Kolkata is set to receive not one but three underground tunnels as part of the ongoing work for the expansion of the metro rail network. Sources say that the work is being carried out taking precautions to protect the century-old building of the Calcutta Municipality.
According to international rules, if there is a distance of two and a half kilometres or more between the two underground metro stations, a station ought to be built in the middle. In the case of the East-West Metro project in Kolkata, the distance between Sealdah and the Esplanade is more than two and a half kilometres.
As a result, the metro authorities thought of building a station at the Subodh Mallick Square. However, there was a noticeable lack of land at the place, which is why a giant shaft or cavity resembling a well is being constructed here.
The tunnels are being constructed around 13 meters below the ground. Two of these are ventilation tunnels, with an emergency tunnel below to facilitate a safe exit for the passengers. The entry point of the tunnel starts at 13 meters below the ground. The ending point of this shaft will be at least 22 meters below the ground. The construction work is being done under constant monitoring of the ITD engineers.
According to Dinesh Dani, who is the project engineer in charge, there are many aquifers in this place from where the water is drawn. Secondly, the century-old Calcutta Municipality building is not far from the spot where the tunnels are being dug. The vibration that is felt while digging the tunnel could also pose a problem for the floor of the Municipality as well as other nearby old buildings. So the work on this shaft is going on slowly but cautiously.