Track gauge

As a track is the distance between the track leading elements of the infrastructure is referred to the railways. Conventional webs, these are the inner edges of the rail heads of a track. Sometimes the term " track width " used. For rail vehicles, the track width of the tracks is given for which the drive is designed. The distance between the wheel flanges is referred to as track gauge.

In Germany, the track width is measured according to § 5 of the Railway Construction and Operating Rules in the range between 0 and 14 millimeters below the top of rail.

After high speed TSI infrastructure, point 4.3.3.10, the track width is to be measured at a height of 14.5 millimeters with a tolerance of 0.5 mm below the top of rail.

In Switzerland, the track width is measured according to the Regulations for the Railways Ordinance (AB -EBV ) for standard gauge and meter gauge 14 mm below the surface rail, and trams for 10 mm below the rail running surface.

Importance

The drives of rail vehicles are designed to be used on track a particular gauge. An exception to this rule are vehicles with umspurbaren drives represents a transition from vehicles between networks with different track widths is only possible with considerable additional effort. Therefore, the track width is an important criterion for the interoperability of the railways. Conversely, however, does not mean the same track width that a transition of vehicles is automatically possible. So in most tram networks is a transition to Railroads same gauge because of different track and wheel geometry not allowed.

Track width tolerance

In connection with gauge only nominal size is usually ( in the German railway construction and operation regulations define as a basic measure ) specified. The actual size, so the actual, local gauge can deviate significantly from the nominal dimension. So applies to standard gauge tracks ( 1435 mm nominal size ) in Germany, a tolerance range.

With the introduction of the railway construction and operations (EBO ) 1967 the track was - according to the revision of the text of the Technical Unit of 1960 - in a standard size of 1435 mm with a lower limit of 1430 mm and an upper limit of 1465 mm ( for main tracks ) or 1470 mm ( sidings ) defined. Track extensions in curves with radii less than 200 m, which were previously subject to a decree of the Federal Minister of Transport, were taken over in the EEO.

Track width differences

The railway companies chose different track widths, as can be seen from the list of gauges.

The choice of a particular gauge had both military as well as economic reasons.

From a military point of view was often the concern that the enemy could use in case of war the railway network for its own purposes. Therefore, the track width differences were often elected to the neighboring country deliberately so that neither a transition of the vehicles still use the threshold to build a three-rail track was technically possible.

From an economic perspective often concern as to prevent competing companies and their vehicles are able to share their own infrastructure. From such motives negotiated some U.S. street railway companies, who wanted to prevent with the fact that their distances could be used by the competing interests of Urban or conventional railways to handle the local freight. In the period of financial decline of the privately funded public transport in the 1920s, the different gauge turned out to be a disadvantage, because the decline in revenue from the passenger could not be offset with additional freight. Examples of such systems are located approximately in Philadelphia and Pittsburgh.

Railway companies chose their gauges also for financial reasons, because the cost of the superstructure of a narrow gauge line are lower than for a standard gauge track, as less wood for sleepers is necessary and the rails are lighter. The smaller differences in length of the two rails of a narrow-gauge railway track in curves reduces the friction of the wheels when driving on narrow arches, resulting in less wear and a smaller rolling resistance in the arches. This in turn allows a Routing with more sheets that are better able to follow the terrain, thereby avoiding expensive engineering structures. Have narrow-gauge railways but because of the smaller vehicles usually a lower transport capacity than webs with larger gauges and hamper where they are built along roads or even to share the road subgrade, the expansion of the road.

The nominal track (obsolete " standard gauge " ) of 1435 mm is distributed worldwide to 75 percent on the rail networks, track widths below this measure occupy 13 percent and 12 percent larger track widths of the rail network ( guide).

Important gauges

• The 1676 -mm track used mainly in India, Pakistan, Bangladesh and Sri Lanka as well as in Chile and Argentina ( 5 ½ feet / 5 ' 6 ") is one of the greatest wide tracks, it is also called Indian broad gauge.
• The slightly deviating Iberian broad gauge of 1668 mm was obtained by averaging the Spanish ( 1672 mm / 6 kast. Feet) and Portuguese (1665 mm / 5 port. feet) broad gauge to facilitate inter-vehicle gangways.
• Railway networks with 1600 mm track gauge ( 5 ¼ feet / 5 '3 " ) exist primarily in Ireland and Northern Ireland and parts of Australia ( states of Victoria and South Australia) and to 20 percent of the Brazilian network. It is also called Irish broad gauge. Too Baden initially built from military - strategic reasons, in this gauge, it has but then rebuilt after a few decades to the normal track of the neighboring lanes.
• In Russia and the other CIS countries, but also in Finland, Mongolia, Estonia, Latvia and Lithuania in 1524 -mm (5 ft / 5 '), now 1520 mm broad gauge was used, it is also called the Russian broad gauge. It also emerged after the measure of the normal track, originally the center of the tread and the rail heads was taken as the distance like the carriages. In this Russian broad gauge but this measure was taken after today's usual style for the clear width.
• The 1435 mm (4 feet 8 ½ inches / 4 ' 8 ½ " ) wide standard gauge is made ​​in China, Mexico and North America almost exclusively and used in the route network of the European Union to 87 percent gauge., The standard gauge network in these countries listed alone already represents more than 40 percent of the world's railway network.
• In southern Africa, Japan and Australia's states Western Australia, Queensland and Tasmania and New Zealand, the 1067 mm (3 ½ feet / 3 ' 6 ") used broad Cape gauge. Countries with Cape gauge are Ecuador, Nicaragua ( removed), Costa Rica, Nigeria, Ghana ( is brought up to 2014 on standard gauge ) and Sudan.
• The meter gauge (1000 mm ) is the most widely used gauge in Brazil, as well as narrow gauge railways and tramways in Germany, Spain and Switzerland, and other countries. The largest contiguous rail network in South America from Brazil to Bolivia and Argentina to Chile also has the meter gauge. About two-thirds of the tracks in Tunisia have meter gauge, as well as the railways in Kenya, Tanzania, Uganda, Ethiopia, Cameroon, Madagascar, Benin, Togo, Ivory Coast, Burkina Faso, Guinea ( partial), Senegal - Mali. In Asia, the meter gauge in India, Bangladesh, Thailand, Myanmar, Malaysia, Cambodia and Vietnam is widespread.
• 950 mm was the predominant gauge for narrow gauge railways in Italy and for narrow-gauge lines that were built in the Italian director. Eritrea also has the 950 mm track. It is also called Italian meter gauge and is based on a different definition of track width. The meter was measured from the center of the rail heads and treads. (See Russian broad gauge )
• 914 mm (3 feet / 3 ') wide narrow gauge railways are used inter alia in the U.S. and the UK. But they are also found in various sugar cane railways in Cuba and Indonesia. The lanes in Guatemala ( decommissioned), El Salvador and Colombia and Peru also have some tracks in that gauge on. The tram Chemnitz had 925mm or a track width of 915 standard gauge before their conversion.
• The 760 mm ( 762mm = 2 ½ ft / 2 ' 6 ") wide Bosnian gauge was first introduced in Bosnia, in the former Austria -Hungary and the successor states.
• Frequently, the 750 -mm narrow gauge was applied, for example in the Saxon narrow gauge railways. In addition to other routes in Germany it is also to be found for example in the Swiss Waldenburgerbahn, further used in many industrial and military paths such as the path of the international regulation of the Rhine. This gauge is the smallest operation can be safely transported by regular or wide-track vehicles using dollies or trolleys.
• For non- public industrial railways and railways and mining, among others, the track width of 600 mm was widespread. But also tracks by public transport, such as the Mecklenburg- Pomeranian narrow gauge track were built in this gauge. In today's Namibia once existed an extensive 1000 km long railway network with only 600 mm gauge.

For more gauges see: List of track gauges

Change of gauge

The different gauges were initially always traveled by different vehicles. However, they are a correspondingly large obstacle to through traffic dar. Various techniques have been developed, such as freight and passenger transport is performed over different gauges away with time.

Gauge changes without adjustment

Different track widths with little difference (up to about 15 mm) can possibly be driven with the same vehicle. It is necessary that the allowable track play is observed in both systems. By using special sets of wheels with wider tread that allow a larger track game, even slightly larger track width differences can be overcome (depending permitted by the speed and other parameters, in some cases up to 60 mm).

Gauge changes by transfer / transhipment

A frequently encountered solution is that people switch between different trains, or the goods are loaded by a carriage to another. Transhipment in freight transport was formerly carried by hand, later also with forklifts or small cranes.

Use of swap bodies

Since nowadays containers and swap bodies are used with standardized measures for the transport of goods by various modes of transport, is this system offers also the transition between gauges. However, container use the gauge of most railway networks from poorly. Particularly for freight with the Iberian Peninsula, swap bodies complete trains will be replaced by powerful cranes. The lower parts of the car remain in each case on a gauge. For such shipments were special cars, including Schiebewandwagen, develops, their bodies compared to containers usually not be transported with other modes of transportation ( truck or ship ). A disadvantage is the required storage space for the free bases on the lane change stations.

Gauge changes by on-board adjustment

Exchange of axles / bogies

In certain railway vehicles, the axles or bogies can be replaced, so a transition to a different track width is possible. However, this assumes that the vehicles otherwise match ( eg clutch, brake system ), or other parts to be converted. Because of the high proportion of two-axle cars in exchange of wheelsets is particularly common in the Iberian Peninsula, as well as freight to Finland. The proportion of the standard gauge network passing freight cars from the Eastern European broad gauge network has decreased in recent years. In the network of former USSR bogie wagons are used almost exclusively, the bogies are exchanged as a whole. The different train and shock devices require the use of dome cars. In travel with the tracks of the former USSR, the bogies and the couplers are changed. Until 1994, also through trains were run to Spain and Portugal in the same way. Since then, only Talgo trains (RD and pendular ) are used for this ( see below).

Dolly / trolley traffic

In particular, for traffic between the main network of railways and shorter narrow gauge lines are dollies or carts ( in Switzerland rolling stool called ) have been developed, with a normalspuriger railroad cars of special equipment is pushed onto the dollies or trolleys and then moves " piggyback ". Because of today small proportion of freight traffic on branch lines dollies and trolleys are only rarely found in use.

On standard gauge trolleys are used for the transportation of new vehicles for narrow gauge trains and trams.

Automatic gauging

The Spanish company Talgo developed a system in which the wheels individually sit on stub axles, which can be moved laterally with their camps. To change the track width of the train has to move across a special Umspuranlage. The axle bearings are unlocked, the relieved wheels apart or compressed by guides until they are able for the different gauge and then re-locked in this position. Talgo trains, both passenger between Spain and France as well as in domestic traffic. Besides Talgo locomotives also with umspurbaren Talgo bogies were developed.

Next umspurbarer landing gear systems also allow the gauging of loaded axles and the transfer of vehicles between standard and meter gauge.

Gauge changes permanent way by mutual adjustment

The Spanish government in 2007 a ​​report commissioned to determine the costs and benefits of a nationwide rail gauge conversion from the current 1668 mm on the European standard gauge ( 1435 mm). The newspaper El Pais estimates that an adjustment of the 12,000 km -long rail network would take at least until 2020.

Gauges in model trains

Similarly, there are at Model Railways different gauges, which are of the image scale and the track width of the selected role model dependent. The world's most widely used Scale H0 1:87 scale using a track gauge of 16.5 mm, which corresponds in this scale the standard gauge of 1435 mm.