The Brihanmumbai Municipal Corporation (BMC) on Wednesday commenced the process of lowering parts of a Tunnel Boring Machine (TBM) into the launching shaft for the twin tunnels under Phase 3-B of the Goregaon-Mulund Link Road (GMLR) project.
BMC Commissioner Bhushan Gagrani visited the site in Dadasaheb Phalke Chitranagari and observed the operations firsthand. Officials highlighted that the work is starting nearly three months ahead of schedule, a move expected to significantly speed up progress on this key infrastructure initiative.
The 12.20-kilometre GMLR is designed to connect Mumbai’s western and eastern suburbs. The project includes twin underground tunnels stretching from Film City in Goregaon to Khindipada in Mulund, with each tunnel measuring approximately 4.70 km and featuring three traffic lanes. The tunnels will pass entirely beneath the hills of Sanjay Gandhi National Park, with diameters of 14.20 metres and 13 metres within the sanctuary zone. They will be outfitted with modern ventilation systems, fire protection measures, drainage channels, and dedicated utility corridors.
BMC officials confirmed that two TBMs, S-118 and S-119, will undertake the excavation. Built by Terratech, each machine spans 14.49 metres in diameter and weighs around 2,175 metric tonnes, making them the largest TBMs ever deployed in Mumbai.
Launching shaft work progresses
The first phase of the launching shaft at the Film City site has been completed. The shaft measures 200 metres long, 50 metres wide, and 30 metres deep, with a concrete cradle at the base (20 m x 20 m x 2.5 m) designed to stabilize and position the TBM during launch.
From March 11, high-capacity cranes of 800-tonne and 350-tonne capacities began lowering TBM components into the shaft. On the first day, the type ‘A’ shield—the main mining element weighing roughly 135 metric tonnes—was successfully positioned.
Officials added that key components of the tunnelling system, including the main shield, cutter head, screw conveyor, main bearing, and erector, have already been partially assembled and will be gradually lowered before final TBM installation. Once fully set up, excavation will begin.
After completing tunnelling from Film City through the national park to Mulund’s Amar Nagar, the TBM will be retrieved via a dedicated shaft in Mulund and dismantled.
Source: Mid-day
