Mumbai Begins 50-Metre Deep Excavation for Its Most Complex Urban Tunnel

Mumbai’s Deepest Urban Tunnel: 50-Metre Excavation Begins in the City’s Heart

Hon. Chief Minister Flags Off Tunnel Boring Operations for the Historic Project

A tunnel designed to save thousands of commuter hours daily- Chief Minister Stated

Mumbai, 3 December 2025

The Mumbai Metropolitan Region Development Authority (MMRDA) today achieved a landmark milestone as the Tunnel Boring Machine (TBM) was officially launched by the august hands of Hon’ble Chief Minister of Maharashtra, Shri Devendra Fadnavis, in the esteemed presence of Hon’ble Deputy Chief Minister and Chairman, MMRDA, Shri Eknath Shinde and in the esteem presence of Shri Mangal Prabhat Lodha, Minister of the Ministry of Skill Development and Entrepreneurship, Co Guardian Minster Mumbai City, MLA, Shri Rahul Narwekar, MLA, and Shri Amin Patel, MLA, Shri Vikram Kumar, IAS, Additional Metropolitan Commissioner–1 and Shri Ashwin Mudgal, IAS, Additional Metropolitan Commissioner–2, Rubal Agarwal, IAS, MD, MMMOCL, Shri Astik Kumar Pandey, IAS, Joint Metropolitan Commissioner were also present for this landmark event.

With this ceremony, the TBM-driven excavation officially commences today, signalling the start of Most Complex Urban Road Tunnel project of this magnitude and complexity.

Technology
The project deploys a Slurry Shield Tunnel Boring Machine (TBM) a cutting-edge, high-precision technology that has already demonstrated exceptional performance in the Mumbai Coastal Road Project. This advanced TBM represents the pinnacle of tunnelling innovation, engineered to deliver unmatched safety, accuracy, and reliability in one of India’s most complex underground environments.

It is specifically designed for:
• Precise and safe excavation
• Mumbai’s challenging coastal geology
• Areas with high water ingress

TBM Engineering Highlights
• Refurbished and re-manufactured locally under OEM supervision
• Cutterhead Diameter: 12.19 metres
• Length: 82 metres
• Weight: Approx. 2,400 tons
• Designed for precision excavation beneath sensitive heritage and high-rise zones

Project Overview
The Mumbai Metropolitan Region Development Authority (MMRDA) is spearheading one of the most ambitious and transformative infrastructure projects in India’s history. This landmark initiative involves the design and construction of a fully underground, state-of-the-art urban road tunnel with seamless approaches, connecting Orange Gate (Eastern Freeway) directly to the iconic Marine Drive (N. S. Road) a breakthrough feat never before attempted at this scale in India.
*•Cost Of the Project: * INR 8,056 Crore
*•Completion Period: * 54 months

Project Details
This project stands as Most Complex urban tunnel of its kind, a bold engineering endeavour unfolding beneath one of the most densely populated and structurally complex zones of Mumbai. The underground alignment has been meticulously planned to navigate through some of the city’s most challenging and sensitive terrains, making it a benchmark in underground construction.
The tunnel passes beneath:
• Several multi-storeyed structures, representing one of the highest concentrations of vertical development in South Mumbai
• Iconic heritage buildings, protected precincts, and irreplaceable architectural landmarks that define the city’s cultural identity
• Central and Western Railway corridors, two of the busiest and most vital lifelines of Mumbai’s suburban transport network
• Mumbai Metro Line-3, at an extraordinary maximum depth of about 50 meters, showcasing unprecedented precision and engineering excellence

• Total length: 9.96 km, which includes approximately 7 km of underground road.
• Each tunnel includes:
o 2 traffic lanes (3.20 m each)
o 1 emergency lane (2.50 m)
o Speed limit: 80 km/hr
• Cross passages: every 300 metres
• Depth: 12 –52 metres
• Features:
o Advanced ventilation systems
o Fire-resistant and safety mechanisms
o Intelligent Transport System (ITS)
o High-performance tunnel lighting
• Seamless integration with Coastal Road and Mumbai Trans Harbour Link (MTHL)
• Physical Progress: 14%

Key Benefits
• Establishes critical East–West coastal connectivity
• Saves 15–20 minutes of travel time
• Enables fuel savings
• Helps reduce air and noise pollution
• Minimises land acquisition and ensures minimal disruption to South Mumbai’s urban environment
With today’s successful launch, the Orange Gate–Marine Drive Urban Road Tunnel enters its active excavation phase, reaffirming MMRDA’s mission to deliver future-ready mobility for Mumbai. This trailblazing TBM launch marks a historic moment showcasing engineering excellence on an unprecedented scale, setting a new national benchmark in underground mobility, and standing as a proud milestone in shaping a modern, resilient, future-ready city.

Hon’ble Chief Minister, Maharashtra Shri Devendra Fadnavis, Said:
“The launch of the Tunnel Boring Machine at Orange Gate marks a transformative leap in Mumbai’s infrastructure journey. This will Save 1000’s of hours of 1000’s of people. This unprecedented urban road tunnel will redefine East–West connectivity and bring world-class engineering to the heart of our city. Maharashtra has consistently delivered pioneering infrastructure, and this project once again positions Mumbai at the forefront of technological advancement and modern mobility. I congratulate MMRDA and all stakeholders for taking this remarkable step towards building a faster, safer, and future-ready Mumbai.”

Hon’ble Deputy Chief Minister Maharashtra Shri Eknath Shinde, Chairman, MMRDA. Said:
“The commencement of TBM excavation for the Orange Gate–Marine Drive tunnel is a proud moment for Mumbai. This project reflects the Government of Maharashtra’s commitment to delivering large-scale, high-impact infrastructure with precision and speed. Navigating dense urban zones, transport corridors, and heritage precincts through advanced tunnelling technology is a milestone in itself. Once completed, this tunnel will significantly reduce travel time, ease congestion, and enhance the overall commuting experience for citizens. MMRDA is shaping a modern, efficient, and globally benchmarked mobility network for Mumbai.”

Dr Sanjay Mukherjee, IAS, Commissioner MMRDA Commented:
“This is a start of a tunnel road network in the densely populated city like Mumbai which represents a transformative leap in urban connectivity and stands as a landmark achievement for the city. With the commencement of TBM operations at Orange Gate, MMRDA marks a defining milestone in Mumbai’s infrastructure journey. The deployment of this advanced Slurry Shield Tunnel Boring Machine showcases our ability to execute one of India’s most complex underground engineering works with precision, safety, and global best practices. Its launch reflects not only the technological strength and meticulous planning behind this project, but also MMRDA’s strong commitment to building future-ready, sustainable, and seamless mobility for Mumbai.”