The speedily progressing construction of the 21 km tunnel from Mumbai Bullet Train station to Shilphata in Maharashtra is evident, as stated by NHSRCL officers.
NHSRCL has dug a 394 metre long Additionally Driven Intermediate Tunnel (ADIT) at Ghansoli for Mumbai-Ahmedabad Bullet Train Project so as to expedite the construction of 21 km tunnel between Bandra Kurla Complex and Shilphata.
When being constructed and operated, ADIT will be directly linked to the main tunnel; it can also serve as an evacuation route in times of fire or any other emergency.
Excavation work on ADIT began on December 6th, 2023 and ended six months later with a total of 214 controlled blasts that discharged about 27,515 kg of explosives using a significant amount of instrumentation expertise.
This means that excavation of ADIT which is an inclined tunnel that is 26 metres deep would open up way for further construction of another NATM – 3.3 km-long tunnel and permit concurrent access for tunnelling on both side over approximately one point six meters depth through New Austrian Tunnelling Method (NATM).
Out of the twenty-one kilometers’ tunnelling activity involved; sixteen were bored by Tunnel Boring Machines while the remaining five was done via NATM method.
“The first seven kilometres of this tunnel will run under Thane Creek, which doubles as intertidal zone,” says officials from NHSRCL silently. “This is India’s first such a kind project,” they added.
For facilitating two lines each carrying bullet trains moving in opposite directions within a single tube-cum-track structure; this proposed 21 km long tunnel will have its sides built using TBMs with cutter heads measuring around thirteen points six meters in diameter.
Bullet train project by NHSRCL must be completed by end year 2028 at the latest. The train will enable users to travel from Mumbai to Ahmedabad in three hours.
These BKC, Vikhroli and Sawli are the three under construction shafts through which sixteen kilometers long tunnel is proposed to pass via Tunnel Boring Machines.
