Tram wires are the overhead electrical cables that supply power to trams, enabling them to run.
These wires are part of a system known as the catenary line. According to the provided information, the catenary line is used specifically to transmit electrical power to our trains and trams. This system is essential because trams, unlike vehicles with internal combustion engines or on-board batteries, draw their operational power directly from this external source.
How the System Works
The catenary line, including the visible tram wires, is powered via rectification sub-stations. These sub-stations play a crucial role by transforming the standard industrial current they receive into the specific type and voltage needed for the transport system.
- For tramways, the appropriate current supplied through these wires is typically 750 volts.
- This voltage is lower than that used for larger rail systems like the RER (which receives 1,500 volts from the same type of catenary line).
Connecting to the Wires
Trams connect to the overhead wires using a device called a pantograph (or sometimes a trolley pole on older systems). This arm extends from the roof of the tram and maintains constant contact with the wire, creating a circuit that allows electricity to flow into the tram's motors. The electricity then powers the tram, and the return current typically flows back through the tram's wheels and the rails.
Importance of Tram Wires
Tram wires are a defining characteristic of many urban tram systems. They represent the infrastructure necessary for electric traction, offering an environmentally friendlier alternative to fossil-fuel-powered transport within cities. The maintenance and reliability of this catenary system are critical for ensuring consistent and safe tram operations.
