Mumbai Metro 7A Future Uncertain: Height Limitations Cause Construction Standstill

The future of the Mumbai Metro 7A line, which connects Gundavali to Chhatrapati Shivaji Maharaj International Airport, is uncertain. During its construction, the Mumbai Metropolitan Region Development Authority (MMRDA) found that the Airport Authority of India (AAI) had not approved the air funnel zone, leading to the need for revised permission, according to a Hindustan Times (HT) report.

An air funnel zone is a designated flight path that ensures aircraft can fly safely. Any obstacles in this zone could pose a risk to aviation safety. The 3.42-kilometre Metro 7A corridor, which includes both elevated and underground sections, is being built by J Kumar Infraprojects Ltd. Systra India and Consulting Engineers Group Ltd form a consortium called Systra MVA Consulting for general consultancy.

Photo Credit: PTI

In November 2023, MMRDA sought AAI's approval to build the Airport Colony station and ramp area. AAI responded on January 2, 2024, but the clearance received was 2.9 metres lower than what was needed for the project. This restriction caused immediate delays as construction could not proceed without adhering to the height limit. MMRDA had to stop work in the affected areas, disrupting the overall project timeline, according to an internal document reviewed by the Hindustan Times.

On January 31, 2024, MMRDA requested another height clearance for the viaduct between the Airport Colony station and the ramp. Unfortunately, on March 18, 2024, AAI issued another No Objection Certificate (NOC) that imposed further height restrictions. This new limitation placed the viaduct height between 0.53 and 2.75 metres, which is below the required height for safe metro operation. As a result, work was halted once more.

MMRDA has again asked AAI for a relaxation of the height restrictions, explaining that changing the height of the metro line is not feasible due to engineering challenges in maintaining the necessary ramp gradient. A senior MMRDA official confirmed that they are still waiting for revised approval.

An internal note indicates that the design of the station did not consider the contents of the NOC, and the drawings were prepared with higher height specifications. It also noted that the initial oversight was due to the General Consultant not referring to the permissible limits issued by AAI before finalising the architectural design for the Airport Colony station.

These issues have significantly impacted the project's timeline and costs, causing inconvenience for airport passengers. Originally scheduled for completion in 2021, the project deadline has been repeatedly pushed back, with the latest target set for December 2026 at an estimated cost of Rs 812 crore. While the Mumbai Metro 3 line reaches the airport, passengers continue to face challenges with last-mile connectivity, often complaining about lengthy detours to reach the terminal. Metro 7A is being constructed between the Aqua line and Terminal 2.

A request for comment sent to Systra India's Managing Director, Hari Kumar Somalraju, has not yet received a response.