articulated bus
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An articulated bus (in Austria also articulated bus - with Fugen-S ) , articulated trolley , articulated train (GLZ) , articulated or articulated bus (colloquially often also called "Schlenki", "Schlenker", "Ziehharmonikabus" or "Knickbus") is a bus or Trolleybus that is built as an articulated vehicle so that it can be used in narrow streets despite its length. The counterpart is the so-called solo bus .
An articulated bus consists of a two- or three-axle front car with a wheelbase that is similar or slightly smaller than that of the solo bus, the joint with bellows and the one or two-axle trailer or rear car , which is supported by the joint on the front car. The engine and drive can be located in the front or rear of the vehicle.
history
In city traffic, the length of buses is limited by the curve radii, which must be driven through without collision. In order to be able to increase the transport capacity on high-demand route sections, bus trailers with additional seats and standing areas were used in the past . Later, trailer operation was largely given up in favor of articulated buses. In some cases, the transport of people in trailers was also prohibited by law, for example in West Germany according to the StVZO from July 1, 1960. In the GDR, on the other hand, it was allowed until the reunification , although it was rarely used in the end. In Switzerland there were numerous companies in both the trolleybus and bus sectors that used trailers. The number of them has decreased due to the advent of articulated buses, but trailers are still used. Trailers are still used in other countries today. In Germany there are again experiments with an exemption.
Forerunners of today's articulated buses were combinations of two or three-axle solo buses with two-axle bus trailers. These were similar to a passenger train on the railroad with a narrow and weather-protected bellows transition connected to each other, but the trailer could also be parked. The Berlin manufacturer Gaubschat presented the first of these coaches , known as the omnibus train , at the IAMA in Berlin in 1937 . The principle was based on a concept by the Italian company Macchi , whose employee Ambrogio Baratelli owned the patent for it.
The first articulated bus as it is today was finally presented by Kaiser Industries in the USA in 1946 . The car was briefly used in scheduled service between Los Angeles and San Francisco. In Europe, Kässbohrer Fahrzeugwerke built the first articulated bus in 1952 as a conventional "snout car", which had no commercial success and remained a one-off. In 1957, Kässbohrer delivered two articulated buses to the USA on the order of Continental Trailways, now in a modern forward control version. The design of the vehicle called "Golden Eagle" could not prevail due to a lack of comfort options and was replaced by the Super Golden Eagle, B. had air conditioning. Based on this, other German manufacturers also designed articulated buses of today's style, i.e. with a wide transition between the front and rear sections. These were specialized car body construction companies that produced them using conventional bus chassis . In addition to Gaubschat, these were Göppel Bus from Augsburg, Emmelmann from Hanover, Vetter from Fellbach and Ludewig from Essen. Early models from the 1950s were often designed in a frame construction, which led to an unfavorable distribution of forces in the chassis . One of the first articulated buses in self-supporting light metal shell construction was the HS 160 USL from Henschel , which was built from 1955 onwards .
Articulated buses are used in Europe today almost exclusively as regular buses in urban and regional transport. Until the 1990s, some bus manufacturers also offered articulated buses for long-distance travel . Since many countries do not grant such buses a permit or entry permit or have them tied to expensive special permits, articulated buses are a marginal phenomenon in tourist traffic. In many cases, such buses have been converted into trade fair or exhibition vehicles. In any case, articulated buses are only suitable for well-developed traffic routes where no maneuvers are required. For narrow mountain passes or hotel parking they are unsuitable.
Constructions
The technical structure of an articulated bus is similar to a vehicle combination with a central axle trailer. The trailer of the articulated bus rests on the front of the vehicle via a drawbar construction ; the actual connection is made via a slewing ring , which is connected to the two car parts by means of slide bearings . A flexible bellows made of elastomer-coated fabric is used to connect both trolley elements so that they are weatherproof and accessible. In the passenger compartment, the transition between the front end of the car and the rear car is realized either by means of a round floor plate that can be rotated through a certain angle, or a plate connected to the front car, which ends in a semicircle with the rear car. The transition piece of the base plate is often provided with side handrails in order to avoid contact with the bellows and the entry of the gusset in the rotating area of the divided base plate.
The main joint and the design of the passenger junction allow the trailer to turn and pitch and the bus to buckle when cornering up to an angle of approx. 50 degrees. In the case of high- floor buses , supply lines between the front and rear of the vehicle are routed below the passenger floor and, in the case of low-floor buses, also in side channels or overhead in a suspended ceiling. Today, bellows can optionally be designed as translucent , i.e. translucent transitions and also colored.
In order to protect the joint and body from damage if the steering wheel is too strong, articulated buses are now equipped with an anti- kink control ( kink protection ). This first warns the driver optically and acoustically before reaching the articulation angle limit. If the joint approaches the end stop, braking is triggered and the vehicle is brought to a standstill.
Apart from special designs, there are basically two drive configurations: the towed and the push-articulated bus. The terms puller or pusher vehicle are often used after the English terms . When Pullerfahrzeug (from the English. To pull = pull ) of the drive in the front, whereby the trailer is pulled like an ordinary trailer. When pusher articulated bus (Engl. To push = push, push ) the drive is in the back of the car.
Classic articulated bus ( puller )
Up until the 1970s, it was common practice in articulated buses to drive the front end of the vehicle, in which the underfloor motor was located - usually in the middle of the vehicle . The poor accessibility of the engine for maintenance work, the high vehicle floor in the passenger compartment and the associated high entrance proved to be disadvantageous. In addition, at higher speeds, the trailer started to roll due to a lack of stabilization.
A further development was the articulated bus with a rear engine but drive in the front end, which was offered as an alternative to the articulated pusher bus developed in parallel. The cardan shaft was guided from the trailer into the front of the car by means of a wide-angle joint under the articulation joint. Here at least the engine was more accessible for maintenance work, the arrangement of the components in relation to the rest of the vehicle fleet was mostly more uniform and the floor of the car could be built lower. In addition to the complex drive shaft guide, however, there was a design disadvantage in that the drive axle was only lightly loaded when the bus was empty, which meant that there was a risk of the drive wheels spinning.
Due to the spread of low-floor technology in bus construction, constructions with an underfloor mid-engine were no longer feasible and the cardan shaft guided through the joint did not allow the passenger compartment to be lowered to the desired size. For a number of years, low-floor buses were therefore only offered as articulated pusher buses. Some foreign manufacturers such as VDL Berkhof or Van Hool are now again offering articulated buses with front-end drive, which is carried out by a tower motor on the left-hand side in the middle of the car , which means that the rest of the car floor can still be kept low-floor. Van Hool had already introduced the principle of the motor between the axles of the front end of the vehicle in 1980 in its AG 280 articulated bus, which was still a classic high-floor vehicle.
Trolleybuses are driven by electric motors to save space and some have a front-end drive in combination with a steered trailing axle (unless an increased roof load requires twin tires on the trailing axle).
Vehicles with mixed drives ( hybrid buses ) usually have a fuel cell or an internal combustion engine with a generator for generating electricity in the rear. As with the trolleybus, it can be driven by electric motors located directly on the central and rear axles, which enables a low-barrier passenger compartment.
Articulated pusher ( pusher )
Since the late 1970s, the most common type of articulated pusher in Germany has been the pusher , the rear motor of which drives the axle (s) of the trailer or, in this case, the rear end . The term trailer is also used in connection with articulated pusher buses, although this is not entirely correct, since in drive technology the term running means passive, non-powered components such as wheels or car parts. The first production vehicle was the O 305 G bus from Daimler-Benz . This vehicle was used for the first time by the municipal transport company Esslingen am Neckar , when it took over the operation of today's lines 119 and 120 on behalf of END Verkehrsgesellschaft from 1978 .
This first series vehicle was preceded by a prototype from FFG Fahrzeugwerkstätten Falkenried in 1975 , which was made up of a single-stage Magirus front end ( 'Urbanbus' ) and the rear section of a Mercedes O 305. With a low entry and a wide front target display, this vehicle was practically the pioneer of today's low-floor buses.
As early as the early 1970s, the Falkenried vehicle workshops developed an electronically controlled, steering angle- dependent articulation angle control that prevents the bus from buckling inadvertently. By using a joint with this articulation angle control, it was possible to connect the rear half of a conventional (two-axle) standard bus with another standard bus shortened by the rear to form an articulated pusher bus. The first test vehicle was made from two parts of a standard type O 305 bus, so that no new body construction was necessary and parts from the series that were already in progress could be used. Since then, other bus manufacturers have also been able to develop existing designs into articulated buses without having to resort to specialized body manufacturers such as Vetter or Göppel. For more than five years, however, Daimler-Benz was the sole user of this construction.
A rare special form of the articulated pusher bus was the type built by Vetter, in which a single-axle, steered front section was placed in front of a two-axle solo vehicle. The rear end of this articulated bus had a steered central axle and a rigid drive axle. However, this construction could not prevail, there were only three vehicles, some of which were converted into normal articulated pusher buses.
When driving, the articulated pusher bus has several advantages over the front-end drive with a steered trailing axle:
- Due to the rigid drive axle and the lack of self-steering, the rear does not shear when cornering. The trailing steering was common in articulated trains with front-end drive, because for reasons of weight distribution and in order to avoid rolling movements, the trailing axles were relocated over the center point to the rear, so that the center distances between the central and trailing axles were quite long. Without follow-up steering, this would have led to significantly smaller inner arcs when cornering (the "cutting of the curve") , so that in this case every right-hand bend would have to be extended further to avoid contact with the curb. With articulated pusher buses without follow-up steering, these effects occur less and the possibility of crossing the sidewalk when exiting a parking bay is avoided because the rear does not swerve as far into the outside of the curve. On buses with a steered trailer, the rear was often made narrower to compensate for this and the overall length was reduced compared to the articulated pusher bus. Reversing is also considerably easier with the articulated pusher bus, as there is no need to articulate against a self-steering axle, which initially pushes the vehicle in the other direction against the given steering impulse. The rigid axle construction is more directional than the passively steered one. However, the winter suitability is somewhat limited, as the articulated pusher buses tend to break away with the central axis on smooth surfaces despite the articulation angle control. Other advantages, on the other hand, are easier access to the rear engine for maintenance work and the possibility of designing the front end in particular in a low-floor design .
Competitors like MAN and IVECO - Magirus-Deutz built the type already shown with a rear engine but drive the second axle in the front section via a homokinetic shaft leading through the joint due to a lack of license rights to the articulation angle control. The axle in the trailing axle was designed as a single-tire and steered trailing axle. These vehicles were usually one meter shorter and, thanks to the steered axle, also more maneuverable, which gave them a small advantage over articulated pusher buses, which, however, did not outweigh the mentioned design disadvantages.
After MAN was also able to offer articulated pusher buses in the mid-1980s after patent protection had expired, both variants ( MAN SG 242 articulated pusher bus and MAN SG 242 H with center-axle drive) were manufactured in parallel for a while. However, the majority of customers chose the articulated pusher bus, which meant that the conventional model was taken out of the range after a short time.
Mixed forms with multi-axis drive
For vehicles with electric traction motors, a multi-axle drive is recommended due to the low space requirements of the motors. In the twin-motor articulated trolleybuses, which are particularly common in topographically demanding cities, one electric motor usually acts on the second axle and another on the third. In many articulated trolleybuses, which are usually driven by a single engine, it is common for the auxiliary diesel drive to act on a different axle than the main electric motor. In some cases, both drives are then used together in order to achieve improved traction on slippery roads - for example with the Mercedes-Benz O 405 GTZ . In hybrid buses such as the Mercedes-Benz Citaro BlueTec Hybrid, the electric drive is also carried out by means of wheel hub motors on the front center axle and also on the trailing rear axle.
Double articulated buses
Articulated double buses have been used in South America for a number of years. In Europe they drive or drove in France ( Bordeaux , now retired), Germany ( Aachen , Hamburg (now retired)), Luxembourg ( Luxembourg (city) ), the Netherlands ( Utrecht ), Lithuania (Kaunas), Hungary (test car in Budapest , 1988) and Sweden ( Gothenburg , Malmö ). These are vehicles from the manufacturers Marcopolo , Ciferal , Renault , Van Hool , Ikarus , Volvo and Hess . Apart from that, double-articulated trolleybuses operate in a few other cities .
At the “Transport '82” in Munich in June 1982, the German manufacturer MAN presented an almost 24-meter-long double articulated MAN SGG 280 bus that could carry 225 passengers. This model was a high-floor VÖV standard bus of the first generation . As was common at MAN at the time, this vehicle was equipped with a motor in the rear, which drove the second axle in the front section and the third axle in the middle section via a cardan shaft guided through the two joints. The trailer had the typical steering axle.
Today, double articulated buses operate as low-floor constructions in the Netherlands, Germany, Sweden, Luxembourg, Austria and Switzerland. Vehicles from the Belgian manufacturer Van Hool (including primarily the AGG 300 ) and the Swiss manufacturer Hess (primarily the Hess lighTram Trolley ) are used.
In 2003, ASEAG was the first German transport company to test double articulated buses from Van Hool in Aachen . This was the borrowed car 916 from GVU from Utrecht, which was used for several months on lines 5 and 45 from May 1, 2003 (with Dutch registration). In September 2005 ASEAG used two of its own vehicles on lines 5 and 45 between the university hospital and Brand and then, in February 2008, six more vehicles, which in Aachen have the dialect name of Öcher Long Wajong .
After a one-year test phase, a large number of slightly modified Van Hool double articulated buses were also used by Hamburger Hochbahn in regular service on the heavily used Metrobus line 5 from December 2005 . The four-axle buses offer seating and standing space for around 180 people over a total length of 24.8 m. The use of the vehicles in Hamburg ended on September 14, 2018. This type was also tested in Dresden on DVB line 61 .
The Swedish manufacturer Volvo has also developed a double articulated bus with the V7500 model. It has been in use in Gothenburg since 2005 and in Bogotá since 2012 .
In August 2012, the former Ehrenhain car body manufacturer Göppel presented a 30½ meter long articulated bus under the name “ AutoTram ”, which can accommodate up to 300 passengers depending on the drive system and seating selected. In contrast to the previous double articulated buses, the middle section has two axles. The vehicle, which was created with the participation of the Fraunhofer Institute for Transport and Infrastructure Systems (IVI), is designed as a test vehicle. Testing will initially take place in Dresden .
Articulated double-decker bus
The largest bus used in public transport is the two-story articulated Jumbocruiser from Neoplan .
Single articulated buses over 18.75 meters
In most European countries, the maximum length for road vehicles is limited to 18.75 m. Buses with a longer length require special permits. However, Mercedes-Benz and MAN each offer single articulated buses with a greater length. Thanks to the space gained and the higher gross vehicle weight due to the additional fourth axle, these buses have a significantly higher capacity.
With the Mercedes-Benz CapaCity, EvoBus presented a prototype in November 2005 which, with a total length of 19.54 meters, offers space for 193 people. The bus has only one joint, but in the rear part behind the drive axle there is another, single-tire, steered axle, so that a greater payload is achieved. The vehicle should remain in the towing curve of a normal articulated bus and - in contrast to a double articulated bus - can be reversed without any problems. According to the manufacturer, the trailer swings out only up to 40 centimeters when the trailer steering axle is locked, instead of more than a meter with a steered axle, but then requires more space in the inner curve, which puts the gain in space into perspective. However, the inside arch can be seen from the driver's seat through the mirror, which makes it easier to drive around obstacles - in contrast to swiveling out the rear that is not visible.
A bus of this type drove - after an initial one-week trial run from November 27th to December 3rd, 2006 - also on the heavily frequented lines 5 and 45 of the ASEAG in Aachen. Since the purchase of several large buses was planned for 2007, they wanted to investigate there whether the CapaCity could be an alternative to Van Hool's double articulated buses. However, ASEAG opted for six more Van Hool AGG 300s. VHH PVG also tested the CapaCity in the Hamburg metropolitan region. From 2007 to 2009, 250 identical CapaCities were delivered to Istanbul for daily use on a special center lane of the ring road crossing the Bosporus. As the first company in Germany, Stuttgarter Straßenbahnen AG has been using the CapaCity in regular scheduled services since August 4th, 2008.
Several copies of the CapaCity also operate in the city traffic of Bratislava (Slovakia).
In August / September 2015, the Berliner Verkehrsbetriebe tested a Mercedes-Benz CapaCity L manufactured by EvoBus with a length of 21 meters and space for 124 passengers for two weeks .
Since 2007, the MAN program has included the Lion's City GXL , a four-axle articulated bus that is similar in design and capacity to the CapaCity . The St. Gallen public transport company was the first and only customer to be supplied with the new bus. However, further development of the Lion's City GXL has been discontinued.
Battery articulated bus
In September 2014, a Solaris Urbino Elektro 18 inductive with a 200 KW fast charging system was presented at INNOTRANS in Berlin, which has been in regular service in Braunschweig since December 2014 . In October 2014, an articulated battery bus was presented for the first time at an exhibition in the Texas city of Houston . The 18-meter-long vehicle from the Chinese manufacturer BYD is produced in the assembly plant in Lancaster (California) on the basis of the BYD ebus .
Door control
The doors in the trailer, which cannot always be seen by the bus driver, are usually secured with a light / radar barrier and a reversing device and are automatically closed. After the door has been released from the driver's seat, the door opens with passenger control and closes after a preset time interval. The closing process is often announced acoustically beforehand. In some regions, however, it is still common that the doors secured by anti-trap protection can also be opened and closed manually from the driver's seat.
Joint lock
In articulated buses, a control system known as an articulated lock , also known colloquially as a kink protection , protects the joint from excessive loads and damage.
With a contact switch in the end stop of the joint (the maximum steering angle is - depending on the vehicle type - about 50 °), the bus is stopped by activating the bus stop brake after an optical / acoustic warning in the dashboard, in order to prevent the joint from buckling too much or even tearing off the joint. The anti-kink protection of an articulated bus should not be confused with the articulation angle control , which in articulated push-pull buses ensures stable vehicle travel by means of hydraulic damping.
Level crossing accident due to joint lock
On September 16, 2015 there was a collision between a regional train of the Metronom Railway Company and an articulated bus near Buxtehude . When passing the level crossing, the articulated lock of the bus was activated, the bus was automatically stopped and could no longer leave the tracks. The bus, occupied by around 60 students, was evacuated in good time thanks to careful action, and one person on the train was slightly injured in the collision.
See also
Web links
Individual evidence
- ↑ Articulated buses , on www.omnibusarchiv.de
- ↑ Articulated large-capacity bus. In: Motor Vehicle Technology 10/1958, pp. 382–383.
- ↑ Swivel joint for articulated buses , system overview from the manufacturer Hemscheidt
- ↑ Hamburg Omnibus Association
- ^ Vetter articulated pusher bus 1978 , Godwin T. Petermann
- ↑ Cousin Bus 16SH. Retrieved December 24, 2019 .
- ↑ Double joint test use in Aachen on wisoveg.de
- ↑ Bye, Tall One !: Today the last XXL bus is rolling through Hamburg . In: MOPO.de . ( mopo.de [accessed on September 16, 2018]).
- ↑ Nahverkehrs-Nachrichten 1/2012 - Abroad
- ↑ One size bigger: CapaCity tested by VHH and PVG ( Memento from January 16, 2014 in the Internet Archive ). In: Coming soon . 12/2006, p. 2f.
- ↑ Manuel Bosch: Magazine: Mercedes Omnibus Days 2007 , stadtbus.de
- ↑ Istanbul: Mercedes-Benz CapaCity as a comfortable, high-capacity express bus, effective and popular. Daimler AG , June 7, 2009, accessed on January 21, 2018 .
- ↑ Unique in Germany: Capacity buses in Stuttgart ( memento of October 2, 2008 in the Internet Archive ). Press release by Stuttgarter Straßenbahn AG, 2008.
- ^ Long, longer, longest , Berliner Verkehrsbetriebe, August 26, 2015
- ↑ Page no longer available , search in web archives: First Lion's City GXL are going to Switzerland
- ↑ "Stadtverkehr", edition 11/08, p. 8
- ↑ Solaris at InnoTrans 2014 in Berlin , Omnibusrevue, September 17, 2014.
- ↑ BYD unveils world's largest battery electric vehicle , BusWorld, October 18, 2014. Accessed December 6, 2014.
- ↑ Patent number DE 3305751 C2 on the patent overview from Google.de
- ↑ at the Mühlenkampstrasse level crossing in Hedendorf , intersection of the diversion route to Bundesstrasse 73 via Mühlenkampstrasse - Am Mühlenbach with the Niederelbebahn
- ↑ Collision on level crossing: female bus driver saves group of students. In: Spiegel Online . September 16, 2015, accessed January 21, 2018 .