Excavation of 394-metre-long tunnel for bullet train project completed in Navi Mumbai

Mumbai: In order to expedite the construction of 21 km long tunnel between Bandra Kurla Complex and Shilphata (Navi Mumbai), the National High Speed Rail Corporation Limited (NHSRCL) has excavated 394 metre long Additionally Driven Intermediate Tunnel (ADIT) at Ghansoli, for the Mumbai-Ahmedabad Bullet Train Project.

The ADIT will give direct vehicular access to the main tunnel during construction and operations, and also be used for the purpose of evacuation process in emergency situations.

As part of the process, a total of 214 controlled blasts were carried out using 27,515 kg of explosives under the supervision of experts, and a high level of instrumentation was used to ensure safe excavation, it said.

“The excavation work for ADIT began on December 6, 2023, and the entire length of 394 metres was excavated in six months,” said officials.

Of the 21 km tunnel in the bullet train project, 16 km will be excavated using tunnel boring machines (TBMs), while NATM will be used for the remaining 5 km, it said.

The NHSRCL said the construction activities related to the 21 km long tunnel from the Mumbai bullet train station at BKC to Shilphata were progressing at a fast pace. About 7 km stretch of this tunnel will be under the sea at Thane Creek (Intertidal zone).

Three shafts at BKC, Vikhroli, and Sawli near Ghansoli are under construction, and these will facilitate the construction of a 16 km-long tunnel through TBMs, it said.

The total cost of the Mumbai-Ahmedabad High Speed Rail Corridor project is pegged at ₹1.08 lakh crore, and as per the shareholding pattern, the Central government is to pay ₹10,000 crore to the NHSRCL, while the two states involved, Gujarat and Maharashtra, are to pay ₹5,000 crore each.

The rest is to be funded by Japan through a loan at 0.1 per cent interest.