Due to the tunnel dimensions, and being under Indian Railways, Kolkata Metro opted Indian metre gauge shell (22.7 m (74 ft 6 in)) with 1,676 mm (5 ft 6 in) tracks for Blue Line, which was later used for Purple and Orange Lines.

On the other hand, Green Line uses the 1,435 mm (4 ft 8+1⁄2 in) standard gauge tracks similar to most other Indian metro networks.

9 rakes were manufactured by Integral Coach Factory (ICF), Chennai and were passed into service in the first phase when the metro initially ran from Esplanade to Bhawanipur.

[7][8][5]These are the first AC trains that were passed into service in 2010, after the elevated corridor from Mahanayak Uttam Kumar to Kavi Nazrul was completed.

[5] 2 prototype rakes manufactured by ICF Chennai and Medha and were supplied to Kolkata Metro by September 2017.

These trains have 3 phase alternating current motors, regenerative braking, stainless steel body, CCTV cameras (not present in rakes, numbered as MR-401 & MR-402), and better passenger information system.

[9][10] There was a need to replace non-AC rakes on Blue Line and so during mid 2015 it was announced that Indian Railways for the first time would rope an international train-maker, China Railway Rolling Stock Corporation (CRRC) based in Dalian.

[11] As per the tender, 14 new rakes composed of 8 coaches each will be supplied to Kolkata metro by CNR Dalian Locomotive company, a subsidiary of CRRC, which will be running on Blue Line.

The first of the 14 rakes from Chinese firm Dalian was slated to arrive by December 2017 but got delayed due to various reasons.

The first rake finally arrived in Kolkata on 3 March 2019 on a vessel at Netaji Subhas Dock (NSD).

The rake was unloaded and taken to Noapara carshed after which trial runs and inspection would be carried out before commencing operations.

Some of the issues related to insufficient power to climb up the slopes in the tunnels and higher oscillation in the bogie.

Another 3 rakes will arrive soon.The bidding by the Spanish company CAF for Green Line was cancelled due to funding related problems.