Mumbai Coastal Road project reaches significant milestone

A136-metre-long giant bow arch string girder was installed by the Brihanmumbai Municipal Corporation (BMC) in the wee hours of Friday

Mumbai: Commuters on the Bandra Worli Sea Link (BWSL) on Friday would have noticed a big, blue structure in the sea near the Worli end of the bridge. Weighing around 2,000 metric tonnes, the 136-metre-long giant bow arch string girder was installed by the Brihanmumbai Municipal Corporation (BMC) in the wee hours of Friday, marking a significant milestone for the city’s ambitious coastal road project. The steel girder will connect the upcoming Mumbai Coastal Road (MCR) with the BWSL.

Mumbai, India. April 26,2024: The erection of the 2,000 metric ton arch bridge connecting the Chatrapati Sambaji Maharaj coastal road (also known as the Mumbai coastal road) and the Bandra Worli Sea Link was successful early on Friday morning. The arch bridge is 2000 tons and 850 meters long, with 4+4+3 lane two sections. It has a 120-meter-long. April 26,2024. (Photo by Raju Shinde/HT Photo)

The BMC used an innovative technique to address the most challenging aspect of connecting the two routes: the girder was installed with the help of tidal waves. The process, which commenced at 2 am on Friday, concluded successfully by 3.25 am.

The girder connects the southbound lanes of MCR to the BWSL. Another 143-metre-long girder will be installed to connect the northbound lanes. The installation of the second girder is planned for May-end, as per the BMC. Once this is done and the remaining work is completed, the next phase of the coastal road can be thrown open to traffic.

Once completed, this will be India’s longest arch bridge passing through the open sea, according to the BMC.

A test of patience, skill

The first girder set sail on a barge from Mazgaon Dock on April 24 at 12.30 pm and arrived in Worli the following day at 4 am. The installation process then commenced at 2 am on Friday, April 26, as the team had to wait for favourable weather conditions.

Progressing in stages with the help of the barge, the girder was carefully manoeuvred between the MCR and BWSL routes. Engineers demonstrated their expertise by gauging sea waves and wind speed to position the platform securely for installation.

To properly connect the girder with the two routes, the team had set up four “mating” or assembly units, two each on the MCR and BWSL routes. At 3.25 am on Friday, the four units were meticulously aligned, completing the connection. Upon completing this crucial step, officers, engineers, and workers jubilantly cheered and applauded, signalling the campaign’s success. Subsequently, the barge that had carried the girder was safely manoeuvred aside.

From Ambala to Mumbai

Weighing 2,000 metric tonnes, the girder is 136 metres long and 18-21 metres wide. The assembly of the girder involved the production of small, pre-fab parts in Ambala, Haryana. The components were transported to Mazgaon Dock via approximately 500 trailers, before being put together. The girder was then ferried to Worli from Nhava port in Navi Mumbai.

Final step

Now that the installation is done, the next step is the cement concretisation of the girder, which will be done using anti-corrosive C5 Japanese technology. Advanced welding technology has been utilised to join spare parts seamlessly.