In a couple of major developments in the ongoing Mumbai-Ahmedabad Bullet Train project, work has already begun at five locations of the proposed 21 km-long first underground-undersea tunnel, while the National High-Speed Rail Corporation Limited (NHSRCL) has handed over 4.8 hectares of land required for the construction of the Bandra Kurla Complex (BKC) station to the contractor.
The 21 km-long single-tunnel, including the 7 km-stretch running under-sea, with two lines, is coming up between BKC station and Shilphata in the neighbouring Thane district.
As per the updates provided by the NHSRCL which is executing India’s first bullet train project between Mumbai and Ahmedabad, work has begun at three shafts —Mumbai High Speed Railway Station (HSR), Vikroli, Sawli (Ghansoli), Shilphata and Additionally Driven Intermediate Tunnel (ADIT).
At the shaft 1 — Mumbai High Speed Railway Station in Bandra located at a depth of 36 metres, 100 percent secant piling work has been completed, while the excavation work is underway.
At the shaft 2 at Vikhroli located at a similar depth of 36 metres, 100 percent piling work has been done, while excavation work is on. “This shaft will be used to lower two Tunnel Boring Machines (TBMs) in two different directions, one towards BKC and another one towards Ghansoli,” a statement put out by the NHSRCL said.
Similarly at the Shaft 3 located at Sawli near Ghansoli in Navi Mumbai, excavation work is currently underway at the shift involving a depth of 39 meters.
While at Shilphata, the portal work has begun, the under-construction ADIT portal will facilitate additional access to the underground/undersea tunnel for faster construction progress.
In all, three TBMs will be used to make around 16 km of the tunnel, while the remaining 5 km tunnel shall be dug through New Austrian Tunnelling Method (NATM).
In a related development, the land required for constructing the BKC station, which is about 4.8 hectares, has been handed over to the contractor by NHSRCL.
The BKC station will be built using the bottom-up method, which means that excavation work will commence from the ground level and concrete work will start from the foundation. The excavation required for the station is quite extensive, reaching a depth of 32 meters, with an approximate volume of around 18 lakh cubic meters.
The NHSRCL is facing challenges in the construction of shafts because the work involves multiple controlled blasting with sufficient noise and air pollution prevention measures so as to cause minimal disturbance to the environment and population in the adjoining areas
It may be recalled that Modi and then Japanese Prime Minister late Shinzo Abe had laid the foundation of the Bullet Train in Ahmedabad in September 2017.
The Shiv Sena-led MVA government, which came into existence on November 28, 2019, had put Modi’s pet Bullet Train on the backburner immediately after it assumed office.
The Narendra Modi government revived the Bullet Train project in little over three weeks after Eknath Shinde of the rebel Shiv Sena faction and senior BJP leader Devendra Fadnavis were sworn in as the chief minister and deputy chief minister respectively on June 30, 2022.
The 508 km-long Mumbai-Ahmedabad High Speed Rail Project(Standard Gauge) at an estimated completion cost of Rs 1,10,000 crore. Out of this Rs 1,10,000 crore, Japan is giving a loan of Rs 88,000 crore. Interest on this loan is minimal i.e. 0.1%, and this loan is to be repaid to Japan in 50 years. Loan repayment period of 50 years with 15 years grace.
In the first phase, the bullet train will cover 508 kilometres between Mumbai and Ahmedabad.