Mumbai, a city that has grown at an enormous pace and is counted among the top mega cities in the world, has a lot to take pride in. And the new terminal building, popularly known as T2, of the Chhatrapati Shivaji International Airport is one of them.

Being one of the main entry points into the country and a trade and financial hub of the country, Mumbai has been experiencing rapid growth in air traffic. The infrastructure and facilities at the existing airport were stretched beyond its peak capacity. In 2006, the Airports Authority of India selected GVK, a leading business conglomerate in India with wide experience in airport development, to build and manage a new airport in Mumbai. It was decided to construct a new terminal building around the existing airport.

GVK selected Larsen and Toubro (L&T) as its engineering, procurement, and construction partner for the prestigious Mumbai International Airport Limited (MIAL) project. In the next eight years, L&T used innovative project practices, and efficient engineering and construction techniques to build a world-class building around a fully-functional, existing airport. In 2016, L&T won the PMI India Project of the Year in the large category for this project.

The new terminal building has a built-up area that is four times larger than the previous terminal. A concourse now joins the two terminals and a 3.3 km, 6-lane elevated road connects the airport with the Western Express Highway to facilitate smooth flow of traffic to the airport. The air traffic control tower stands at a height of 83.8 meter.

L&T reconstructed two of the existing runways to strengthen and widen them within defined time windows so that it did not affect the everyday operation of the airport.

Some standout features of the airport:

At the peak of the construction phase, the site had about 15,000 workers, 1,000 engineers, 200 sub-contractors, and 4,000 airport operational staff. The on-site design team consisted of 250 engineers and architects. Project planning involved handling of more than 200 specialized national and international agencies.

The project was constructed under certain severe constraints. J. Gopalakrishnan, deputy project director - MIAL project, L&T, explains the main challenges: “We had to double passenger capacity at India’s busiest airport by building a massive infrastructure right in the heart of Mumbai with no extra land to expand into and no time to shut down the existing airport. It was a highly sensitive project from a commercial, political, and security point of view. Finally, what we delivered is a worldclass product within a limited timeframe.”

The L&T team’s primary task was to plan and construct the new building by demolishing small sections of the existing building that housed various facilities of the existing airport, without letting it affect operations. The philosophy was “get it right the first time,” simply because there was neither the time for rework nor room for
deviation.

The sheer scale of the project made matters complicated. The table on page 8 shows the magnitude of the project during the construction phase.

The airport had been envisioned not just as a facility with world-class facilities and features but also as one that leaves a pleasant, lasting impression in a visitor’s mind. During the finishing stage, the project team worked towards creating the vision of “a thousand peacocks dancing.

One of the biggest tasks during this stage was the erection of a glass fiber reinforced gypsum canopy for a mega roof ceiling of over 80,000 square meter. “Every single square inch of the terminal, be it interior or exterior, had to have the touch of perfection to not just create a landmark project but also an edifice that would be regarded as one of the world’s most stunning airport terminals,” says CJA Davidraj, deputy project director – finishes, MIAL project, L&T.

Procurement was a complex exercise since it involved large volumes of materials that had to be of a standardized quality. Materials were sourced from over 25 countries.

Before the launch, the project team got down to the task of testing, commissioning, successfully integrating over 75 various systems, and carrying out 200 project operation trials.

“Some of the operative words that describe the project are ‘planning, co-ordination, quality, execution, and timeliness.’ Managing the huge work force was like leading an army, many of who were experts in various domains, drawn from various parts of the country and the globe,” says N. Namachivayam, head – airfield works, MIAL project, L&T.

L&T employed latest technologies, innovative construction methods, and creative project management practices to achieve better results.

The team used “rubbilization” for apron construction, a method by which an existing panel of pavement quality concrete was crumbled and reused as a granular sub-base. It did away with time-consuming breaking of the old pavement and re-constructing over it.

Since there were several service lines passing through the facilities, the team conducted a clash analysis of all mechanical, electrical, and plumbing services with the airport systems using state-of-the-art three-dimensional modelling and visualization techniques. With this, the team identified any potential areas where these service lines could interfere with each other, and thereby prevented disruptions.

There were over 1,500 vendors and sub-contractors from around the world working on the project, and a major challenge was to bring them under the L&T Quality Management System (QMS). L&T created a common platform that acquainted all the vendors of L&T’s QMS during the pre-qualification stage. Thereafter, it was monitored through system audits and process inspections from the pre-dispatch to the commissioning stage.

L&T took up “destruction for construction,” by which 32,000 cubic meters of concrete was crushed with hydraulic concrete crushers and reused by re-crushing 2,500 tons of reinforcement steel retrieved from demolished structures. This method resulted in 35 percent cost saving compared to the conventional demolition method.

Since there was limited scope for rework, the team had to issue detailed method statements, followed by mock-ups and strict adherence of the charted sequence and stage wise quality control check of execution to ensure smooth and seamless implementation.

Since the deadlines were stringent, it was important to get the right resources at just the right time. They had to consistently think out of the box in terms of construction sequences, erection methodology, and the equipment to be deployed.

Using a green building concept, the team designed a daylight harvesting system at the departure area on level four. A skylight of around 36,000 square meter lets in sunlight in good measure; all electrical lights are integrated with the skylight in such a manner that as sunlight gradually reduces in the evening, the electric lamps come on. The transition is so smooth that a visitor will hardly notice the switch over from natural to electrical lighting.

To overcome the problem of constructing around functioning runways, L&T used quick set concrete mix. In just 3-4 hours after this concrete is used to upgrade a runway, it was ready for aircraft movement.

“Overall, it was one of our toughest assignments but we were able to deliver a world-class facility on time. We achieved this because of our design excellence, construction capabilities, the freedom to take calculated risks, and teamwork. We followed project management across departments and functions such as contracts management, material management, quality management, safety management, subcontractor management, and change management,” says Niranjan Simha, project director, MIAL, L&T.