Related Searches    A trolleybus (also known as trolley bus,
trolley coach, trackless trolley, trackless tram or simply
trolley) is an electric bus powered by two overhead 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
(also called a streetcar) since trolleybuses use rubber tires
(which act as electrical insulators), rather than electrically
conductive steel wheels on rail. There are trolleybuses in many
cities around the world.   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 13 June 1882, after which there
was little progress in Europe, although separate experiments
were conducted in the USA. The next development was when Lombard
Gérin operated an experimental line at the Paris Exhibition of
1900 after four years of trials. M