The National High Speed Rail Corporation Ltd (NHSRCL) on Thursday opened tenders for the 21- kilometer tunnel between Bandra Kurla Complex (BKC) and Thane now that 39,570 square metres of land have become available for the Mumbai-Ahmedabad bullet train project at Vikhroli.

The tunnel's projected price is $100,000,000,000 and it extends 7 kilometres under Thane Creek. 99% of the land needed for the high-speed rail corridor in Maharashtra has now been acquired by NHSRCL.

Two businesses, Larsen & Toubro and Afcons, submitted proposals for the building of the single-tube tunnel, which will have a diameter of 13 metres, according to NHSRCL officials on Thursday. The development follows the Bombay high court's dismissal of a Godrej case challenging the project's seizure of their land in Vikhroli.

The tunnel is estimated to have cost $5 billion per kilometre. Three boring machines, at the least, would be needed for the endeavour.

The 508-kilometer route's only subterranean stop, BKC, will have 6 platforms that are each 415 metres long and can accommodate 16-coach bullet trains. It will link to Metro 2B and have a depth of 25 metres.

The authorities also displayed the designs for the stations at Virar, BKC, and Thane. The station at Virar is probably close to the hill, therefore it will show the winds coming from the mountain. Ulhas River will be close to Thane Station, causing waves to build on the roof. While the BKC will be built to look like the Arabian Sea's clouds and waves.