Mumbai, July 4 -- Plans are underway to connect India's first underground bullet train station at Bandra Kurla Complex (BKC) with two metro rail lines and other buildings and commercial complexes around it, said officials. There will be an underground tunnel with a travelator connecting the bullet train station to the Kotak-BKC station of the underground metro Line-3 (Cuffe Parade to Array Colony), and a foot over bridge (FOB) linking it to the IL&FS station on the under-construction Metro Line-2B (DN Nagar to Mandale). The linking initiative is a part of the larger multi-modal integration (MMI) aiming to connect the Mumbai High Speed Rail (HSR) station on the Mumbai-Ahmedabad HSR corridor with local transport infrastructure. On July 1, the National High Speed Rail Corporation Limited (NHSRCL), Mumbai Metropolitan Region Development Authority (MMRDA) and Mumbai Metro Rail Corporation Limited (MMRCL) met for one of the first discussions regarding the plan. Officials from the NHSRCL said that, to facilitate connectivity, they planned to carve out a tunnel during the ongoing construction of Mumbai HSR. "This tunnel would be 1.1 km long and connect to Line-3 at the Kotak-BKC station," said an official of the NHSRCL, adding that the location of the tunnel had been identified. "The intricacies of who will bore this tunnel, its cost, and other details are not chalked out yet," the official added, saying that they planned to make four connecting outlets which could link the station to nearby areas. NHSRCL officials estimate the cost of the linking tunnel to be between Rs.100-Rs.150 crore or more depending on the final plan. The tunnel would resemble subways that the city has built at CSMT and Churchgate railway stations with shops on either side. The official said that an FOB beginning at the topmost layer of the bullet train station will connect to the under-construction metro line 2B. "The station is coming right next to the Mumbai HSR station on the main Bandra-Kurla road and shall be barely 50 meters away," added the official. As per the NHSRCL, the Mumbai HSR station, covering an area of 5 acres, and costing over Rs.3,600 crore is expected to be ready by late 2027. The station, 495 m long, extends another 500 m underground, and is set to have three levels. The first and lowest, at a depth of 30m-35m, will contain the train platforms. Above it, the second layer will have a concourse area, ticketing counters, rooms for the train drivers, entry and exit gates, and the entrance to the tunnel which will connect the station to the Aqua line. The topmost layer will be at the road-level and is set to contain shops, restaurants and commercial spaces. Buildings and commercial complexes around the Mumbai HSR station have approached NHSRCL seeking direct connectivity into their premises. Officials said that Diamond Bourse has approached the rail authorities regarding a direct bridge or subway to their compound which would benefit diamond traders and merchants from Surat. At present excavation work is underway at Mumbai HSR station, and the soil and muck is being dumped at Bhiwandi....