Mumbai: The BMC is gearing up for a significant milestone in its coastal road project as it prepares to bridge the crucial gap between the southbound arm and the Bandra-Worli sea link by April 16 or 17. This endeavor involves launching a pivotal 120-meter girder with a distinctive bowstring arch, heralding a significant engineering feat in the city’s infrastructure landscape.

According to Mantayya Swami, deputy engineer of the Mumbai Coastal Road Project,, the erection of these girders poses considerable challenges, particularly due to the rocky seabed conditions. Traditional lifting and assembly methods using cranes are impractical in such an environment. Already, three girders spanning 46 meters, 44 meters, and 60 meters have been successfully installed in the southbound arm.

“The assembly of the 120-meter bowstring arch bridge, stationed at Nhava village jetty, will commence on April 12. It will then be loaded onto a barge, which will embark towards the Worli site, expected to reach by April 15-16. Weather permitting, the arch bridge will be positioned on the pier by April 16-17,”Swami stated.

The linkage between the coastal road’s Worli terminus and the sea link will span 850 meters, predominantly comprising 270 meters of steel and the rest concrete. This endeavor is managed by AECOM, BMC’s general consultant for the project, overseeing contracts and design aspects. The decision to extend the navigation span from 60 meters to 120 meters, following public interest litigations and objections from local stakeholders, prompted extensive deliberations among project stakeholders.

AECOM serves as the primary consulting firm for the BMC’s southern coastal road initiative, overseeing contract management and design responsibilities on behalf of the municipal corporation. Vipul Surana, team leader at AECOM, emphasized the considerable impact of the design alteration on project timelines. “The challenge of erecting the span mid-sea without bottom support necessitated innovative solutions. After careful evaluation, the prefabricated and pre-assembled structure proposed by Hindustan Construction Company (HCC) received unanimous approval,” Surana explained.

Surana stressed the importance of favorable weather conditions for the lifting operation of the 120-meter girder arch bridge. “Ideal weather conditions entail minimal rainfall, absence of lightning, and wind speeds below 20 meters per second. Furthermore, adequate lighting and safety provisions are essential to facilitate uninterrupted operations, including during nighttime if required,” he elaborated.

Arvind Singh, the project manager overseeing the construction of the coastal road by the HCC-Hyundai Development Corporation Joint Venture, emphasized the intricacy of the project’s design. He stated, “Considering its complexity, we entrusted the design to the DM Engineering-Spectrum consortium, renowned for their expertise in similar projects.” Singh highlighted DM Engineering’s provision of an arch model featuring a 120-meter navigation span and a composite deck with varying lengths of 46 meters, 60 meters, and 44 meters.

As progress continues, one girder has already been deployed in the north-bound arm, with the remaining girders scheduled for launch later in April. The north-bound arm’s arch is slated for installation in May, subject to favorable weather conditions, marking yet another milestone in Mumbai’s ambitious coastal road project.