India’s First Underwater Tunnel for Kolkata Metro

Kolkata, West Bengal was the first Indian city to have metro operational way back in 1984 and now its creating a marvel of modern technology by constructing India’s first underwater metro rail tunnel crossing Hooghly river.

Kolkata Metro and New Line 2

Kolkata Metro Rail Corporation KMRC logo

At present Kolkata metro consists of one operational line, Line 1 / North-South Line serving Noapara-Kavi Subhash Metro Station running on a track of 27.22 km, and serving 24 stations.

Line 2 of the Kolkata Metro / East-West Line is now under construction. Line 2 shall connect Kolkata and Howrah, running from Teghoria to Howrah through Hooghly. East-West Line shall be 16.6 km long, with 5.8 km elevated and two 10.8 km underground twin metro rail tunnels, one East Bound and one West Bound. It is estimated that 10 lakh passengers per day shall be traveling through it by 2035. The East-West metro line shall considerably save travel time between the two cities.

Important Orders and Status of Line 2

The contract for underground tunnel work was awarded to joint venture between Indian construction firm Afcons Infrastructure and Russian firm Transtonnelstroy. This contract was awarded in 2010, worth Rs. 938 Cr. with the scope of designing and execution.

Ansalso STS, an Italian major was awarded signaling and communication system work of the project.  Gammon and Simplex were awarded the contract for building overground stations and viaduct.  In 2016 BEML won the contract for supplying 14 rakes having 6 coaches rolling stock  and in 2017 Panasonic Manufacturing and Zhuzhou CRRC Times Electric bagged the contract for platform screen door on all 12 stations.

Present Status of Line 2

At present Phase I of line 2 has completed 95% of elevated route and 5.4 km of underground tunnel. Kolkata Metro Rail Corporation Ltd. (KMRCL) has received partial financial support from Japan Bank for International Cooperation.

India’s first Hooghly underwater metro rail tunnel is expected to be ready by 2021.

Under Water Tunnel’s Features

The twin tunnels being constructed under water shall be 520 meter long, connecting Howrah metro station and Mahakaran (iconic Writers’ Building) metro station. The train shall be under water for 1 minute time with train speed of 80 km per hour.

The tunnel depth would be 13 m below the water and tunnel crown extra dose will be 13 m below the river bed. The internal diameter shall be 5.55 meter, where as the external diameter of the tunnel shall be 6.1 meter.