A double-decker challenge to replace Elphinstone bridge

Mumbai: While motorists brace for the impact of the demolition of the 112-year-old Elphinstone Road Over Bridge (ROB) later this month, civic authorities are a worried lot too.

Lying ahead of them is the Herculean task of demolishing the British-era bridge that not only passes over railway tracks catering to the Central and Western lines but is also surrounded by two railway stations and several buildings. If that wasn’t enough, the authorities also plan to install a double-decker single-fabricated steel open web girder weighing a massive 4,200 metric tonnes (MT).

The girder, costing ₹167 crore, will support a double-decker bridge that will eventually replace the Elphinstone ROB. The lower tier will be the actual replacement of the 112-year-old ROB, a crucial east-west connector that passes over railway tracks near the Prabhadevi and Parel stations. The upper deck will be a section of the 4.5-km-long Sewri-Worli connector, a signal-free bridge enabling seamless connectivity between the Mumbai Trans Harbour Link, also known as Atal Setu, on the island city’s eastern coast and the Bandra-Worli Sea Link in the west.

Both decks of the double-decker bridge will have four lanes each, with a footpath for pedestrians on the lower tier connecting to the two railway stations. The current single-decker bridge has only two lanes.

While the new ROB is being constructed by the Maharashtra Rail Infrastructure Development Corporation (MRIDC), also called MahaRail, the Sewri-Worli connector is being built by the Mumbai Metropolitan Region Development Authority (MMRDA).

Engineers are working on identifying the challenges in not only demolishing the existing ROB but also figuring out a way to launch the colossal 132-metre-long girder within a limited radius. In the vicinity are railway tracks and stations, old residential colonies for the middle class, and swanky office spaces.

The MMRDA is altering the alignment of the new bridge slightly to ensure that only two nearby structures have to be demolished, compared with 19 if they stuck to the current alignment. This realignment has allowed the authorities to save ₹4,000 crore from the overall project cost, officials said.

It’s not just motorists and pedestrians who will be impacted by the demolition and rebuilding work. The dismantling of existing ROB over railway tracks will require simultaneous blocks on both the Central and Western lines, officials said. This requires meticulous planning and execution as the blocks will impact commuters travelling on the Churchgate-Virar and CSMT-Kalyan routes.

Additionally, demolishing and rebuilding the ROB will require at least two cranes with a capacity of 800 MT each. Placing such large cranes in the area will be challenging, with either end of the ROB connecting to roads intersecting congested areas like Prabhadevi, Parel, Dadar and Worli, which are heavily used by vehicles and pedestrians.

“There is limited work space available for assembling the steel superstructure,” said a MahaRail official. “We intend to place two 95-100-metre-long track beams with intermediate support for launching the girder, which will be rolled over the rail tracks. We will also need space for in-situ work that cannot be done onsite. All this, while keeping in mind that citizens taking the local trains or vehicles are not impacted.”

Officials said the new double-decker bridge is expected to be completed in 18-24 months. According to MMRDA officials, 60% of the work on the Sewri-Worli Connector, which is being built at a cost of ₹1,600 crore, is already complete. The deadline for its completion is early 2026.