Kolkata, Nov 27 (Reporter) Metro Railway, Kolkata, country's first such underground passenger connectivity, has undertaken an ambitious plan of replacing its Steel 3rd rail with Aluminium third rail in Blue Line, which is gradually progressing, Kolkata Metro source said on Wednesday. " On completing 40 years glorious service to the Nation, our Metro successfully replaced the Steel third rail with Aluminium third rail o­n the main line at Central station recently. With the implementation of this plan, our Metro now belongs to the league of London, Munich, Moscow and Istanbul Metros," Kolkata Metro spokesman Kausik Mitra said. At least fourteen countries of Asia use the third rail system for providing DC traction power to its rakes. Kolkata Metro has been the fifth in Asia to have a Metro system. Kolkata Metro and Hong Kong Metro were the first two Metros in the world to come out with solutions of Cooling Stations / Tunnels. Both Metros designed differently and both cooling systems have been working successfully even after 40 years of design, Mitra said. Similarly Steel third rail, manufactured by SAIL, a central government PSU, has been providing power to rakes successfully for 40 long years in Kolkata Metro. With the evolution of technology, advanced systems of the 80’s are becoming irrelevant and energy inefficient in today’s era driven by green technologies. Keeping in mind the above facts, the Ministry of Railways has decided in 2012 that all new Metro Corridors will be built with Aluminium third rail. Accordingly, all Corridors of Metro Railway, except the 40-year old Blue Line are having Aluminium third rails. After implementing Aluminium third rail in Green Field Projects, the Ministry of Railways has decided to replace Steel third rail of 34-km length of Blue Line. Accordingly open tenders were floated and contracts were awarded to the Indian subsidiary of REHAU Group Company who assured that more than 60 % of contract value shall be sourced from India and remaining from Germany. " All of us are aware that o­n 07.09.24, 14.09.24 and 28.09.24, Kolkata Metro successfully replaced Steel third rail of its two-yard lines at Girish Park & Maidan and mainline at Central station by Aluminium third rail brought from Germany with remaining components procured from India engaging local work forces under supervision of Metro Railway Engineers headed by Sumit Kayal an officer of Joint Director Level. After successful replacing of yard line's and main line’s third line, team headed by Shri Sumit Kayal took the challenge o­n the night of 23.11.24 to replace SAIL manufactured Steel third rail by Aluminium third rail of the main line in between Mahatma Gandhi Road and Central station and completed the work successfully," Kolkata Metro said in a statement. 'Challenge before the team was to complete the entire work perfectly so that commercial service did not get affected. This replacement work was as good as commissioning of a new system with addition to removal of the old system. The section is approximately 650 meters in length in DN line," it added. Aluminum’s electrical conductivity is 38 million siemens per meter whereas Steel has a value of 6 million siemens per meter. This physical characteristic of Aluminium helps to attain lesser voltage drops and lesser energy losses compared to Steel third rail. Apart from nearly no voltage drop, the third rail will help to achieve faster acceleration of the train and reduce the head way of running Metros. As a result, the entire additional expenses for replacing this third rail shall be realized within five years through saving in operational cost. Additionally, Aluminium third rail will reduce carbon emission by 50,000 tons in its lifetime. Apart from this, Aluminum third rail will require less maintenance and have more codal life because of absence of corrosion. Aluminum weighs 169 pound /cubic foot and steel weighs 490 pound / cubic foot. So manpower required to handle Aluminium third rail is much lesser. New third rail will not require any welding as two Aluminum rails can be joined with the help of splice joint. It will help to maintain the air quality inside the tunnels and shall have no risk of cable fire while welding. Aluminium third rail will also reduce heat load to the AC system as inside the tunnel lesser heat will be generated for the low resistance value of the Aluminum compared to Steel...////...