Track gauge

Rise for the San Francisco tram at the Duboce and Noe station in February 2012. You can appreciate the use of metal trays that fix the lanes to ensure the accuracy of the width of the track.

Road width
Tram Metro Miniature trains Railway modeling
Wide way X Breitspurbahn 3000 mm (9' 10.10") X Brunel 2140 mm (7'0.30") Indian 1676 mm (5' 6") Iberian 1668 mm (5' 5.70") Irish 1600 mm (5' 3") Russian 1520 mm (4' 114/5" International width (Stephenson) International 1435 mm (4' 81/2" Close path Scotch 1372 mm (4' 6") Cape Verde 1067 mm (3' 6") Metric 1000 mm (3' 32/5" Three feet 914 mm (3') Three Swedish feet 891 mm (2' 11.10") Imperial 762 mm (2' 6") Bosnian 760 mm (2' 529/32" Two feet 610 mm (2') 600 mm 600 mm (1' 113/5" X Decauville 400 mm (1' 3.70") Minimum X Fifteen inches 381 mm (15 plg) Wide change Mixed width path Conversion of track width List Axis change
This box: See Discussion edit

The track gauge, also known as gauge in Argentina, Bolivia, Chile, Paraguay and Uruguay (where it is also called scantillon >), is the distance between the inner faces of the rails, measured 14 mm below the running plane in straight alignment.

Since the 1830s, when Stephenson's success in developing the first modern steam locomotives fostered the spread in Britain of the proper gauge for his engines (1435 mm (4' 8 ^_1/2")), various historical events led this gauge to become the most widely used in the world, becoming known as “international gauge” or “international gauge”. standard". However, another series of circumstances promoted for different reasons (mainly economic, technical or practical) the existence of an enormous diversity of track gauges, designed to satisfy the most varied transport needs.

By convention, international track gauge (1435 mm (4' 8_^1/2")) is used to distinguish wide tracks (those with a width greater than the standard track) of the narrow tracks (those with a smaller gauge). This is not always the case, and in some countries where the standard gauge is not used (or it is not the official one), normally a narrow track is considered to be any road with less separation between lanes than the country's own.

At the beginning of the XXI century, there were on the order of 1.3 million kilometers of roads worldwide; of which 720,000 km (55%) were standard gauge, about 385,000 km (30%) were broad gauge; and some 207,000 km (15%) were narrow gauge.

History

First track gauges

Mining rail in Alaska.

By agreement, the distance between the internal (or active) faces of the two lanes that configure the track is defined as a width of track or trout, measured at 14 mm below the surface (or plane) of the lane.

Animal Traction Mining Train at the Tunnel Sutro (Comstock Veta Silver Plates, Nevada).

The earliest form of railroad consisted of wooden cars that were pulled individually on wooden rails, almost always into or from a mine or quarry. Initially, the wagons were towed by human force or by draft animals; subsequently replaced by mechanical means. The wooden rails wore out very quickly, so early on they were reinforced with flat cast iron plates to reduce wear. In some areas, the iron plates were L-shaped, with the vertical part of the L guiding the wheels; setting up a "platform". Later, the guiding element moved from track to wheels, and flanged wheels eventually became universal, forcing the spacing between the rails to be compatible with the spacing of the wagon wheels.

As the rolling system for wagons was improved, teams of horses were able to pull short chains of interconnected wagons, and tracks could extend from the immediate vicinity of the mine or quarry usually to a waterway. The wagons were built with pre-established measurements and the track was configured to meet the needs of the horses and the wagons, so the track width became a critical factor. On the Penydarren railway, built in south Wales in 1802, a 4 ft 4 in (1,321 mm) intermediate tamping zone separated the outside of the rail supports.

Cast iron rails shaped like a Cromford and High Peak rail.

The Penydarren Tram probably made the first run with a locomotive in 1804. It was considered a success for the locomotive, but not for the track, which was not strong enough to carry its weight. A considerable step forward was taken when cast iron rails were first used, with the main axis of their section arranged vertically, offering a much stronger profile to resist bending forces. The situation was further improved when fish belly rails were introduced.

This system required a precise match between rail spacing and wheel set configuration, reinforcing the importance of track width. Railways were still seen as local affairs, with no future connection to other lines in mind, so the choice of track gauge remained a pragmatic decision based on local requirements and criteria, and probably determined by railway designs. existing (road) vehicles in each zone.

Thus, the Monkland and Kirkintilloch Railway (1826), located in the west of Scotland, used a gauge of 4 ft 6 in (1,372 mm); the Dundee and Newtyle Railway (1831) in the north-east of Scotland adopted a gauge of 4 ft 6.5 in (1,384 mm); and the Redruth and Chasewater Railway (1825) in Cornwall chose a gauge of 4 ft (1,219 mm).

For its part, the Arbroath and Forfar Railway opened in 1838 with a gauge of 5 ft 6 in (1,676 mm), and the Ulster Railway of 1839 used a gauge of 6 ft 2 in (1880 mm).

Rise of the standard width

One of Stephenson's first locomotives.

In the 19th century, in the world in general and specifically in the coal mines of England, the usual separation between the wheels of the wagons ranged between 1.40 and 1.50 m, an adequate width so that the horses that pulled the wagons could walk without problems between the rails. It was in these mines that Richard Trevithick later introduced the power of steam, inventing the railway.

Early locomotives, dating from the early 19th century century, had very diverse configurations, but George Stephenson developed a locomotive practice for the Killingworth Mine Railway, where he worked as an engineer. His designs were so successful that they became the most widely used, and when the Stockton and Darlington Railway opened in 1825 he used his locomotives, with the same gauge as the Killingworth line, which was 4 ft 8 in (1,422 mm). Possibly, if he had designed the line when he was working at the Wylam mine, its width would probably have been 5 ft (1,524 mm).

The Stockton and Darlington line was immensely successful, and when the Liverpool and Manchester Railway was built, also designed by Stephenson, which would become the world's first intercity line (opened in 1830), the same line was used broad. In fact, when the Rainhill trials were held in 1829 to select the locomotive to be used on the line (Stephenson's The Rocket would be the winning machine), the track was already at this gauge. It was also highly successful, and the gauge would later be adjusted to 4 ft 8.5 in (1,435 mm) to improve circulation around tight corners.

It was in this way that the dimension of the width that would later become the international standard was established: adding half an inch to the width used in some mining wagons that, in turn, had been established within the usual patterns of the time (between 1.4 and 1.5 m), in which the size of the horse's rump had a notable influence.

Gauge differences in Great Britain

Brunel's wide-ranging railroad heading towards the interior of London.

For a few decades, some large-width lines of the Great Western Railway became mixed tracks for standard width (Dicot Railway Center in Oxfordshire).

Liverpool-Manchester was quickly followed by other trunk railways, with the Grand Junction Railway and the London & Birmingham Railway amassing an increasing length of international gauge track. When the Bristol developers planned a rail line from London, they hired innovative engineer Isambard Kingdom Brunel, who decided to use wider track to give rolling stock greater stability at higher speeds. Consequently, the new line, the Great Western Railway, adopted a gauge of 7 ft (2,134 mm), which was later adjusted to 7 ft 1/4 in (2,140 mm). This line became known as a broad gauge railway. The Great Western (GWR) was also very successful, managing to expand its network either directly or through associated companies, extending the reach of broad gauge to much of England and Wales.

At the same time, standard gauge railways were being built in other parts of Britain, and British technology was exported to European countries and to some parts of North America, also using standard gauge. Great Britain was polarized into two zones: the one that used the gauge tracks devised by Isambard Kingdom Brunel and the one that used the standard gauge tracks. In this context, standard gauge lines were known as "narrow gauge" to indicate the contrast with "broad gauge." Some shorter local lines selected other non-standard gauges: for example, the Eastern Counties Railway adopted a 5 ft (1,524 mm) gauge. Most of them were soon converted to standard gauge, but the Great Western's broad gauge continued to spread.

The largest railway companies wanted to expand geographically, and in practice large parts of Great Britain were considered to be under their control. When a new independent line was proposed to link a previously disconnected area, track gauge was a crucial factor in determining the criteria the line would adopt: if it was broad gauge, it should adopt a Great Western Railway-friendly policy; and if it was narrow gauge (standard), it should be favorable to the other companies. The battle to persuade or coerce that choice became very intense, and it was called the War of the widths.

As the transportation of passengers and cargo between the two areas became increasingly important, the difficulty of switching from one gauge to another, the gauge jump, became a serious problem. problem with strong economic repercussions. In 1845, a Royal Commission on Railway Gauges was set up to analyze the growing problem, which led to the Railway Gauge Regulatory Act of 1846, which prohibited the construction of new gauge lines other than branches of the rail network. existing width. Eventually the broad gauge network was changed to standard gauge, a progressive gauge conversion process that was completed in 1892. The same act mandated the use of 5 ft 3 in (1,600 mm) gauge in Ireland.

Width selection in other countries

Different widths from left to right: 1435 mm (4' 8_^1/2"), 1000 mm (3' 3_^2/5"), and 600 mm (1' 11"_^3/5"), (Chino Museum of the Railway, Beijing).

Russian Width: Majorenhof Train Station (today: Majori) in Jurmala, Latvia. Beginnings of the centuryXX..

Mixed wide path in Bangladés: Indian width and metric width. The common lane on both widths appears on the left.

In general terms, with some exceptions, long journeys (with distances greater than 200 or 300 km), in which large masses of population were concentrated and in which the length of travel times had a commercial importance significantly, they tended to be carried out on standard or broad gauge, which in turn meant on many occasions the link with the same gauge to secondary destinations for political reasons and rationalization of the national rail networks. On other lines, generally of a second order, in territories with less economic activity and normally with complicated orography, and where the speed of the trains was not considered a key factor, narrow-gauge railways were chosen (from 1000 mm or less), which was considerably cheaper to implement than broad gauge trains.

In many countries, track gauge selection was pragmatic, with the track being tailored to the type of imported rolling stock. If the locomotives came from elsewhere, especially in the early days, the track would be built to accommodate the imported rolling stock. In some cases the standard gauge was adopted, although many countries or companies chose a different gauge as their national gauge, either by government policy or as a matter of individual choice. The gauge of two of the world's largest broad gauge networks world, the Russian gauge and the Indian gauge, are the result of administrative resolutions supported by more or less well-founded technical decisions. In the United States, after the Civil War, once the large companies in the north of the country were consolidated, the gauge of the tracks of the southern states ended up being unified in 1886. Thus, 18,500 km of tracks with a gauge of 1520 mm were they switched to standard width in record time.

Proof of this fact is the coexistence in many places of networks of different widths within the same country, although the historical tendency in many nations has been to unify the width of their networks.

However, in addition to the aforementioned historical circumstances, there are cases in which the difference in width has also traditionally been attributed (although the plausibility of these reasons is not always justified) to three types of causes: technical issues derived from the orography, economic reasons and strategic reasons:

• From a technical point of view, increase track width, especially in the early decades of the development of steam locomotives, allow to employ machines with wider boilers (increasing their power), or also use larger wheels to be able to circulate more quickly (situating the boilers in the middle, and not above the wheels). In the first case, this requirement served to allow in Spain, a complicated country of spelling, to opt for a width of 1668 mm (5' 5.70"), according to the Arguments of the report Subercase. In the second case, the 7-foot width 1/4 plg (2140 mm) preconducted by Isambard Kingdom Brunel would allow its new locomotives to reach in the Great Western Railway inaccessible speeds to the standard width trains of the time. However, the vertiginous refinement of steam machines in the following decades made these arguments lose the weight they initially had.

In the case of the narrow road, the technical reasons are combined with the economics, and are mainly related to the orography, since a narrower way allows for a lower cost in the construction of the tunnels. This was the case in Spain, for example, with the new General Ferrocarry Law of 1877, which led to the construction of economic railways in mountainous areas and was to move from 360 to 1900 km of narrow route between 1880 and 1900. As a general rule, for long journeys a greater width was chosen to obtain greater profitability, and in shorter and steeper sections, where the layout was sinuous and complicated, the narrow path was chosen, as it was more economical.

• Economic reasons relate to the maintenance of closed markets, hindering the entry of products from other countries. In practice, while the shift in width poses an inconvenience to the traffic of goods by rail between states, the emergence of other increasingly effective means of transport (such as road transport) and the possibility of transferring goods between trains with relative effectiveness (such as in the case of containers) relegate this reason to a secondary role. At the time, it became a deterrent factor used by local transport companies in the United States to make it difficult to purchase by larger companies. In practice, the change in width is a brake on imports, but also exports, so, at the expense of the enormous costs that would result in changing thousands of kilometres of roads and the renewal of mobile material, the long-term trend for its obvious advantages is to unify the widths between neighbouring systems, as has already happened first in England, later in almost all Europe, also between the north and the south of the United States, and shortly thereafter in Canada.

• The alleged defensive motives respond to the belief that it is very difficult to introduce troops and armaments in a country with different track width, unless they are transferred to trains with that width. However, the German army strangled 28,700 km (from the Russian width of 1520 mm to the standard width of 1435 mm) in its advance by the USSR between 1941 and 1943. If what you want is to prevent an invasion, it is best to install roads with a much lower width that would prevent the passage of larger trains in tunnels and bridges.

As already noted, narrow gauge was widely used in mountainous regions, as construction costs tended to be lower and made it possible to take sharper turns, which in turn allowed the track to follow the terrain reducing the need to build large tunnels and bridges, significantly lowering the cost of infrastructure works, which were already smaller (requiring smaller section tunnels and viaducts capable of withstanding lower loads, since the trains are smaller). The diffusion of two of the most widespread narrow gauge types, Cape gauge (from 1067 mm) and metric gauge (from 1067 mm -space:nowrap">1000 mm) was linked to British (in the first case) or French (in the second) financial presence or influence in large parts of Africa, South America and Southeast Asia. In fact, metric gauge provided the French alternative to the 3 ft 6 in (1,067 mm) gauge initially extended by English mining companies. Japan and Taiwan have modernized many of their Cape gauge lines. These railways, conveniently updated, like those existing in Switzerland and Spain with metric gauge, are far from the precarious systems that still operate in some parts of central Africa.

Trocha Decauville

Railroad Decauville in Balcarce, Argentina (hacia 1920)

There is some confusion as to what should or should not be called the "Decauville trail". The French company Decauville, created in 1875, manufactured both rails and a wide variety of railway material for industrial use and transport in general. One of his most widespread inventions, due to its ease of installation, was the 600 mm wide Decauville track, in which the rails were integrated with the sleepers in a single piece of steel. The ease of its installation popularized its use in mining, industry and in war. This Via Decauville (which is not the same as the corresponding trail) was later built in other lower and higher measurements. The denomination "decauville gauge", which in France applies only to the measurement of 600 mm, in Argentina is generally used to define all the economic gauges less than a meter (1000 mm), although in many other parts of the world it does not have a defined meaning.

Consolidation of the Stephenson gauge as an international gauge

Train Eurostar, able to circulate through France and England through the Channel Tunnel

It took a few years for Stephenson's breadth to acquire the adjective international. A first step, already mentioned, took place on August 18, 1846, when the British Parliament set exactly 4 feet 8 1/2 inches (approximately 1435 mm) the gauge with which to build the lines in England, Scotland and Wales, putting order to the diversity of gauges with which the British railway had grown after the inauguration of the Liverpool-Manchester line. With this, the Stephenson gauge had become the British national gauge, but Switzerland, as a border country with four other countries, was the driving force behind an international conference to standardize track gauge. Thus, in 1886, at the Berne Conference, the definitive step was taken, recommending the Stephenson gauge of 1435 mm (4' 8_^1/2") as international standard width.

Today, approximately between 55 and 60% of the railways on the planet use standard gauge, and all the high-speed lines built in Europe (including Spain), China and Japan, are they have performed internationally.

Timeline

The following is a series of relevant dates in the development of the different track gauges:

• 1825: 4-foot width 8.5 plg (1435 mm) chosen by George Stephenson
• 1827: 5-foot width (1524 mm) chosen by Horatio Allen for the Canal Company and the South Carolina Railway
• 1836: Ancho of 23 1/2 plg (597 mm) chosen by Henry Archer for the Ferrocarry of Festiniog to circulate more easily on mountainous terrain (the first narrow-road passenger service in Britain began in 1865) (originally thrown by horses)
• 1838: Width of 7 feet 1/4 plg (2140 mm) chosen by Isambard Kingdom Brunel
• 1842: 5-foot wide (1524 mm) chosen by George Washington Whistler for the Moscow-St.Petersburg Railway, based on the practice of the south of the USA. U.S.
• 1844: 1668 mm width (5' 5.70") fixed in Spain by the Subercase Report
• 1846: 5-foot width 3 plg (1600 mm) chosen in Ireland as a compromise solution
• 1853: 5-foot wide 6 plg (1676 mm) chosen by James Broun-Ramsay in India following Scottish practice
• 1862: 3-foot width 6 plg (1067 mm) chosen by Carl Abraham Pihl for the Røros Line in Norway in order to reduce costs
• 1865: 3-foot wide 6 plg (1067 mm) chosen by Abraham Fitzgibbon for the Queensland Railways in order to reduce costs
• 1870: 3-foot width (914 mm) chosen by William Jackson Palmer for the West Denver and Rio Grande Railway, also to reduce costs (inspired by the Festiniog Railway)
• 1874: Ancho de 15 plg (381 mm) chosen by Arthur Heywood at the Duffield Bank Railway
• 1875: 400 mm width (1' 3.70") used in the Decauville tracks
• 1877: 2-foot wide (610 mm) chosen by George E. Mansfield for the Billerica and Bedford Railway to reduce costs (inspired by the Festiniog Railway)
• 1880: 1000 mm width (3' 3_^2/5") normalized by French law
• 1887: 2-footed width 6 plg (762 mm) chosen by Everard Calthrop to reduce costs; with designs for a standard rolling stock fleet

Units

Widths are defined in units of the imperial system, the metric system, or the International System of Units.

Imperial units were established in the United Kingdom by the Weights and Measures Act of 1824. US Customary Units for length did not agree with the Imperial system until 1959, when the international yard was defined as 0.9144 meters, that is, 1 foot is equal to 0.3048 meters and 1 inch is 25.4 mm.

The list shows the imperial and other units that have been used for gauge definitions:

Track gauges in the world

Locomotora diésel Jung, of the Patrimonial Train of the Cajón del Maipo, Chile. 600 mm road width

Steam locomotive for 15" width (381 mm) in Wisconsin Dells, Wisconsin, USA. U.S.

FEVE train (currently Renfe Cercanías AM) in Cistierna (metrical width)	Nearby trains in Barcelona (Iberian rubber)
Ave Series 103 RENFE (international law)	Talgo Renfe Series 130, Patito. Variable width (illary-standard)
Spain has wide, standard and metric track networks

These are some examples of the most widely used track gauges in the world. In many countries several of them coexist:

• 260 mm - Used in the tourist train Economic Railway Sud, located in the Predio del Ferroclub Argentino headquarters Remedios de Escalada, in the Railroad Piedra Baya, located in Merlo, province of San Luis, Argentina, in the Rudyard Lake Steam Railway, located in Staffordshire, England, and other tourist railways in the world.
• 500 mm - Used in the tourist Ferrocarril Austral Fueguino, west of Ushuaia, south of Argentina.
• 600 mm - Used in the Artikutza Mining Train (closed), Museo Minero de Utrillas (Aragón), FC Turística del Alto Llobregat, FC del Museu de les Mines de Cercs (Barcelona), FC del Museo del Ferrocarril de Asturias (Gijón) and Ecomuseo Minero de Samuño in Spain, in the Decauville System in Portugal MilitarXXI in the Ecological Train of the Forest.
• 610 mm - Used in Argentina in the Camber Railway in the Falkland Islands.
• 650 mm - Used in HUNOSA, Spain.
• 750 mm - Used in many industrial and mountain railways, for example the Ramal Ferro Industrial Eva Perón and branches of the Patagonian Railway in Argentina (including the Ing. Jacobacci - Esquel, popularly known as “La Trochita”), FC of the Museo del Ferrocarril de Asturias (Gijón), mountain railways in Germany, Spain (Gerona-San Feliu de Guíxols, closed in 1969), Estonia, Finland, Greece, Indonesia, Latvia, Lithuania, Poland, Ukraine and Switzerland.
• 762 mm - Used in Austria, Bosnia Herzegovina, Bulgaria, Hungary, India, Nepal, Poland, Czech Republic, Romania and Sri Lanka.
• 800 mm - Used in some zipped mountain railroads in Switzerland, Scotland (Snowdon) and industrial railroads in Germany, Poland and Romania.
• 891 mm - Used in the Roslagsbanan Sweden network.
• 914 mm (1 yard)- Used in the Yukon network of Canada, Colombia, U.S. secondary network. UU., El Salvador, Guatemala, Peru and Spain (FC de PortAventura Park, railroad, Tram de Sóller and Railroads de Mallorca, from 1875 to its metric widening in 1981).
• 950 mm (Italian metric width) Used in Italy: all lines in Sardinia, lines "Ferrovia Circumetnea" (Catania), "Ferrovia Circumvesuviana" (Napoles), and in Eritrea and Somalia.
• 1000 mm (metric width) - Used in East Africa and West Africa, Germany, Argentina (in the network of the General Railway Belgrano and in the Train to Development), Bolivia, Brazil, north and branch network Talca - Constitution in Chile, Spain (Historical Train of Arganda, and Line C-9 (Cercanías Madrid), in the line Llobregat-Anoia of the FGC, the lines of the Valencian Railways of Mallorca
• 1050 mm - Used in the Hiyaz Railway (Syria-Jordan-Saudi Arabia)
• 1067 mm (English: Cape gauge) - Used in Angola, Queensland and Western Australia, Botswana, Ecuador, Salitrero Railroad Maria Elena - Tocopilla in Chile, Costa Rica, Philippines, Ghana, Honduras, Indonesia, zairaisen network in Japan, Rio Tinto FC Spain, Mozambique, Namibia, Nicaragua, Nigeria, New Zealand, Republic of the Congo, South Africa, Sudan, South Sudan, Tanzania, Taiwan.
• 1200 mm - Used in the FC Rheineck - Walzenhausen (cremallera) in Switzerland.
• 1219 mm - Used in the FC of Tharsis to the Port of Huelva Spain, closed in 1999.
• 1372 mm (also called) Scottish trout) - Used formerly in Scotland and only by the Keio line in Japan today.
• 1429 mm (also called modified standard width) - Used only in Washington Metro in the United States.
• 1435 mm (also called international width, medium trout, standard width or UIC width) - Used in North Africa, Alaska, Argentina (Ferrocarril General Urquiza, Subte de Buenos Aires, Premetro, Tren de la Costa, Metrotranvía de Mendoza Tramway Historic of Buenos Aires and Tramvía Histórico de Rosario), New South Wales and ANR Australia, Canada, in Chile (Metro del Santiago) U.S., in much of Europe (in Spain, only in high speed lines, in the lines L2, L3, L4, L5, L6, L7, L9, L10, L11 and L12 of the Metro of Barcelona, in line 1 of the Metro of Seville and in the lines L6, L7, S1, S2, S5 and Ossen Railways of the Generality of Catalonia), India (in metro systems), Iran, Panama Used in India only for metropolitan railways.
• 1445 mm - Used in the main lines of the Madrid Metro.
• 1520 mm (Russian rubber) - Used in Slovakia, Mongolia, East Poland, Russia and in all countries that were part of the former Soviet Union (the previous width was 1524 mm).
• 1524 mm (Russian rubber) - Used in Finland and (before 2000) in Panama, now (1435 mm).
• 1600 mm - Used in Victoria and South Australia, Brazil and Ireland, Grand Duchy of Baden (Germany) (1840 - 1855).
• 1668 mm (Iberian width) - Used in Spain (conventional network, the previous width was 1674 mm) and Portugal (the previous width was 1665 mm).
• 1672 mm - Used in Portugal (the previous width was 1665 mm).
• 1674 mm (old Spanish, equal to 6 feet Spanish) - Used in Spain and on Line 1 of Barcelona Metro.
• 1676 mm (wide trout) - Used in Argentina (in the networks of General Roca Railway, General Mitre Railway, General San Martín Railway and Sarmiento Railway), Bangladés; in the Limache-Puerto Train, Valparaíso and central and southern networks of Chile (EFE); India, Pakistan, Sri Lanka and in the San Francisco Metro, USA. U.S..
• 2140 mm - The largest global width (between 1836 and 1892) was that of the British company Great Western Railway, with Brunel design. The original width was 2134 mm but was soon extended to 2140 mm.

There may be others of different sizes, but those indicated are the most common.

Distribution of railway lines according to the main gauges

The total length of railway lines in the world is a data in constant evolution, due both to the constant construction of new lines and to the gradual disappearance of low-profit lines in many countries of the world. Likewise, the figures may vary significantly if tram or metro networks are included or not.

Distribution by country

According to the data below, approximately 55% of the world's railways use the 1435 mm (4' 8_^1/2"):

Distribution by geographical area

As an order of magnitude, it can be considered that by the end of the XX century (1986) they existed throughout the world of order of 1.25 million kilometers of railway lines, with the following distribution:

Distribution of road types by country

(*) Russia is considered to be included in its entirety. Source: K. Henderson (1986)

Total distribution by types of width

Estimated totals for each type of width: