A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform.
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.
The Finnish railway network consists of a total track length of 9,216 km (5,727 mi). The railways 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 coupling system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles to one another.
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.
A variable gauge system allows railway vehicles in a train to travel across a break of gauge between two railway networks with different track gauges. For through operation, a train must be equipped with special bogies holding variable gauge wheelsets which contain a variable gauge axle (VGA).
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).
Camrail is a company operating passenger and freight traffic between the two largest cities in Cameroon and several smaller cities. The company was formed in 1999 and granted a 20-year concession to operate the Cameroon National Railway. The company is a subsidiary of French investment group Bolloré and the railway has been operated by Comazar, a subsidiary of Bolloré, since 1999. According to the Comazar website, the government of Cameroon owns the track while the rolling stock is owned by Camrail.
The Scharfenberg coupler is a commonly used type of fully automatic railway coupling.
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.
The South African Railways Class 91-000 of 1973 was a narrow-gauge diesel–electric locomotive.
Janney 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. They are also known as American, AAR, APT, ARA, MCB, knuckle, Buckeye, tightlock, Henricot or Centre Buffer Couplers.
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.
Buffers and chain couplers are the de facto International Union of Railways (UIC) standard railway coupling used in the EU and UK, and on some surviving former colonial railways, such as in South America and India, on older rolling stock. Buffers and chain couplers are an assembly of several devices: buffers, hooks and links, or turnbuckle screws.
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.
Digital automatic coupling (DAC) is a type of railway coupling developed in the 2020's to replace the English buffers and chain couplings, initially in Europe.
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