Final consignment of second TBM reaches Goregaon as GMLR tunnel works near key milestone

Work on Mumbai’s ambitious Goregaon–Mulund Link Road (GMLR) project reached a key milestone on Tuesday, with the final consignment of the second tunnel boring machine (TBM) scheduled to arrive at the Goregaon work site by Thursday night. Civic officials said preparations are underway to begin lowering and assembling the first TBM by March, with actual tunnel boring targeted to commence by June 2026.

The Rs 6,500-crore GMLR project, spanning 6.62 km, is aimed at significantly reducing travel time between Goregaon in the western suburbs and Mulund in the east. A major component of the project is the 5.3-km-long twin tunnels to be constructed beneath the Sanjay Gandhi National Park (SGNP). Each tunnel, with an external diameter of 14.42 metres, will be excavated using a TBM, with tunnelling set to begin from the Goregaon end.

To facilitate this, the Brihanmumbai Municipal Corporation (BMC) has been excavating a massive ‘launching shaft’ in the Film City area of Goregaon since last year. From March 2025, the civic body began receiving consignments of the first TBM from Japan. On Tuesday, officials confirmed that the final shipment of the second TBM is also expected to reach the site this week.

“From March 10, we plan to start lowering parts of the first TBM into the launching shaft. This will include four gantries, after which the assembly will be carried out inside the shaft,” a senior BMC official told The Indian Express. “The assembly process will take at least three months, following which we aim to begin actual tunnelling work from June 2026.”

Officials clarified that the lowering and assembly of the second TBM will be taken up at a later stage.

Meanwhile, excavation of the launching shaft is progressing at a brisk pace. Municipal authorities said that around 1,400 to 1,550 cubic metres of soil and rock are being excavated daily using about 120 vehicles. The shaft, designed to be 200 metres long, 50 metres wide and 30 metres deep, has currently been excavated to a depth of 23 metres across its full length and width.

The twin tunnels form part of the third phase of the GMLR, envisioned as Mumbai’s fourth east–west corridor. The project’s first phase involves road widening, followed by a second phase comprising flyover construction in the western suburbs along with the TBM-driven tunnels. The subsequent phase includes a road-over-bridge at Nahur, connecting to the final phase—an elevated flyover up to Airoli.

In December 2025, the BMC floated tenders for this final phase, which includes a 1.33-km-long flyover from Nahur to Airoli and cloverleaf interchanges to improve connectivity between Mumbai and Thane, at an estimated cost of Rs 1,293 crore.

Nayonika Bose is a Senior Correspondent with The Indian Express’ Mumbai bureau. While ... Read More