Encyclopedia
A
trolleybus is a
bus powered by two overhead electric wires, from which it draws
electricity using two
trolley poles. Two poles are required in order to accommodate the return current, which cannot pass to the ground as in the case of an electric
tram or
streetcar since trolleybuses use rubber
tires, rather than steel wheels on rail. There are trolleybuses in many cities around the world.
Background
The history of the trolleybus dates back to 29 April 1882, when Dr.
Ernst Werner von Siemens ran his "Elektromote" in a
Berlin suburb. This experimental demonstration continued until 13 June 1882, after which there was little progress in Europe, although separate experiments were conducted in the USA. The next development was when Lombard Gérin operated an experimental line at the
Paris Exhibition of 1900 after four years of trials. Max Schiemann made the biggest step when on 10 July 1901 the world's first passenger-carrying trolleybus operated at Bielathal in
Germany. Schiemann built and operated the Bielathal system, and is credited with developing the under-running trolley current collection system, with two horizontally parallel overhead wires and rigid trolleypoles under tension to keep them up to the wires. Although the Bielathal system only operated until 1904, Schiemann had developed what is now recognised as the standard trolleybus current collection system. In the early days, however, there were a few different methods of current collection being developed. The Mercedes-Stoll system, designed by Carl Stoll, was once operated near
Dresden between 1902 and 1904, and in
Vienna. The Lloyd-Köhler or Bremen system was tried out in Bremen, and the Filovia was demonstrated near
Milan.
Leeds and
Bradford became the first cities to operate passenger-carrying trolleybuses in the
UK on 20 June 1911. Bradford was also the last to operate trolleybuses in the UK, closing on 26 March 1972. The last rear entrance trolleybus in Britain was also in Bradford, now owned by the Bradford Trolleybus Association.
Birmingham was the first to replace a tram route with trolleybuses, while
Wolverhampton under the direction of Charles Owen Silvers was responsible for turning the "trackless tram" into the trolleybus. There were 50 trolleybus operations in the UK in total, with
London being the largest. By the time trolleybuses arrived in British in 1911, the Schiemann system was well established and was the most common, although the short-lived
Stockport system used the Lloyd-Kölher system, and
Keighley used the Cedes-Stoll method.
In the USA, some cities, led by the
Brooklyn-Manhattan Transit Corporation , subscribed to the all-four concept of using buses, trolleybuses,
trams and
rapid transit subway and/or elevated lines , as appropriate, for routes ranging from lightly-used to heaviest trunk line. Buses and trolleybuses in particular were seen as entry systems that could later be upgraded to rail as appropriate. Although the BMT in
Brooklyn built only one trolleybus line, other cities, notably
San Francisco, California and
Philadelphia, Pennsylvania, built larger systems and still maintain "all-four". If you include cable cars as another mode, San Francisco could be called "all-
five," as the cable cars provide a general
transportation function in addition to being a tourist attraction.
Advantages
Trolleybuses are particularly advantageous in hilly cities, as
electric power is more effective than
diesel power in climbing steep hills, and trolleybuses'
rubber tires have better
adhesion than streetcars' steel wheels upon steel rails.
San Francisco and
Seattle, USA, both very hilly cities, use trolleybuses.
Like other
electric vehicles, trolleybuses are often seen as more environmentally friendly than
fossil fuel or
hydrocarbon-based vehicles , but the power is not "free", and instead has to be produced at centralised
power plants, with its attendant transmission losses. On the other hand, centrally-produced power has the advantage of being more efficient, not bound to a specific fuel source, and more amenable to pollution-control as a single-source supply than individual vehicles, each with their own power generation, exhausting noxious gases and particulates at street level.
Also, unlike buses or trams, trolleybuses are almost totally silent, without the noise of a diesel engine or the wheels on the rails. The main noise tends to come from auxiliary systems such as power steering pumps and air conditioning. Early trolleybuses without these systems were even quieter, and in the UK at least were often referred to as the "Silent Service". The quietness did have its disadvantages though, with quite a number of pedestrians falling victim to what was also known as "the Silent Death".
One advantage is that they can generate electric power from kinetic energy whilst braking, a process known as regenerative braking.
Another area where trolleybuses enjoy a special niche is in locations where
hydropower is abundant and cheap. Examples of this are the extensive trolleybus systems in
Vancouver,
British Columbia,
Canada and
Seattle,
Washington, USA. The latter city doubly benefits, due to the steep road grades near the
Downtown waterfront and on
Queen Anne,
First, and
Capitol Hills.
Trolleybuses are used extensively in large European cities such as
Athens,
Moscow,
Saint Petersburg,
Kiev,
Belgrade and
Vilnius, as well as smaller ones, like
Lausanne,
Salzburg and
Nancy. Cities, especially located on hills, have chosen trolleybuses over diesel buses because the electric engine is capable of producing much more torque than a diesel engine. Moreover, the electric engine can be temporarily "overpowered", that is, more than the average power can be obtained from the engine for a short period of time, e.g. when climbing a steep hill. Also, realizing the advantages of these zero-emission vehicles, some other European cities have started to expand their systems again. Other cities such as
Lecce will introduce new trolleybus systems.
Some have suggested that the trolleybus will become obsolete in a future
hydrogen economy. However, direct electric transmission, as used in trolleybuses, is far more efficient than conversion of energy into hydrogen, transportation and storage of the hydrogen and its conversion back into electricity by fuel cells.
China is experimenting with a new form of electric bus that runs without powerlines. This bus runs on power stored in large onboard
supercapacitors, which are quickly recharged whenever the electric bus stops in any bus stop. A few prototypes were being tested in
Shanghai in early 2005.
Restraints
With the raise of hybrid designs the trolleybus is no longer "captive" to its overhead trolley wires. Re-routings, temporary or permanent, are not usually readily available outside of "downtown" areas where the buses may be re-routed via adjacent business area streets where other trolleybus routes operate. Dewirements sometimes occur, leaving the bus stranded without power, although these events are relatively rare on systems with well-maintained overhead wire, hangers, fittings and "contact shoes." Some systems, such as
Muni in San Francisco and TransLink in
Vancouver, have circumvented this problem by installing battery packs on their trolleybuses to allow them to drive for short distances in case they cannot follow the standard route. Also capacitators may be used to drive small distances without connections to the grid.
Boston is using
dual-mode buses on its new Silver Line that run on overhead electricity on a fixed right of way and then transition to city streets using
diesel power. In
Philadelphia, Pennsylvania, whose five trolleybus lines have been suspended for partial reconstruction, new trolleybuses on order will also have a means of operating short distances without wire. In
Athens, Greece, which has an extensive trolleybus system, in 2003-2004 all trolleybuses were replaced with new vehicles that are equipped with a diesel engine that allows them to run off-line for a considerable distance.
Limitations in the creation of power lines also limits the use of trolleybuses. Limitations may also arise when super-tall trucks need to use a route, preventing the installation of lines. Nevertheless the implementaion is less expensive and faster compared to tramways.
Trolleybuses can pass one another in regular service, if two separate sets of wires with a switch are provided.
Trolleybuses were generally implemented only when they confer one of the advantages listed above, because of the high cost of their infrastructure compared to the alternative, the standard bus. With increasing diesel costs and particle and NOx problems in cities, trolleybuses may be seen as the best suited relief for medium sized cities.
While at one time numerous cities operated this mode of transport, it is on average uncommon today in North America, though it is still a common form of transport in many European, Russian, Brazilian and Chinese cities, generally occupying the niche between street railways and diesel-powered buses. There were also new systesm set up just recently.
Trolleybus wire switch
Trolleybus wire switches are a standard piece of equipment in places where the line forks into two others or two lines join into one. The switch pictured here is a fully automatic one; the driver controls it by means of the application of power to the bus's motor. If the "straight through" option is desired, the driver coasts through the switch. All parts of switch are still in their initial positions when trolleybus goes under the switch. If the "turn" option is desired, the driver passes the switch while applying power to the bus's motor. The switch detects the current drop in the wires caused by the draw on power of the motor and activates a small
electromagnet to change the switch position. After a short period of time the electromagnet automatically turns off and, due to attached spiral coils, the switch returns to the normal "straight through" configuration.
Trolleybuses in Russia
The first trolley vehicle in Russia was built in
Saint Petersburg in 1902 on Frese machinebuilding factory. It utilised a carriage-type current receiver like the early von Siemens prototypes. There was no attempt to organize passengers or cargo services at this time.
The first operational trolleybus service was introduced in 1933 in
Moscow. In Soviet cities with underground metropolitan railways, trolleybus systems were intended to replace tramcars. In reality such plans were partially performed in 1950s rather than in 1930s. The first Soviet-made passenger trolleybus LK-1 was named after Politburo member Lazar Kaganovich. It was a dangerous and unreliable vehicle, quickly replaced by more advanced YaTB vehicles. These cars, both passenger and cargo, were the mainstay of Soviet trolley fleet before
Great Patriotic War. At this time new trolleybus systems were opened in
Leningrad,
Kiev and few other major Soviet cities.
It may appear strange that in the time of the Great Patriotic War, new trolleybus systems were opened in
USSR. The need for mass transit in cities away from the front was urgent, but construction of tram lines was too expensive and time-consuming. Buses were largely mobilized to the
Red Army as staff and medical vehicles. The remains of the bus fleet quickly stalled due to fuel shortages. The trolleybuses proved a good solution. Some vehicles, wires and other equipment were evacuated from Moscow in 1941; these materials were used for erecting new lines and systems in other cities. In the front-line city of Leningrad, trolleybus service ceased operations in November 1941 and was not restored until the end of the war. City trams were relaunched in April 1942 and performed without interruption under siege conditions. This restored Soviet plans of mass transit development in the form of co-existence of subways, trams, and trolleys.
The postwar period saw an explosion of development and expansion of trolleybus systems in the
Soviet Union. Many cities and towns introduced passenger and cargo trolleybus services, sometimes interfering with tram operations. Production at the time was limited to the monopoly
Zavod imeni Uritskogo . It produced thousands of MTB-82,
ZiU-5,
ZiU-9 passenger trolleybuses for domestic purposes and for export. ZiU-9s were sold to
Greece,
Colombia,
Argentina and eastern bloc countries. Three ZiU-9 cars were on loan in 1973 for testing purposes in
Helsinki,
Finland.
The collapse of the Soviet Union led to insufficient funding for many municipal trolleybus systems, but they proved more resilient than municipal tram or bus operations. There are no closed trolleybus systems in areas of modern
Russia that are at peace. The trolleybus system in
Grozny was completely destroyed in the
First Chechen War. Reconstruction is in planning. There are two systems with uncertain futures, in
Voronezh and
Shakhty. In other cities the development of trolleybus passenger services continues. Two new systems were introduced in Moscow suburbs Khimki and Vidnoe in the second half of 1990s. ZiU has lost its monopoly in producing trolley vehicles. Today a number of domestic factories offer trolleybuses for the Russian market.
Preservation
The world's largest collection of preserved trolleybuses is at
The Trolleybus Museum at Sandtoft in England. Examples are also preserved at The
East Anglia Transport Museum and The
Black Country Living Museum in England, the
Brisbane Tramway Museum and the Adelaide Electric Traction Museum in
Australia. In Foxton,
New Zealand, preserved trolleybuses operate on the public highway on their own system.
The Bradford Trolleybus Association is currently restoring Bradford Trolleybus 758, the last rear entrance trolleybus in Britain. Bradford Trolleybus 758 is kept at
The Trolleybus Museum at Sandtoft. The Bradford Trolleybus Association urgently need funds to continue the restoration of this historic Trolleybus. For more information, go to www.bradfordtrolleybusassociation.co.uk .
In Lausanne, the Association Retrobus preserves old trolleybuses and enables them to circulate in town, especially on summer weekends.
The
Illinois Railway Museum also maintains a historical collection of trolleybuses from
Chicago, Illinois,
Dayton, Ohio,
Cleveland, Ohio,
Des Moines, Iowa,
Vancouver British Columbia and
Milwaukee, Wisconsin.
Russian transport museums have a variety of historic trolleybuses made by local manufacturers. In
Moscow vintage vehicles are only available for public in transport-dedicated exhibitions and parades of old vehicles in different celebration days. In
Saint Peterburg and
Nizhny Novgorod museum cars are also may be hired for city excursions and parties.
See also
Books
Sebree, Mac, and Paul Ward. 1973. “Transit’s Stepchild, the Trolley Coach” . Los Angeles: Interurbans.
Sebree, Mac, and Paul Ward. 1974. "The Trolley Coach in North America" . Los Angeles: Interurbans.
Mick Leak. 2006. "The Story Of Britain's Last Rear Entrance Trolleybus In Public Service - Bradford 758. Published By The Bradford Trolleybus Association. Bradford. United Kingdom.
Periodicals
"Trolleybus Magazine" . National Trolleybus Association . Bimonthly.
"Trackless" The Quarterly Magazine Published By The Bradford Trolleybus Association For Its Members.
References
- , accessed January 30, 2004
External links
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- - Has photos of Trolleybuses in Vancouver & Edmonton , and Wellington
- — available in English, German and Russian.
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- / "Seventy years of Kiev trolleybus", Zerkalo Nedeli , December 10-16, 2005, and .
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