Kolkata Metro Line 4

The Kolkata Metro Line 4 or the Yellow Line, also known as the Noapara - Barasat Line of the Kolkata Metro in India is a 16.876 km long metro route from Noapara to Barasat in North 24 Parganas, which is under construction. It is being built by RVNL, Senbo & ITD. It will run mostly underground viaducts. The track will be elevated until Jessore Road Station and then go underground towards Barasat metro station. It will have an interchange station at the NSCBI Airport with Kolkata Metro Line 6.

Stations
The stations of this corridor are:

Progress of Dum Dum Cantonment metro station
An amount of Rs 227 crore contract to build this station along with a mostly at-grade 2.16 km section from the Bagjola Canal to the existing ramp of the Airport Circular Railway track was awarded to Senbo Engineering Limited all the way back in June 2011. Since then, the station’s civil structure has been built, but work for the at-grade track section could not be started due to land acquisition issues along the line’s proposed alignment. But the rehabilitation work has completed in 2020, and the work is going smoothly. Recently girders were placed over Eastern Railway tracks. The metro station is set to be operational by 2024.

Project development
The project will be completed in three phases. The first phase of work from Noapara to Biman Bandar is under progress. In the second phase work from Biman Bandar to New Barrackpore will be done and in the last phase from New Barrackpore to Barasat work will be done. But the development work from New Barrackpore to Barasat got struck for the last eight years since it was sanctioned because of encroachments and the Airport Authority of India objected the elevated stretches from New Barrackpore to Barasat. Later, after objections from AAI, a decision was taken to convert this into an underground stretch. On 29 June 2019 sanction for material modification for underground construction at an additional cost of inr 16150000000 was sent to Railway Board by Metro. For this underground tunneling AAI has agreed to shift their fuel tanks, buildings and cables and the project is expected to be started from 2020.

Construction of an underground integrated station for Line 6 and line 4 has begun at NSCBI Airport land just 150 m away from the terminal building.

'The development of New Barrackpore to Barasat was supposed to go elevated to cut down the expenses, but the stretch was in doubt due to huge encroachment problem. But in February 2021, Prime Minister Narendra Modi gave his nod to construct this stretch underground, giving respite to thousands of families who were supposed to be evicted for the development of the elevated stretch. In order to lower the cost of the underground work, latest technology TBM will not be used, instead old technology of cut and cover method will be used for metro.

Line 4 has been divided into three phases now.
 * Phase 1: Noapara - Biman Bandar (under construction)
 * Phase 2: Biman Bandar - New Barrackpore (construction has been started, tender floated by RVNL to carry out construction work)
 * Phase 3: New Barrackpore - Barasat (construction to begin soon)