Trolleybus

 ( Buses By Type ) 

Throughout this period, trackless freight systems and electric canal boats were also built.

Leeds and Bradford became the first cities to put trolleybuses into service in Great Britain, on 20 June 1911. Supposedly, though it was opened on 20 June, the public was not admitted to the Bradford route until the 24th. Bradford was also the last city to operate trolleybuses in the UK; the system closed on 26 March 1972. The last rear-entrance trolleybus in service in Britain was also in Bradford and is now owned by the Bradford Trolleybus Association. Birmingham was the first UK city to replace a tram route with trolleybuses, while Wolverhampton, under the direction of Charles Owen Silvers, became world-famous for its trolleybus designs.Dunbar p. 84 There were 50 trolleybus systems in the UK, London's being the largest. By the time trolleybuses arrived in Britain in 1911, the Schiemann system was well established and was the most common, although the Cédès-Stoll (Mercédès-Électrique-Stoll) system was tried in West Ham (in 1912) and in Keighley (in 1913).Dunbar p. 83J. S. King, Keighley Corporation Transport, (Advertiser Press Ltd, 1964, no ISBN) p. 39 et seq.

Smaller trackless trolley systems were built in the US early as well. The first non-experimental system was a seasonal municipal line installed near Nantasket Beach in 1904; the first year-round commercial line was built to open a hilly property to development just outside Los Angeles in 1910. The trackless trolley was often seen as an interim step, leading to tram. In the US, some systems subscribed to the all-four concept of using buses, trolleybuses, streetcars ( trams, trolleys), and rapid transit subway and/or elevated lines (metros), as appropriate, for routes ranging from the lightly used to the heaviest trunk line. Buses and trolleybuses in particular were seen as entry systems that could later be upgraded to rail as appropriate. In a similar fashion, many cities in Britain originally viewed trolleybus routes as extensions to tram (streetcar) routes where the cost of constructing or restoring track could not be justified at the time, though this attitude changed markedly (to viewing them as outright replacements for tram routes) in the years after 1918.Dunbar, p. 90 Trackless trolleys were the dominant form of new post-World War I electric traction, with extensive systems in among others, Los Angeles, Chicago, Boston, Rhode Island, and Atlanta; San Francisco and Philadelphia still maintain an "all-four" fleet. Some trolleybus lines in the United States (and in Britain, as noted above) came into existence when a trolley or tram route did not have sufficient ridership to warrant track maintenance or reconstruction. In a similar manner, a proposed tram scheme in Leeds, United Kingdom, was changed to a trolleybus scheme to cut costs.

Trolleybuses are uncommon today in North America, but their use is widespread in Europe, Asia, South America and in countries which were part of the Soviet Union. Generally trolleybuses occupy a position in usage between street railways (trams) and motorbuses. Worldwide, around 300 cities or metropolitan areas on 5 continents are served by trolleybuses (further detail under Use and preservation, below). also operate trolleybus networks to serve workers. Wuyang Coal Mine in Xiangyuan County, Changzhi, Shanxi has the last remaining mine trolleybus system in China.]]

This mode of transport operates in large cities, such as Belgrade, Lyon, Pyongyang, São Paulo, Seattle, Sofia, Saint Petersburg, and Zurich, as well as in smaller ones such as Dayton, Gdynia, Lausanne, Limoges, Modena, and Salzburg. As of 2020, Kyiv has the largest trolleybus system in the world in terms of route length, while Minsk, has the largest system in terms of number of routes. Sweden's Landskrona has the smallest system in terms of route length, while Czech Republic's Mariánské Lázně is the smallest city to be served by trolleybuses. Opened in 1914, the Shanghai trolleybus system is the oldest currently operating system in the world. With a length of 86 km, route #52 of Crimean Trolleybus is the longest trolleybus line in the world. See also Trolleybus usage by country.

Transit authorities in some cities have reduced or discontinued the use of trolleybuses, while others, wanting to add or expand use of zero-emission vehicles in an urban environment, have opened new systems or are planning new systems. For example, new systems opened in Lecce, Italy, in 2012; in Malatya, Turkey, in 2015; Trolleybus Magazine No. 321 (May–June 2015), p. 90. and in BRT Marrakesh in 2017. Beijing Bus and Shanghai have been expanding their respective systems, with Beijing growing to a 31-line system operated with a fleet of over 1,250 trolleybuses. In North Korea, the newest city to have a network is Manpo in December 2019. Since the year 2022, the city of Prague is constructing a new trolleybus system. Meanwhile, in 2023, plans for a trolleybus line in Berlin were scrapped in favour of a solution with battery-powered vehicles (motorbus).

Modern-design trolleybuses File:Irisbus Cristalis ETB 12 n°115 TCL Place Carnot.jpg|Irisbus Cristalis in Limoges File:Parma - TEP - Van Hool Exquicity 18 T.jpg|Van Hool Exquicity 18T in Parma File:AKCM-420 in Minsk - 04.jpg|AKSM-420 Vitovt in Minsk File:King County Metro XT60 trolleybus 4507 on Broadway (2016).jpg|New Flyer XT60 in Seattle File:9525493 at Gulou (20240405122447).jpg|Youngman JNP6183BEV in Beijing File:12-11-02-bus-am-bahnhof-salzburg-by-RalfR-24.jpg|Solaris Trollino 18 in Salzburg File:Castellón Solaris Trollino MetroStyle trolleybus arriving at UJI terminus (2024).jpg|Trolleybus in Castellón de la Plana File:Malatya trolleybus 4403 at Bugday Pazari in 2017.jpg|Trolleybus in Malatya

• Cheaper infrastructureThe initial start up cost of is much higher, due to rail, signals, and other infrastructure. Trolleybuses can pull over to the curb like other buses, eliminating the need for special boarding stations or boarding islands in the middle of the street, thus stations can be moved as needed.
• Better hill climbingTrolleybuses' rubber tyres have better adhesion than trams' steel wheels on steel rails, giving them better hill-climbing capability and braking.
• Easier traffic avoidanceUnlike trams (where side tracks are often unavailable), an out-of-service vehicle can be moved to the side of the road and its trolley poles lowered. The ability to drive a substantial distance from the power wires allows trackless vehicles to avoid obstacles, although it also means a possibility that the vehicle may steer or skid far enough that the trolley pole can no longer reach the wire, stranding the vehicle. Trackless trolleys also are able to avoid collisions by manoeuvring around obstacles, similar to bus and other road vehicles, while trams can only change speed.
• QuietnessTrolleybuses are generally quieter than trams.
• Easier trainingThe control of trolleybuses is relatively similar to motorbuses; the potential operator pool for all buses is much larger than for trams.

• Like any bus, much less capacity than trams.
• More control requiredTrolleybuses must be driven like motorbuses, requiring directional control by the driver.
• Higher rolling resistanceRubber-tired vehicles generally have more rolling resistance than steel wheels, which decreases energy efficiency.
• Less efficient use of right-of-wayLanes must be wider for unguided buses than for streetcars, since unguided buses can drift side-to-side. The use of guidance rail allows trams running in parallel lanes to pass closer together than drivers could safely steer.
• Difficulties with platform loadingImplementation of level platform loading with platform gap, either at design stage or afterwards, is easier and cheaper to implement with rail vehicles.
• Wear of rubber tires leads to significant rubber pollution.

• Difficult to re-routeWhen compared to Bus, trolleybuses have greater difficulties with temporary or permanent re-routings, wiring for which is 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. This problem was highlighted in Vancouver in July 2008, Other reports stated that the (electrical) explosion did not affect power supply to the trolleybuses (only implied by this article). when an explosion closed several roads in the city's downtown core. Because of the closure, trolleys were forced to detour several miles off their route in order to stay on the wires, leaving major portions of their routes not in service and off-schedule.
• AestheticsThe jumble of overhead line may be seen as unsightly. Intersections often have a "webbed ceiling" appearance, due to multiple crossing and converging sets of trolley wires.
• Dewirements sometimes come off the wire. Dewirements are relatively rare in modern systems with well-maintained overhead wires, hangers, fittings and contact shoes. Trolleybuses are equipped with special insulated pole ropes which drivers use to reconnect the trolley poles with the overhead wires. When approaching switches, trolleybuses usually must decelerate in order to avoid dewiring, and this deceleration can potentially add slightly to traffic congestion. In 1998, a dewirement in Shenyang on poorly maintained infrastructure killed 5 people and ultimately led to the destruction of the trolleybus network.
• Unable to overtake other trolleybusesTrolleybuses cannot overtake one another in regular service unless two separate sets of wires with a switch are provided or the vehicles are equipped with off-wire capability, with the latter an increasingly common feature of new trolleybuses.
• Higher capital cost of equipmentTrolleybuses are often long-lived equipment, with limited market demand. This generally leads to higher prices relative to internal combustion buses. The long equipment life may also complicate upgrades.
• More training requiredDrivers must learn how to prevent dewiring, slowing down at turns and through switches in the overhead wire system, for example.
• Overhead wires create obstructionTrolleybus systems employ overhead wires above the roads, often shared with other vehicles. The wires can restrict tall motor vehicles such as delivery trucks ("Truck") and double decker buses from using or crossing roads fitted with overhead wires, as such vehicles would hit the wires or pass dangerously close to them, risking damage and Electric arc. The wires also may impede positioning of overhead signage and create a hazard to activities such as road repairs using tall excavators or piling rigs, use of scaffolding, etc.

An early example was the "All Service Vehicle" (ASV), developed by the Public Service Company of New Jersey and Yellow Coach between 1935 and 1948. These were trackless trolleys capable of operating as gas-electric buses when off-wire.

In the late 20th century, dual-mode buses typically used their diesel engines for regular service on streets without overhead wires and switched to electric power in tunnels or environmentally sensitive areas to eliminate local emissions. Notable examples include:

• Seattle: From 1990 to 2005, King County Metro operated specially ordered articulated Breda buses in the Downtown Seattle Transit Tunnel. They ran as electric trolleybuses in the tunnel and switched to diesel power for on-street operation. Most of these were retired in 2005, though a few were converted to run exclusively as trolleybuses until 2016.
• Boston: The Massachusetts Bay Transportation Authority (MBTA) used dual-mode buses on its Silver Line (Waterfront) route from 2004 until June 2023, employing a similar operational strategy to manage air quality in tunnels.

These classic diesel-electric dual-mode buses have since been largely phased out in favor of newer technologies.

This capability has become increasingly common, particularly in North America, Europe, and China, where the vast majority of new trolleybuses delivered since the 1990s are fitted with at least a limited off-wire system. Notable adopters of such vehicles include Muni in San Francisco, TransLink in Vancouver, and systems in Beijing. In 2008, SEPTA in Philadelphia placed new trackless trolleys in service equipped with small hybrid diesel-electric power units for this purpose. Trolleybus Magazine No. 267 (May–June 2006), p. 71. National Trolleybus Assn. (UK).

This allows the trolleybus to operate for significant distances—often in excess of 15 km—on battery power alone, enabling the extension of routes or the electrification of new lines without needing to build overhead wires along the entire route. The term "In-Motion Charging" was introduced as a branding concept by Erik Lenz from Vossloh Kiepe in 2014 to highlight this key advantage.

The main advantages of IMC over conventional battery-electric buses are the smaller and lighter battery required, the elimination of charging delays at terminals, and a reduced need for dedicated charging infrastructure. This technology is now used in cities such as Beijing, Shanghai, Ostrava, Saint Petersburg, and Bergen. Entirely new trolleybus systems in Marrakesh, Baoding, and Prague were designed exclusively around IMC vehicles.

Trolleybuses are quieter than internal combustion engine vehicles. Mainly a benefit, it also provides much less warning of a trolleybus's approach. A speaker attached to the front of the vehicle can raise the noise to a desired "safe" level. This noise can be directed to pedestrians in front of the vehicle, as opposed to motor noise which typically comes from the rear of a bus and is more noticeable to bystanders than to pedestrians.

Trolleybuses can share overhead wires and other electrical infrastructure (such as substations) with tramways. This can result in cost savings when trolleybuses are added to a transport system that already has trams, though this refers only to potential savings over the cost of installing and operating trolleybuses alone.

Multiple branches may be handled by installing more than one switch assembly. For example, to provide straight-through, left-turn or right-turn branches at an intersection, one switch is installed some distance from the intersection to choose the wires over the left-turn lane, and another switch is mounted closer to or in the intersection to choose between straight through and a right turn (this would be the arrangement in countries such as the United States, where traffic directionality is right-handed; in left-handed traffic countries such as the United Kingdom and New Zealand, the first switch (before the intersection) would be used to access the right-turn lanes, and the second switch (usually in the intersection) would be for the left-turn).

Three common types of switches exist: power-on/power-off (the picture of a switch above is of this type), Selectric, and Fahslabend.

A power-on/power-off switch is triggered if the trolleybus is drawing considerable power from the overhead wires, usually by accelerating, at the moment the poles pass over the contacts (the contacts are lined up on the wires in this case). If the trolleybus "coasts" through the switch, the switch will not activate. Some trolleybuses, such as those in Philadelphia and Vancouver, have a manual "power-coast" toggle switch that turns the power on or off. This allows a switch to be triggered in situations that would otherwise be impossible, such as activating a switch while braking or accelerating through a switch without activating it. One variation of the toggle switch will simulate accelerating by causing a larger power draw (through a resistance grid), but will not simulate coasting and prevent activation of the switch by cutting the power.

A SelectricTrademark of Ohio Brass Co., maker of trolley wire fittings and equipment and trolley poles. The typewriter from IBM bearing that name had not been invented yet. switch has a similar design, but the contacts on the wires are skewed, often at a 45-degree angle, rather than being lined up. This skew means that a trolleybus going straight through will not trigger the switch, but a trolleybus making a turn will have its poles match the contacts in a matching skew (with one pole shoe ahead of the other), which will trigger the switch regardless of power draw (accelerating versus coasting).

For a Fahslabend switch, the trolleybus' turn indicator control (or a separate driver-controlled switch) causes a coded radio signal to be sent from a transmitter, often attached to a trolley pole. The receiver is attached to the switch and causes it to trigger if the correct code is received. This has the advantage that the driver does not need to be accelerating the bus (as with a power-on/power-off switch) or trying to make a sharp turn (as with a Selectric switch).

Trailing switches (where two sets of wires merge) do not require action by the operator. The frog runners are pushed into the desired position by the trolley shoe, or the frog is shaped so the shoe is guided onto the exit wire without any moving parts.