Kolkata would become a member of the elite club of London, Moscow, Berlin, Munich, and Istanbul Metro as it plans to replace the steel third rail with a composite Aluminium third rail.
A statement from the Indian railway ministry said that Metro Railway Kolkata had floated a tender for the replacement of the existing third rail, in the first phase to cover the section between Dumdum to Shyambazar.
“In the second phase, work would be taken up from Shyambazar to Central and J D Park to Tollygunge. In the third phase, the section between Mahanayak Uttam Kumar (Tollygunge) to Kavi Subhash (New Garia) shall be taken up. So, a total 35 RKm main line steel Third Rail shall be replaced in stages,” the statement read.
Kolkata Metro Railway is India’s first underground train service, starting operations on 24 October 1984. This has been serving as a lifeline for the people of Kolkata for nearly 40 years.
In Kolkata Metro Railway, the power to Metro Rake is supplied to rolling stock at 750V DC through steel Third Rail. The Third Rail Current Collector (TRCC) made of steel fitted on a metro rake collects the current from the Third Rail. Kolkata Metro Railway using steel Third Rail for the last 40 years. Kolkata Metro Railway has now decided to use composite Aluminium Third Rail in all the upcoming corridors being undertaken for construction along with retrofitment in existing corridors with steel Third Rail.
There are eight key advantages of aluminium composite third rail over steel third tail
- Reduction in resistive current loss and improved Traction voltage level as the resistance of steel Third Rail is around six times higher than composite Aluminium Third Rail.
- On average, for 10 km corridor with use of Aluminium composite Third Rail would require 01 no. less Traction Substation compared to steel Third Rail i.e. a straight saving of approx.₹210 Crores capital investment for a 35 km of Metro corridor.
- The reduced voltage drop shall facilitate achieving faster acceleration with the same rake available with Kolkata Metro Railway.
- Reduced maintenance and life cycle cost. The requirement of painting of Third Rail every 5 years may not be needed anymore. The frequency of measurement of Third Rail dimension may reduce significantly. There may be no possibility of damage due to rusting etc
- Improvement in the efficiency of train operations.
- Huge improvement in Energy Efficiency and reduction in carbon footprint.
- Estimated energy saving using composite Aluminium Third Rail may be approximately 6.7 million units per annum.
- Improved headway of the trains.