Flashback Friday: Take a trolley ride part II

By: Gordon Lowe


Gordon Lowe continues his investigation into what made Australia’s old trolley buses so special

Flashback Friday: Take a trolley ride part II
A trolley bus’ rubber tyres give far better adhesion than a tram

 

A trolley bus is defined as an electric bus powered by two overhead wires from which it draws electricity using two trolley poles. Two poles are required to return current as it cannot pass to the ground like an electric tram.

Trolley buses use rubber tyres which act as electrical insulators rather than electrically conductive steel wheels on rail. I suppose you could say that the trolley bus is a ‘Clayton’s Tram’. Trolley buses have many advantages over diesel-powered units. They are particularly useful on hilly routes as electric power is more effective than diesel for climbing steep hills. Unlike combustion engines, electric motors draw power from a central plant and can be overloaded for several minutes without damage.

In the United States for example, San Francisco and Seattle are both hilly districts and use trolley buses partly for this reason. Another (and probably the most important) reason is improved air quality. In terms of acceleration and braking performance, trolley buses easily outperform diesel buses on flat stretches as well.

A trolley bus’ rubber tyres give far better adhesion than a tram which runs on steel wheels on steel rails. The trolley outperforms trams in terms of hill climbing and braking. Another advantage of the trolley bus is because they don’t run on rails, they can pull over to the kerb as a diesel bus does, eliminating boarding islands in the streets.

The overhead poles have the ability to swing from side to side giving the trolley bus a good degree of flexibility when moving to the right or to the left while on the road. Fortunately, trolley bus services throughout the world are still alive and well — particularly in Europe.

Even our cousins in Wellington, New Zealand have the foresight and wisdom to run a trolley bus service in that beautiful city. At its zenith, trolley bus services in Brisbane covered more than 28 kilometres of overhead wiring.

Even by modern-day standards, the Brisbane network was very comprehensive and was well patronised. So much so, that even with a total fleet of 36 trolley buses (after 1960), Brisbane never had enough trolleys to fill peak-hour requirements on five of the city’s trolley bus routes.

Diesel buses were used to supplement the lack of trolley buses. As mentioned in the previous trolley bus article, an acquaintance of mine once travelled on the trolley buses in Brisbane. He remarked how quiet they were when he was onboard.

 He also recalled: "The only noise was the rumble and swishing of the rubber tyres on the road. There were no fumes, no pollution and hardly any engine noise whatsoever, just a faint hum." Bringing back the trolley bus could be something for Brisbane’s ‘can do’ Lord Mayor, Campbell Newman, to think about. 

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