Mumbai could get its first underground rail line

MUMBAI: Mumbai will get its first underground rail line, if all goes according to plan. Taking a cue from the Mumbai metro, whose Line 3 is the city’s first-ever underground transport corridor, the Central Railway (CR) hopes to tunnel underground to build its fifth and sixth lines between Parel/Currey Road and Chhatrapati Shivaji Maharaj Terminus (CMST) in South Mumbai.

The route in question covers Phase 2 of a project to build a fifth and sixth railway corridor along the Kurla-Parel-CSMT stretch of the CR’s suburban system. Phase 2 is a 7.4-km line from Parel to CSMT. Phase 1, from Kurla to Parel, covers 10.1 km and is currently underway.

Given the considerable challenges in land acquisition and rehabilitating project affected persons (PAPs) for mega projects like these, the railway believes tunnelling under the city would skirt these issues, making it a smoother ride. After all, if the Mumbai metro can do it, why not the railways, they argue.

Nonetheless, it’s an ambitious plan, and it’s still in its early stages. The Mumbai Rail Vikas Corporation (MRVC) and Central Railway have met a few times but are yet to chalk out a plan for the proposed underground rail line. The outcome of technical feasibility studies will determine which agency will execute the project.

Railway officials said the line would be 7.4 km long and built 20-25 metres under the overland railway tracks. Aligning with them, it would skirt buildings, roads and underground utilities, which typically pose a huge challenge to any underground project.

“We are still analysing the possibility of going underground between Parel and CSMT stations for the fifth and sixth rail lines, and the necessary studies will be undertaken before finalising it. We are preparing terms of reference for the process, and will appoint a consultant,” a senior railway official told HT.

“We will have to assess the availability of land for tunnel boring machines to enter/exit at CSMT and Parel, which will be identified during the study. Once underground, we can have alternative alignments to end the tunnel at the CSMT end,” he said.

Two entry/exit points are being considered for the proposed tunnel at the CSMT end – one inside the terminus and the other near the terminus. In the first instance, the tunnel can enter/exit CSMT inside the terminus, next to the suburban railway corridor or close to the long-distance train platforms, whichever is feasible, the official said.

As an alternative, an entry/exit point on the P D’Mello side of CSMT may be considered. Here, however, there are two likely challenges. The alignment of the proposed Metro 11 line, an underground metro corridor from Wadala to CSMT, would have to be taken into consideration. The Central Railway would also have to take into account the underground CSMT station of Metro 3.

The tentative cost of the entire project (Phase 1 and 2) if the underground corridor is approved is pegged at ₹3,000 crore, almost three times the original cost, with only overland lines. When originally sanctioned in 2008, the estimated cost was ₹890.89 crore. It has since been revised to ₹1,337 crore.