Kolkata Metro has successfully completed a significant upgrade by replacing the steel third rail on the Blue Line with an advanced Aluminium third rail. This milestone is part of a green energy initiative to modernize the city’s metro system, improve efficiency, and reduce operational costs.
Government-Backed Initiative for Enhanced Efficiency
The replacement project was a critical part of Metro Railway’s modernization efforts, with the Ministry of Railways approving the switch in 2012 for all new metro corridors. This decision aims to improve energy efficiency and support the country’s green energy goals. The new Aluminium third rail is expected to reduce energy losses and voltage drops, leading to faster acceleration and reduced headways for metro trains.
The work began on November 30, 2024, when a dedicated team led by Shri Sumit Kayal and Senior Section Engineer Abhishek Sinha replaced approximately 700 meters of steel third rail from Girish Park to Central stations, including Mahatma Gandhi Road. The team worked during a narrow 5-hour window overnight to ensure the metro service was not disrupted during peak hours. The new system has been installed with greater alignment precision, ensuring better safety for passengers.
Aluminium third rail offers several advantages over steel, including superior electrical conductivity. With a conductivity of 38 million siemens per meter, Aluminium significantly reduces energy losses compared to steel’s 6 million siemens per meter. As a result, this upgrade will lead to better operational efficiency, faster train acceleration, and ultimately cost savings within five years. Moreover, the switch to Aluminium is expected to reduce carbon emissions by 50,000 tons over the rail’s lifespan.
The project has also been designed to improve safety, with the new third rail requiring less maintenance and offering a longer lifespan. Unlike steel, which requires welding, Aluminium rails are joined using splice joints, which reduces the risk of cable fires and improves air quality inside the tunnels.
With 1800 meters of steel third rail already replaced and the entire project set to be completed before August 15, 2025, this upgrade marks a major step forward for Kolkata’s metro system, aligning with the government’s push towards a more sustainable, energy-efficient urban transit network.