Two more TBMs for Mumbai Line Three

26 September 2017

India - The first of two slurry machines destined for the UGC03 contract of Mumbai Metro Line Three underwent factory acceptance in September.

The 6.65m-diameter Robbins machines will be operated by a joint venture of Dogus and Soma to bore parallel 3.5km tunnels. The alignment will pass through three cut and cover stations along the way.

Ground conditions will consist of fresh to weathered basalt and breccia up to 100MPa UCS, with water pressure up to 3 bar.

According to the contractor, slurry will suit the variable but hard rock local ground conditions. The 17” cutters will be fitted with wear protection, and wear detection bits. Grizzly bars will put a 250mm limit on boulders entering the cutterhead.

The 33.5km-long Line 3 of Mumbai Metro being constructed by the Mumbai Metro Rail Corporation (MMRC) will consist of 26 underground stations and one at-grade station. The line is expected to be operational by 2021.