Namma Metro Pink Line: 84% tunnelling over

Namma Metro’s longest underground section crossed another milestone on Wednesday as the sixth of its nine Tunnel Boring Machines (TBMs) completed the task assigned to it. 

Euphoria swept through the under-construction Langford Town metro station after TBM Vamika emerged out of the shaft. Officials and engineers from Bangalore Metro Rail Corporation Limited (BMRCL) and Afcons Infrastructure Ltd were present on the occasion. Afcons is the contractor for this underground section. 

Vamika took 132 days to tunnel 721 metres between Lakkasandra and Langford Town stations, or 5.4 metres per day on average. It did the job two months sooner. The breakthrough was actually expected in October. 

This was Vamika’s final drive. It previously tunnelled 613.2 metres between South Ramp and Dairy Circle stations and 743.4 metres between Dairy Circle and Lakkasandra stations. 

With Vamika completing its job, Rudra is the only TBM undertaking tunnelling on the Lakkasandra-Langford Town section, according to BMRCL. It was relaunched for its third and final drive in June, and tunnelled 86.8 metres by July 31. It has to cover 633.2 metres more and is expected to achieve the breakthrough in December, the BMRCL said. 

Cumulatively, six TBMs (Urja, Varada, Avni, Lavi, Vindhya, and Vamika) have tunnelled 17.62 km out of the total 20.991 km. 

While the BMRCL hopes to complete the remaining tunnelling (3.371 km) by the end of this year, the deadline appears ambitious. 

With three more TBMs still in action (see the table) and boring 5-6 metres per day on average, tunnelling is expected to be completed only next year.  

The Pink Line will connect Kalena Agrahara (Bannerghatta Road) in the south to Nagavara in the northeast. It’s 21.25-km long and has an 8.16-km-long elevated section (from Kalena Agrahara to the South Ramp). Nagavara, MG Road, Jayadeva Hospital and possibly Dairy Circle will be the interchange stations. Nagavara will also connect to the airport line while MG Road will link the Purple Line. 

The BMRCL has officially committed to opening the Pink Line by March 2025, though officials are hopeful of a December 2024 deadline. 

Additional trains from Majestic to MG Road

Starting September 1, Namma Metro will run three short-loop, one-way trains from Majestic to MG Road on the Puple Line during the morning peak hour on weekdays (Mondays to Fridays), the BMRCL said in a statement. AS Shankar, Executive Director (Operations and Maintenance), BMRCL, told DH that the train would leave Majestic at 9.18 am, 9.45 am and 10.15 am. “There will be no short-loop trains from MG Road to Majestic because ridership doesn’t warrant it,” he added.

TBMs still at work

1) Rudra: The machine was relaunched on July 14 for its last drive to tunnel the Lakkasandra-Langford Town section and is expected to break through in December. 

2) Tunga: The machine was relaunched on Feb 16 for its second drive to tunnel 1,186m from Venkateshpura to KG Halli. As of July 31, it tunnelled 347.2m and had to cover 838.8m more. The breakthrough is expected by Jan 31, 2024. After that, it will be deployed for its last drive to tunnel 935m from KG Halli to Nagavara. 

3) Bhadra: The machine was relaunched on Oct 10, 2022, for its second drive to tunnel 1,184.8m from Venkateshpura to KG Halli. As of July 31, it tunnelled 778.4.2m and had to cover 406m more. The breakthrough is expected by Nov 30, 2023. After that, it will be deployed for its last drive to tunnel 939m from KG Halli to Nagavara.