MMRDA’s assessment points to SYSTRA–CEG–SMCIPL for failing to adequately factor airport height restrictions and OHE requirements at the design stage; authority pursued clearances five times, from AAI to Civil Aviation Ministry
Special Correspondent
Mumbai: A serious height-clearance problem on Mumbai Metro Line 7A has raised questions over the planning and design undertaken by the project’s General Consultant, SYSTRA–CEG–SMCIPL, with nearly ₹260 crore worth of already-executed work potentially exposed if additional aviation clearance is not granted. According to project details shared with TheNews21, the problem is not with the height of the Airport Colony station itself, which is within the approved aviation limits. The difficulty arises from the additional height required for the Overhead Equipment, or OHE, that is essential to operate the metro system.
In the ramp section, the OHE poles require about 2.4 metres of additional height over the approved limit. At different locations along the elevated stretch, the additional requirement ranges from 0.025 metre to 2.244 metres. That gap should ordinarily have been identified and resolved at the design and General Arrangement Drawing stage, before civil construction had advanced this far. MMRDA’s position is that the responsibility for comprehensive planning, design coordination, GAD preparation and consideration of statutory and technical requirements rested with the General Consultant consortium, SYSTRA–CEG–SMCIPL. The project is now at a stage where that omission, if not regularised through additional clearance, could prove expensive.
The problem surfaced after construction had advanced
Metro 7A is an extension of Metro Line 7 and connects Andheri East with Chhatrapati Shivaji Maharaj International Airport Terminal 2. The alignment includes both elevated and underground sections and passes substantially through airport-controlled land. MMRDA and the Airports Authority of India had entered into a Memorandum of Understanding on October 11, 2021. Given the location of the corridor, airport height restrictions were never a peripheral issue. They were central to the design.
The General Consultant was expected to coordinate not merely the civil structure, but the requirements of the complete metro system, including operational equipment that would eventually sit above the viaduct. That is where the present controversy lies. The civil structure may remain within the approved height envelope, but the metro cannot function without OHE infrastructure. If the height of the operational equipment exceeds the aviation clearance already granted, then the design was incomplete from an operational point of view. This is not a minor drafting error that can be corrected on paper. By the time the discrepancy came into sharp focus, construction had already progressed substantially. Metro 7A has crossed 70 per cent overall progress, while the Airport Colony elevated station has reached an advanced stage of construction. Large portions of the civil work in the affected stretch have already been executed.
Five letters, but no final clearance yet
MMRDA has been trying to resolve the issue since April 2024. The authority first wrote to the Regional Executive Director of AAI’s Western Region on April 25, 2024. It then approached the Chief Executive Officer of Mumbai International Airport Limited on September 24, 2024. A further communication was sent to the concerned General Manager of AAI on January 29, 2025, followed by another letter to the MIAL CEO on March 20, 2025. On May 29, 2025, the matter was escalated to the chairman of the appellate committee under the Ministry of Civil Aviation.
In all, MMRDA pursued the matter through five separate communications and at progressively higher levels. The additional height clearance, however, remains crucial. If approval is granted, the existing civil construction can largely be protected and work on the metro systems can proceed. If it is denied, the consequences could be far more serious.
Why the viaduct cannot simply be lowered
At first glance, the solution may appear simple: reduce the height of the viaduct or alter the alignment. Technically, it is not. Metro 7A continues from the existing Metro 7 alignment and then descends towards the underground airport section. The permissible gradient for metro operations imposes strict engineering limitations on how quickly the alignment can rise or fall. Project records indicate that the height and alignment at this stage cannot be changed easily without affecting the larger engineering geometry of the corridor.
That means any major redesign now could require alteration, demolition or reconstruction of portions already built. The value of work that could be affected is estimated at around ₹250 crore to ₹260 crore. And that may not be the end of the financial exposure. Any reconstruction would bring fresh civil costs, extension of the contract period, additional supervision, system delays and consequential cost escalation.
Why should the taxpayer pay for a consultant’s error?
This is where the issue moves beyond engineering and becomes one of accountability. If a General Consultant is appointed specifically to plan, design, coordinate drawings and ensure that statutory and technical requirements are factored into the project, then airport height restrictions in a corridor passing through airport land cannot be treated as an unforeseen development. Nor can the height required for OHE equipment be regarded as an afterthought. It is part of the basic operational requirement of an electrified metro system. If MMRDA’s assessment ultimately establishes that the General Consultant failed to incorporate these requirements at the appropriate stage, the question is no longer only whether the aviation authorities will grant a relaxation.
The larger question is: who will pay if they do not? ₹260 crore is not merely a figure in a project estimate. It is public money. If portions of the viaduct have to be altered or rebuilt because of a design or planning lapse, should that burden fall on MMRDA and, ultimately, the taxpayer? Or will MMRDA invoke the contractual liability of SYSTRA–CEG–SMCIPL and recover the financial loss from the consultant?
Clearance may solve the engineering problem, but not the accountability issue
For MMRDA, the immediate priority is understandably to secure the additional aviation clearance and protect the infrastructure that has already been created. That is the practical course. A clearance would avoid demolition, save time and prevent a potentially large financial hit. But even if the clearance comes through, one issue will remain unanswered. How did a metro project passing through one of the most tightly regulated aviation zones in the country reach an advanced stage of construction before the full height requirement of its operational electrical system became a problem? That question cannot be buried merely because a technical solution is eventually found.
If General Consultants are paid to prevent precisely such failures at the planning stage, then responsibility must follow when those failures surface. And if the clearance does not come and ₹260 crore worth of work is affected, MMRDA will have an even more difficult question to answer: Will it recover the loss from SYSTRA–CEG–SMCIPL, or will Mumbai’s taxpayers once again be asked to pay for somebody else’s mistake?
