Mumbai’s Water Tunnel Project TBM passes FAT

A 3.2m diameter TERRATEC Open TBM for use on the Municipal Corporation of Greater Mumbai’s (MCGM) Amar Mahal II Tunnel Project in Maharashtra, has passed the Factory Acceptance Test (FAT), making it ready to be shipped to the site where contractor Patel Engineering Limited will complete a water transfer tunnel.

This TBM is designed to work effectively in the geology expected along the project alignment. The project requires the TBM to have a modular design that allows it to be launched and potentially received via shafts (or alternately disassembled inside the tunnel). The Cutterhead is equipped with 18 heavy-duty back-loading disc cutters. The VFD controlled electric motors enabling the cutter head to rotate at over 10rpm with optimum torque.

To allow safe tunnelling through all the sections of the alignment, the machine has been designed with ground supporting equipment which includes a fixed probe drilling unit, two rock bolting drills and a steel arches erector.

The TBM will be deployed by contractor Patel Engineering Limited, on the AMT-II tunnel which is one of a number of projects presently being carried out by MCGM to augment and improve its water distribution system in order to meet increased demand and ensure reliable supply.

The project will consist of two TBM drives totalling 5,350m in length between three shafts of depth up to 105m. The finished 2.5m diameter tunnel contract from Amar Mahal (Hedgewar Udyan) to Trombay Low-Level Reservoir (TLLR) and further up to Trombay High-Level Reservoir (THLR) at an average depth of 80 to 90m is for water transfer.