Plate F.png|100px|center]]
|-
|rowspan="2" |'''H''' || {{convert|10|ft|8|in|m|2|disp=table}}<ref name="Guide"/>||  {{convert|20|ft|3|in|m|2|disp=table}} ||{{convert|62|ft|7|in|m|2||disp=table}}<ref name="Guide"/> ||e.g. Including the height of [[Intermodal container|double stacked containers]] in [[well car]]s. The cross section at the bottom of the well car differs from the X section of all other AAR plates. X section at center of car<ref name="gauge2" /><ref>April 2001 [[Official Railway Equipment Register]] {{cite web |title=Archived copy |url=http://www.railresource.com/content/wp-content/uploads/2010/06/orerrr_126_1_sample.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130509020851/http://www.railresource.com/content/wp-content/uploads/2010/06/orerrr_126_1_sample.pdf |archive-date=9 May 2013 |access-date=23 November 2012}} {{cite web |title=Archived copy |url=http://www.uprr.com/customers/attachments/rule16.pdf |url-status=dead |archive-url=https://web.archive.org/web/20100401022710/http://www.uprr.com/customers/attachments/rule16.pdf |archive-date=1 April 2010 |access-date=23 November 2012}}</ref><ref name="Guide">{{Cite web|url=http://worldtraderef.com/WTR_site/Rail_Cars/Guide_to_Rail_Cars.asp|title=Guide to Railcars|date=31 October 2011|archive-url=https://web.archive.org/web/20111031040725/http://worldtraderef.com/WTR_site/Rail_Cars/Guide_to_Rail_Cars.asp |archive-date=31 October 2011 }}</ref> Width of {{convert|10|ft|8|in|m|2}} only possible at the [[Bogie|trucks]]<ref name="gauge2" /> || [[File:Gabarit AAR Plate-H.png|100px|center]]
|-
|{{convert|10|ft|1|in|m|2|disp=table}}<ref name="gauge2"/>  ||  {{convert|20|ft|3|in|m|2|disp=table}} ||{{convert|63|ft|9|in|m|2||disp=table}} ||e.g. Including the height of [[Intermodal container|double stacked containers]] in [[well car]]s. The width at greater than {{cvt|63|ft|9|in|m|2}} covered by ''' AAR Plate D1'''<br />The cross section at the bottom of the well car differs from all other AAR Plates.<ref name="gauge2" /><ref>April 2001 Official Railway Equipment Register {{cite web |url=http://www.railresource.com/content/wp-content/uploads/2010/06/orerrr_126_1_sample.pdf |title=Archived copy |access-date=23 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130509020851/http://www.railresource.com/content/wp-content/uploads/2010/06/orerrr_126_1_sample.pdf |archive-date=9 May 2013 }} {{cite web |url=http://www.uprr.com/customers/attachments/rule16.pdf |title=Archived copy |access-date=23 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20100401022710/http://www.uprr.com/customers/attachments/rule16.pdf |archive-date=1 April 2010 }}</ref> in well cars<ref name="Guide" />|| [[File:Gabarit AAR Plate-H.png|100px|center]]
|-
|rowspan="2" | '''---''' ||{{convert|9|ft|10.25|in|m|2|disp=table}}<ref name="Guide"/>|| {{convert|3|ft|11|in|m|2|disp=table}}<ref name="Guide"/>||{{convert|66|ft|0|in|m|2|disp=table}}<ref name="Guide"/> || rowspan="2" | e.g. {{convert|85|ft|2+1/2|in|m|2|adj=on}}<ref name="Guide"/> long [[flatcar]]s, *Height of deck at center of car<ref name="Guide" /> Width covered by  '''AAR Plate D1'''.<ref name="gauge2" />||rowspan="2" | 
|-
| {{convert|9|ft|1|in|m|2|disp=table}}<ref name="Guide"/>  
|-
| '''J'''|| {{convert|10|ft|8|in|m|2|disp=table}} ||{{convert|19|ft|0|in|m|2|disp=table}} ||{{convert|55|ft|0|in|m|2|disp=table}} || Truck centers can be more. Widths covered by  '''AAR Plate D1'''.<ref name="gauge2" />||
|-
| '''K''' || {{convert|10|ft|0|in|m|2|disp=table}}  || {{convert|20|ft|3|in|m|2|disp=table}}<ref name="gauge2" /> || {{convert|65|ft|0|in|m|2|disp=table}}||e.g. [[Autorack]] (road vehicles on trains).  Width at center of car covered by  '''AAR Plate D1'''<ref name="gauge2" /><ref name="Guide"/><ref name="autorack">{{Cite web|url=http://www.gbrx.com/PDFtecbulletins/GenFreightAutoMax.pdf|title=Autorack}}{{Dead link|date=December 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><!-- <ref name="Guide.1">{{Cite web |url=http://worldtraderef.com/WTR_site/Rail_Cars/Guide_to_Rail_Cars.asp |title=Guide to Railcars |access-date=26 March 2011 |archive-date=31 October 2011 |archive-url=https://web.archive.org/web/20111031040725/https:// |url-status=dead }}</ref> -->||
|-
| '''L''' || {{convert|10|ft|8|in|m|2|disp=table}}||{{convert|16|ft|3|in|m|2|disp=table}} ||{{convert|46|ft|3|in|m|2|disp=table}} || For locomotives only<ref name="gauge2" /> ||
|-
| '''M''' || {{convert|10|ft|8|in|m|2|disp=table}}||{{convert|16|ft|3|in|m|2|disp=table}} ||{{convert|46|ft|3|in|m|2|disp=table}} || For locomotives only <ref name="gauge2" />|| 
|}

Technically, AAR Plate B is still the maximum height and truck center combination<ref name="gauge" /><ref name="gauge2" /> and the circulation of AAR Plate C is somewhat restricted. The prevalence of excess-height rolling stock, at first ~{{convert|18|ft|m|2|abbr=on}} [[Piggyback (transportation)#Rail|piggybacks]] and [[Boxcar#Hicube boxcar|hicube boxcars]], then later [[autorack]]s, airplane-parts cars, and flatcars for hauling [[Boeing 737]] fuselages, as well as {{convert|20|ft|3|in|m|2|abbr=on}} high double-stacked [[Intermodal container|containers]] in [[Well car|container well cars]], has been increasing. This means that most, if not all, lines are now designed for a higher loading gauge. The width of these extra-height cars is covered by '''AAR Plate D1'''.<ref name="gauge" /><ref name="gauge2" />

All the Class I rail companies have invested in longterm projects to increase clearances to allow double stack freight. The mainline North American rail networks of the Union Pacific, the BNSF, the Canadian National, and the Canadian Pacific, have already been upgraded to '''AAR Plate K'''. This represents over 60% of the Class I rail network.<ref>{{cite journal |title=Railway Line Clearances and Car Dimensions including Weight Limitations of Railroads in the United States, Canada, Mexico and Cuba |journal=Railway Line Clearances and Car Dimensions Including Weight Limitations of Railroads in the United States, Canada, Mexico and Cuba.|oclc = 10709088}}</ref>

===== Gallery =====
<gallery mode="packed" hrights="140"px">
File:Boeing 737 fuselage train hull 3473.jpg|[[Boeing 737 Next Generation]] [[fuselage]] being transported by rail on a [[flatcar]]
File:DTTX 724681 20050529 IL Rochelle.jpg|[[Double-stack rail transport|Double-stack container service]] requires the highest loading gauge in common use in North America.
File:ETTX 905721 20050529 IL Rochelle.jpg|A Norfolk Southern autorack on a [[TTX Company|TTX]] flatcar also requires the highest loading gauge in common use in North America.
File:Santa_Fe_TOFC_(Trailer_on_Flat_Car)_(10589289363).jpg|A [[Atchison, Topeka and Santa Fe Railway|Santa Fe]] [[semi-trailer]] carried on a flatcar as part of a [[Trailer-on-flatcar|TOFC]] train.
</gallery>

==== Passenger service ====
[[File:Gabarit AAR passager.png|thumb|Standard AAR passenger loading gauge (does not accommodate Amtrak "Superliners" nor ex-AT&SF "Hi-Level" cars)]]

The old standard North American [[passenger car (rail)|passenger railcar]] is {{convert|10|ft|6|in|m|2|abbr=on}} wide by {{convert|14|ft|6|in|m|2|abbr=on}} high and measures {{convert|85|ft|0|in|m|2|abbr=on}} [[Headstock (rolling stock)#Length over headstocks|over coupler pulling faces]] with {{convert|59|ft|6|in|m|2|abbr=on}} [[Bogie|truck]] centers, or {{convert|86|ft|0|in|m|2|abbr=on}} over coupler pulling faces with {{convert|60|ft|0|in|m|2|abbr=on}} truck centers. In the 1940s and 1950s, the American passenger car loading gauge was increased to a {{convert|16|ft|6|in|m|2|abbr=on}} height throughout most of the country outside the Northeast, to accommodate [[dome car]]s and later [[Superliner (railcar)|Superliner]]s and other [[Bilevel rail car|bilevel]] commuter trains. Bilevel and Hi-level passenger cars have been in use since the 1950s, and new passenger equipment with a height of {{convert|19|ft|9+1/2|in|m|2|abbr=on}} has been built for use in Alaska and the Canadian Rockies. The [[structure gauge]] of the [[Mount Royal Tunnel]] used to limit the height of bilevel cars to {{convert|14|ft|6|in|m|2}} before it was permanently closed to interchange rail traffic prior to its conversion for the [[Réseau express métropolitain|REM]] rapid transit system.{{Citation needed|date=November 2021}}

==== New York City Subway ====
The [[New York City Subway]] is an amalgamation of three former constituent companies, and while all are [[standard gauge]], inconsistencies in loading gauge prevent cars from the former [[Brooklyn–Manhattan Transit Corporation|BMT]] and [[Independent Subway System|IND]] systems ([[B Division (New York City Subway)|B Division]]) from running on the lines of the former [[Interborough Rapid Transit Company|IRT]] system ([[A Division (New York City Subway)|A Division]]), and vice versa. This is mainly because IRT tunnels and stations are approximately {{convert|1|ft|mm|0}} narrower than the others, meaning that IRT cars running on the BMT or IND lines would have [[platform gap]]s of over {{convert|8|in|mm|0}} between the train and some platforms, whereas BMT and IND cars would not even fit into an IRT station without hitting the platform edge. Taking this into account, all maintenance vehicles are built to IRT loading gauge so that they can be operated over the entire network, and employees are responsible for [[mind the gap|minding the gap]].

Another inconsistency is the maximum permissible railcar length. Cars in the former IRT system are {{convert|51|ft|m|2}} {{as of|2013|12|lc=y}}. Railcars in the former BMT and IND can be longer: on the former [[Rapid transit operations of the BRT and BMT#Divisions|Eastern Division]], the cars are limited to {{convert|60|ft|m|2}}, while on the rest of the BMT and IND lines plus the [[Staten Island Railway]] (which uses modified IND stock) the cars may be as long as {{convert|75|ft|m|2}}.<ref>{{cite web |title=NYC Fun Facts: Not All NYC Subway Trains Are the Same Size |url=https://untappedcities.com/2017/08/02/nyc-fun-facts-subway-tracks-have-different-widths-in-nyc/ |website=Untapped Cities |access-date=11 July 2018 |date=2 August 2017}}</ref><ref>[[Second Avenue Subway]] [http://web.mta.info/capital/sas_docs/sdeis.htm Draft Environmental Impact Statement], {{cite web|url= http://web.mta.info/capital/sas_docs/sdeis/glossary.pdf |title=Glossary }}&nbsp;{{small|(45.6&nbsp;[[Kibibyte|KiB]])}}</ref>

====Boston (MBTA)====
The [[Massachusetts Bay Transportation Authority]]'s (MBTA) rapid transit system is composed of four unique subway lines; while all lines are standard gauge, inconsistencies in loading gauge, electrification, and platform height prevent trains on one line from being used on another. The first segment of the [[Green Line (MBTA)|Green Line]] (known as the [[Tremont Street subway]]) was constructed in 1897 to take the streetcars off [[Boston]]'s busy downtown streets. When the [[Blue Line (MBTA)|Blue Line]] opened in 1904, it only ran streetcar services; the line was converted to rapid transit in 1924 due to high passenger loads, but the tight clearances in the tunnel under the [[Boston Harbor]] required narrower and shorter rapid transit cars.<ref>{{cite book| last = Clarke| first = Bradley| title = The Boston Rapid Transit Album| publisher = Boston Street Railway Association| year = 1981| location = Cambridge, Mass.| page = 8}}</ref> The [[Orange Line (MBTA)|Orange Line]] was originally built in 1901 to accommodate heavy rail transit cars of higher capacity than streetcars. The [[Red Line (MBTA)|Red Line]] was opened in 1912, designed to handle what were for a time the largest underground transit cars in the world.<ref name=Fischler>{{cite book|last1=Fischler|first1=Stanley I.|title=Moving millions : an inside look at mass transit|date=1979|publisher=Harper & Row|location=New York|isbn=0-06-011272-7|edition=1st|url-access=registration|url=https://archive.org/details/movingmillions00stan}}</ref>{{rp|127}}

====Los Angeles (LACMTA)====
The [[Los Angeles Metro Rail]] system is an amalgamation of two former constituent companies, the [[Los Angeles County Transportation Commission]] and the Southern California Rapid Transit District; both of those companies were responsible for planning the initial system. It is composed of two heavy rail subway lines and several light rail lines with subway sections; while all lines are standard gauge, inconsistencies in electrification and loading gauge prohibit the light rail trains from operating on the heavy rail lines, and vice versa. The LACTC-planned [[A Line (Los Angeles Metro)|Blue Line]] was opened in 1990 and partially operates on the route of the [[Pacific Electric]] interurban railroad line between downtown Los Angeles and Long Beach, which used overhead electrification and street-running streetcar vehicles. The SCRTD-planned [[B Line (Los Angeles Metro)|Red Line]] (later split into the Red and [[D Line (Los Angeles Metro)|Purple]] lines) was opened in 1993 and was designed to handle high-capacity heavy rail transit cars that would operate underground. Shortly after the Red Line began operations, the LACTC and the SCRTD merged to form the [[Los Angeles County Metropolitan Transportation Authority|LACMTA]], which became responsible for planning and construction of the [[C Line (Los Angeles Metro)|Green]], [[L Line (Los Angeles Metro)|Gold]], [[E Line (Los Angeles Metro)|Expo]], and [[K Line (Los Angeles Metro)|K]] lines, as well as the [[D Line Extension]] and the [[Regional Connector]].

=== Asia ===
Major trunk raillines in East Asian countries, including China, North Korea, South Korea, as well as the [[Shinkansen]] of Japan, have all adopted a loading gauge of {{cvt|3,400|mm |ftin}} maximum width and can accept the maximum height of {{cvt|4,500|mm |ftin}}.<ref name= "reh">{{Cite book |id=和書 |author= 久保田博 |script-title=ja:鉄道工学ハンドブック |pages= 148–149 |publisher= [[グランプリ出版]] |isbn= 4-87687-163-9 |date= 13 February 1997 |language= ja|author-link= 久保田博 }}</ref>
{{clear}}

==== China ====
The maximum height, width, and length of general Chinese rolling stock are {{cvt|4,800|mm|ftin}}, {{cvt|3,400|mm|ftin}} and {{cvt|26|m|ftin}} respectively, with an extra ''out-of-gauge'' load allowance of height and width {{cvt|5300|by|4450|mm|ftin}} with some special shape limitation, corresponding to a [[structure gauge]] of {{cvt|5500|by|4880|mm|ftin}}.<ref>National Standard GB146.1–83 Rolling stock gauge for standard gauge railways</ref> China is building numerous new railways in sub-Saharan Africa and Southeast Asia (such as in Kenya and Laos), and these are being built to "Chinese Standards". This presumably means track gauge, loading gauge, structure gauge, couplings, brakes, electrification, etc.<ref>[[Janes World Railways]]</ref>{{circular reference|date=March 2022}} An exception may be [[Double-stack rail transport|double stacking]], which has a height limit of {{cvt|5,850|mm|ftin}}. Metre gauge in China has a gauge of {{cvt|3050|mm|ftin}}.

{{clear}}

==== Japan, standard gauge ====
[[File:Rolling-Stock-Gauge-in-Japan.svg|left|thumb]]
Translation of legend:
* Blue: Rural railway vehicle gauge (Rural Railway Construction Rules 1919)  
* Grey: Conventional [[Cape gauge]] (3 ft 6 in track gauge) railway vehicle limits (Ordinary Railway Structure Rules 1987) 
* Figures in () are previous Cape gauge rolling stock limits (Railway Construction Rules 1900)
* Green: Shinkansen vehicle limits 

Trains on the [[Shinkansen]] network operate on {{Track gauge|1435mm|allk=on}} track and have a loading gauge of {{cvt|3,400|mm|ftin}} maximum width and {{cvt|4,500|mm|ftin}} maximum height.<ref>{{cite web |url=http://www.mlit.go.jp/pubcom/06/pubcomt129/03.pdf |script-title=ja:鉄道に関する技術上の基準を定める省令等の解釈基準 |publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]] |language=ja}}</ref> This allows the operation of double-deck high-speed trains.

''Mini Shinkansen'' (former conventional {{track gauge|1067mm|lk=on|disp=or}} narrow gauge lines that have been [[Track gauge conversion|regauged]] into {{track gauge|sg|allk=on|disp=or}}) and some private railways in Japan (including some lines of the [[Tokyo subway]] and all of the [[Osaka Metro]]) also use standard gauge; however, their loading gauges are different.

The rest of Japan's system is discussed under [[#Japan, narrow gauge|narrow gauge]], below.
{{clear}}

==== Hong Kong ====
{{expand section|date=April 2019}}

{{clear}}

==== South Korea ====
The body frame may have a maximum height of {{cvt|4,500|mm|ftin}} and a maximum width of {{cvt|3,400|mm|ftin}} with additional installations allowed up to {{cvt|3,600|mm|ftin}}. That width of 3,400&nbsp;mm is only allowed above {{cvt|1250|mm|ftin}} as the common passenger platforms are built to former standard trains of {{cvt|3200|mm|ftin}} in width.

{{clear}}

==== Philippines ====
There is currently no uniform standard for loading gauges in the country and both loading gauges and platform heights vary by rail line.

The [[North–South Commuter Railway]] allows passenger trains with a carbody width of {{Cvt|3100|mm|ftin}} and a height of {{Cvt|4300|mm|ftin}}. Additional installations shall also be allowed up to {{Cvt|3300|mm|ftin}} at a platform height of {{Cvt|1100|mm|ftin}} where it is limited by half-height [[platform screen doors]]. Above the platform gate height of {{Cvt|1200|mm|ftin}} above the platforms, out-of-gauge installations can be further maximized to the Asian standard at {{Cvt|3400|mm|ftin}}.<ref name="ps">NSCR and SLH bid documents <!-- Uses Google Drive links --> at {{Cite web|title=Foreign Assisted Projects|url=https://ps-philgeps.gov.ph/home/index.php/bid-opportunities/foreign-assisted-projects|date=2021-04-06|access-date=2022-11-25}}</ref>

Meanwhile, the [[PNR South Long Haul]] will follow the Chinese gauge and therefore use a larger carbody width of {{Cvt|3300|mm|ftin}} from the specifications of passenger rolling stock, and a height of {{Cvt|4770|mm|ftin}} per P70-type boxcar specifications.<ref name="ps"/>

=== Africa ===
Some of the new railways being built in Africa allow for double-stacked containers, the height of which is about {{cvt|5,800|mm|ftin}} depending on the height of each container {{cvt|2,438|mm|ftin}} or {{cvt|2,900|mm|ftin}} plus the height of the deck of the flat wagon about {{cvt|1,000|mm|ftin}} totalling {{cvt|5,800|mm|ftin}}. This exceeds the China height standard for single stacked containers of {{cvt|4,800|mm |ftin}}. Additional height of about {{cvt|900|mm|ftin}} is needed for overhead wires for [[25 kV AC]] electrification.

The permissible width of the new African standard gauge railways is {{cvt|3400|mm|ftin}}.

{{clear}}

=== Australia ===
The standard gauge lines of [[New South Wales Government Railways]] allowed for a width of {{cvt|9|ft|6|in|m}} until 1910, after a conference of the states created a new standard of {{cvt|10|ft|6|in|m}}, with corresponding increase in track centres.{{Citation needed|date=September 2025}} The narrow widths have mostly been eliminated, except, for example, at the mainline platforms at [[Gosford railway station|Gosford]] and some sidings. The longest carriages are {{cvt|72|ft |6|in|m|2}}.{{Citation needed|date=November 2021}}

The [[Commonwealth Railways]] adopted the national standard of {{cvt|10|ft|6|in|m}} when they were established in 1912, although no connection with New South Wales was made until 1970.<!-- It was argued that rolling stock utilisation would be improved if they did connect. However the loading gauge of the two systems made this problematic as the loading gauge of NSW was smaller. However CR rolling stock built to the NSW loading gauge could work through. -->{{Citation needed|date=November 2021}}

A [[New South Wales T set|T set]] of the late 1980s was {{convert|3000|mm|ftin|1|abbr=on}} wide. Track centres from [[Penrith railway station, Sydney|Penrith]] to [[Mount Victoria railway station|Mount Victoria]] and [[Gosford railway station|Gosford]] and [[Wyong railway station|Wyong]] have been gradually widened to suit. The [[New South Wales D set|D set]] intercity sets are however {{convert|3100|mm|ftin|1|abbr=on}} wide, so further, costly modification was required beyond [[Springwood railway station|Springwood]],<ref>[https://www.smh.com.au/national/nsw/new-intercity-trains-too-wide-for-rail-line-to-stations-in-blue-mountains-20161005-grvmns.html New intercity trains too wide for rail line to stations in Blue Mountains] ''[[Sydney Morning Herald]]'' 5 October 2016</ref> which was completed in 2020.<ref>{{cite web | url=https://www.bluemountainsgazette.com.au/story/6848014/rail-upgrade-completed-to-fit-new-trains-on-blue-mountains-line/ |title=Rail upgrade completed to fit new trains on Blue Mountains Line |work=[[Blue Mountains Gazette]]|first=Damien | last=Madigan | date=2020-07-24 |access-date=2021-06-11}}</ref>

The [[Kwinana railway line|Kwinana]], [[Eastern Railway, Western Australia|Eastern]] and [[Eastern Goldfields Railway|Eastern Goldfields]] lines in [[Western Australia]] were built with a loading gauge of {{cvt|12|ft|mm}} wide and {{cvt|20|ft|mm}} tall to allow for trailer on flatcar (TOFC) traffic when converted to dual gauge in the 1960s.<ref>[https://web.archive.org/web/20211118152224/https://portal.engineersaustralia.org.au/system/files/engineering-heritage-australia/nomination-title/HRP.WA%20Standard%20Gauge%20Railway%20Kalgoorlie%20to%20Perth.Nomination.Dec%202012.pdf Nomination of Western Australian Standard Gauge Railway for an Engineering Heritage Australia Heritage Recognition Award] [[Engineers Australia]] September 2011</ref>

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

=== Indian Gauge ===
* The smallest loading gauge for a {{RailGauge|1676mm}} gauge railway is the [[Delhi Metro]], which is {{cvt|3250|mm|ftin}} wide and {{cvt|4140|mm|ftin}} tall.
* [[Indian Railways]] has a maximum passenger loading gauge of {{cvt|3660|mm|ftin}}<ref>{{Cite book|last=Mundrey|url=https://books.google.com/books?id=PzA3N6eP4TYC&pg=PA12|title=Railway Track Engineering|date=2000-09-01|publisher=Tata McGraw-Hill Education|isbn=978-0-07-463724-1|language=en}}</ref> and a freight loading gauge of 3,250&nbsp;mm, with development allowing a width of {{cvt|3710|mm|ftin}}.<ref>{{Cite web |url=http://irimee.indianrailways.gov.in/instt/uploads/files/1454673172611-sod.pdf |title=Archived copy |access-date=21 June 2020 |archive-url=https://web.archive.org/web/20180920152726/http://www.irimee.indianrailways.gov.in/instt/uploads/files/1454673172611-sod.pdf |archive-date=20 September 2018 |url-status=dead }}</ref> 
* [[Sri Lanka Railways]] has a loading gauge of between {{cvt|3200|mm|ftin}} and {{cvt|4267|mm|ftin}}.<ref>[http://www.unescap.org/sites/default/files/tarsc-fulltext_1980.pdf DEVELOPMENT OF THE TRANS-ASIAN RAILWAY TRANS-ASIAN RAILWAY IN THE SOUTHERN CORRIDOR OF ASIA-EUROPE ROUTES]</ref>

=== 5 ft and Russian gauge===
In Finland, rail cars can be up to {{convert|3.4|m|ftin|abbr=on}} wide with a permitted height from {{convert|4.37|m|ftin|abbr=on}} on the sides to {{convert|5.3|m|ftin|abbr=on}} in the centre.<ref>{{cite web|date=15 December 2009|title=Lastprofiler Finland|url=http://www.greencargo.com/sv/Godsvagnar/Start/Lastprofiler/Lastprofiler-Finland/|url-status=dead|archive-url=https://web.archive.org/web/20111111100302/http://www.greencargo.com/sv/Godsvagnar/Start/Lastprofiler/Lastprofiler-Finland/|archive-date=11 November 2011|access-date=18 September 2012|publisher=Green Cargo|language=sv}}</ref> The [[track gauge]] is {{Track gauge|1524 mm|lk=on}}, differing {{cvt|4|mm|in|frac=32}} from the {{Track gauge|1 520 mm|lk=on}} Russian track gauge.

The Russian loading gauges are defined in standard GOST 9238 (ГОСТ 9238–83, ГОСТ 9238–2013) with the current 2013 standard named "Габариты железнодорожного подвижного состава и приближения строений" (construction of rolling stock clearance diagrams [official English title]).<ref name=gost9238>{{cite web|url=http://protect.gost.ru/document.aspx?control=7&id=185371|title=ГОСТ 9238-2013|date=1 July 2014|url-status=live|archive-url=https://web.archive.org/web/20180415124726/http://protect.gost.ru/document.aspx?control=7&id=185371|archive-date=15 April 2018}}</ref> It was accepted by the [[GOST|Interstate Council for Standardization, Metrology and Certification]] to be valid in Russia, Belarus, Moldova, Ukraine, Uzbekistan and Armenia.<ref name=gost9238 /> Loading gauge is generally wider than Europe, but with many exception standards.

* T: standard loading gauge
** T: 5,300&nbsp;mm height, 3,750&nbsp;mm width
** T<sub>c</sub>: 5,200&nbsp;mm height, 3,750&nbsp;mm width: for tank and dumper cars
** T<sub>pr</sub>: 5,300&nbsp;mm height, 3,500&nbsp;mm width: extra ''out-of-gauge'' cargo load for main tracks
* 1-T: guaranteed loading gauge for all ex-USSR lines including old tunnels.
** 1-T: 5,300&nbsp;mm height, 3,400&nbsp;mm width
* VM: for international stock for 1435&nbsp;mm lines, standards for different lines
** 0-VM: 4,650&nbsp;mm height, 3,250&nbsp;mm width
** 1-VM: 4,700&nbsp;mm height, 3,400&nbsp;mm width
** 02-VM: 4,650&nbsp;mm height, 3,150&nbsp;mm width
** 03-VM: 4,280&nbsp;mm height, 3,150&nbsp;mm width

The standard defines static envelopes for trains on the national network as T, T<sub>c</sub> and T<sub>pr</sub>. The static profile 1-T is the common standard on the complete 1520&nbsp;mm rail network including the CIS and Baltic states. The structure clearance is given as S, S<sub>p</sub> and S<sub>250</sub>. There is a tradition that structure clearance is much bigger than the common train sizes. For international traffic, the standard references the kinematic envelope for GC and defines a modified GC<sub>ru</sub> for its high-speed trains. For other international traffic, there are 1-T, 1-VM, 0-VM, 02-VM and 03-VM<sub>st</sub>/03-VM<sub>k</sub> for the trains and 1-SM for the structure clearance.<ref name=gost9238 />

The main static profile T allows for a maximum width of {{convert|3750|mm|ftin|frac=16|abbr=on}} rising to a maximum height of {{convert|5300|mm|ftin|frac=16|abbr=on}}. The profile T<sub>c</sub> allows that width only at a height of {{convert|3000|mm|ftin|frac=16|abbr=on}}, requiring a maximum of {{convert|3400|mm|ftin|frac=16|abbr=on}} below {{convert|1270|mm|in|frac=16|abbr=on}}, which matches with the standard for train platforms (with a height of {{convert|1100|mm|in|1|abbr=on|disp=sqbr}}). The profile T<sub>pr</sub> has the same lower frame requirement but reduces the maximum upper body width to {{convert|3500|mm|ftin|frac=16|abbr=on}}. The more universal profile 1-T has the complete body at a maximum width of {{convert|3400|mm|ftin|frac=16|abbr=on}} still rising to a height of {{convert|5300|mm|ftin|frac=16|abbr=on}}.<ref name=gost9238 /> Exceptions shall be double-stacking, maximum height shall be {{convert|6150|mm|ftin|frac=16|abbr=on}} or {{convert|6400|mm|ftin|frac=16|abbr=on}}.

The structure gauge S requires buildings to be placed at minimum of {{convert|3100|mm|ftin|frac=16|abbr=on}} from the track centreline. Bridges and tunnels must have a clearance of at least {{convert|4900|mm|ftin|frac=16|abbr=on}} wide and {{convert|6400|mm|ftin|frac=16|abbr=on}} high. The structure gauge S<sub>p</sub> for passenger platforms allows {{convert|4900|mm|ftin|frac=16|abbr=on}} only above {{convert|1100|mm|ftin|frac=16|abbr=on}} (the common platform height) requiring a width of {{convert|3840|mm|ftin|frac=16|abbr=on}} below that line.<ref name=gost9238 /> The exceptions shall be double-stacking, minimum overhead wiring height must be {{convert|6500|mm|ftin|frac=16|abbr=on}} (for maximum vehicle height of {{convert|6150|mm|ftin|frac=16|abbr=on|disp=sqbr}}) or {{convert|6750|mm|ftin|frac=16|abbr=on|disp=sqbr}} (for maximum vehicle height of {{convert|6400|mm|ftin|frac=16|abbr=on|disp=sqbr}}).

The main platform is defined to have a height of {{convert|1100|mm|in|1|abbr=on}} at a distance of {{convert|1920|mm|in|1|abbr=on}} from the center of the track to allow for trains with profile T. Low platforms at a height of {{convert|200|mm|in|1|abbr=on}} may be placed at {{convert|1745|mm|in|1|abbr=on}} from the center of the track. A medium platform is a variant of the high platform but at a height of {{convert|550|mm|in|1|abbr=on}}.<ref name=gost9238 /> The latter matches with the TSI height in Central Europe. In the earlier standard from 1983, the profile T would only be allowed to pass low platforms at {{cvt|200|mm|in|2}} while the standard high platform for cargo and passenger platforms would be placed no less than {{convert|1750|mm|in|1|abbr=on}} from the center of the track.<ref>{{cite web|url=http://vsegost.com/Catalog/43/4382.shtml|title=ГОСТ 9238-83 Габариты приближения строений и подвижного состава железных дорог колеи 1520 (1524) мм|website=vsegost.com|url-status=live|archive-url=https://web.archive.org/web/20160917235231/http://vsegost.com/Catalog/43/4382.shtml|archive-date=17 September 2016}}</ref> That matches with the T<sub>c</sub>, T<sub>pr</sub> and the universal 1-T loading gauge.

=== Iberian gauge ===
{{main|Iberian-gauge railways}}In Spain, rail cars can be up to 3.44 m (11&nbsp;ft 3.5 in) wide with a permitted height of 4.33 m (14&nbsp;ft 2.5 in) and this loading gauge is called iberian loading gauge. It is the standard loading gauge for conventional (iberian gauge) railways in Spain.

In Portugal, there are three railway loading gauge standards for conventional (iberian gauge) railways: Gabarito PT b, Gabarito PT b+ and Gabarito PT c. Gabarito PT b (also called CPb) and Gabarito PT b+ (also called CPb+) allow rail cars to be 3.44 m (11&nbsp;ft 3.5 in) wide with a permitted height of 4.5 m (14&nbsp;ft 9 in), although CPb+ has a slightly larger profile area. Gabarito PT c allows rail cars to be 3.44 m (11&nbsp;ft 3.5 in) wide with a permitted height of 4.7 m (15&nbsp;ft 5 in). Gabarito PT b and PT b+ are both used, being PT b+ more common overall. Gabarito PT c is currently not used. In Lisbon, there is a suburban railway line, the [[Cascais Line]], that follows a fourth non-standard loading gauge.{{expand section|date=August 2020}}

=== Irish Gauge ===
{{main|5 ft 3 in gauge railways}}

==== Ireland and Northern Ireland ====
{{main|Iarnród Éireann|NI Railways}}
{{expand section|date=August 2022}}

==== Australia ====
{{expand section|date=August 2022}}

==== Brazil ====
{{expand section|date=August 2022}}

== Narrow gauge ==
{{Main|Narrow gauge railways}}
Narrow gauge railways generally have a smaller loading gauge than standard gauge ones, and this is a major reason for cost savings rather than the railgauge itself. For example, the [[Lyn locomotive]] of the [[Lynton and Barnstaple Railway]] is {{convert|7|ft|2|in|m}} wide. By comparison, several standard gauge [[New South Wales 73 class locomotive|73 class locomotives]] of the [[New South Wales Government Railways|NSWR]], which are {{convert|9|ft|3|in|m}} wide, have been converted for use on {{RailGauge|610mm}} cane tramways, where there are no narrow bridges, tunnels or track centres to cause trouble. The [[South African Class 6E1, Series 9|6E1]] locomotive of the {{RailGauge|1067mm}} [[South African Railways]] are {{convert|9|ft|6|in|m|1}} wide.

A large numbers of railways using the {{RailGauge|762mm}} gauge used the same rolling stock plans, which were {{convert|7|ft|0|in|m|abbr=on}} wide.

=== Great Britain ===

==== Ffestiniog Railway ====
{{Main|Ffestiniog Railway}}
* gauge = {{RailGauge|1ft11.5in|first=met|lk=on}}
* width (brakevan mirrors) = {{convert|6|ft|10|in|m}}<ref>{{cite book |title=Festiniog Railway |volume=2 |first=James |last=Boyd |date=17 October 2002 |page=365 |isbn=0-85361-168-8 }}</ref>
* width (brakevan body) = {{convert|6|ft|0|in|m}}
* height = {{convert|5|ft|7.5|in|m}}
* length = (carriage) {{convert|36|ft|0|in|m}}<ref>{{cite news |url=http://nla.gov.au/nla.news-article51793858 |title=The Festiniog Railway |newspaper=[[Rockhampton Bulletin]] |location=Qld. |date=17 April 1873 |access-date=3 December 2011 |page=3 |via=National Library of Australia }}</ref>

==== Lynton and Barnstaple Railway ====
{{Main|Lynton and Barnstaple Railway}}
[[File:BaldwinLocomotiveLyn.jpg|thumb|[[Builder's photo]] of Lyn]]
* gauge = {{RailGauge|1ft11.5in|first=met}}
* [[Lyn (locomotive)]] over [[Headstock (rolling stock)|headstocks]]
** length = {{convert|23|ft|6|in|m|2|abbr=on}}
** width = {{convert|7|ft|2|in|m|2|abbr=on}}
** height = {{convert|8|ft|11|in|m|2|abbr=on}}
* Passenger
** length = {{convert|39|ft|6|in|m|2|abbr=on}}
** width = {{convert|6|ft|m|2|abbr=on}} wide,
** width over steps = {{convert|7|ft|4|in|m|2|abbr=on}}
** height = {{convert|8|ft|7|in|m|2|abbr=on}}

=== Japan, narrow gauge ===
{{Main|Rail transport in Japan}}
[[File:Rolling-Stock-Gauge-in-Japan.svg|thumb|left]]
Translation of legend: 
* Blue: Rural railway vehicle gauge (Rural Railway Construction Rules 1919)  
* Grey: Conventional [[Cape gauge]] (3ft 6in track gauge) railway vehicle limits (Ordinary Railway Structure Rules 1987) 
* Figures in () are previous Cape gauge rolling stock limits (Railway Construction Rules 1900)
* Green: Shinkansen vehicle limits 

The Japanese national network operated by [[Japan Railways Group]] employs narrow gauge {{RailGauge|1067mm}}. The maximum allowed width of the rolling stock is {{convert|3000|mm|ftin|abbr=on}} and maximum height is {{convert|4100|mm|ftin|abbr=on}}; however, a number JR lines were constructed as private railways prior to nationalisation in the early 20th century, and feature loading gauges smaller than the standard. These include the [[Chūō Main Line]] west of [[Takao Station (Tokyo)|Takao]], the [[Minobu Line]], and the [[Yosan Main Line]] west of [[Kan'onji Station|Kan'onji]] ({{convert|3900|mm|ftin|abbr=on|disp=or}} height). Nevertheless, advances in [[Pantograph (rail)|pantograph]] technology have largely eliminated the need for separate rolling stock in these areas.

There are many private railway companies in Japan and the loading gauge is different for each company.<ref name = "Kubota">{{Cite book | author = Hiroshi Kubota | title = Railway Engineering Handbook | pages = 148 | publisher = Grand Prix publishing | isbn = 4-87687-163-9 | date = 13 February 1997 | language = ja}}</ref>
{{clear}}

=== South Africa ===
{{main|Rail transport in South Africa|Transnet Freight Rail|Passenger Rail Agency of South Africa}}
The South African national network employs {{RailGauge|1067mm}} gauge. The maximum width of the [[rolling stock]] is {{convert|3048|mm|ftin|0|abbr=on}} and maximum height is {{convert|3962|mm|ftin|0|abbr=on}},<ref name = "Kubota" /> which is greater than the normal British loading gauge for standard gauge vehicles.

=== New Zealand ===
{{main|Rail transport in New Zealand|KiwiRail}}
The railways use {{RailGauge|1067mm}} gauge. The maximum width of the rolling stock is {{convert|2830|mm|ftin|abbr=on}} and maximum height is {{convert|3815|mm|ftin|frac=8|abbr=on}}.<ref>{{cite web |title= National Rail System Standard 6 – Engineering Interoperability Standards |url= http://www.kiwirail.co.nz/uploads/Publications/NRSS%206%20-%20Engineering%20Interoperability%20Standards%20(Issue%204,%20Effective%20Date%2019-04-2013).pdf |publisher= KiwiRail |date= 12 April 2013 |access-date= 6 September 2015 |url-status= dead |archive-url= https://web.archive.org/web/20160124060125/http://www.kiwirail.co.nz/uploads/Publications/NRSS%206%20-%20Engineering%20Interoperability%20Standards%20(Issue%204,%20Effective%20Date%2019-04-2013).pdf |archive-date= 24 January 2016 }}</ref>

=== Other ===
{{RailGauge|762mm}} gauge for the [[Rail transport in Great Britain|United Kingdom]] and [[Sierra Leone Government Railway|Sierra Leone]]:
* [[Minimum railway curve radius|Minimum radius]]: {{convert|132|ft|m}}
* Width: {{convert|7|ft|0|in|m|2}} (see [[Everard Calthrop]])
* Wagon length (freight): {{convert|25|ft|0|in|2}} over [[Headstock (rolling stock)|headstocks]]
* Wagon length (passenger): {{convert|40|ft|0|in|m|2}} over headstocks
* Tank engine length: {{convert|29|ft|6|in|m|2}} over headstocks

== Structure gauge ==
{{Main|Structure gauge}}
[[File:2014 Replacement of New Road Bridge, Milton Ernest, Bedfordshire.png|thumb|right|Increasing the structure gauge can involve substantial work. The UK's [[Midland Main Line]] being upgraded in 2014.]]

The structure gauge, which refers to the dimensions of the lowest and narrowest bridges or tunnels of the track, complements the loading gauge, which specifies the tallest and widest allowable vehicle dimensions. There is a [[Engineering tolerance#Clearance (civil engineering)|gap]] between the structure gauge and loading gauge, and some allowance needs to be made for the dynamic movement of vehicles (sway) to avoid mechanical interference causing equipment and structural damage.

== Out of gauge ==
While it may be true that trains of a particular loading gauge can travel freely over tracks of a matching structure gauge, in practice, problems can still occur. In an accident at [[Moston station]], an old platform not normally used by freight trains was hit by a train that wasn't within its intended W6a gauge because two container fastenings were hanging over the side. Analysis showed that the properly configured train would have passed safely even though the platform couldn't handle the maximum design sway of W6a. Accepting reduced margins for old construction is normal practice if there have been no incidents but if the platform had met modern standards with greater safety margin the out of gauge train would have passed without incident.<ref>''[[The Railway Magazine]]'' April 2015, p12</ref><ref>{{cite news|title=Here is a platform alteration|url=http://www.rail.co.uk/rail-news/2015/here-is-a-platform-alteration/|work=rail.co.uk|date=17 February 2015|url-status=live|archive-url=https://web.archive.org/web/20160820111636/http://www.rail.co.uk/rail-news/2015/here-is-a-platform-alteration/|archive-date=20 August 2016}}</ref><ref>{{cite web|title=Report 17/2015: Trains struck platform at Moston, Manchester|url=https://www.gov.uk/government/news/report-172015-trains-struck-platform-at-moston-manchester|website=gov.uk|publisher=Rail Accident Investigation Branch|date=7 October 2015|url-status=live|archive-url=https://web.archive.org/web/20160924053746/https://www.gov.uk/government/news/report-172015-trains-struck-platform-at-moston-manchester|archive-date=24 September 2016}}</ref>

Trains larger than the loading gauge, but not too large, can operate if the structure gauge is carefully measured, and the trip is subject to various special regulations.
{{clear}}

== Gallery ==
<gallery mode="packed" heights="160px" caption="Examples of loading gauges">
File:BS Ladelehre Westbahnhof.JPG|German equipment outline gauge
File:Lademass.jpg|Template to check if the load is exactly within the loading gauge
File:Loading gauge at Moccone.jpg|Equipment outline gauge at [[Moccone]]
File:Loading Gauge Eritrea.jpg|[[Eritrean Railway|Eritrean]] loading gauge 
</gallery>

==See also==
{{Div col|colwidth=23em}}
* [[Berne gauge]]
* [[Bridge]]
* [[Clearance car]]
* [[Engineering tolerance|Clearance space]]
* [[Cut (earthworks)|Cut]]
* [[Platform gap]]
* [[Railway platform height]]
* [[Ride height]]
* [[Structure gauge]]
* [[Tunnel]]
{{Div col end}}

==References==
{{Reflist|30em}}

== Further reading ==
* ''[[Jane's World Railways]]'' yearbook contains many though not all loading gauge diagrams.

==External links==
* [http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32002D0732 2002/732/EC: Commission Decision of 30 May 2002 concerning the technical specification for interoperability relating to the infrastructure subsystem of the trans-European high-speed rail system]
* [http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/loadgauge/loadgauge.htm ''Loading Gauges'' at The Self Site] {{Webarchive|url=https://web.archive.org/web/20160303201424/http://www.aqpl43.dsl.pipex.com/MUSEUM/LOCOLOCO/loadgauge/loadgauge.htm |date=3 March 2016 }}
* [https://www.norfolksouthern.com/en/ship-by-rail/shipping-tools/equipment/railcar-guide Norfolk Southern Railcar Guide & Fleet Specifications]
* [http://www.rica.org/ Railway industrial Clearance Association]
* [http://myweb.tiscali.co.uk/gansg/2-track/02track3.htm British Track Gauge & Loading Gauge] {{Webarchive|url=https://web.archive.org/web/20090812052709/http://myweb.tiscali.co.uk/gansg/2-track/02track3.htm |date=12 August 2009 }}
* [https://www.worldcat.org/oclc/10709088 Railway line clearances and car dimensions including weight limitations of railroads in the United States, Canada, Mexico and Cuba.]
* [http://gritton.org/greg/rail/docs/clearance/AAR_plates_with_UIC.gif AAR plates with UIC]
* [http://www.emdx.org/rail/Gabarit/index.html AAR "plate" loading gauge diagrams compared to UIC (pdf & Autocad)]<!-- Do not remove again -->

{{Rail tracks}}

[[Category:Permanent way]]
[[Category:Rail loading gauge]]