As a result, the winning bidder may only manufacture a maximum 25% metro cars required for Metro 3 outside India. The MMRC rejected criticism that the restrictions would favour BEML, Bombardier and Alstom, the only companies that manufacture rolling stock in India, by stating that a foreign company that won the bid could sub-contract to an India-based manufacturer. The MMRC restarted the bidding process, under the new conditions, in May 2017. The agency sought to procure 31 eight-car train sets. Each coach is 22.6 metres long and 3.2 metres wide. The MMRC received pre-qualification bids from seven firms - Alstom Transport India Ltd India & Alstom Transport S.A France (Consortium), CAF S.A, Spain, CRRC Nanjing, CRRC Changchun & CRRC International Corporation Ltd China (Consortium), Hitachi Ltd (Japan), Kawasaki Heavy Industries Japan & BHEL (Consortium) India, and Mitsubishi Corporation, Japan. In September 2018, the MMRC awarded a EUR 315 million contract to French transportation major Alstom Transport and its Indian subsidiary to supply 248 coaches for Metro 3. The contractor will be responsible for the design, manufacture, supply, installation, testing and commissioning of 31 train sets of eight cars each. The trains will have a carrying capacity of 2,350 passengers and a seating capacity of around 300 passengers in each coach in longitudinal seating arrangements. All coaches will be designed and developed at Alstom's engineering centre in Bangalore, and manufactured by the company's plant in Sri City, Andhra Pradesh. Metro 3 will be driverless. The line has an automation level of grade 4. However, the line will employ drivers during its first year in operation. Trains on the line will also utilize a time-interval system which allows them to maintain the minimum possible distance required for safety between each other. As all trains are connected with the operation control centre, every train is aware of the speed and distance of all other trains. Metro 3 will utilise a communications-based train control (CBTC) signalling system. There are no signals on the line, and speed and distance between the trains is monitored by onboard computers that are connected with a central computer in the operations control centre. MMRDA joint project director Dilip Kawathkar stated that AC power was chosen for Line 3 "after a proper study by a team of experts" which found that the AC model was "a better option".