BENGALURU: After boring for 936.6 metres from Kadugondanahalli (KG Halli) to Nagawara, Tunnel Boring Machine `Tunga' had its breakthrough on Wednesday. This was the third leg for the TBM, launched on February 3 this year, making it the eighth machine to complete its job. Tunnelling has now been completed for 20.58 km out of the 20.99 km underground network of the Pink Line of Bengaluru Metro with the last one still tunnelling.
The Pink Line has a launch deadline of September 2026, said Bangalore Metro Rail Corporation Limited Managing Director Maheshwar Rao.
Tunga tunnelled from Venkateshpura to Tannery Road in its first leg. It was taken out using a vertical shaft and then sent from Venkateshpura to tunnel in the opposite direction KG Halli in its second leg before it was launched on its third leg in February this year.
Among the challenges 'Tunga' encountered was a sinkhole encountered at KG Halli in June this year which brought operations to a standstill for some time. Bhadra, the final TBM, is tunnelling in the same direction and has completed over 60% of its tunnelling so far.