Trolley pole facts for kids

A trolley wheel, part of a trolley pole, on a tram.

A trolley pole is a long, thin pole, usually made of wood or metal. It's used to get electricity from special wires hanging above the street. This electricity powers trams (also called streetcars) and trolley buses. Think of it like a giant arm that connects the vehicle to its power source overhead.

How Trolley Poles Work

Trolley poles are essential for electric vehicles that get their power from overhead wires. Here's how they work:

• The pole has a small wheel or a sliding shoe at its top. This part touches the "live" overhead wire.
• Electricity flows from the wire, through the pole, and into the vehicle's motors.
• This electricity makes the wheels turn, moving the tram or trolley bus along its route.
• The pole is spring-loaded, which means it pushes up against the wire to keep a good connection.

Who Invented Overhead Wires?

The idea of using overhead wires to power electric vehicles was developed in the 1880s. A person named Frank J. Sprague is often given credit for this important invention. His work helped make electric trams and trolley buses possible, changing how people traveled in cities.

Trolley Poles on Different Vehicles

Trolley poles are mostly seen on two types of public transport:

• Trams (Streetcars): These are electric vehicles that run on rails in city streets. Many older trams and some modern ones still use trolley poles to get power.
• Trolley Buses: These are like regular buses but they run on electricity from overhead wires instead of fuel. They don't have rails and can steer around obstacles, but they must stay connected to the wires. Trolley buses usually need two poles, one for the positive wire and one for the negative wire, to complete the electrical circuit.

Other Ways to Collect Power

While trolley poles are common, there are other ways electric vehicles collect power from overhead lines or other sources:

• Pantographs: These are large, Z-shaped frames that sit on top of trains or trams. They collect electricity from a single overhead wire and can handle higher speeds and more power than trolley poles.
• Bow Collectors: An older type of collector, similar to a pantograph but shaped like a bow, also used to collect power from overhead wires.
• Third Rail: Some trains get their power from a special electrified rail placed alongside the main tracks, instead of from overhead wires.

Images for kids

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  A trolleybus with a pair of trolley poles on its roof

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  Machining spare trolley pole wheels

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  Modern trolley poles on Vancouver's low-floor trolley buses

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  Trolley retrievers on the back of a 1949 trolleybus

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  Pantograph (left) and trolley pole in use on Queens Quay West, Toronto

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  Overhead wires over a switch in Toronto, showing paths for pantographs and trolley poles.

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  Classic PCC streetcars with trolley poles are still used in Boston.

See also

In Spanish: Trole de pértiga para niños