If you have ever seen an electric train running on overhead wires, you may have noticed that it usually raises the rear pantograph to collect power. A pantograph is a device that slides along the wire and transfers electricity to the train. But why does the train use the rear pantograph instead of the front one?
There are several reasons for this choice. One is that using the rear pantograph reduces the wear and tear on the wire, as the front pantograph acts as a guide and clears any obstacles or debris on the wire. Another reason is that using the rear pantograph improves the stability and contact of the device, as the aerodynamic force pushes the pantograph upwards and the train pulls it forward. A third reason is that using the rear pantograph avoids any sparks or flashes that may occur when the pantograph switches from one wire to another, which could distract the driver or damage the equipment.
Using the rear pantograph is not a universal rule, however. Some trains may use the front pantograph in certain situations, such as in cold climates to scrape frost off the wire, or when the rear pantograph is faulty or damaged. Some trains may even use both pantographs at the same time, to increase the power supply or to balance the load. The choice of which pantograph to use depends on various factors, such as the speed, the voltage, the weather, and the design of the train and the wire.
The pantograph is an ingenious invention that allows electric trains to travel at high speeds without losing contact with the overhead lines. By using the rear pantograph, the trains can optimize their performance and efficiency, while also preserving the condition of the wire and the device.
