Kolkata Underwater Metro (Green Line): Timings, Ticket Fares, Route & Entry Gates (2026 Guide)

What is the Kolkata Underwater Metro?

The Kolkata Underwater Metro is the western section of Green Line 2 (East–West Metro) connecting the historic twin cities of Howrah and Kolkata. Inaugurated for commercial passengers in March 2024, it incorporates India's very first underwater railway transportation tunnel built under the perennial Hooghly River.

Prior to this subaqueous corridor, commuters travelling between Howrah Railway Junction and Central Kolkata (BBD Bagh and Esplanade) endured arduous journeys on congested buses, slow ferries, or peak-hour taxi queues over the historic Howrah Bridge and Vidyasagar Setu. With the underwater metro, crossing between Howrah and Kolkata takes a seamless 45 seconds under the riverbed.

45-Second Riverbed Crossing

The metro train glides through the 520-meter subaqueous section under the Hooghly River at a depth of 32 meters below ground level in just 45 seconds.

Route Map & Station Sequence

The operational western section of the Green Line currently covers four major subterranean stations connecting Howrah and Kolkata:

Howrah Maidan (Western Terminal, connected to Howrah Bus Terminus and GT Road)
Howrah Metro Station (Deepest metro station in India at 33m; direct subway link to 23 railway platforms)
Mahakaran (Writers’ Building, BBD Bagh Central Business District, Lalbazar)
Esplanade (Mega Transit Hub with underground interchange to Blue Line 1 and future Purple Line 3)

Train Timings & Service Frequency

Services operate continuously throughout the week with special afternoon-only schedules on Sundays. Always note Sunday timing differences before traveling to the station.

Sunday Morning Notice

Commercial metro trains do not run on Sunday mornings on the Green Line. Services begin at 14:15 hrs (2:15 PM). If crossing the river on Sunday morning, use the Howrah-Fairlie Place ferry or local buses.

Green Line (Underwater Corridor) Timetable Overview
Day of Week	First Train	Last Train	Peak Headway
Monday – Saturday	07:00 AM	09:45 PM	Every 10 – 12 mins
Sunday (Afternoon Start)	02:15 PM	09:50 PM	Every 15 mins

Ticket Fares & Smart Card Discounts

Ticket pricing on the underwater metro remains exceptionally affordable, offering massive cost savings over cabs and app taxis:

Howrah Maidan to Howrah Metro Station: ₹5
Howrah to Mahakaran (Underwater River Crossing): ₹10
Howrah to Esplanade (Complete corridor): ₹10
Smart Card Discount: Cardholders receive an automatic 10% bonus value on every recharge of ₹100 or more.
Mobile QR Tickets: Purchase through the official Aamar Kolkata Metro app to bypass station ticket queues entirely.

Howrah Railway Station Subway & Entrance Gates

Howrah Metro Station is directly integrated into the Indian Railways concourse at Howrah Station, eliminating the need to step outside into road traffic.

Arriving by long-distance or suburban train on platforms 1 to 15 (Old Complex)? Follow the overhead "Metro Railway" directional signboards toward the Old Complex subway to enter the metro concourse directly.

Arriving on platforms 17 to 23 (New Complex)? Take the connecting foot overbridge or passenger walkway directly toward the central metro entry plaza.

Luggage Scanner at Concourse

All baggage must pass through CISF X-ray scanning before entering the turnstiles. Allow 5 minutes during peak railway arrival hours.

Tunnel Depth & Key Engineering Facts

The Hooghly subaqueous tunnel is regarded as a benchmark in Indian structural engineering:

Depth: 32 meters below ground level (approximately 13 meters below the riverbed).
Tunnel Length under water: 520 meters across the width of the river.
Waterproofing Technology: Advanced hydrophilic rubber gaskets and steel-reinforced precast concrete segments prevent any moisture or water seepage.
Emergency Cross-Passages: Twin tunnels are interconnected every 250 meters with emergency safety evacuation walkways.

Tips for Daily Commuters & Tourists

Make the most of your river crossing experience with these commuter guidelines:

Spot the Blue LED Illumination: As the train enters the underwater portion, the tunnel walls light up with vivid blue LED strips to visually signal that you are cruising beneath the riverbed.
Transferring at Esplanade: Changing from Green Line to Blue Line (North-South)? Follow the green and blue floor indicators to switch platforms inside the paid area without buying a second token.
Avoid Platform Crowd Surges: Boarding at Howrah during train arrival rushes? Walk down toward coaches 3 and 4 where crowding is noticeably lower than the center doors.

Frequently Asked Questions (FAQs)

Find quick, verified answers to the most common commuter queries regarding the Kolkata underwater metro.

Can passengers see fish or water through the windows of the underwater metro?

No. The train runs through heavy precast concrete tunnels bored 13 meters underneath the riverbed sediment. Special blue LED strip lights illuminate the tunnel walls to visually indicate the underwater transit.

How long does the train take to travel under the Hooghly River?

The train cruises across the 520-meter subaqueous section between Howrah and Mahakaran stations in approximately 45 seconds.

What is the ticket fare from Howrah Railway Station to Esplanade?

The single-journey token fare is only ₹10, making it vastly more economical and faster than taxis crawling across the Howrah Bridge.

Does mobile network work inside the underwater metro tunnel?

Yes. Kolkata Metro has deployed high-capacity telecom radiating cables (leaky coaxial cables) to provide seamless 4G and 5G cellular network coverage across the underwater tunnel and underground platforms.

Can I interchange from the underwater Green Line to the Blue Line at Esplanade?

Yes. Esplanade features a seamless underground passenger concourse allowing direct interchange between Line 2 (Green Line) and Line 1 (Blue Line) without exiting the turnstiles.

Is photography permitted inside the underwater metro?

Casual smartphone photos and selfies on platforms or inside rakes are widely tolerated. However, tripods, commercial filming equipment, and photographing security personnel or CCTV cameras are strictly prohibited.