In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many different track gauges exist worldwide, gauge differences often present a barrier to wider operation on railway networks.
A coupling or coupler is a mechanism, typically located at each end of a rail vehicle, that connects them together to form a train. The equipment that connects the couplers to the vehicles is the draft gear or draw gear, which must absorb the stresses of the coupling and the acceleration of the train.
A transporter wagon, in railway terminology, is a wagon (UIC) or railroad car (US) designed to carry other railway equipment. Normally, it is used to transport equipment of a different rail gauge. In most cases, a transporter wagon is a narrower gauge wagon for transporting a wider gauge equipment, allowing freight in a wider gauge wagons to reach destinations on the narrower gauge network without the expense and time of transshipment into a narrower gauge wagons.
With railways, a break of gauge occurs where a line of one track gauge meets a line of a different gauge. Trains and rolling stock generally cannot run through without some form of conversion between gauges, leading to passengers having to change trains and freight requiring transloading or transshipping; this can add delays, costs, and inconvenience to travel on such a route.
The Finnish railway network consists of a total track length of 9,216 km (5,727 mi). Railways in Finland are built with a broad 1,524 mm track gauge, of which 3,249 km (2,019 mi) is electrified. Passenger trains are operated by the state-owned enterprise VR that runs services on 7,225 km (4,489 mi) of track. These services cover all major cities and many rural areas, though the coverage is less than the coverage provided by the bus services. Most passenger train services originate or terminate at Helsinki Central railway station, and a large proportion of the passenger rail network radiates out of Helsinki. VR also operates freight services. Maintenance and construction of the railway network itself is the responsibility of the Finnish Rail Administration, which is a part of the Finnish Transport Agency. The network consists of six areal centres, that manage the use and maintenance of the routes in co-operation. Cargo yards and large stations may have their own signalling systems.
A buffer is a part of the buffers and chain coupler system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles together.
Type H Tightlock couplers are a variety of Janney coupler, typically used on North American mainline passenger rail cars. They have mechanical features that reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types used by North American freight railroads.
Variable gauge systems allow railway vehicles to travel between two railways with different track gauges. Vehicles are equipped with variable gauge axles (VGA). The gauge is altered by driving the train through a gauge changer installed at the break of gauge which moves the wheels to the gauge desired.
The African Union of Railways is an organisation under the auspices of the new African Union dealing with railways. It is similar to the International Union of Railways (UIC).
Rail transport in Russia runs on one of the biggest railway networks in the world. Russian railways are the third longest by length and third by volume of freight hauled, after the railways of the United States and China. In overall density of operations /length of track, Russia is second only to China. Rail transport in Russia has been described as one of the economic wonders of the 19th, 20th, and 21st centuries.
The Scharfenberg coupler is a commonly used type of fully automatic railway coupling.
Bogie exchange is a system for operating railway wagons on two or more gauges to overcome difference in the track gauge. To perform a bogie exchange, a car is converted from one gauge to another by removing the bogies or trucks, and installing a new bogie with differently spaced wheels. It is generally limited to wagons and carriages, though the bogies on diesel locomotives can be exchanged if enough time is available.
Rail transport in Montenegro is operated by four separate companies, which independently handle railway infrastructure, passenger transport, cargo transport and maintenance of the rolling stock. The four companies were a part of public company Railways of Montenegro until it was split up in 2008.
SA3 couplers or Willison coupler and Russian coupler are railway couplings used primarily in Russia and states influenced by the former Soviet Union, such as Finland, Poland, and Mongolia.
A barrier vehicle (BV), barrier wagon, match wagon or translator coach is used to convert between non-matching railway coupler types. This allows locomotives to pull railway vehicles or parts of a train with a different type of coupler. A match wagon has an identical dual coupling at both ends.
Knuckle couplers are a semi-automatic form of railway coupling that allow rail cars and locomotives to be securely linked together without rail workers having to get between the vehicles.
A Norwegian coupling or coupler, is a manually operated coupling at each end of some narrow-gauge railway rolling stock. It consists of a central buffer incorporating a hook that drops into a slot in the opposing central buffer. The system is only found on narrow gauge railways with a gauge of 1067 mm or less on which low speeds and train loads allow a simpler system than, for example, knuckle couplers. Norwegian couplings are not particularly strong, and may be supplemented by auxiliary chains. Not all Norwegian couplings are compatible with one another since they vary in height and width. Some may permit a hook from both rail vehicles to be in place; others may be limited to one.
From time to time, a railway decides that it needs to upgrade its coupling system from one that is proving unsatisfactory, to another that meets future requirements. This can be done gradually, which can create many problems with transitional incompatibilities, or overnight, which requires much planning.
The Cape Government Railways 0-4-0ST of 1873 was a South African steam locomotive from the pre-Union era in the Cape of Good Hope.
Different types of railroad rolling stock have different couplers depending on the purpose and type of equipment being used and its intended destination. European rolling stock tend to use buffers and chain couplers while American rolling stock uses a Janney coupler or "knuckle coupler". These are incompatible with each other, but where some railroads have obtained older, less expensive used rolling stock from different countries or regions, instead of having to standardize on one form of coupler, it may be useful to be able to use either type of coupler on a piece of rolling stock without having to remove anything.
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