Page "Tram" Paragraph 7

Although tram and tramway have been adopted by many languages, they are not used universally in English ; North Americans prefer trolley, trolleycar or streetcar.

The term streetcar is first recorded in 1840.

When electrification came, Americans began to speak of trolleycars or later, trolleys, believed to derive from the troller, a four-wheeled device that was dragged along dual overhead wires by a cable that connected the troller to the top of the car and collected electrical power from the overhead wires, sometimes simply strung, sometimes on a catenary.

The trolley pole, which supplanted the troller early on, is fitted to the top of the car and is spring-loaded in order to keep the trolley wheel or alternately, a grooved lubricated " skate ", at the top of the pole, firmly in contact with the overhead wire.

The terms trolley pole and trolley wheel both derive from the troller.

Trams using trolley-pole current collection are normally powered through a single pole, grounded through the wheels and rails.

The motor circuit is designed to allow electrical current to flow through the underframe.

Although this use of " trolley " for tram was not adopted in Europe, the term was associated with " trolleybus ": a rubber-tyred vehicle without tracks, which draws its power from overhead wires.