The balance lever coupling, also known as rocking lever coupling or compensating coupling, is a type of central buffer coupling that has found widespread use, especially in narrow-gauge railways. In Switzerland this type of coupling is called a central buffer with two screw couplings, abbreviated to Zp2, [1] or referred to as a central buffer coupling with coupling hooks on the side [2]
The UIC standard coupling is not suitable for narrow gauge railways with their often tight curve radii. By exchanging the tension and compression devices, the standard screw coupling used on standard gauge railroads became the central buffer coupling with screw coupling on the side connected to a balance lever [3]
The balance lever coupling has a movable balance lever mounted transversely behind the buffer, to which a draw hook is attached on the left side of the center buffer and an eye with a screw coupling on the right side. In the center of the screw coupling is a screw with a left-hand thread on one side and a right-hand thread on the other. To connect, the screw coupling of each vehicle is hooked into the hook of the other coupler. The screws in the screw couplers are then tightened with the ball handle attached to them. The turnbuckle-style arrangement pulls the vehicles together so that a preload is applied to the center buffers of the couplers, providing a smooth, jerk-free ride. The couplers' balance levers distribute the load evenly between the two screw couplers. The balance levers may be located in front of or behind the buffer beams, in which case the hook and eye for holding the screw coupling pass through recesses in the buffer beam.
In the case of simple designs, the screw is partly replaced by a triangular isosceles chain link. This chain link has side lengths of different lengths, so the length of the coupling chain for separating or tensioning the train can be varied by simply turning the chain link.
With the introduction of transporter wagons, the balancing lever coupling was combined with the funnel coupling on most of the narrow-gauge railways in order to be able to couple the rolling carriage by means of a dome boom. An additional auxiliary coupling for coupling the trolleys is common on Polish narrow-gauge railways. On the Rhaetian Railway, the roller bogies (roller carriages) are equipped with normal couplings; if necessary, flat wagons can be lined up as barrier vehicles in between.
In Switzerland, the center buffer couplings are only referred to as manually operated couplings, but not as automatic couplings. Two types are used. [4]
| Center coupling | |||||||||||||
| Center buffer with two screw couplers (Zp2) | Center buffer with one screw coupler (Zp1) | ||||||||||||
Examples of the use of the balance lever coupling today are:
The Bodensee–Toggenburg railway is a mainly single-track standard-gauge line connecting Romanshorn on Lake Constance and the Toggenburg region in Eastern Switzerland. It was built by the Bodensee-Toggenburg-Bahn (BT), a former railway company, which existed from 1910 until its merger with the "old" Südostbahn (SOB) to form the "new" Südostbahn (SOB) on 1 January 2001. Today, the line together with the Wattwil–Ebnat-Kappel section forms the eastern network of the Südostbahn.
Brake van and guard's van are terms used mainly in the UK, Ireland, Australia and India for a railway vehicle equipped with a hand brake which can be applied by the guard. The equivalent North American term is caboose, but a British brake van and a caboose are very different in appearance, because the former usually has only four wheels, while the latter usually has bogies. German railways employed brakeman's cabins combined into other cars.
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 buffer stop, bumper, bumping post, bumper block or stopblock (US), is a device to prevent railway vehicles from going past the end of a physical section of track.
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.
Robert Hudson Ltd was a major international supplier of light railway materials, based in Gildersome, near Leeds, England. The name was later changed to Robert Hudson (Raletrux) Ltd.
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.
The railcar couplers or couplings listed, described, and depicted below are used worldwide on legacy and modern railways. Compatible and similar designs are frequently referred to using widely differing make, brand, regional or nick names, which can make describing standard or typical designs confusing. Dimensions and ratings noted in these articles are usually of nominal or typical components and systems, though standards and practices also vary widely with railway, region, and era. Transition between incompatible coupler types may be accomplished using dual couplings, a coupling adapter or a barrier wagon.
The three engines of DRG Class 99.22 were standard, narrow gauge locomotives (Einheitsloks) in service with the German Reichsbahn. They had operating numbers 99 221 to 99 223.
The construction and operation of Swiss railways during the 19th century was carried out by private railways. The first internal line was a 16 km line opened from Zürich to Baden in 1847. By 1860 railways connected western and northeastern Switzerland. The first Alpine railway to be opened was under the Gotthard Pass in 1882. A second alpine line was opened under the Simplon Pass in 1906.
The Rhaetian Railway Ge 2/4 was a class of metre gauge 1′B1′ electric locomotives formerly operated by the Rhaetian Railway (RhB), which is the main railway network in the Canton of Graubünden, Switzerland. Four members of the class are now preserved, with one of them in operational condition.
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.
Flüelen railway station is a railway station in the Swiss canton of Uri and municipality of Flüelen. It is located on the Gotthard railway. The station is situated between the parallel Axenstrasse, the main road through Flüelen, and Bahnhofstrasse, with the main station buildings on Bahnhofstrasse.
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.
The PKP class Lyd1 is a narrow gauge diesel locomotive class, covering two similar models built in Poland: WLs150 built by Fablok, and its development WLs180 (803D) manufactured by Zastal. It was used by Polish State Railways (PKP) on the narrow gauge railways in Poland, and on industrial railways.
The Rorschach–St. Gallen railway line is a standard gauge railway line in the Swiss canton of St. Gallen and belongs to the Swiss Federal Railways (SBB).
Suhr railway station is a railway station in the municipality of Suhr, in the Swiss canton of Aargau. It is located at the intersection of the standard gauge Zofingen–Wettingen line of Swiss Federal Railways (SBB) and the 1,000 mm gauge Schöftland–Aarau–Menziken line of Aargau Verkehr.
