Articulated tram (tram)
Articulated wagon are tram motive or -beiwagen consisting of a plurality of joints movable interconnected car bodies are made. This means that long vehicles can be built that can still negotiate the narrow arches typical of tram networks.
Directly connected two-axle vehicles
The simplest form of an articulated car are two two-axle vehicles that are directly connected to one another and have a carriage transition in the form of a bellows . An example of this were the railcars 160–162 of the type Ce 2/4 built in 1932 for the Bern tram . These were three older two-axle motor vehicles built in 1914, which were connected to two-axle old-style trailers with bellows. They were in use until 1959. The twin railcar 501 of the Stuttgart trams , which was assembled in 1937 from railcars 565 and 566 built in 1912, was built according to the same principle . However, it failed because of the transition design that was unsuitable for rigid two-axle vehicles, which tended to derail, especially in S-curves, and was withdrawn from the stock in 1940.
In 1950 and 1951, the Leipziger Verkehrsbetriebe also tried to combine two small two-axle vehicles to form an articulated vehicle, primarily in order to get by with fewer conductors. The four type 27 railcars 925 to 925 were used, which in turn were converted in 1930 from type 16 LESt railcars built between 1906 and 1913 . Two carriages were connected with a close coupling, and steel rods next to each other served as a transition bridge, which were alternately attached to the head piece of one of the two carriages and could move each other in the longitudinal direction. The transition was closed by a bellows modeled on an express train carriage. The floor height of the platforms at the transition was increased to that in the car interiors, resulting in a continuous interior that was only slightly drawn in at the transition. There were no entrances at the crossover, at the ends of the double carriages there was a large, permanently open doorway and a partition wall with a double sliding door. The double wagons were given the type designation 227. Technically, the transition construction worked, but the users complained about the noises caused by the transition design and the poor running properties. They were also unpopular with conductors because of the double workload. In 1955 and 1956, both double cars were separated again and the single cars were then sold individually.
Jakobs articulated trolley
The first articulated bogie wagons in Europe were built in 1926 for Duisburg by the Johann Caspar Harkort company. One of the two Harkort cars was received by the Duisburg transport company until 2016 and used for special trips in the Duisburg city area until the beginning of 2015. For this purpose, the car had also been converted for operation in the Duisburg city railway tunnel .
However, this design was only produced in large series from 1956 by the Düsseldorfer Waggonfabrik (Duewag), other manufacturers followed. This design was based on an Italian patent, where such cars were built from 1946. The joint forms a portal that rests directly on the bogie.
Initially, two-part six-axle wagons with one joint were created, and the first eight-axle wagon was delivered in 1957 by inserting a middle part and another joint. In 1967, this modular principle resulted in four twelve-axle cars for the Rhein-Haardtbahn , which at 38.5 meters were the longest tram cars in the world at the time. Mannheim and Duisburg later extended some of the wagons with another Jakobs bogie to include a low-floor middle section. Jakobs bogie articulated wagons were mainly delivered as railcars. Articulated sidecars were only built for the Rhein-Haardtbahn and the belt line of the Vienna Electric Light Railroad , from which the U 6 line emerged in 1989 .
For a long time, low-floor wagons were not built with Jacob frames, because the installation space is limited due to the low floor height. Therefore the running gear and the articulated construction were separated, which inevitably results in one of the following constructions (short articulated trolley, semi-mounted end trolley or floating middle section). With the 15T , the manufacturer Škoda Transportation finally succeeded in designing low-floor articulated wagons with Jakobs bogies in 2009.
Examples of Jakobs bogie wagons:
Short articulated trolley
Short-articulated trolleys are vehicles that require one bogie for each part of the trolley. The following different constructions have been developed:
In the design developed by Maschinenfabrik Esslingen (type GT4 ) for the mountain routes of the Stuttgart trams in 1959 , the two bogies are connected by a carrier - the articulated carrier. The car bodies are supported on one side on "their" bogie and on the other side on the joint that rests on the joint beam. It is not possible to separate the car parts. Of a total of 380 wagons, 350 went to Stuttgart, Freiburg im Breisgau , Reutlingen , Neunkirchen (Saar) and - used from Stuttgart - Ulm received further wagons ; after 1990 used wagons were also sent to Nordhausen , Halberstadt , Augsburg , Halle , Arad and Iași .
In the design developed by Hansa Waggonbau for the Bremen tram , each part of the car rests on its own bogie, while the joint is not supported. The individual car parts can only be separated from each other in the workshop. 1959 to 1967 these cars were delivered to Bremen and 1968 to Bremerhaven . The curve adjustment of the car body was controlled by a linkage . If the car drives into a curve, the individual car parts begin to turn until the vehicle has completely entered the curve. In doing so, the rear first shears towards the inside of the curve and only in the curve to the outside of the curve. To form longer trains, railcars and sidecars were used.
Production for Bremen was taken over in 1973 by Wegmann & Co. in Kassel , which supplied articulated railcars and articulated trailers. In these vehicles , which are also outwardly more modern , the curve adjustment was initially controlled hydraulically . However, this control did not prove itself and was retrofitted later. 30 Wegmann railcars were completely reconstructed between 2015 and 2018 for the Timișoara tram in Romania and were given the new type designation Armonia .
ČKD Tatra developed the type Tatra KT4 , which was built from 1976 in a total of 1801 units for Yugoslavia , the Soviet Union , North Korea and above all the GDR (type KT4D). The joint is mechanically controlled by crossed transmission rods linked to the bogie frame and the joint portal. There is only one degree of freedom around the vertical axis, in straight tracks as well as on hilltops and in tubs, the car behaves like a long four-axle vehicle. These cars were only supplied as railcars, but they are capable of multiple traction .
Low-floor short articulated trolley
The short-articulated tram from Bremen has been widely used since 1989 as a low-floor trolley in three or four parts. With these trolleys, the articulation control is completely omitted, the articulation rather sets itself automatically through the restoring forces of the air springs. MAN , AEG and later Adtranz delivered these articulated vehicles to Bremen, Berlin, Munich, Nuremberg and others; Düwag built a series of 40 cars for Frankfurt am Main ( type R ). The new Siemens Avenio model and its Budapest predecessor Combino Plus also follow this principle.
Articulated car with semi-mounted end car
These articulated wagons consist of a self-supporting wagon part on which end wagons are supported. In 1928, WUMAG designed a prototype with a two-axle intermediate car on which two single-axle end cars were supported. In the 1950s and 1960s, two-part vehicles were built, partly as conversions of older cars that were extended by an end car - the trailer with a two-axle bogie - for Duisburg, Aachen and Freiburg ( Sputnik type ), partly as new constructions, for Cologne , Krefeld , Remscheid and Bremen (with single-axle trailer) and Augsburg (type GT5 with three-axle front end and two-axle trailer). The Austrian variant is the Viennese type F built in 1963 , these cars were in use until 1996.
Four-axis middle part
Starting in 1971, Freiburg im Breisgau purchased three-part vehicles of a further developed design, the Düwag GT8 type Freiburg , with four-axle middle and semi-mounted end wagons, each with a two-axle bogie. From 1989, various three-part low-floor wagons with a low-floor center section were built: as new buildings for Würzburg and Freiburg, as conversions of older wagons for Cottbus and Mülheim . From 1990 on, Düwag built 70 percent low-floor wagons with four-wheeled, later also eight-wheeled center sections for Kassel , Bochum , Halle and other companies. Because of the low-floor design, most of these wagons were equipped with loose wheel drives controlled by the articulation angle of the adjacent joint . The LVB type 36 NGT8 for Leipzig was given slightly shortened intermediate car bodies with small wheel bogies and continuous axle shafts instead. Similar designs are the low-floor wagons from LHB for Magdeburg , DWA for Kassel and the medium - floor two-system wagons from Bombardier for Saarbrücken .
Short middle part
Trains with a short middle section used in large numbers were the Zurich VBZ Be 4/6 (Mirage) . Extremely short middle sections are common in articulated trams on the Cologne tram . The high-floor variant K5000 of the manufacturer's Bombardier Flexity Swift run on a Jakobs bogie , while the middle-floor K4000 and K4500 run on loose wheel sets that are fixed in the floor frame of the middle section for reasons of space . On the new K4500 VB, the car body of the middle section is over two meters long. Special designs are the high-floor tram cars TW 2000 and TW 2500 in Hanover and the three-part low-floor cars in Karlsruhe , which also have short, two-axle intermediate cars.
Articulated trolley with a floating middle section
These articulated trolleys consist of two independent trolley parts with their own chassis, which are connected to one another by two articulated connections and an intermediate piece - the free-floating middle part. The middle section - often called the sedan chair - and the joints serve to compensate for the wagon parts that slide against each other in curves.
The first such wagons were built for Berlin , Dresden and Leipzig from 1928 , but initially remained loners. In 1932 and 1935, two railcars each for the Amsterdam tram were equipped with so-called twin cars with an additional floating middle section. Compared to a previous two-car train consisting of motor coaches and sidecars, this achieved twice the engine power of the train, whereby one conductor could be saved.
In the 1950s, the design was taken up again, initially to connect two-axle trains consisting of railcars and sidecars by adding a middle section to form four-axle articulated vehicles, as in Duisburg and Stuttgart ( SSB DoT4 ), and later also as new vehicles, e.g. for Dortmund , Kassel , Munich and Oberhausen . In Mülheim , two particularly powerful railcars were built by converting them, which were operated with a four-axle open- plan car.
From 1959 VEB Waggonbau Gotha delivered over 300 four-axle articulated wagons of the types G4-61 and G4-65 to Leipzig, Erfurt , Potsdam and other companies, some wagons even to the USSR . In Poland , articulated cars of the types PN and WPK were built from one two-axle Konstal N railcar and one ND sidecar, but only small series of these were built. In West Germany , Austria and Poland, the cars were often retired before older vehicles. Compared to other types of construction, the articulated construction was too complex, with two-axle chassis compared to bogie wagons the running was too restless. In addition, many of these wagons had too much mass and the associated clumsiness: the Munich type P 1 and the Viennese types D and D 1 in particular suffered from this.
Low-floor multi-articulated trolley
This construction was taken up again in the low-floor multi - articulated wagons built from 1993 , for the following types:
- 6MGT and 8MGT for Mannheim , Ludwigshafen and the Rhein-Haardtbahn
- Alstom Citadis
- Bombardier Flexity Outlook
- CAF Urbos 2 and 3
- NGT6DD and NGT8DD of the city of Dresden
- LHB GT6N for Würzburg
- Siemens Combino or Avenio M
- Škoda Elektra
- Stadler Variobahn
Dresden and Leipzig low-floor cars
For Dresden (types NGT D8DD and NGT D12DD ) and Leipzig (type NGT12-LEI ), Bombardier has developed vehicles in its Flexity Classic family in which the sedan chairs are arranged between four-axle car parts.
From the beginning until the 1970s
From 1918 onwards, the first articulated wagons were built in Germany as prototypes for individual transport companies, for example a sidecar for Dresden in 1918 and two wagons with Jakobs bogies for Duisburg in 1926 . In Germany, however, there was initially little interest in these vehicles, as they could not respond to a changed passenger flow. Therefore, open- plan cars with sidecars were preferred at the time .
The joint designs were only taken up again after the war. Jakobs articulated wagons were built in series in Italy from 1946, in Germany from 1953 in a few copies for Stuttgart and from 1956 in large numbers by the Düsseldorfer Waggonfabrik (Duewag) for transport companies in almost all of Germany and also for many foreign transport companies.
From 1959 onwards, the Esslingen machine works - mainly for Stuttgart - and Hansa Waggonbau - for Bremen and under license for Munich - with their short articulated wagons competed with Düwag. Compared to the Jakobs articulated wagon, the proportion of these designs remained only small in West Germany. The type of ČKD Tatra corresponding to the West German short articulated wagons was built in the form of the KT4D in large numbers for the companies of the GDR and other Comecon countries.
In addition to or mostly before the large series, there were also small series as custom-made products for individual transport companies, so the trams in Bremen received a series of three -axle articulated railcars and in Augsburg five-axle articulated multiple units ( steering three -axle vehicles with two-axle trailer).
Parallel emerged in the 1950s and 1960s remodeling -Gelenkwagen from older vehicles, mostly as individual pieces. The starting point was two-axle, three-axle and four-axle vehicles. Either two individual wagons were connected to one another by an articulation with a floating middle section, or individual wagons were lengthened with an articulation and trailer. The aim was to save on conductors using the passenger flow principle - initially due to a lack of staff and later to reduce staff costs. For example, railcars went to Augsburg, Braunschweig , Bremen, Duisburg , Mülheim , sidecars to Bremen, Duisburg and Stuttgart.
The development since the 1980s
The development of the low-floor articulated trolley began in the 1980s : at that time, the articulated area could only have a low-floor design when the joint was floating freely. This meant that Jacob's bogies were ruled out for most low-floor wagons, and other technologies were required. The low-floor short articulated wagon of the type Bremen from MAN , then Adtranz , and the three-part articulated wagon with attached end wagons for Kassel from Düwag were widely used.
In 1993 the construction of multi-articulated wagons began in mostly smaller series for individual companies, first the Variobahn from ABB , later Adtranz, for Chemnitz , followed in 1994 by similar wagons from Düwag for companies in the Rhine-Neckar area and from Düwag and DWA for Dresden . Only the Combino supplied by Düwag, now Siemens , achieved large numbers again and was widely used.
In the course of the concentration of the tram vehicle manufacturers, there was also a gradual streamlining of products. Adtranz combined the designs developed by the predecessor companies in the modular vehicle concept » Incentro «, Bombardier finally combined the different vehicle types in the » Flexity « family, from low-floor trams to high-floor light rail vehicles in a wide variety of designs, from the two-part low-floor articulated car for Dessau to multi-part multi-articulated wagon includes. In most of the former Eastern Bloc states , Tatra T4s and comparable designs were used as large trains with up to three individual wagons until the 1990s . However, most of the establishments had already made the transition to conductors-less operations in the 1960s and 1970s. Here the change to articulated wagons took place after 1989 so that the drivers were given an overview of the entire passenger compartment of the entire train.
Up to the 1990s, articulated vehicles over 30 meters in length were the exception. It was rather shorter units driven in traction or hung with sidecars. With the low-floor multi-articulated wagons, longer single wagons instead of trains have been procured since the 1990s. Cars up to and over 40 meters in length are not unusual, for example for the Rhein-Haardtbahn , Augsburg , Dresden , Düsseldorf , Freiburg and Karlsruhe . The currently longest tram car in the world is the nine-part Budapest Urbos 3 with 56 meters.
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