Articulated bus
An articulated bus, articulated cars, articulated ( GLZ ) -pivot or Gliederbus ( often colloquially referred to as " Schlenki ", " dangling " or " Ziehharmonikabus ") is a bus or trolley bus, which is built as an articulated vehicle to Despite its length, even in tight roads to be used. The counterpart is the so-called rigid bus.
An articulated bus consists of the two - or three-axle front carriage with a similar size or slightly smaller wheelbase than an articulated bus, the joint with bellows and a two-axle trailer or car or rear, which is supported on the front of the car over the joint. Motor and drive can be located in the front or rear of vehicle.
History
Particularly in city traffic, the length of buses due to tight curves is very limited gradable. To still be able to bid on high demand sections sufficient capacity without additional buses must be used earlier bus trailer were used to carry passengers. Later it was towing a trailer almost everywhere in favor of articulated buses. Allowed Partial passenger transportation by trailers was also prohibited by law, such as in West Germany according to the traffic regulations since 1 July 1960. In the GDR, however, it was up to the turn, although last barely use was made of it. In Switzerland, there were both in a trolley - bus and in the range numerous companies who used trailers. Their number has been reduced by the advent of the articulated bus though, but trailers are used as before. Trailers are now also in other countries still used. In Germany, there has recently been attempts with special permission.
Forerunner of today's articulated buses were combinations of two or three-axle articulated bus and two axle bus trailer. Although these were similar to a passenger train at the railway with a narrow and protected from the weather Faltenbalgübergang linked but the trailer could be parked. The first of these Omnibuszug mentioned teams presented the Berlin manufacturer Gaubschat 1937 at the IAMA in Berlin. The principle was based on a concept of the Italian company Macchi whose employees Ambrogio Baratelli owned the patent for this.
The first articulated bus today embossing finally presented in 1952 before the Kässbohrer vehicle works. Based also constructed more German manufacturer articulated buses today's coinage, that is, with a broad transition between the front and rear of vehicle. These were to specialized body corporate, that made these using conventional bus chassis. Besides Gaubschat these were Göppel bus from Augsburg, Emmelmann from Hanover, cousin from Fellbach and Ludewig from food. Early models of the 1950s were often still carried out in frame construction, which led to an unfavorable Kräftverteilung in the chassis. One of the first articulated buses in self-supporting light-metal monocoque construction was one of the built 1955 Type HS 160 USL by Henschel.
Articulated buses are used today in Europe almost exclusively as buses in the city and regional transport. Until the 1990s, some bus manufacturers also offered articulated buses for long distance travel. Since many countries such buses shall not authorize or entry permit or this tie in with costly exemptions, articulated buses are a marginal phenomenon in travel. In many such buses to fair or exhibition vehicles were rebuilt. In any case, to articulated buses are only for well-developed transport infrastructure, where no maneuvers are required. For narrow mountain passes or hotel parking such buses are unsuitable.
Constructions
The technical structure of an articulated bus is like a vehicle combination with center- in principle. The trailer of the articulated bus is connected via a drawbar design on the front of the car; the actual connection is via a turntable and two ball joints. Over a flexible bellows elements both cars are weather resistant and can be walked connected. In the passenger compartment, the transition between front car and trailer either through a round and rotating base plate is realized, which was supplied as an option depending on the manufacturer with handrails, or connected to the front of the car plate towards semi-circular and flush to the trailer with the trailer. Both structures are in a position to take up all rotational and pitching movements of the articulated bus. Below the walk-in floor plate next to the actual joint construction also all electrical, pneumatic and hydraulic supply lines.
In order to protect the joint from damage that may occur especially with excessive steering, in modern vehicles, a bend protection control ( Abknicksicherung ) is installed. This initially warns the driver visually and audibly before reaching the bend angle limit. The joint is on the limit stop, braking is initiated and brought the vehicle to a standstill.
There are - apart from special designs - two basic types of drive configurations, the ( solid ) and the push - articulated bus. In professional circles, the vehicles are also distinguished by the English meanings according to Puller or Pusherfahrzeuge, depending on the location of the drive. When Pullerfahrzeug ( from the English. = To pull pull ) the drive is in the front, where the trailer like an ordinary trailer being towed. When pusher articulated ( engl. to push = push, press ), the drive is in rear of vehicle.
Classical articulated ( Puller)
Until the 1970s, it was common to drive the front of the car with articulated buses, in which - usually in the center of the car - was the underfloor engine. A disadvantage proved to the poor accessibility of the engine for maintenance, the high vehicle floor in the passenger compartment and the high entry associated with it. In addition, at higher speeds occurred snaking movements of the trailer due to lack of stabilization.
A further development presented here represent the articulated bus with rear engine, but drive in front of the car, which was offered as an alternative to articulated pusher. The propeller shaft was led by the trailer by means of a wide-angle joint by the bellows in the front of the car. Here the engine is accessible for maintenance, the arrangement of the components to other fleet was at least mostly uniform, also could be built the car floor is lower and thus gradually poorer. Structural disadvantage was here that in addition to the elaborate joint waveguide by the bellows the drive axle with an empty bus was only lightly loaded, with the attendant risk of slipping of the driving wheels was.
With the advent of low-floor technology in bus constructions with underfloor central engine or long -run prop shafts were no longer feasible, so that the articulated pusher long time had virtually no alternative. Some foreign manufacturers such as Berkhof or Van Hool but one meets this type with articulated front carriage drive today again. Here the drive is in the front by a left side arranged in the center of the car tower motor, so that the rest of the car floor can be designed through low floor. Just go trolleybuses or vehicles with Mischa shoots ( hybrid buses), can be in not requiring a space- intensive underground operator, often with front carriage drive and steered dolly, unless higher roof loads require dual tires on the trailer. Although these vehicles have often also have a rear auxiliary motor. However, since this drives a generator to produce electricity and they shall be no direct, mechanical power transmission to a drive shaft, the auxiliary motor can be placed largely free in the vehicle. Here then both central and rear axle can be driven.
Articulated pusher ( Pusher )
Since the end of the 1970 years in Germany is the most commonly articulated pusher (pusher ) to meet its rear engine the axle (s) of the slave drives. The term trailer is also used in connection with thrust articulated buses, although this is not entirely correct, as it is understood in drive technology under the term running passive, non-powered components such as wheels or car parts. First production vehicle was the type bus O 305 G of Daimler -Benz. This vehicle was first used at the Municipal Transport Company Esslingen am Neckar, as this since 1978 on behalf of the END transport company operating the present lines 119 and 120 took over.
Back in the early 1970s developed the FFG vehicle Falkenried an electronically controlled, steering angle-dependent bending angle control, which prevents accidental kinking of the bus. By the use of a hinge with this articulation angle control, it was possible to connect the rear half of a conventional ( two-axle ) with a truncated standard bus to the rear of another standard bus to an articulated pusher. Advantage was that bus manufacturers ( the first user of this construction Daimler -Benz in particular ) were now able to fully establish himself and articulated buses offer. Since the first test vehicle was made of two parts of a standard omnibus of type O 305, no new body design was also necessary, so that could be used on parts of the ongoing series. The previously required bodybuilder as cousin or Göppel no longer had to be taken advantage of. A rare special form of thrust articulated bus took this one built by the cousin type, in which a two-axle rigid truck a single axis, steerable front part was to be sent. In the back of this car articulated bus, a guided central axis and the rigid drive axle were. Although this design is also very good running and driving characteristics had, she could not prevail.
When driving the articulated pusher brings against the front carriage drive with steered dolly some advantages: Due to the rigid drive axle and thus lack the self-steering rear cares when turning less from. For reasons of weight distribution and to avoid rolling movements in articulated buses with front carriage drive the Nachläuferachsen were laid over the center to the rear, so that there are quite a long center distances between the middle and dolly. This results in cornering significantly smaller inner arches, so that a curve must be extended further in order to avoid curb contact. A possible sweeping the walkway at exit from a holding bay is avoided when a pusher articulated by the lack of self-steering, as the rear is not veering so far into the curve exterior. To address this drawback, the buses steered Nachäufer often had a narrow tapered tail and a relative to the articulated pusher lower total length. Also the reverse when articulated pusher is greatly simplified, as not to be articulated against a self-steering axle, which pushes the vehicle initially opposed the given steering impulse in the other direction. The rigid axle design is compared with the passive -guided trail faithful. However, the winter performance is somewhat limited, since the thrust articulated buses tend on slippery surfaces with the central axis despite kink angle control for breaking. Other benefits, however, are the easier access to the engine for routine maintenance and the low design especially the front end. In addition, the rear engine favors the low-floor design.
Competitors such as MAN and Magirus- Deutz built for lack of license rights to the bend angle control in the late 1970s the initially mentioned type, wherein the motor is likewise fitted at the rear, but a leading through the joint, constant velocity shaft drive the second axle in the front. The axis of the trailer was designed as einzelbereifte and steered trailing axle. These vehicles were usually one meter shorter and by the nachgelenkte axis also necessarily what towards them thrust articulated buses gave a small advantage, but in which the mentioned structural disadvantages outweighed.
After also MAN could accommodate mid -1980s thrust articulated buses in the program for a while both variants (MAN SG 242 articulated pusher and MAN SG 242 H with center axle drive ) were offered in parallel. The choice of the customers fell but relatively clear on the pusher articulated so that the traditional model was taken after a short time from the program.
Mixed forms with multi-axis
Especially for vehicles with electric traction motors, due to the small footprint of a multi-axis drive motors on. In the usual, especially in cities topographically sophisticated twin- joint trolleybuses usually a combination of the two principles occurs, that is, a drive acting on the second axis and the other on the third. In addition, it is also common in many single-engine articulated trolleybuses that the auxiliary diesel drive on a different axis acts as the main electric motor. Partly also, both drives are shared to ensure even on smooth roads sufficient traction - such as the Mercedes- Benz O 405 GTZ. In hybrid buses like the Mercedes- Benz Citaro BlueTec Hybrid, the electric drive wheel hub motors are also on the front of the car center line as well as the trailer rear axle.
Double articulated buses
Double articulated buses are used for several years in South America. In Europe they drive in France ( Bordeaux, now retired ), Germany (Aachen, Hamburg), Luxembourg ( Luxembourg (city) ), the Netherlands (Utrecht ), Hungary and Sweden ( Gothenburg ). There are vehicles, the manufacturer Marco Polo, Ciferal, Renault, Van Hool, Icarus and Hess.
The German manufacturer MAN presented at the " transport '82 " in Munich in June 1982, a nearly 24 -meter-long double-articulated bus of the type MAN SGG 280, which could accommodate 225 passengers. In this model, there was a mittelflurigen VÖV standard bus of the first generation. As is customary at the time at MAN, this vehicle was equipped with a motor in the car trunk, which drive the second axle in the front and the third axis in the middle part of a guided by the two joints propeller shaft. The trailer had the typical steering axle.
Today double articulated buses as low-floor constructions in the Netherlands, Germany, Sweden and Luxembourg. This primarily vehicles of the Belgian manufacturer Van Hool, most notably the type AGG 300, used.
As the first German transport companies ASEAG tested in Aachen in 2003 Double articulated buses Van Hool manufacturer. In September 2005, the two sat ASEAG own vehicles on lines 5 and 45 between University Hospital and a fire, and then, in February 2008, six more vehicles that have the dialectal name Öcher Long Wajong in Aachen.
After a year of testing a large number of slightly modified double articulated buses Van Hool be used in regular service on heavily loaded Metrobus Line 5 December 2005 by the Hamburg elevated railway. The four-axle buses offer a total length of 24.8 m sitting and standing room for about 180 people. This type was also tested in Dresden on the line 61.
The Swedish manufacturer Volvo has developed the Model V7500 a double articulated bus. It is used since 2005 in Gothenburg, and since 2012 in Bogota.
The Augsburg body manufacturer Göppel introduced in August 2012 under the name "Auto -Tram " a 30.5 meter double- articulated bus in front which can accommodate up to 300 passengers, depending on the chosen drive system and seating. In contrast to the existing double- articulated buses, the central portion is biaxially. The vehicle, which was created with the participation of the Fraunhofer Institute for Transportation and Innovation Research is designed as a test vehicle. The testing takes place first in Dresden.
Double -decker articulated bus
The largest used in public transport bus is the two-storey articulated Jumbocruiser the company Neoplan.
Single articulated buses over 18.75 meters
In most European countries, the maximum length is limited to road vehicles to 18.75 m. Buses with a greater length require special permits. However, Mercedes -Benz and MAN offer to each individual joint buses with a greater length. By thus gained space as well as by the higher permissible total weight due to the additional fourth axis, these buses have a significantly higher capacity.
EvoBus has introduced the Mercedes -Benz CapaCity in November 2005, a prototype that provides 193 people with a total length of 19.54 meters. The bus has only one joint, but in the rear portion is located behind the drive shaft, a further einfachbereifte, mitgelenkte axis, so that a greater load is achieved. The vehicle shall remain in the drag curve of a normal joint bus and is - as opposed to a double-articulated - no problems backwards drivable. According to the manufacturer of the trailer swings in locked trailer steering axle of only up to 40 centimeters, instead of over a meter with steered axle, but then you need more space in the inner curve bow, bringing the space gain perspective again. However, the inner bow can be seen from the driver's seat through the mirror, what the negotiating obstacles - in contrast to the pivoting of the non-visible tail - simplified.
A bus drove this type - for a first -week trial run from November 27 to December 3, 2006 - also at the Aachen ASEAG on the busiest routes 5 and 45, since the acquisition of several large -capacity buses was planned for 2007, we wanted to explore there whether the CapaCity could constitute an alternative to the double articulated buses of the company Van Hool. The ASEAG decided nevertheless to six more Van Hool AGG 300 The VHH PVG tested the CapaCity in the metropolitan region of Hamburg. The delivery of a series of 50 vehicles for Istanbul began in late 2007. Was the first company in Germany to Stuttgart Tram AG CapaCity the set since August 4, 2008, in regular traffic.
In the MAN program was since 2007 the Lion's City GXL, a four-axle articulated bus, which is the CapaCity similar in design and capacity. As the first and only customer, the transport authority of St. Gallen were supplied with the new bus. However, the further development of the Lion's City GXL has been set.
Further developments
When articulated buses are operated trace out similar services as a tram can be provided. One then speaks of a bus trace.
The doors in rear part, which can not always be seen by the bus driver, are typically secured by Licht-/Radarschranke and a reversing and automatically closed. After release from the driver's door, the door opens and closes operated passenger after a preset time interval. Often, the closing process is previously announced acoustically.