AMAR METRO
KOLKATA
PRESS RELEASE
THE PHASE-I OF REPLACEMENT OF STEEL THIRD RAIL WITH ENERGY EFFICIENT HIGHLY CONDUCTIVE ALUMINUM THIRD RAIL COMPLETED
Kolkata, 27-07-2025
Metro Railway is gearing up its assets for improved headway. The impact of this change will be massive on commercial Metro services. After a gap of 38 years, steel-made current conducting third rail has been replaced with aluminum third rail in the North-South Metro (Blue Line). This change will ensure 84% reduction in energy loss which is Rs. 1 Cr / year per km of route. Metro Railway, Kolkata now belongs to the league of Singapore, London, Moscow, Berlin, Munich and Istanbul Metros where such replacement work of third rail has already been done and Metro services are running smoothly there.
The replacement works with highly conductive Aluminum third rail started a few months back at Girish Park Y-siding and Maidan station and Y-siding. The main component i.e. highly conductive Aluminum third rail was dispatched through sea transport from Hamburg port of Germany. The material of first shipment was received in Kolkata Port in July 2024. Metro Railway, Kolkata has planned the introduction of 35-km Aluminum third rail in 2024-2026. The Phase-I of 19.6 km work has been completed during night non-commercial hours without affecting daily operations.
This highly conductive Aluminum third rail has the capacity to reduce the system voltage drops and subsequent energy losses, thanks to its superior electrical conductivity. This less voltage drop in the third rail will help to achieve faster acceleration in the running Metros. As a result, for completing one trip lesser time will be required and in turn Metro will acquire the capability to run services at reduced interval during the peak hours. That will be an improvement in the efficiency of Metro operations. In this new system, huge amount of energy will be saved which will in turn help the Metro to reduce its operational cost. As a result, the entire expenses for replacing this third rail could be realized within three years.Additionally, Aluminium third rail will reduce carbon emission by 50000 ton in its lifetime.
On 26.07.2025 night Metro Railway, Kolkata replaced the steel third rail in Main Line at Mahanayak Uttam Kumar station area. In Phase-I, this replacement has been done from Shyambazar to Mahanayak Uttam Kumar DN line and Shyambazar to Park Street UP line. In Phase-II, Park Street to Mahanayak Uttam Kumar UP line and Shyambazar to Dum Dum UP and DN lines will be replaced. The work of Phase- II is already under execution. The Phase-II work is expected to be completed before December 2025. In Phase-III, replacement has been planned between Mahanayak Uttam Kumar to Kavi Subhas stations. Phase- III work has already been sanctioned by Railway Board.
The main challenge of Main line was to change the rail by maintaining alignment, height and distance perfectly and completing the work within non-commercial hours. Earlier replacement work of Steel third rail by highly conductive Aluminum third rail at Girish Park and Maidan siding were completed respectively on 07.09.2024 and 15 09.2024. After the replacement work, one battery operated locomotive was run multiple times to ensure smooth Third Rail Current Collector movement over installed third rail. With experience gathered at Giris Park Y-siding, Maidan Y-siding and Central Mainline, the replacement of the main line was completed.
The work of replacement of steel third rail was approved by Railway Board in 2023-24 and the work was awarded to a German company in December 2023. Detailed engineering, manufacturing of components and site preparation was done in phases. Metro Railway deputed staff and supervisor led by Deputy Chief Electrical Engineer/ Maintenance Shri Sumit Kayal and Senior Section Engineer Shri Abhishek Verma. The work was completed before commercial service on Sunday Morning. 150-200 labours worked daily since last one year so that commercial services are not affected.
The replacement work was extremely critical and demanding as delay in completion on every day’s work might have led to traffic disruption in the morning. So, all steps used to be monitored critically and after detailed minute to minute planning, back up planning and fall-back strategy in place the work was executed. First, new pedestals were made of appropriate height with best material available in market (M65 pre mix concrete to avoid any adulteration and quality compromise). Then all materials like third rail components and shroud boards used to be brought to the site and kept in safe location. on the execution day, existing steel rails used to be cut at marked locations and dismantled. After that new GRP (glass reinforced plastic) insulators used to be placed on pedestals. Then the new highly conductive Aluminum third rail would be placed on insulators adjusting height and distance and Interconnection between existing power supply systems done with cables. After all adjustment of mid-point anchor, expansion joints and cable connectors one final checking of tightness of all fasteners used to be done and the shroud boards used to be placed on the rail.
This Aluminum third rail requires less maintenance and is highly reliable and stable. In a hot and humid city like Kolkata this replacement will be very much beneficial and inside the tunnel lesser heat will be generated during the time of contact of Third Rail Current Collector (TRCC) with this third rail. For maintenance work the new third rail will not require any welding as two such rails can be joined with the help of splice joint. It will help to maintain the air quality inside the tunnels.
