Indian Railways is planning to convert Kolkata Metro steel third rail to composite aluminium third rail. With this initiative of Indian Railways, Kolkata Metro Railway will now be equipped with modern facilities similar to London, Moscow, Berlin, Munich and Istanbul Metro.
India's first metro built by Indian Railways on 24 October 1984 - Kolkata Metro Railway has been serving as the lifeline of Kolkata for almost 40 years.
- In Kolkata Metro Railway, power to Metro rakes is supplied to rolling stock at 750 V DC through steel third rail. The steel made Third Rail Current Collector (TRCC) mounted on the metro rake collects electric current from the third rail.
- Kolkata Metro Railway has been using steel third rail for the last 40 years. Kolkata Metro Railway has now decided to use composite aluminium third rail in all upcoming corridors being constructed along with retro fitment in existing corridors with steel third rail.
- With this state-of-the-art makeover, Kolkata Metro Railway will now be at par with London, Moscow, Berlin, Munich and Istanbul metros with modern facilities and join the club of the same.
- In these places too, the metro has changed from steel third rail to aluminium third rail.
- In this regard, Metro Railway Kolkata has floated a tender for replacement of existing Third Rail in the first phase to include the section between Dumdum to Shyambazar.
- In the second phase, work will be started from Shyambazar to Central and JD Park to Tollygunge.
- While in the third phase, work will be started on the section between Mahanayak Uttam Kumar (Tollygunge) to Kavi Subhash (New Garia).
The advantages of aluminium composite third rail over steel:
- There will be reduction in resistive current loss and better traction voltage level as the resistance of steel third rail is about six times higher than that of composite aluminium third rail.
- Fewer traction substations as compared to steel third rail i.e. direct saving of capital investment of about Rs 210 crore for 35 km metro corridor.
- The low voltage drop will facilitate faster ramp-up with a single rake available with the Kolkata Metro Railway.
- Improving efficiency of train operations.
- The next part of the trains will be better.
- Vast improvement in energy efficiency and reduction in carbon footprint.
- The estimated energy savings per year by using composite aluminium third rail can be around 6.7 million units.
- Reduced maintenance and cost – painting of third rail every 5 years is no longer required. The frequency of measurement of the third rail dimension can be significantly reduced. There will be no possibility of damage due to corrosion.