Sion ROB reconstruction advances with installation of second 500-tonne girder

Mumbai’s Sion Road Over Bridge (ROB) reconstruction has moved ahead with the installation of both main steel girders, each weighing around 500 tonnes, Central Railway said on Sunday.

The second girder was launched during a three-hour night block between Matunga and Kurla, following the installation of the first girder earlier.

The two girders were positioned over the active railway corridor during separate night blocks to limit disruption to suburban train services.

54.5-metre span to accommodate additional tracks

The new bridge will have a railway span of around 54.5 metres, compared with approximately 40 metres in the earlier structure. The wider span is required to make room for the additional railway lines planned as part of the CSMT-Kurla 5th and 6th line project.

The two semi-through steel girders were fabricated in Nagpur and assembled at the eastern approach of the bridge before being moved into position over the railway tracks.

The launching operation involved temporary trestles, hydraulic systems and winching equipment, along with alignment and safety checks before the girders were positioned.

Deck work to begin next

With the main girders now in place, construction will move to the next stage, including the deck slab, road approaches, surfacing and crash barriers.

The reconstruction of the Sion ROB is expected to restore the east-west road connection between the Eastern Express Highway, LBS Road and Dharavi Road once the bridge is completed and opened to traffic.

The old bridge had been closed, affecting traffic movement in the area and forcing motorists to use alternative routes.

The Sion ROB is being reconstructed in connection with the CSMT-Kurla 5th and 6th line project, which involves adding railway infrastructure along the busy suburban corridor.

First 500-tonne semi-through steel girder launched in June

Earlier in June, the Central Railway launched a 500-tonne semi-through steel girder for the reconstruction of the Sion ROB

The girder was launched during a night traffic block between Matunga and Kurla stations as part of the Chhatrapati Shivaji Maharaj Terminus (CSMT), Kurla fifth and sixth line project.

Major engineering operation completed

The operation involved positioning and launching the massive steel span over active railway tracks within a limited block period.

Railway officials described it as one of the most challenging phases of the bridge reconstruction project.

The girder was fabricated in Ambala and later assembled at the project site near the Kalyan-end approach of the bridge.

Prior to the launch, engineers completed several preparatory works, including the installation of temporary trestles, launching arrangements and alignment checks.

Despite the challenges of working in a densely populated urban area and above one of the country’s busiest suburban railway corridors, the launch was completed successfully.