The 2.9m-wide 65m-long air-conditioned trains will accommodate up to 975 passengers, 140 of them seated. All 75 vehicles will be assembled at Alstom's recently-completed Sricity plant in Andhra Pradesh.

The 750V dc third-rail trains will be used on the 25.6km north-south line from Aluva to Pettna, which will have 22 stations and a design capacity of 15,000 passengers per hour per direction.

The contract includes an option for 25 additional trains.