The BrihanMumbai Municipal Corporation (BMC), on Monday, unveiled the Tunnel Boring Machine (TBM), which will be used for digging a 3.98 kilometre underground tunnel between Priyadarshini Park (Malabar Hills) and Girgaum for the Mumbai Coastal Road Project.
The diameter of the TBM is 12.19 metres and it has been manufactured by China Railway Construction Heavy Industry Company Limited (CRCHI).
The TBM arrived in India in April this year. Presently, it is being stationed at Priyadarshini Park. Due to the massive size, the TBM was dismantled into smaller parts that were brought to the construction site via trucks. The approximate weight of the tunnel is 1,500 megatons and it has been transferred to the launch ramp using a 200 wheel self propelled transporter.
On Monday, BMC officials placed the TBM on the launch site and stated that boring for the tunnel will begin by the middle of December. "Reassembling of the TBM is almost complete and will be launched by the middle of this month. The tunnel will be a part of the 10 kilometre stretch connecting Priyadarshini Park and Worli," stated a senior executive engineer involved in the project.
The tunnel will run 25 metres below the surface in Girgaum and 75 metres below the surface in Malabar Hill. "The total boring process will take around nine to ten months. We will start digging from the Priyadarshini Park site and carry out the boring of the first tunnel till the Girgaum Chowpatty. From there, the machine will be taken out and will be taken back to Priyadarshini side as we start boring the second parallel tunnel. Boring each side is expected to take five months," the official explained.
Civic officials informed that the 20 per cent of the project has been completed and the entire project will be finished by July, 2023.
"The deadline of the project got delayed due to various legal proceedings and the ongoing pandemic. However, we aim to finish the project by July, 2023," the BMC stated in a statement.
The Coastal Road Project is divided into three packages. The first package will cover 3.82 kms, the second package will cover 2.71 kms and the third package will cover 4.05 kms. Underground parking facilities will be constructed at Worli and Haji Ali.
The proposed Coastal Road Project will be 10.58 kms long and it will have 4x4 lanes along with elevated corridors, pools and underground tunnels. A separate bus lane for the Bus Rapid Transit System (BRTS) will also be constructed for the project.