Bombardier Guided Light Transit
Encyclopedia
Public transport
Public transport is a shared passenger transportation service which is available for use by the general public, as distinct from modes such as taxicab, car pooling or hired buses which are not shared by strangers without private arrangement.Public transport modes include buses, trolleybuses, trams...
system manufactured by Bombardier Transportation
Bombardier Transportation
Bombardier Transportation is the rail equipment division of the Canadian firm, Bombardier Inc. Bombardier Transportation is one of the world's largest companies in the rail-equipment manufacturing and servicing industry. Its headquarters are in Berlin, Germany....
and used in the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
cities of Nancy and Caen
Caen
Caen is a commune in northwestern France. It is the prefecture of the Calvados department and the capital of the Basse-Normandie region. It is located inland from the English Channel....
.
Both of the systems in these cities are referred to as "tram
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...
ways on tyre
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
s", and in common with tram systems they use a surface guidance system and in normal operation are powered by electricity drawn from an overhead wire
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
. However, while the vehicles are guided by a central guidance rail, they ride on rubber tyres, not on rails. There has been disagreement about whether they should be called "trams", for that reason and also because they are capable of being steered and operating independently of the guidance rail, using auxiliary diesel engines. GLT is effectively a model of guided
Guided bus
Guided buses are buses steered for part or all of their route by external means, usually on a dedicated track. This track, which often parallels existing roads, excludes other traffic, permitting the maintenance of reliable schedules on heavily used corridors even during rush hours.Guidance systems...
dual-mode bus
Dual-mode bus
A dual-mode bus is a bus that can run independently on power from two different sources, typically electricity from overhead lines or batteries, alternated with conventional fossil fuel ....
, but when GLT vehicles use a pantograph
Pantograph (rail)
A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...
to collect current, as do those in Caen, they are not commonly considered to be trolleybus
Trolleybus
A trolleybus is an electric bus that draws its electricity from overhead wires using spring-loaded trolley poles. Two wires and poles are required to complete the electrical circuit...
es. English transport publications generally refer to the GLT and the competing Translohr
Translohr
Translohr is a guided bus system manufactured by Lohr Industrie of France. It is used in Clermont-Ferrand, Tianjin, Padua and in the mainland Mestre district of Venice in Italy. Translohr runs on rubber tires and is guided by a single central rail....
system as "rubber-tyred tramways", but rarely simply as "tramways", as they are not tramways in the conventional sense, but neither are they buses when pantograph-equipped and operating in service as designed (i.e., in electric mode).
GLT is one of the only models (together with the Innovia APM) of rubber-tyred vehicles produced by Bombardier’s transport division, which is otherwise focused on rail transport
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
.
Characteristics
Translohr
Translohr is a guided bus system manufactured by Lohr Industrie of France. It is used in Clermont-Ferrand, Tianjin, Padua and in the mainland Mestre district of Venice in Italy. Translohr runs on rubber tires and is guided by a single central rail....
are often described as the tram equivalent of rubber-tyred metro technology, but this is not strictly accurate; while the GLT follows a central rail, the rail does not support the vehicle, and the actual wheels which are as independent as those of a regular bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...
. The wheels of rubber-tyred metros, on the other hand, are bound and guided by their rails in the same way as are steel-wheeled trains. Unlike trams and Translohr vehicles, GLT vehicles have a steering wheel
Steering wheel
A steering wheel is a type of steering control in vehicles and vessels ....
, though it is not used when following a guidance rail. On the GLT line in Nancy, more than one-third of the 10-km route has no guide rail, and steering is controlled entirely by the driver on those sections. The Nancy GLT system is operated by the Société de Transports de l'Agglomération Nancienne, or STAN.
With two articulation points and a total length of 24.5 metres, GLT vehicles are shorter than most modern trams, but quite long compared to regular buses. They are designed to look much like trams, although they are unidirectional and have bus-like rear-view mirror
Rear-view mirror
A rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight ....
s.
They have 100% low floors, seat forty passengers, and have standing room for as many as 105.
In Caen, where the central guidance rail has been installed on all sections of the passenger-service route, the vehicles collect their power from a pantograph
Pantograph (rail)
A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...
, returning it through the central guidance rail, and use their diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s and steering wheels only while travelling to and from the depot. Use of a pantograph effectively requires that a surface guidance system be used, to ensure the vehicle remains approximately centred below the overhead wire
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
, so that its pantograph does not slip out from underneath the wire. The Caen vehicles thus cannot move laterally away from the overhead wire except when running in diesel mode (as conventional buses), and for this reason the Caen route is not commonly considered to be a trolleybus
Trolleybus
A trolleybus is an electric bus that draws its electricity from overhead wires using spring-loaded trolley poles. Two wires and poles are required to complete the electrical circuit...
system.
Nancy’s fleet of 25 GLT vehicles use dual trolley pole
Trolley pole
A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" overhead wire to the control and propulsion equipment of a tram or trolley bus. The use of overhead wire in a system of current collection is reputed to be the 1880 invention of Frank J....
s to collect and return their electric power, in order to allow the use of existing wires
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
constructed for use by the town's previous generation of trolleybus
Trolleybus
A trolleybus is an electric bus that draws its electricity from overhead wires using spring-loaded trolley poles. Two wires and poles are required to complete the electrical circuit...
es and to permit operation, where desired by the transport authority, away from the guide rail. The Nancy vehicles follow a guidance rail on about 60% of the route, and thus the Nancy route uniquely is considered to be both a rubber-tyred tramway and a trolleybus line. The system was first brought into use for passenger service in February 2001, but operation was suspended from March 2001 through March 2002 while Bombardier performed upgrades to the vehicles.
In Caen, the GLT fleet began operation in November 2002, incorporating the changes made to Nancy’s vehicles during the upgrade. They are operated by the Compagnie des Transports de l'Agglomération Caennaise under the name Twisto.
Advantages
Another advantage over trams, which was particularly of interest to planners in Nancy, is that rubber tyres give significantly more traction than steel wheels, and so can be used to climb steeper hills, up to a grade or slope
Slope
In mathematics, the slope or gradient of a line describes its steepness, incline, or grade. A higher slope value indicates a steeper incline....
of 13%. The Nancy route T1 includes a section with a 13% grade.
Compared to buses, the use of a guidance rail allows GLT vehicles running in parallel lanes to pass closer together than drivers could safely steer. They can also draw up to level, tram-like platforms that allow for easier boarding, and give access to passengers dependent on wheelchair
Wheelchair
A wheelchair is a chair with wheels, designed to be a replacement for walking. The device comes in variations where it is propelled by motors or by the seated occupant turning the rear wheels by hand. Often there are handles behind the seat for someone else to do the pushing...
s without requiring the time-consuming deployment of ramps or ‘kneeling’ systems.
Disadvantages
The GLT systems in place have experienced some mechanical problems which, though they have largely been resolved, have discouraged some other cities from adopting the technology. The vehicles have shown a tendency to move erratically when running free, and do not respond well should the driver mistakenly attempt to steer while following the guidance rail (for example, to avoid a jaywalkingJaywalking
Jaywalking is an informal term commonly used in North America to refer to illegal or reckless pedestrian crossing of a roadway. Examples include a pedestrian crossing between intersections without yielding to drivers and starting to cross a crosswalk at a signalized intersection without waiting...
pedestrian or an animal running into the street).
In addition, due to the tyres running over the same spot in the road, in both Nancy and Caen there has been significant rutting of the roadway, resulting in extensive repairs at significant cost to the operator. This could be considered to add to the already high running costs.
Ride quality is also said to be poor, not much of an improvement on a bus, due to the 4 wheeled design, whereas trams have bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
s with shock absorbers.
Problems with the guidewheel breaking have also emerged, leading the trolleybus to swerve off its roadway. This is due to the high centrifugal force
Centrifugal force
Centrifugal force can generally be any force directed outward relative to some origin. More particularly, in classical mechanics, the centrifugal force is an outward force which arises when describing the motion of objects in a rotating reference frame...
s exerted on the wheel when it goes round corners. As a result of the breakages, a speed limit of 10k/h is now enforced on corners.
One of the main aims of the system, to achieve a lower cost per kilometre than trams, has failed. Other French tramways achieve a cost per kilometre at least 10% lower than that for the guided bus. Similarly, the cost per person of the vehicles is also noticeably higher with the guided bus than a tram.
Where snow
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
fall is an issue, this system may not be practical.
Critics of the system also point out that unlike a conventional tramway, GLT is a proprietary
Property
Property is any physical or intangible entity that is owned by a person or jointly by a group of people or a legal entity like a corporation...
system, meaning that once having installed it, a city would face difficulties
Vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs...
in purchasing vehicles from any manufacturer other than Bombardier. A standard tramway, on the other hand, can easily accommodate vehicles from multiple suppliers; Nancy’s neighbour Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...
, for example, recently chose the Citadis
Citadis
The Citadis is a low-floor tram built by Alstom in La Rochelle, France, and Barcelona, Spain. 1,140 Citadis are currently in use in 28 cities, among others: Bordeaux, Grenoble, Lyon, Montpellier, Orléans, the Paris area, and Barcelona, Dublin, Gdańsk, Katowice, Adelaide, Melbourne, Jerusalem and...
tram from Alstom
Alstom
Alstom is a large multinational conglomerate which holds interests in the power generation and transport markets. According to the company website, in the years 2010-2011 Alstom had annual sales of over €20.9 billion, and employed more than 85,000 people in 70 countries. Alstom's headquarters are...
to supplement its existing Bombardier Eurotram
Flexity Outlook
The Flexity Outlook is a family of 100% low-floor articulated light-rail trams manufactured by Bombardier Transportation. Part of the larger Flexity product line , Flexity Outlook cars fall into two distinct sub-categories with dramatically different appearances...
fleet.
Because of the significant problems encountered by the cities which have opted for the Bombadier Guided Bus, one of which has demanded compensation for the costs it has had to pay out for the GLT, Bombadier will not sell any more GLT systems, at least until all the issues have been resolved.
Legal status
GLT vehicles are legally considered buses, and they must bear number plateVehicle registration plate
A vehicle registration plate is a metal or plastic plate attached to a motor vehicle or trailer for official identification purposes. The registration identifier is a numeric or alphanumeric code that uniquely identifies the vehicle within the issuing region's database...
s, rear-view mirror
Rear-view mirror
A rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight ....
s and lights
Automotive lighting
The lighting system of a motor vehicle consists of lighting and signalling devices mounted or integrated to the front, sides, rear, and in some cases the top of the motor vehicle...
. Unlike trams and Translohr vehicles, GLT vehicles have a steering wheel
Steering wheel
A steering wheel is a type of steering control in vehicles and vessels ....
(though it is not used when following a guidance rail), and are capable of operating independent of the guideway.
See also
- Bus rapid transitBus rapid transitBus rapid transit is a term applied to a variety of public transportation systems using buses to provide faster, more efficient service than an ordinary bus line. Often this is achieved by making improvements to existing infrastructure, vehicles and scheduling...
- Guided busGuided busGuided buses are buses steered for part or all of their route by external means, usually on a dedicated track. This track, which often parallels existing roads, excludes other traffic, permitting the maintenance of reliable schedules on heavily used corridors even during rush hours.Guidance systems...
- Rubber-tyred trams
- TramTramA tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...
- TranslohrTranslohrTranslohr is a guided bus system manufactured by Lohr Industrie of France. It is used in Clermont-Ferrand, Tianjin, Padua and in the mainland Mestre district of Venice in Italy. Translohr runs on rubber tires and is guided by a single central rail....
- Véhicule Automatique Léger (VAL)
External links
- Guided Light Transit official web site
- Railfaneurope.net Nancy photo gallery
- world.nycsubway Nancy and Caen photo gallery
- “Misguided Bus”? Nancy’s BRT Debacle Exposes Pitfalls of “Half-Price Tramway” - an article critical of GLT
- New Era Hi-tech Buses - containing much historical information, including pictures of the developmental prototypes at the test track in Belgium.
- Guided bus information and pictures