Final Tunnel Breakthrough completed on Bangalore Metro Phase 2 Project

Bengaluru, India (Metro Rail Today): A significant milestone has been achieved in the construction of the Bangalore Metro Phase 2 project as ITD Cementation India celebrated the final breakthrough of tunnel boring machine (TBM) Bhadra at Nagawara Station’s South Shaft on 28th October 2024. This marks the completion of 100% tunneling works for the 73.92 km Bangalore Metro Phase 2, including the entire underground section of the Pink Line (Reach 6).

The breakthrough was the 26th and final TBM breakthrough in the Phase 2 underground section, representing a major achievement in the development of the metro's expansive tunnel network. With this milestone, tunneling work for the 20,992-meter underground stretch is now complete, allowing work to shift focus towards other aspects of the project, including systems installation and station finishing.

The Role of TBM Bhadra

TBM Bhadra, a Herrenknecht mixed-shield Earth Pressure Balance (EPB) machine, played a key role in the completion of the 4.591 km Package RT-04 segment, which includes the tunneling works between Tannery Road and Nagawara. Bhadra’s latest assignment saw it excavate a 937-meter tunnel northward from Kadugondanahalli to the Nagawara Cut & Cover Shaft-1. The tunnel was bored at an average rate of 4.4 meters per day through mixed face hard rock conditions, highlighting the challenges faced in this section of the project.

This was Bhadra’s fourth breakthrough in the course of its journey, and it brings the total number of breakthroughs for Package RT-04 to eight. Over its course, Bhadra has completed four major drives, starting from Venkateshpura in June 2021. Below is a summary of the tunneling journey:

• Venkateshpura to Tannery Road (822m): June 2021 – July 2022
• Tannery Road to Shadi Mahal TBM Retrieval Shaft (222m): July 2022 – December 2022
• Venkateshpura to Kadugondanahalli (1184m): February 2023 – February 2024
• Kadugondanahalli to Nagawara C&C-1 (937m): April 2024 – October 2024

ITD Cementation’s Scope in the Bangalore Metro Phase 2

ITD Cementation India was awarded Package RT-04 as part of the Bangalore Metro Phase 2 project, which involved the construction of 6.34 km of twin tunnels and several key underground stations, including those at Tannery Road, Venkateshpura, Kadugondanahalli (formerly Arabic College), and Nagawara. The company’s scope also covered the construction of a 360-meter ramp at Nagawara Station.

The completion of tunneling work in Package RT-04 is a significant step toward the eventual operation of the Pink Line of the Bangalore Metro. With the final TBM breakthrough completed, work is now focused on cross-passages between parallel tunnels for passenger safety and maintenance purposes, which are currently in various stages of completion.

The Pink Line’s Underground Network

The Pink Line (Reach 6) of the Bangalore Metro Phase 2 spans 21.386 km and includes a mix of elevated and underground sections. The underground section, which is approximately 13.92 km, has been particularly challenging due to the difficult geotechnical conditions encountered. However, the successful deployment of nine TBMs has allowed for the timely completion of this section.

With the completion of tunneling works, all nine TBMs deployed across three contractors for Phase 2 have now finished their respective assignments. The TBMs included:

• TBM Urja: Commissioned by Larsen & Toubro in July 2020
• TBM Bhadra: The final machine to start in June 2021
• Other TBMs: Varada, Avni, Urja, Lavi, Vindhya, Vamika, Rudra, and Tunga

These TBMs have successfully completed tunneling across four major packages, including:

• Package RT-01 (Afcons Infrastructure): Completed by TBM Rudra in October 2023
• Package RT-02 (Larsen & Toubro): Completed by TBM Lavi in February 2023
• Package RT-03 (Larsen & Toubro): Completed by TBM Vindhya in February 2023
• Package RT-04 (ITD Cementation): Completed by TBM Bhadra in October 2024

The Road Ahead for Bangalore Metro Phase 2

While tunneling works for the Pink Line have concluded, the project still faces some challenges in terms of system procurement and train-set availability. The critical path now depends on the delivery of trains from BEML, which was awarded the rolling stock contract in August 2023. The first of the 53 train sets is expected to roll out from BEML’s Bengaluru complex by Q4 2025, with commercial operations likely to begin by Q3 2026, once sufficient trains have been tested and are ready for service.

In the meantime, the project team is focusing on the final stages of station construction and systems installation, with the aim of completing the civil, architectural, and systems work by the end of 2025. Despite delays caused by the slow procurement of rolling stock, the successful completion of tunneling works for the Pink Line remains a historic achievement and sets the stage for the eventual launch of this critical part of Bangalore’s metro network.

The successful completion of tunneling works on the Bangalore Metro Phase 2 Pink Line represents a major accomplishment for the project, with ITD Cementation India and all the contractors involved making significant strides toward the line’s completion. With the final TBM breakthrough now behind us, attention shifts to finalizing the remaining works and preparing the line for the much-anticipated opening, which promises to transform urban mobility in Bangalore.

As the project moves forward, Bangalore Metro Phase 2 continues to showcase the city’s commitment to sustainable public transport, connecting key regions and improving accessibility for millions of residents.