Kolkata Circular Railway is a railway line that encircles the entire city of Kolkata. It starts from Dum Dum Junction in the north and passes through Patipukur, Kolkata Station ,Bagbazar,Sobhabazar,Burrabazar,B.B.D.Bagh,Prinsep Ghat,Eden Gardens, Kidderpore, Remount Road, Majherhat,New Alipur,Lake Gardens,Ballygunge,Sir Gurudas Banerjee Halt, Bidhannagar Road and finally back to Dum Dum Junction.
With the increasing population of Calcutta metropolis, and road transport being unable to cope with the demand due to bottlenecks in roads, it was felt necessary to introduce some other source of transport which will ease off the problem particularly at peak hours. Out of various modes including Tramcars and trolleybus, the railway was found to be most suitable. Unlike other metropolitan cities Calcutta does not have any rail route running through the heart of the city or piercing through the central district area, where more commuters will be seeking their transport.
Previously a railway line existed between Dum Dum to Ultadanga for transport of wagons to Chitpur goods yard and some part between BBD bag to Majherhat existed for a long time for transport of goods from port area to the godowns of Calcutta port along the Ganges. These were built during the early EIR period when the river Hooghly was navigable to this area. Gradually with the silting of Hooghly and inaccessibility of bigger ships, these lines were out of use. With these existing lines being rehabilitated and small patches created at a few places it could establish a through connection between Dum Dum Junction and Prinsep Ghat along the bank of Hooghly.
The original line was a single line track with loading and unloading sidings and wharfs. A few platforms were built and simultaneous reception facilities were constructed at some stations. The line was commissioned from Dum Dum Junction to Prinsep Ghat on 16 August 1984. In fact the lines from Calcutta port were already existing for an interchange yard for E.Rly. and these lines are being modified/extended/ realigned for Circular Railway. Previously the trains were hauled by Diesel Shunters. The electrification works have been completed and four Electrical Multiple Unit (EMU) trains originally destined for Sealdah during office hours have been diverted to central business district of Calcutta directly avoiding Sealdah station. It has been received with overwhelming support from commuters and the earning has quadrupled with the introduction of EMUs. Once connected to Majerhat it can easily ply up to Dum Dum to complete the circle. This has been a boon to the office goers. Eastern Railway runs Electrical Multiple Unit on Circular Railway. The Circular Railway is directly managed by The Eastern Railway. The Circular Railway as part of the Kolkata Suburban Railway along with the Kolkata Metro provide connectivity through the city. The line was a single line track from Tala station to Princep ghat station. But in platform area it becomes double line for crossing. From Princep Ghat the line becomes fully single until it reaches to Majerhat.
Kolkata's Circular Railway has been extended from Dum Dum Cantonment to Biman bandarNetaji Subhash Chandra Bose International Airport. A 3.8 km extension from DumDum Cantonment station and includes two elevated stations Jessore Road and Biman Bandar. It runs at grade to UK Dutta Road and then on an elevated structure to the airport passing through Jessop, Jessore Road, VIP Road, and the domestic terminal road. This project was undertaking by the Kolkata Metro.