That’s why, K P Maheshwari, director of the special purpose vehicle building the financial capital’s first Metro Rail corridor from Versova though Andheri to Ghatkopar, is weary of questions on why there’s no “visible” progress.

Mumbai’s much-awaited first Metro Rail corridor, a 11.4-km stretch, is to be built at a cost of Rs 2,356 crore. At Rs 206 crore per km, that’s almost twice Delhi Metro’s average elevated rail cost per kilometre in Phase 1, owing mostly to the constraints unique to Mumbai.

And among the most daunting of these challenges will be a cantilever bridge spanning 98 metres across busy railway tracks at Andheri—balanced on a pier on either side of the tracks.

These two piers will themselves be tricky to build since the area outside the railway stations, especially on the western side, comprises narrow lanes with small buildings packed in tight, and movement through the crowds laborious. In fact, the pier on the western side of the tracks is located right outside a religious place. “We have designed the entire alignment of the bridge without touching any building between the tracks and SV Road,” says Maheshwari.

Once the piers are erected, all commuters will see is the bridge progressing segment by segment from either pier, each box-shaped segment stressed to the earlier one with high-tensile steel cables and simultaneously stressed vertically to the pier to avoid any accidents.

There is more. The box segments for the concrete bridge are each 6 metres tall, while the multi-axle trailer they will be transported on has a bed height of 1.2 metres. Ferrying such tall segments from Wadala to Andheri, a distance of 18 km in Mumbai’s traffic, will be a challenge on its own. “We’ll be casting the top bracket-shaped portions of these segments in situ,” says Maheshwari. “It’s not possible to cart anything taller than 6 metres on the trailers.”

Also at Andheri, another huge challenge will be a complex four-level station for passengers to reach the platform that will be over 20 metres above the ground—the metro route crosses the Jog flyover seven metres above it, 21 metres off the ground.

For now, what’s visible along the route is a series of piles being constructed for load-testing. To assess foundation strength, piles 1 metre in diameter will be tested with a 1,100 tonne-load. One test per kilometre is the norm, but “we’re doing additional tests where soil strata changes abruptly” according to Maheshwari. With a 28-day period for each pile to strengthen, the tests will be complete in a month.

Simultaneously, at Wadala, work is underway on a casting yard where the ground is being reinforced to bear the weight of concrete girders and heavy custom-made gantries. Drains to assist the curing of concrete and internal roads come next.

Other departments are placing orders fast: Barricades, each weighing 250 kg, to be screwed into the ground; equipment, long-lead items like customised gantries and precise calculations for qualified, experienced labour. The speed of work is indicative of the company’s aggressive completion schedule. Maheshwari says: “Civil works for the viaduct and 12 stations will be complete in 20 months.”

A Global Touch
* Detailed designs for all 12 stations are now getting the final nods. The company appointed Townland from Hong Kong, an architectural design firm that’s designed several metro rail stations globally. Their designs are being married with those of Project Management Consultant Parsons and Brinckerhoff (USA) and Systra (France). Decades ago, P&B built the world’s first metro line, in New York
* A traffic management study by MVA, a sister-firm of Systra, is ready. It includes detailed plans for diversions, for public transport, for two-wheelers, etc. BEST buses will be least affected, the company promises.