Mumbai: Central Railway has completed all works pertaining to the railway span of the reconstructed Sion Road overbridge (ROB). The completion marks a significant milestone in the CSMT-Kurla fifth and sixth railway lines project under Mumbai Urban Transport Project (MUTP)-II B, while bringing restoration of east-west road connectivity at Sion a step closer.Having missed its Aug 15 deadline, the ROB is now expected to be completed by Sept 30. Approach works being executed by BMC are currently in progress. The opening of the complete bridge to road traffic will follow completion of these works and the necessary arrangements with the authorities concerned.The new railway portion comprises a 54.5m single span with an overall width of 29m. It incorporates two semi-through steel girder assemblies with reinforced cement concrete deck slabs, supported on 1,200mm-diameter pile foundations and pile caps. The longer single-span arrangement replaces the earlier two-span configuration and provides the space required for the proposed additional railway lines.Reconstruction involved dismantling the old structure, constructing foundations and supporting works, fabricating and assembling the steel girders, launching them across the railway tracks, and completing the deck slabs and associated finishing works. Each of the two massive girder assemblies weighed around 500 tonnes, making their handling and placement a major engineering operation.The girder launch operations were undertaken in stages in June and Aug. Execution above the operational railway corridor required detailed planning, temporary supporting arrangements and close coordination among the construction, operating and electrical departments. Critical activities were carried out during planned traffic and power blocks, with careful sequencing of work around railway operations.Following the launch and lowering of the girders onto their permanent supports, the deck slabs and remaining railway span works were completed. All works within the railway span scope are now complete in all respects.Located near Sion station, the original bridge was constructed in 1912 and extended on either side in 1980. Having served the city for over a century, the structure had developed distress. Its reconstruction was necessary both to replace the ageing bridge and to accommodate two additional tracks under the fifth and sixth lines project.The bridge’s completion is tied to the Dharavi ROB’s reconstruction—traffic department’s permission for its closure will be granted once the former is completed.The fifth and sixth lines will support greater railway capacity and improved operational flexibility on Mumbai’s busy rail network.
