Assembly of Bengaluru's 4 new Tunnel Boring Machines (TBM) can not be completed. Chinese experts responsible for the assembly of the machines can not arrive in India because international flights are not allowed. TNIE writes that 3 of the TBMs have been partially assembled and the 4th one is still to start the assembly.

It was not possible to finish the assembly remotely via video link. Finishing the assembly will not be enough. Because the contractor L&T will need the Chinese experts to operate the machines.

Indian contractor Larsen and Toubro Limited (L&T) will use these 4 TBMs to bore the tunnels for the Bengaluru Metro (Namma Metro) Phase II. L&T has been assigned by Bengaluru Metro Rail Corporation Limited (BMRCL)  to do the job. L&T decided to buy 4 Tunnel Boring Machines from China Rail Construction Heavy Industry (CRCHI). Unlike the Eearth Pressure Balance tunnel boring machines used in the Phase 1 by other contractors, BMRCL had urged the Phase 2 contractors to use slurry TBMs. With L&T, it was the first time CRCHI able to sell tunnel boring machines in India.

CRCHI machines started arriving in India in February 2020 via the Chennai port. Then came the coronavirus times and everything came to an extreme slow down. Even 2 of the TBMs were stuck in Tamil Nadu border and had to be brought to the site via obtaining a special government permit.

Contrary to Phase 2, a mixed-bag of TBMs had been used in Phase 1. One contractor, Coastal-TTS has used two Herrenknecht EPB tunnel boring machines (Herrenknecht S-725 and Herrenknecht S-726) and one Italian SELI TBM. The other contractor, CEC-Soma-CICI has used 2 Hitachi-Zosen slurry TBMs which performed very well. Therefore BMRCL has asked the contractors of Phase 2 to use slurry TBMs.

https://www.newindianexpress.com/cities/bengaluru/2020/jun/18/metro-tbms-wait-for-chinese-drill-experts-2158040.html