What is a trolleybus?
Key:
24 – Trolley boom
25 – Trolley base
26 – Power wiring
27 – Main switch
28 – Hand brake
29 – Instrument panel
30 – Hooter
31 – Battery switch
32 – Master controller
33 – Contactors
34 – Brake pedal
35 – Power pedal36 – Resistances grille
37 – Auxillary motor
38 – Resistances
39 – Compressor
40 – Air reservior
41 – Traction motor
42 – Drive shaft
43 – First differential
44 – Second differential
A trolleybus is a bus driven by electricity collected from overhead wires, usually at around 600 volts. Various mechanical ways of collecting the power were tried in the early 1900s before roof mounted ‘booms’, virtually the same as used on electric trams, became the enduring answer and a trolleybus’s most identifiable feature.
Above is London trolleybus 142, an AEC ‘C’ class of 1935. Metropolitan-Cammell Carriage+Wagon Co Ltd 70 seat body. English Electric electrical equipment. 95hp motor. 0-30mph in 23 seconds, 35-0mph in 14 seconds. Laden weight 13 tons. Worm and nut steering. 10.33 rear axle ratio. Air brake exhaust air cooled resistances. 24v lighting. Slider trolley heads. Power and electrical braking on one pedal.
Early trolleybuses operated in France, Italy and Germany, from 1900 onwards, used on 98 systems, demonstrations or trials by 1915. The world’s first commercial trolleybus operation was between Fontainbleau and Samois between 1901 and 1913 using Lombard Gerin ‘Trolley Automoteurs’. Self powered power collector running above the wires. 2 x 8hp motors. Series-parallel control. Jeantaud body, 18 seats. 12kph top speed. 11.48:1 gear and chain ratio.
In the UK, trolleybuses were originally seen as a cheaper option for lightly trafficked routes or as feeders to tram services. Britain had 50 operators between 1911 and 1972 running in many large towns & London suburbs.
