While the early systems still used near-series omnibus vehicles, the more recent developments often look more like modern tram vehicles . These include the Tramways sur pneumatiques (trams on rubber tires) made by Lohr Industrie and Bombardier .
So-called perambulator wagons reached a certain popularity as early as the end of the 19th century ; these were early road-rail vehicles that represented a mixture between horse- drawn trams and horse-drawn buses and could run on regular grooved tram tracks as well as freely steered. A derivative of this was the electric tram-omnibus from Siemens & Halske presented in 1898 , which in turn represented a mixture of electric tram and battery- powered bus .
International Transport Exhibition Hamburg 1979
The track bus principle from Daimler-Benz (vehicles) and Züblin (track) was presented to the general public for the first time at the International Transport Exhibition (IVA) in Hamburg in 1979, where five Mercedes-Benz O 305s were in use on 24 exhibition days. In the system known at the time as the omnibus train, or O-train for short , conventional regular-service buses were forced to run on a lane with lateral, approximately 20-centimeter-high guide bars. There are so-called tracking rollers on the front axle, which steer the bus in the lane; articulated buses also have so-called nudging rollers on the rear axles, which secure the distance from the tracking beams on bends. The lane bus can leave this lane at certain sections without the lane guide strips, be steered in the conventional way by the driver and be threaded back into the lane via driveways with an insertion funnel.
The aim of the O-Bahn was to combine the advantages of railways (high capacity, low space requirements, safe route, high level of travel comfort) and buses (integration into road traffic, more flexible development of sparsely populated areas, inexpensive mass-produced vehicles). A modular system was planned, which can be gradually expanded both on the vehicle and the infrastructure side. For the rolling stock, solo wagons, articulated wagons or double articulated wagons were provided, and for the routing, in addition to the usual tracks, tunnels and elevated elevated routes - optionally also with overhead lines . Lane guidance should primarily be used in the area of heavily frequented trunk lines served by several lines .
For the diesel bus operation in the tunnel and the associated ventilation problem, experiments were also carried out with an extraction system. For this purpose, the exhaust pipe of the buses in question was extended upwards and received a special attachment that fits precisely between two rubber lips. The pipeline that ran parallel to the driveway on the tunnel ceiling was sealed with these lips. When entering the tunnel, the bus automatically clicked into the suction tube. For the corresponding tests, the 730-meter-long Bettingberg tunnel was equipped with a track bus concrete track and a suction pipe in the 1980s as part of the Lohr – Wertheim railway line, which was closed in 1976 . The then Mannesmann Rexroth AG from nearby Lohr am Main was responsible for this .
Rastatt test facility (from 1979)
On the Mercedes-Benz factory premises in Rastatt, there was an electrified O-Bahn test facility from 1979, on which the various system components were tested in camera.
The system was later considerably expanded and presented to the international press from May 26th to 28th, 1982. In the final stage, the test facility comprised two separate routes around three kilometers in length, on which buses with both mechanical and electronic track guidance and switches were tested. The roadway consisted of precast concrete parts from Züblin with ground-level and elevated sections and a tunnel. A high-speed route was designed for speeds of up to 100 km / h.
A total of four different vehicles were used on the Rastatt facility, based on near-series buses and components:
- an O 305 GG built in 1981 ( bidirectional vehicle , double articulated trolley, single-arm pantograph, only in use in Rastatt)
- an O 305 GTD built in 1983 (duo articulated bus, handed over to the trolleybus Esslingen am Neckar in 1986 )
- two O 405 GTDs built in 1987 (duo articulated bus, one of which was handed over to the Kapfenberg trolleybus in 1990 )
Long-term experiment in Essen (since 1980)
A first track bus route was laid out in 1980 for demonstration purposes in Essen-Haarzopf on a 1.3-kilometer stretch in Fulerumer Straße and used by EVAG . In 1983 a second 1.0 kilometer long section followed in Wittenbergstrasse, which was used in mixed operation by tram until 1986. There, for the first time, track-guided operation with duo buses also took place , which in addition to the diesel engine had an electric drive as in trolleybuses. The line in Wittenbergstrasse was electrified until 1988.
In 1985, an approximately 3½-kilometer stretch in the central reservation of the Ruhr Schnellweg (A 430, since 1992 A 40) was added to Essen-Kray , where the tram previously operated. From 1991, the track buses also drove in electrical operation on a suitably prepared route through the tram tunnel , and the vehicles were also equipped with automatic train protection devices. On the occasion of an extension of the tunnel in 1991, the vehicles were retrofitted with doors on the left-hand side of the vehicle in order to be able to serve central platforms at two newly opened stations. In September 1995, the lane bus operation in the tunnel was discontinued after numerous malfunctions, only a few days later the electrical operation in the Kray district and with it the duo bus operation ended.
A tender was published for this in 2005, which also called for a test vehicle in advance. In September 2007, a Citaro II articulated wagon with a tower engine was then tested for this purpose at EVAG. The car was tested on all of the remaining track buses in Essen. The Citaro itself is a series vehicle that was converted for track bus operation at the Neu-Ulm plant. The car also has emergency running elements in the wheels of the front axle. In the event of a flat tire, these make it possible to take the bus out of the track using its own power.
Despite the width of 2.55 meters, the test car was able to drive the existing routes without any problems. Only in the area of the stops did the curbs have to be adjusted where they protruded slightly into the track bus profile. This was particularly the case on the route to Kray, as the curbs had partially shifted due to the weather. However, major adjustments to the route itself are not necessary, so that the system can still be operated with the vehicles that are now up to date. 47 vehicles (16 solo cars (4151–4166) and 31 articulated cars (4651–4681)) are to be delivered for Essen.
The first-mentioned track bus route in Essen-Fulerum (Haarzopf) was closed at the beginning of 2009 and dismantled in October 2012. All O 405 N2 were taken out of service in the course of 2009, the solo buses lost their track roles and are used on other lines.
In August 2014 it became known that EVAG or the Via-Verkehrsgesellschaft was already considering giving up track bus operations entirely. The reasons given were increased costs due to a lack of spare parts and problems with maintaining the lanes still in existence at the time. However, there was no alternative solution for the then four track bus lines up to this point.
The penultimate lane bus route at Stadtwaldplatz was closed on October 11, 2016 and was dismantled and greened. Since then, the buses have been serving new, barrier-free stops at the roadside. In the direction of the city forest, there will in future be a bus lane at the level of the Schillerwiese.
A solution is still being sought for the last remaining stretch between Kray and the water tower, as the regular traffic jams on the A40 should continue to be bypassed. However, the median is too narrow for a non-lane bus lane. A resumption of tram operations is therefore also being considered. However, new track buses from Mercedes-Benz were delivered for 2020 to enable continued operation of the route.
Project Regensburg (1983)
In December 1983 the planning for a spur bus tunnel in Regensburg was comparatively far advanced . In the area of the listed and winding old town, the Regensburger Verkehrsbetriebe (RVB) and its chairman of the supervisory board, the then Lord Mayor Friedrich Viehbacher (CSU), planned a 1520 meter long trunk route in the tunnel for Regensburg city traffic . It would have started in front of the Regensburg main train station with a tunnel ramp in Maximilianstraße and included the underground stations Königsstraße, Domplatz , Haidplatz and Arnulfsplatz . Behind Arnulfsplatz, the buses would have surfaced again. The tunnel would have been excavated using the mining method at a depth of ten to thirteen meters below the surface of the terrain. Three of the four 32-meter-long stops that would have been equipped with side bus platforms would also have had to be built using mining techniques. The radius of the tunnel tubes should be 3.9 meters, the total costs around 100 million D-Marks. In addition, the engineers estimated the cleaning, maintenance and energy requirements of the exhaust fans alone to be 500,000 Deutschmarks per year. In addition, the local fire brigade would have had to purchase new special cross-steered fire and rescue vehicles. Ultimately, the project failed because of the fear that tunneling under the old town, which is built on alluvial sand, could lead to a lowering of the water table. This in turn could have caused considerable damage to the historical building fabric.
Mannheim (1992 to 2005)
In Mannheim-Feudenheim there was an 800 meter long track bus route between May 1992 and September 2005 that was only used in one direction of travel. It was created in order to be able to use the existing separate track body of the tram to bypass a section of road prone to congestion. The two approximately 50 centimeter wide lanes consisted of wooden planks that were laid lengthways. The dismantling of the line began in September 2005, as the majority of the buses equipped with guide rollers were decommissioned for reasons of age. A conversion of newer buses was not planned. It also plays a role that newer buses are usually built with a vehicle width of 2.55 meters and are therefore five centimeters wider than older buses, which would have required either expensive custom-made products or route modifications. The section was then equipped with an asphalt roadway and grooved rail track and can thus be used with normal buses.
The world's longest track bus route is the Cambridgeshire track bus between Cambridge and St Ives with 25 kilometers, which opened on August 7, 2011. The second longest distance of twelve kilometers, in the Australian city on March 2, 1986 Adelaide opened O-Bahn Busway .
Other installations can be found in Great Britain , where there are spur bus routes in Leeds , Bradford , Crawley and Ipswich . A test section in Birmingham has since been abandoned. The track bus route in Edinburgh was in operation from December 2004 to January 2009 on part of the route of the local tram .
Tramway sur pneumatiques
Bombardier GLT / TVR
In the 1980s, BN (La Brugeoise et Nivelles) in Belgium developed bus-like double articulated vehicles on eight rubber wheels, which are guided by a grooved steel rail embedded in the middle of the asphalt, but can also be steered conventionally. This system, known as GLT (Guided Light Transport), was able to drive electrically, as with the O-Bus, via double overhead lines or with a diesel engine. A prototype was demonstrated in Brussels in 1985, and from 1988 a test track between Jemelle and Rochefort was operated.
The originally high-floor vehicles were further developed by Bombardier in the 1990s. From 1997, the new low-floor vehicles were then referred to as TVR ( Transport sur voie réservée ) (also due to their focus on the French market).
The first installation of the new system took place in 2000 in the French city of Nancy , where the existing network of trolleybuses was supplemented. The vehicles of the Tramway de Nancy have two-pole pantographs and can run both as track -guided buses and on other parts of the route as trolleybuses driven by the driver. Public operation of the STAN began on February 11, 2001, but after two accidents in March, operations were shut down for a year and the vehicles were revised.
In the following installation in Caen , also in France, almost identical vehicles were used as in Nancy. However, the Tramway de Caen (also called Twisto ), which opened on November 15, 2002 and closed on December 31, 2017 , used single-pole pantographs, as they are also used in classic trams. Since the current was returned via the guide rail located on the floor, only track-guided operation was possible.
The TVR system did not prove itself, the manufacturer Bombardier has taken the vehicles out of the range. The last tram in Caen ran on December 31, 2017, and a "normal" tram has been operating there since July 27, 2019 . In Nancy, too, the system is to be replaced by a tram in 2022.
The Translohr technology developed by Lohr Industrie , like the TVR, uses a rail embedded in the center. The vehicles are bi - directional articulated vehicles that can only drive on track- guided routes (in contrast to the freely steerable TVR).
Since 2015 there have been a total of seven Translohr systems in four countries. In addition to the Clermont-Ferrand Translohr , these are the T5 and T6 lines in the Paris area, Padua and ( Venice -) Mestre in Italy, Tianjin and Shanghai in the People's Republic of China and Medellín in Colombia.
From May 1984 to December 1985 there was a test in Fürth with inductively guided track buses from MAN and Daimler-Benz . Operation took place in regular driving on a demonstration system in Königswarterstraße. After the end of the tests, however, no further routes were built.
Under the name CiVis (lat .: citizen) a system was developed by Renault and Matra in France which is supposed to combine the advantages of buses and trams . For anti-trust reasons, the system later went to the Irisbus company .
A dashed double line is applied to the road surface using a special paint. A camera tracks this marking and an image processing system checks the information from the camera. The on-board computer then takes over steering the vehicle. The bus driver only has to accelerate and brake. If there are obstacles in the lane, the driver can take control again. CiVis can avoid obstacles like a bus and then thread its way back into the marking path. The advantage is a high degree of flexibility while driving. There are already 300 buses in use with this system.
Control via the image processing system still harbors systemic problems, since correct recognition and interpretation is sometimes inhibited by environmental influences (reflections when wet, snow cover).
Under the name AutoTram , the Fraunhofer Institute for Traffic and Infrastructure Systems (IVI) in Dresden is developing a transport system with optical track guidance as well as being driven by flywheel storage .
A major constructive problem with track buses and similar systems using rubber roadway technology is the design of the superstructure.
Everyone who has looked at the road surfaces at busy bus stops knows the problem . Within a few months, clear ruts form , which are deepened by the braking process and appear wavy in the longitudinal profile.
When driving in the lane guidance, this formation of grooves is increased even on the open road and means that the grooves have to be filled up at periodic intervals. For this reason, the use of asphalt should not be used for track bus routes.
The stone paving, popular at bus stops, is also ruled out due to the considerable reduction in driving comfort.
What remains are technologically sophisticated surfaces made of fiber-reinforced concrete layers , concrete bonded with synthetic resin or steel roadways with a structured surface to prevent the tires from slipping. Emergency running devices (in the event of a burst tire) made of steel are necessary anyway. In addition, it may be necessary to heat the carriageway on inclines in order to avoid the formation of black ice in the repeatedly emerging ruts. In the higher speed range (over 25 km / h), the driving dynamics of the lane bus also place the highest demands on the road geometry.
The formation of corrugations can sometimes be observed in curves on track systems . It is created in particular by inhibiting the slightly oscillating movements of the wheel flange wheel sets. The track geometry is adapted to this movement by a slight inclination of the rail heads towards the track axis and the conical shape of the iron wheel sets. Automobiles also have a similar design of the wheel sets to achieve a more stable road holding. The fact is, however, that even constant straight travel is composed of a series of flat pendulum movements of the vehicle around its center of gravity to the left and right. This becomes an essential factor for long straight journeys in lane guidance, even for a bus, as the lane surfaces as well as the rail heads have to be inclined slightly inwards in order to avoid the formation of corrugations on the lanes next to the grooves and thus bumpy straight travel. This in turn requires precise coordination with the vehicle driving on it.
Areas of application - general statements
In view of the demands on the lane of a track bus, it can be seen that so much money has to be spent on reducing the formation of ruts, improving the driving geometry and driving dynamics, on safety devices against tire blowouts and, last but not least, on the various track guidance systems that the costs increase related to the respective lifetime, with those of a normal track body are comparable. The individual vehicle costs significantly less to buy, but the lifespan of buses is also shorter than that of tram vehicles. Tracked bus routes are therefore to be used primarily as system additions in fast-growing small and medium-sized towns without existing trams. If these have clearly defined, heavily frequented, but short overland axes to connect individual scattered settlements in the greater area, the track bus can be a suitable means of transport here.
The track bus is also suitable as a placeholder for future axes of higher-quality means of transport and to increase the attractiveness of existing bus routes, which can only be converted into rail routes in the long term due to lack of financial strength. If the demands on the driving speed are not too high and if it is in the 30 km / h range, then the above-described driving path problems can also be managed with little financial outlay.
- Railway wheel / pneumatic wheels
- Bus rapid transit
- Perambulator operation
- Bettingberg tunnel # Today's use
- Erich Hoepke: Omnibuses in the traffic system of metropolitan areas . Planning, operation and control system - technology of buses, trolleybuses, duo buses and track buses. Expert, Renningen-Malmsheim 1995, ISBN 978-3-8169-1164-7 .
- Experience with operations in Essen, road cuts
- Transport Public Public transport ( Memento from November 19, 2012 in the Internet Archive ) (French)
- English-language site with photos and a film from Essen
- Youtube video of a track bus ride in Essen from Kray to the water tower over the route in the middle of the A 40
- Der Stadtverkehr, issue 7/1982
- A kind of symbiosis . In: Der Spiegel . No. 7 , 1988 ( online ).
- Track buses (O-Bahn) , on omnibusarchiv.de
- Bettingberg Tunnel , tunnelportale.de
- Mercedes-Benz Classic-Wiki: Chronicle 1981–1990 ( Memento from August 26, 2010 in the Internet Archive )
- Der Stadtverkehr, issue 7/1982
- lane buses (O-Bahn). October 5, 2007, accessed January 14, 2017 .
- Michael Mücke: Too expensive, too vulnerable - Essen track bus on the brink of collapse. In: westen.de. August 28, 2014, accessed January 14, 2017 .
- Michael Mücke: Evag is not giving up the track bus route on the A40 for the time being. In: WAZ. October 3, 2015, accessed January 14, 2017 .
- Michael Mücke: The tram is to replace the track bus on the A40 in Essen. In: WAZ. January 11, 2016, accessed January 14, 2017 .
- Bus tunnel under Regensburg: That is in the old report , article on wochenblatt.de , published on January 30, 2014, accessed on March 27, 2017
- DER SPIEGEL, born in 1985: Medieval Regensburg wants to introduce a new type of local public transport - the U-Bus
- Underground: Back to the future with Schlegl - the bus tunnel idea is 30 years old , article on regensburg-digital.de , published on January 20, 2014, accessed on March 27, 2017
- Mannheim track bus on the siding. In: pro-bahn-bw.de. Archived from the original on March 7, 2012 ; accessed on January 14, 2017 .
- Alternative urban transportation ( Memento of April 16, 2009 in the Internet Archive ), on irisbus.com