Click it and Unblock the Notifications
Bengaluru's upcoming Namma Metro Phase 3A, also known as the Red Line, will have shorter underground stations to reduce costs. The overall project cost has been cut by ₹2,920 crore after a review by central authorities. This 36.59-km line will connect Sarjapur in the southeast to Hebbal in the north,
passing through the Central Business District (CBD), and is expected to be completed by 2031.
Approval of Detailed Project Report
The Karnataka cabinet approved the Detailed Project Report (DPR) in December 2024, estimating the total cost at ₹28,405 crore, making it the most expensive Metro phase to date. However, the Union Ministry of Housing and Urban Affairs (MoHUA) found the costs to be too high and asked the Bangalore Metro Rail Corporation Limited (BMRCL) to reevaluate them. French consultancy firm Systra was hired to reassess the figures.
Tunnelling Process
The major cost differences were in tunnelling, underground station length, and electrical and mechanical works. Tunnelling was the biggest concern. While BMRCL had estimated ₹300 crore per km, MoHUA's benchmark for 2024 was ₹159 crore. BMRCL argued that Bengaluru's soil is highly variable, making tunnelling more expensive than in other cities. After review, the tunnelling cost was reduced to ₹210 crore per km. To further reduce costs, underground stations will now be 170 metres long instead of 210 metres. This change was made by optimizing space for operational rooms. Since six-coach trains need only 135 metres of platform, this will not affect commuters.
Beginning of Preliminary Work
Preliminary work, including geotechnical investigations, has already begun. These studies examine soil and rock properties to plan tunnelling and foundation design. Phase 3A will include both underground and elevated sections, with a double-deck viaduct between Sarjapur and Koramangala. Moreover, the Ministry's approval for the final DPR is expected by the end of this year.
