The most important challenge of Traction Distribution is to supply electric power to running Locomotive. Many systems have been evolved over the period based on power handling technologies available at that time and now 25 kV traction power supply is predominantly prevailing over Indian Railways.  Transfer of power from stationary equipment to running locomotive is either through overhead equipment or third rail. Third rail is preferred for low voltage application up to 750V and where line is either underground or elevated to ensure avoidance of accidental touch by human beings. Higher AC voltage is preferred for two reasons namely