The Overhead System:
The overhead system has suspended wires (OHW) above the length of the track. The power will be collected by the pantograph on top of the vehicle, which make contact with the Trolley Wire.
Trolley wire or Contact wire:
Trolley wire is used as an overhead power source for electric vehicle. TW or catenary wire comes in different sizes: 181, 161, 129, 107 and 81 mm2 .
It collects electric current from the contact or trolley wires via trolley shoe.
Like Tram-Pole, it also collects electric current from the contact or trolley wires. (YT: 3.67-5.97) _ (HR: 4.42-6.1_6.6)
There are two types of operation used in Melbourne;
To provide services to both tram-pole and pantograph.