Namma Metro’s Tunnel Boring Machine (TBM) Tunga has set a new record. In July, Tunga tunnelled through 308 metres, surpassing the previous record of 273 metres set by TBM Urja in May 2022, according to Bangalore Metro Rail Corporation Limited (BMRCL).

According to BMRCL, “In July 2024, BMRCL achieved its maximum tunnelling to date. TBM Tunga completed 308 metres of tunnelling between K.G. Halli and the Nagawara retrieval shaft. This surpasses the previous record of 273 metres set by TBM Urja between Cantonment and Pottery Town in May 2022.”

BMRCL has deployed nine TBMs for the construction of Namma Metro lines across Bengaluru. Seven of these machines — Urja, Varada, Avni, Lavi, Vindhya, Vamika, and Rudra — have successfully completed their tasks.

The eighth TBM Tunga commenced its final drive from K.G. Halli to Nagawara, covering 935 metres, this February 2 for the Pink Line. The ninth TBM, Bhadra, is currently working on its final assignment, a 939-metre northbound tunnel from K.G. Halli to Nagawara.

In July, tunnelling operations with Tunga were halted owing to a sinkhole that appeared on the road surface in K.G. Halli. Officials reported that the sinkhole, measuring approximately 2.5 to 3 metres in width and 3 metres in depth, was probably caused by an air pocket. After the sinkhole was repaired, Tunga resumed tunnelling.

Officials anticipate that Tunga will surface at Nagawara, the terminal station of the Pink Line, on October 30. Having commenced its final drive on February 3, Tunga has already tunnelled 469 metres of the total 938-metre target.

Officials expect the Pink Line to open in 2025. Progress on this stretch has experienced considerable delays owing to various factors, including tender cancellations owing to high bids, changes in alignment before final approval, challenges with land acquisition, and other obstacles.

Officials now expect that the entire stretch may be completed and opened in 2025.