The technology behind driverless trains

By 2030, 5o Indian cities are expected to run on the mass rapid transport system. More people will migrate to cities in coming decades taking global city dwellers population to 6.4 billion. Conventional urban transport systems will not able to cope with the changes about ‘how and when we move’. The capacity of mass transit systems can rarely be expanded to the extent actually necessary in that case. In order to make more efficient use of existing infrastructure, existing metro lines are being modernised and increasing equipped with automated train control and safety system. More than 40 cities globally have adopted automated driverless metro trains. In India, demand for driverless metro train technology is very high. What makes automation possible in trains?

The technology behind driverless trains in called Communication Based Train Control (CBTC). CBTC technology operates through the communication between the train and equipment on the track for managing traffic. It helps identify the exact position of a train more accurately than traditional methods which depend on signal systems. The CBTC is going to be a radical move in the nation’s rail transport by displacing the presence of the loco pilot in the train. It ensures efficiency and safety of the metro in a truly international style.

Conventional metro rail requires signalling and intervention of train pilot. Whereas, the function of CBTC enabled trains is completely data based. In most CBTC rail networks, data between trains and trackside equipment are transferred using wireless communication networks, such as global system for mobile communications-railway (GSM-R) and wireless local area network (WLAN). For urban mass transit systems, WLAN is a better choice due to the availability of equipment. WLAN-based CBTC has been deployed across the major cities of the globe. In India, WLAN-based CBTC is under process in Kochi Metro Phase 1 and Delhi Metro line 8. Other Indian cities namely Ahmedabad, Mumbai, Hyderabad etc also plan to deploy driverless train technology.

In megacities like Mumbai, Delhi, Beijing and Tokyo, the number of people travelling during peak hours in very high. On automated lines, trains can run at a very short interval one after another. The capacity of an existing track can be increased by almost 50%. The difference of 90 seconds between trains is feasible. Additional trains can be deployed depending upon the need without disturbing the original timetable.

To make driverless train tech possible, additional systems like platform screens, platform track monitoring system, remote sensing and intrusion avoidance is a must. These systems eliminate the risk of fatality on tracks and improve system efficiency. If passenger pulls an emergency brake, the situation in the train can be accessed by control centre with the aid of passenger area surveillance. Since the train is connected to control centre through LAN, necessary measures can be taken to avoid any further incidence. Smoke detectors inside the train and on the track report to control room in case of fire and the train is halted at next stop.

Driverless trains are energy efficient due to optimised acceleration, traction and smooth braking. On the basis of line data, the automated system calculates exactly where and how the train should be accelerated or braked to arrive it punctually at next stop. Former train pilot can work as train attendant to service passengers and can act immediately during emergencies.

According to Union Internationale des Transports Publicis (UITP), by 2025 some 2300km of driverless metro lines will be operational in the world, compared with around 800km today. The increasingly widespread use of CBTC enabled transport systems along with rising standard of living in developing countries will encourage the competitiveness of automated technology. Almost all upcoming metro projects in India will run on driverless train tech. Kochi Metro was the first to implement CBTC followed by Delhi Metro Line 8. Mumbai Metro is expected to break global records as upcoming Line 2, Line 3, Line 4 and Line 7 have already issued financial bids to induct CBTC enabled trains. Today, most driverless trains run in Europe and the middle east. That is about to change as winds of automation are soon heading to India and China.

– Chaitanya Kulkarni

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