Both systems have distinct pros and cons that dictate their application:

• Third Rail System:

  • Advantages: It is generally cheaper and quicker to install compared to overhead lines as it requires less complex infrastructure. It is also less affected by weather conditions like strong winds or freezing rain.

  • Disadvantages: A third rail system is considered more dangerous due to the exposed live rail at ground level. It also has speed limitations and requires substations to be spaced closer together due to lower voltage and greater power loss. It is also susceptible to operational disruptions from snow accumulation and flooding.

• overhead line (Catenary) System:

  • Advantages: It is the preferred choice for high-speed and long-distance railways because it can operate at a much higher voltage, reducing power loss and allowing for wider spacing between substations. This system is generally safer for personnel on the ground as the power source is elevated.

  • Disadvantages: The initial installation cost is significantly higher due to the need for extensive support structures (masts and gantries) and wires. The system can be more vulnerable to extreme weather events such as strong winds, ice, or lightning.