Power and Control: The Role of SCADA in Railway Infrastructure

While signaling controls the trains, SCADA (Supervisory Control and Data Acquisition) controls the infrastructure. It allows operators to remotely monitor and manage traction power, tunnel ventilation, and station facilities from a central location.

Power and Control: The Role of SCADA in Railway Infrastructure
December 8, 2025 11:16 am
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SCADA (Supervisory Control and Data Acquisition) systems are the “central nervous system” of railway infrastructure. While signaling systems are busy preventing train collisions, SCADA ensures the railway has the power to run and the environment is safe for passengers.

What Does SCADA Monitor?

In a modern railway or metro environment, the SCADA system collects data from thousands of sensors and allows controllers to issue commands remotely. Its three main pillars are:

  • Traction Power (Electrification): This is the most critical function. Operators can energize or de-energize specific sections of the catenary or third rail remotely. This is vital during maintenance or emergencies (e.g., a person on the tracks).
  • Station Facilities (BMS): Monitoring the status of elevators, escalators, lighting, and ticket gates.
  • Environmental Control: Managing tunnel ventilation fans, especially for smoke extraction in case of a fire, and drainage pumps to prevent flooding.

How It Works

The system consists of field devices called RTUs (Remote Terminal Units) located at substations and stations. These units collect data (e.g., “Voltage is 750V” or “Fan is OFF”) and send it via fiber optics to the Operation Control Center (OCC). There, operators view the entire network on large Human-Machine Interface (HMI) screens.

Difference from Signaling

It is a common misconception to mix them up:

SystemPrimary FocusKey Function
Signaling (CTC)Trains & TrafficSpeed control, Route setting.
SCADAInfrastructure & PowerPower distribution, Facility management.