The National High Speed Rail Corporation (NHSRCL) has announced that in order to accelerate progress on the ambitious Mumbai-Ahmedabad bullet train project, an additional 394-meter intermediate tunnel has been constructed at Ghansoli in Mumbai. It has been stated by the NHSRCL, the special purpose company overseeing the bullet train project, that the new tunnel will expedite the 21-kilometer main tunneling work between BKC and Shilphata, which is adjacent to the Thane creek.
According to the release, the new 26-meter-deep terminal, which is 3.3 kilometres long, will facilitate simultaneous access to create approximately 1.6-metre tunnels on each side for the main 21-kilometer tunnel. It has been further mentioned that for the main 21-kilometer tunnel, 16 kilometres will be excavated using tunnel boring machines, while the remaining 5 kilometres will be constructed using the New Austrian Tunnelling Method.
It has been reported that excavation for the intermediate tunnel began on December 6, 2023, and the full 394 meters were completed in six months. This process involved 214 controlled blasts using 27,515 kg of explosives under expert supervision. It has been informed that the intermediate tunnel is designed to provide direct vehicular access to the main tunnel during construction and operation and can also serve as an evacuation route in emergencies.
Construction is rapidly progressing on the 21-kilometer section from the Mumbai Bullet Train Station to Shilphata in Maharashtra. It has been highlighted that approximately seven kilometers of this tunnel will pass under the Thane creek, an intertidal zone, marking the first of its kind in India. It has been specified that this single-tube tunnel will house two tracks for the bullet train, which will travel at speeds of up to 320 km/hr within the tunnel. Currently, 16 kilometers of the tunnel are under construction at BKC, Vikhroli, and Savli, using tunnel boring machines.
