KOLKATA (Metro Rail News): Kolkata Metro Railway, India’s first metro system established by Indian Railways on October 24, 1984, has been a vital lifeline for Kolkata, the “City of Joy,” for almost four decades.
The power to Metro Rake is supplied to rolling stock at 750V DC through steel Third Rail. This Third Rail Current Collector (TRCC), composed of steel and affixed to the metro rake, gathers current from the Third Rail. Remarkably, Kolkata Metro Railway has employed the steel Third Rail for the past 40 years. However, the metro authority has now decided to embrace a shift to composite Aluminium Third Rail for all upcoming corridors and retrofit existing corridors still equipped with steel Third Rail. This transition will make Kolkata Metro Railway a member of the elite club of London, Moscow, Berlin, Munich, and Istanbul, which have already adopted Aluminium Third Rails.
To facilitate this change, Metro Railway Kolkata has initiated a tender process for the replacement of the current Third Rail. The first phase will encompass the section between Dumdum and Shyambazar. Subsequently, in the second phase, the work would be executed from Shyambazar to Central and J D Park to Tollygunge. The third phase will address the section from Mahanayak Uttam Kumar (Tollygunge) to Kavi Subhash (New Garia). Consequently, a total of 35 RKm of mainline steel Third Rail will be gradually replaced.
The evident advantages of the composite Aluminium Third Rail over the steel variant are as follows:
- A reduction in resistive current loss and enhancement of Traction voltage levels, as the resistance of steel Third Rail is approximately six times higher than that of the composite Aluminium Third Rail.
- On average, a 10 km corridor utilizing Aluminium composite Third Rail would necessitate 01 no. less Traction Substation in comparison to steel Third Rail. This translates to a direct cost reduction of around ₹210 Crores in terms of capital investment for a 35 km Metro corridor.
- The decrease in voltage drop will enable quicker acceleration with the same rake available within the Kolkata Metro Railway.
- Diminished maintenance and life cycle costs. The need for repainting the Third Rail every five years may become unnecessary. Moreover, the necessity for frequent measurements of Third Rail dimensions may significantly decrease, while risks of damage due to rust may be eliminated.
- Augmented operational efficiency.
- Notable enhancements in Energy Efficiency and reduction in carbon footprint.
- An estimated energy conservation of approximately 6.7 million units annually through the utilization of composite Aluminium Third Rail.
- Enhanced train headway.
In essence, Kolkata Metro Railway’s decision to transition from steel Third Rail to composite Aluminium Third Rail marks a significant step towards improved operational efficiency, cost-effectiveness, and sustainability.
