Ayesa Engineering delivers critical sections of Mumbai Metro Line 3, the city’s first fully underground metro corridor

• Ayesa Engineering delivered critical sections and multiple stations of Mumbai Metro Line 3 (the Aqua Line), the city’s first fully underground metro corridor
• Line 3 is projected to cut road congestion by 15%, eliminate 261,000 tonnes of CO₂ annually and remove 665,000 private vehicle trips from Mumbai’s streets every day by 2041.

July 2026. Ayesa Engineering has delivered critical sections and multiple stations of Mumbai Metro Line 3 (the Aqua Line), the city’s first fully underground metro corridor and a landmark project for sustainable urban mobility. Mumbai Metro Line 3, also known as the Aqua Line in recognition of Mumbai’s historic waterfront, is the city’s first fully underground metro corridor.

The 33.5-kilometre line, developed at a cost of approximately USD 3.3 billion, runs from Cuffe Parade in the south to Aarey in the north, crossing some of Mumbai’s most densely populated areas. Designed to carry up to 1.4 million passengers per day by 2031, it is already cutting journey times to under an hour, easing congestion and strengthening multimodal connectivity through integration with suburban rail, other metro lines and the city’s airport.
Ayesa Engineering was appointed to provide comprehensive design solutions for Section UGC 02, one of the most technically demanding stretches of the entire line. This segment runs beneath residential neighbourhoods, historic buildings and highly constrained urban infrastructure, incorporating deep tunnels, underground stations, shafts and auxiliary structures under complex and highly variable ground conditions.

The scope of services provided by Ayesa Engineering included the full design of tunnels using tunnel boring machines (TBMs) and the New Austrian Tunnelling Method (NATM); geotechnical engineering, including interpretative reports, instrumentation and monitoring systems, and impact analyses; and the structural design of stations, shafts and cross passages using cut-and-cover and NATM methods.

The company also developed the architectural design of the stations, covering functional planning, passenger circulation, interior design and material selection, all within a fully integrated BIM environment. The commission also included the design of mechanical, electrical and public health systems, covering ventilation, fire protection, power distribution and tunnel services, together with technical support during construction through design and constructability reviews.

Delivery was supported by a fully integrated BIM environment, using advanced 3D modelling and finite element analyses to manage settlement risk and optimise soil–structure interaction throughout construction.

Stations Designed for People

Ayesa Engineering designed the stations and entrances at Girgaon, CSMT, Kalbadevi and Grant Road, among the most technically demanding on Mumbai Metro Line 3 from both structural and architectural perspectives.
Working within severe land constraints and dense, heritage-sensitive urban environments, the team developed stations that balanced complex engineering requirements with the needs of passengers. Girgaon Station, for example, has an internal width of just 9 metres and extends to depths of up to 21 metres below ground. To create a greater sense of space within this constrained footprint, the station was designed around a double-height spatial concept that enhances both comfort and the passenger experience.

Throughout the stations, the designs prioritised safe and intuitive passenger movement, clear wayfinding and seamless concourse-to-platform connectivity. Station entrances were carefully positioned to maximise natural daylight, reduce energy demand and create welcoming public spaces, while material selections balanced durability, ease of maintenance and compatibility with the surrounding architectural character.

Supporting a More Connected Mumbai

Line 3 is expected to deliver substantial long-term benefits, including an estimated 15% reduction in road congestion, around 261,000 tonnes fewer CO₂ emissions per year and nearly 665,000 daily private vehicle trips avoided by 2041, resulting in fuel savings and improvements in air quality and overall quality of life.

Ayesa Engineering’s participation in Mumbai Metro Line 3 further strengthens its international track record in metro and public transport, with more than sixty major railway and metropolitan systems delivered across multiple continents. This experience underlines the company’s capability to address complex underground infrastructure in high-density urban environments.

According to Luis Sánchez Carreto, Ayesa Engineering’s EMEAA Transport Director:
“Our work on Mumbai Metro Line 3 is an iconic project of sustainable urban mobility. It reflects Ayesa Engineering’s technical depth and our end-to-end ability to design complex underground infrastructure in some of the world’s most demanding urban environments, combining engineering precision and architectural vision to improve the lives of millions of people.”