Construction work for the much-anticipated twin tunnels under the Goregaon-Mulund Link Road (GMLR) is scheduled to begin next month, as per official updates. Preparations have been accelerated with the arrival of critical machinery parts required for tunneling operations. Components of the Tunnel Boring Machine (TBM), imported from Japan, have already been delivered to the Jawaharlal Nehru Port Trust (JNPT) and transported to the project site in Mumbai. The final shipment is expected by mid-August, after which the machine will be assembled over a four-month timeline.
Under Phase 3(B) of the GMLR development, a 6.65-kilometre corridor is being established. This will include a 1.22-kilometre triple-lane box tunnel at Film City and twin tunnels stretching beneath the Sanjay Gandhi National Park (SGNP). The excavation of 5.30 kilometres of tunnel will be conducted using TBMs, while the remainder will include approach roads and the box tunnel structure.
The tunnel route has been planned to start from Film City in Goregaon East and extend to Amar Junction in Mulund. A maximum depth of 160 metres below the ground has been designed for the tunnels, with safety cross-passages to be installed at 300-metre intervals. Challenging terrain such as forest areas, hills, and farmlands within SGNP will be traversed by the tunnels. The excavation will be undertaken using two TBMs launched from Film City.
It was confirmed by civic officials that 54 containers carrying the TBM components have already been received. An additional 23 containers are awaited. Once the full set is delivered, the equipment will be assembled on-site. A second TBM is expected to arrive in Mumbai by the end of December. Final environmental clearance for the diversion of 19.43 hectares of forest land was granted earlier this month by the Union Ministry of Environment, Forest and Climate Change. This approval has allowed for the tunneling process beneath SGNP to proceed legally and logistically.
The twin tunnels, each spanning 4.7 kilometres in length and 45.7 metres in width, have been designed with modern facilities. Features such as lighting systems, fire detection and suppression technology, CCTV surveillance, and dedicated control rooms will be installed at both ends. Utility ducts for drainage and potential future water pipelines have also been integrated into the design. The Brihanmumbai Municipal Corporation (BMC) has projected an October 2028 deadline for the tunnel completion. Once the full 12.2-kilometre GMLR project is operational, it is expected that travel time between Goregaon and Mulund will be reduced dramatically—from 75 minutes to just 25—providing seamless east-west connectivity across Mumbai.