India’s First Underwater Metro To Launch August 22: Kolkata’s Green Line Set To Transform Urban Transit

Kolkata is poised to make history with the launch of India’s first underwater metro service, as Prime Minister Narendra Modi prepares to inaugurate the final stretch of the East-West Metro corridor—also known as the Green Line—on August 22, 2025. This landmark development will connect Howrah Maidan to Salt Lake Sector V, traversing beneath the Hooghly River and completing a long-awaited infrastructure marvel that promises to redefine commuting in the City of Joy.

The inauguration will also include two other metro extensions: the Noapara–Jai Hind (airport) stretch of the Yellow Line and the Hemanta Mukhopadhyay–Beleghata section of the Orange Line. Together, these projects mark a significant leap forward in Kolkata’s mass transit capabilities, just ahead of the Durga Puja rush.

Key Highlights From The Metro Expansion

- PM Narendra Modi will inaugurate three metro projects in Kolkata on August 22  
- The Green Line will become fully operational, connecting Howrah Maidan to Salt Lake Sector V via an underwater tunnel  
- The underwater section spans 520 meters beneath the Hooghly River, completed in just 45 seconds of travel time  
- The Yellow Line will now link Noapara to Jai Hind (Kolkata airport), offering the city’s first direct metro access to the airport  
- The Orange Line will extend from Ruby Crossing to Beleghata, improving connectivity for eastern and southern suburbs  
- The inauguration ceremony will be held at Jessore Road metro station on the Yellow Line  

Engineering Marvel Beneath The Hooghly

The underwater tunnel between Howrah and Esplanade is a feat of modern engineering, constructed using tunnel boring machines and reinforced concrete segments. It is India’s first transportation tunnel to pass beneath a major river, and its completion marks a milestone in urban infrastructure.

The tunnel’s design ensures safety and durability, with advanced flood protection systems and real-time monitoring. Commuters will experience a smooth, silent ride through the 520-meter stretch in under a minute, making it one of the fastest and most efficient river crossings in the country.

Connectivity And Commuter Benefits

The full operationalization of the Green Line will:

1. Link Howrah and Sealdah railway stations directly to Salt Lake’s IT hub  
2. Reduce travel time between western and eastern Kolkata by up to 40 percent  
3. Enable seamless interchange with the Blue Line at Esplanade  
4. Alleviate traffic congestion in Bowbazar and central Kolkata  
5. Provide metro access to over 5 lakh daily commuters across the corridor  

The Yellow Line’s airport extension will benefit flyers and suburban residents, while the Orange Line’s new stretch will ease travel for those in densely populated eastern neighborhoods.

Challenges And Delays Overcome

The Sealdah–Esplanade section of the Green Line faced multiple delays due to subsidence incidents in Bowbazar, a historic area with fragile soil and heritage structures. Engineers had to halt tunneling and reinforce the ground before resuming work. Despite these setbacks, the project has now reached completion, with safety clearances and trial runs successfully conducted.

The metro operator, Metro Railway Kolkata, confirmed that all systems are ready for public use following the Prime Minister’s inauguration.

Looking Ahead: A New Era For Kolkata Transit

With these expansions, Kolkata joins the ranks of global cities offering underwater metro services, alongside London, Shanghai, and Istanbul. The city’s metro network now spans over 100 kilometers, with further extensions planned into September.

The Centre has allocated Rs 13,955 crore for railway infrastructure in West Bengal this year, with 101 stations undergoing redevelopment and multiple Vande Bharat and Amrit Bharat trains already in service.

As the countdown to August 22 begins, Kolkata’s commuters can look forward to faster, safer, and more connected journeys—ushering in a new era of urban mobility.

Sources: Times of India, Hindustan Times, NewsBytes, ABP Live, MSN India.