Engineers from Larsen & Toubro on this past Monday quietly commissioned Tunnel Boring Machine (TBM) Avni at Shivajinagar Station, without any major launch event, for building tunnels on the 21.386 km Line-4 (Reach 6 / Pink Line) of the 73.92 km Bangalore Metro Phase 2 project.
This Ø6.67m slurry machine (DZ669) is overall the project’s second, after TBM Urja (DZ670), and the first machine to start excavation works for the city’s 2.755 km package RT-02’s 2141 meter twin tunnels between Shivaji Nagar – MG Road – National Military School (formerly Vellara Road).
As of now, Avni has built 1 temporary ring, comprising of 5 segments + 1 smaller ‘key’ segment, within the station box while the 2nd ring is being built.
As shared earlier, the machine was dispatched from TBM manufacturer China Railway Construction Heavy Industry Co., Ltd. (CRCHI)’s plant in Changsha after completing factory acceptance tests (FAT) in November 2019. Its parts arrived in the city in February and workers began lowering them into the station’s southern-end in May.
In late-August, engineers completed local site acceptance tests (SAT) and last week moved the machine ahead to the head-wall’s eye-seal.
For more updates, check out the Bangalore section of The Metro Rail Guy!