The reconstruction of the Sion Road Overbridge (ROB) has reached a major milestone, with Central Railway completing all work related to the railway portion of the bridge. The development brings the restoration of east-west road connectivity at Sion closer to completion.
The reconstructed ROB is part of the CSMT-Kurla fifth and sixth railway lines project under Mumbai Urban Transport Project (MUTP)-II B. Although the bridge missed its earlier August 15 deadline, officials now expect the complete structure to be ready by September 30, subject to the completion of approach works being undertaken by the Brihanmumbai Municipal Corporation (BMC).
The bridge will be opened for road traffic after the remaining approach work and required coordination with the concerned authorities are completed.
New Railway Span Designed for Additional Tracks
The rebuilt railway section features a 54.5-metre single span with an overall width of 29 metres. The structure consists of two semi-through steel girder assemblies with reinforced concrete deck slabs, supported by 1,200-mm-diameter pile foundations and pile caps.
The single-span design replaces the earlier two-span arrangement and creates the additional space required for the proposed fifth and sixth railway lines.
Reconstruction involved dismantling the old bridge, constructing new foundations, fabricating and assembling steel girders, launching them over the operational railway tracks and completing the deck and associated works.
Each of the two large girder assemblies weighed approximately 500 tonnes, making their installation a complex engineering exercise.
Girder Launch Conducted in Phases
The girder launching operations were carried out in phases during June and August. Since the work was undertaken over active railway tracks, extensive planning and coordination were required among construction, operating and electrical teams.
Major operations were scheduled during designated traffic and power blocks to minimise disruption to railway services. After the girders were launched and lowered onto their permanent supports, the deck slabs and other railway-span works were completed.
Central Railway has now declared all work falling under its railway-span scope complete.
Century-Old Bridge Being Replaced
Located close to Sion railway station, the original ROB was built in 1912 and subsequently extended on both sides in 1980. After serving Mumbai for more than a century, the structure had developed significant structural distress.
Its replacement became necessary not only because of its age but also to accommodate the infrastructure planned under the fifth and sixth railway lines project.
Link to Dharavi ROB Reconstruction
The Sion bridge’s reopening is also connected to the reconstruction of the Dharavi Road Overbridge. The traffic department’s permission to close the Dharavi ROB is expected to be granted after the Sion bridge is completed, allowing the next phase of work to proceed.
The fifth and sixth railway lines between CSMT and Kurla are intended to increase railway capacity and provide greater operational flexibility on Mumbai’s heavily used suburban and long-distance network.
Once the approach works are completed and the bridge is opened, commuters will regain an important east-west road connection in Sion, while the rebuilt structure will also support Mumbai’s broader railway capacity expansion.
Source: Times of India
