After successful completion and expansion of Line 1, the experience of India’s first metro and the success of the Delhi metro network contributed to the sanction of the East-West Metro corridor, from Howrah Railway Station to Salt Lake Sector V, through an order dated 30th July 2008. Thus began the fascinating journey of building the East–West Corridor (Line 2), the line which would connect Howrah and Sealdah Railway Stations, two of the busiest railway stations in the world and which would pass through under Hooghly river, the first such river crossing in the country. During the past ten years the project has undergone through various hindrance, glitches, ups & downs, route modifications, replanning, recommissioning, highs like successful tunnel building under the Ganges, lows like Bowbazar accident etc. After all odds & evens currently the East-West Metro spans over a distance of total 16.6 km of which 5.8 km of elevated tracks & 10.8 km of underground tracks. As of now there are 12 planned stations (which will increase further post sanction of expansion of the network upto Santragachi) of which six are underground & six are elevated stations.

Saltlake Sector V (Elevated) - Karunamayee (Elevated) - Central Park (Elevated) - City Center (Elevated) - Bengal Chemicals (Elevated) - Saltlake Stadium (Elevated) - Phoolbagan (Underground) - Sealdah (Underground) - Esplanade (Underground) - Mahakaran (Underground) - Howrah Station (Underground) - Howrah Maidan (Underground)

Expansion planned upto Santragachi (Elevated) via Ramrajatala (Elevated).

Running through the heart of Kolkata, bridging two of the city’s most populous areas, the corridor has been planned to drastically cut down on travel cost and time. Normally, one would take at least an hour and a half and multiple modes of transport to travel between the extremities of the city at peak hours on a weekday.

Recognizing the precarious situation of travel in Kolkata, KMRCL at the planning stage decided to adopt technologies to minimize discomfort to the citizens even if it meant substantial additional expenditure. The underground portion of the corridor has adopted the latest boring rocess, rather than the top – down cut and cover process (which citizens have experienced during the construction of the North – South metro) ,sparing the citizens inconvenience and traffic snarls to no end. And to bore the tunnels, “Earth Pressure Balance” Tunnel Boring Machines have been procured from abroad. The almost 2-story high boring machines will be able to bore upto 15 metres a day, excavating up to 500 m³ of earth a day with a complete normalcy of life on the surface !

The technological precision and expertise was required for a project of a magnitude that makes it possible to travel under the mighty Hooghly river in a state-of the-art metro line. Through the startling scale of the project was self-evident, the Eurostar (connecting Paris and London) offers an apt analogy for the level of technology harnessed by KMRCL. It was an almost dreamlike appeal with uncompromised efficiency – travelling more than a 10-storied below the water surface for almost ½ kilometer across the Hooghly !!! The reinforced concrete segmental tunnel linings have a thickness of more than a quarter of a meter and are caulked with a composite gasket of neoprene and hydrophilic rubber to seal the tunnel from ingress of water. This marvel of modern technology is a resounding first of its kind in India.