Mumbai: The Mumbai Metropolitan Region Development Authority (MMRDA) Wednesday officially kick-started the tunnelling process for the Orange Gate-Marine drive twin tunnels by pressing the Tunnel Boring Machine (TBM) into action for the purpose.
The twin tunnels, which will connect the Eastern Freeway to the Mumbai Coastal Road, are expected to be complete by December 2028.
Speaking to reporters at Orange Gate, CM Devendra Fadnavis, who was present at the occasion along with Deputy CM Eknath Shinde, said, “We know that after exiting the Eastern Freeway, citizens get stuck in traffic congestion. People come in 20-25 minutes from the Eastern suburbs and then get stuck in traffic at its exit for another 30-45 minutes. This will also help commuters from western suburbs reach the Navi Mumbai airport.”
Fadnavis said, while the deadline is December 2028, internally the state government is pushing for completion of the project at least six months before the specified deadline.
The Orange Gate-Marine Drive twin tunnels will be altogether 9.96 kilometres in length of which about seven kilometres will be under the ground. Each tunnel of two lanes and one emergency lane will be about 3.2 kilometres long and will have a speed limit of 80 kmph.
The project is estimated to cost Rs 8,056 crore.
Currently, traffic from the Eastern Freeway, which connects Chembur and Ghatkopar, converges on the already congested P D’Mello road, making the last mile to South Mumbai hubs such as Colaba, Churchgate and Nariman Point a harrowing commute.
Fadnavis said the Orange Gate-Marine Drive tunnel will be an engineering marvel as it will run under about 700 old buildings, including over a hundred heritage structures. It will also go under two railway lines as well as the Aqua line of the Mumbai Metro.
According to the MMRDA, the tunnel will be built about 12 to 52 metres below the ground.
The 82-metre-long TBM is a slurry-shield type machine that is said to be most suitable for Mumbai’s coastal geology and high water ingress. The same TBM was used to bore the twin tunnels part of the Mumbai Coastal Road.
Fadnavis said the state government, then under the Uddhav Thackeray-led Maha Vikas Aghadi (MVA), initially planned to build a flyover at the end of the Eastern Freeway to bring traffic seamlessly on Marine Drive.
“But, we decided that it is almost impossible to build a flyover here because it is difficult to halt traffic for the construction. There’s not enough space either. Building a flyover here would have been more challenging than the construction of the flyover at the Mohammad Ali Road,” Fadnavis said.
Tunneling prep for Thane-Borivali twin tunnels
Last week, in another milestone, the MMRDA Tuesday completed the Thane-side portal excavation and lowered a 13.34-metre TBM cutterhead, which will enable the authority to prepare for tunnelling for this project too.
The 11.8-kilometre underground twin tunnels will connect Ghodbunder Road in Thane to the Western Express Highway at Borivali. The project will enable motorists to cover the distance that currently takes over an hour in just 15 minutes. Each of the two tunnels will have three lanes and one emergency lane.
The TBM being used for the Thane-Borivali twin tunnels with a diameter of 13.34 metres is said to be India’s largest tunnel boring machine with the biggest diameter. This project too is expected to be completed by 2028.
(Edited by Amrtansh Arora)