East–West metro is the second metro corridor to connect Kolkata with Howrah by an underwater metro line below the Hooghly River. The length was supposed to be , underground and elevated. However, the project was stalled several times due to land acquisition and slum relocation issues. A major route realignment in 2013 increased the length to . The elevated stretch is long while the underground stretch is . The planned intersection with Line 1 at Central was re-aligned to Esplanade (interchange with Line 1 and Line 3). In September 2019, during the construction of the eastbound tunnel (from Esplanade to Sealdah), a TBM hit an aquifer under Bowbazar, causing a major collapse in the area, delaying work on that section for several months. These issues have caused massive delays to the project, and foreign currency losses had led to an 80 percent cost escalation of the project to nearly .