Trolleybus

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Image:Public Transfer TrolleyBus Bratislava.jpg A trolleybus (also known as electric bus, trolley bus, trolley coach, trackless trolley, trackless tram or simply trolley) 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.

1 Background
2 Advantages
3 Disadvantages
4 Trolleybuses in Russia
5 Preservation
6 Books
7 Periodicals
8 External links
9 References

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Background

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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 13th June 1882 after which there was little progress in Europe, although separate experiments were conducted in the USA. The next development in the history of the trolleybus was when Lombard Gérin operated an experimental line at the Paris Exhibition of 1900 after 4 years of trials. It was, however, Max Schiemann who made the biggest step when on 10th July 1901 the world's first passenger-carrying trolleybus operated at Bielathal (near Dresden) in Germany. Schiemann, who built and operated the Bielathal system, is credited as 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 system for current collection on all trolley systems around the world. 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 always operated near Dresden between 1902 & 1904 and in Vienna. The Lloyd-Köhler or Bremen system was trialled in Bremen, and the Filovia was demonstrated near Milan.

It was Leeds and Bradford who became the first to operate passenger-carrying trolleybuses in the UK on 20th June 1911. Bradford were also the last to operate trolleybuses in the UK when the system closed on 26th March 1972. There were 50 trolleybus operations in the UK in total, with London being the largest. By the time trolleybuses arrived on British shores 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 the Keighley system implemented the Cedes-Stoll method.

In the USA, some cities, led by the Brooklyn-Manhattan Transit Corporation (BMT—New York), subscribed to the all-four concept of using buses, trolleybuses, trams (in U.S. called streetcars, trolleys or light rail) and rapid transit subway and/or elevated lines (metros), 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 Brooklyn system under the BMT 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 do provide a general transportation function in addition to being a tourist attraction.

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Advantages

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Trolleybuses are particularly important in hilly cities, as electric power is more effective than diesel in climbing steep hills, and trolleybuses' rubber tires have better adhesion than streetcars' steel wheels upon steel rails. This is especially important in hilly cities such as San Francisco and Seattle, USA.

Like other electric vehicles, trolleybuses are often seen as more environmentally friendly than hydrocarbon-based vehicles (gasoline, diesel, alcohol, etc.), 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 things 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.

Image:Vancouver trolley2101 050720.jpg 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, Kiev and Belgrade, as well as smaller ones, like Lausanne, Salzburg and Nancy. Cities, especially located on hills, have chosen trolleybuses over traditional buses because the electric engine is capable of producing much more power 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 (by a factor of two or more) 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.

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Disadvantages

Image:Us-san-francisco-trolleybus.jpg Image:Trolleybus Arnhem.jpg The trolleybus is "captive" to its overhead trolley wire, and so re-routings, temporary or permanent, are not usually readily available outside of "downtown" areas where the buses maybe re-routed via adjacent business area streets where other trolleybus routes operate. Dewirements, although relatively rare on systems with well-maintained overhead wire, hangers, fittings and the trolley "contact shoes" on the poles of the buses themselves, do at times occur, with the buses being left stranded on infrequent occasions. Some systems, such as Muni in San Francisco and TransLink in Vancouver, have gotten around 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. 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, which has an extensive trolleybus system, in 2003-2004 all trolleybuses were replaced with new vehicles that are equipped with a diesel motor that allows them to run off-line for a considerable distance.

In more general terms, trolleybuses suffer from being "neither fish nor fowl" in current transportation planning. Except in the cases mentioned above where they have special advantages, they have difficulty competing with the efficiencies of light rail on the one hand, or the flexibility and low start-up costs of motorbuses on the other. Also, from a public perception point of view, they are viewed little different to motorbuses, unlike trams or "light rapid transit", which are often viewed more like trains.

While at one time numerous cities operated this mode of transport, it is uncommon today in North America, though it is still a common form of transport in many European and Asian cities, generally occupying the niche between street railways and diesel-powered buses.

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Trolleybuses in Russia

The first trolley vehicle in Russia was built in Saint Petersburg in 1902 on Frese machinebuilding factory. It utilised carriage-type current receiver like the early von Siemens prototypes. There was not any attempt to organize passengers or cargo transfer services at this time.

First trolleybus operational service was introduced in 1933 in Moscow. Soviet authorities considered the trolleybus as innovative decision in mass transit area. With underground metropolitan railways trolleybus systems were intended to replace tramcars in Soviet cities. In reality such plans were partially performed in 1950-ies rather than in 1930-ies. First Soviet-made passenger trolleybus LK-1 was named after Lazar Kaganovich, the permanent member of Stalin's government. It was quite dangerous and unreliable vehicle, so it was replaced to 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 is quite strange for the first glance that in the time of the Great Patriotic War a number of new trolleybus systems was opened in USSR. But there are no any controversies - the need of mass transit in rear cities was urgent, but construction of tram lines was too expensive and time-consuming. A lot of buses were mobilized to Red Army as staff and medical vehicles, the decimated remains of bus fleet quickly stalled due to fuel shortages. The trolleybuses proved themselves as a good solution of the problem. 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 front-line city of Leningrad trolleybus service ceased operations in November 1941 and did not restored until the end of the war. In comparison, city trams were relaunched in April 1942 and further worked without interruptions under siege conditions. This corrected Soviet plans of mass transit development to co-existence of metro, tram and trolley.

After-war period was explosion-like development and expansion of trolleybus systems in Soviet Union. Many cities and towns introduced their trolleybus services (both passenger and cargo), sometimes with interference of tram operations. The monopolist trolley vehicle producer at that time was Zavod imeni Uritskogo (ZiU, plant named after Moisei Uritsky). It produced thousands of MTB-82, ZiU-5, ZiU-9 passenger trolleybuses for domestic purposes and for export. ZiU-9s were successfully sold to Greece, Colombia, Argentina, Finland and eastern bloc countries.

Collapse of the Soviet Union lead to insufficient funding of many municipal trolleybus systems, but they showed themselves as more able to survive than municipal tram or bus operators. There are no closed trolleybus systems in modern Russia in peace conditions, only trolleybus system in Grozny was completely destroyed in First Chechen War. Now there are some talks about its reconstruction. Also there are two systems in uncertain future conditions, in Voronezh and Shakhty towns. In other cities the development of trolleybus passenger services is still going on and even two new systems were introduced in Moscow suburbs Khimki and Vidnoe at the second half of 1990-ies. ZiU lost it's monopoly in producing trolley vehicles; there are a number of other factories which are offering trolleybuses for Russia domestic market.

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