Goregaon-Mulund underground tunnel work speeds up as second TBM begins digging under SGNP

The ambitious GoregaonMulund Link Road GMLR project in Mumbai has reached a major milestone with the second tunnel boring machine TBM named Vihar commencing excavation on November 7 an official statement saidThe excavation work on both underground tunnels beneath Sanjay Gandhi National Park SGNP is now underwayThe development comes as the first TBM Tulshi has already completed more than 270 metres of excavation since it became operational on August 17 2026The Brihanmumbai Municipal Corporation BMC said the launch of the second machine will allow work on both tunnels to progress simultaneously helping speed up the construction of the project which aims to significantly reduce travel time between Mumbais eastern and western suburbsTwo TBMs now working on twin tunnelsThe GMLR is a 1220kmlong infrastructure project connecting Mumbais eastern and western suburbs Under Phase 3B the BMC is constructing two underground tunnels between Dadasaheb Phalke Chitranagari in Goregaon East and Amar Nagar in Mulund West passing beneath Sanjay Gandhi National ParkThe two tunnels will be 534 km long each and will be constructed using advanced Tunnel Boring Machine technologyThe first TBM Tulshi was commissioned after completing technical procedures and trials on August 17 It has so far excavated more than 270 metres towards Mulund with an average excavation speed of around six metres per day The BMC plans to gradually increase this speed to 10 metres per day depending on work progressThe second TBM Vihar has now started excavation after successfully completing its Site Acceptance TestWhat makes TBM Vihar specialVihar uses advanced Single Shield Earth Pressure Balance EPB technology similar to Tulshi Its cutter head has a diameter of 1449 metres while the entire machine is 83 metres longThe machine comprises a 22metrelong shield section and a 61metrelong threestorey backup gantryThe EPB technology helps maintain control over soil pressure at the excavation face ensuring ground stability and allowing the tunnels to be constructed in a controlled and safe mannerDuring the Site Acceptance Test the machines mechanical electrical hydraulic and control systems were inspected against prescribed technical standards Its equipment and safety systems were also tested to ensure they were ready for actual excavationSixlane underground connectivity between Goregaon and MulundEach of the two underground tunnels will have a total length of 6675 metres Of this 5340 metres will be excavated using TBMs while the remaining 1335 metres will comprise box tunnels entry and exit ramps and shaftsThe tunnels will have an internal diameter of 13 metres Each tunnel will accommodate three traffic lanes providing a total of six lanes three in each directionBoth TBMs will begin excavation from Goregaon and proceed towards Amar Nagar in Mulund West Once completed the tunnels will provide direct underground connectivity between Mumbais eastern and western suburbs reducing dependence on existing road routesThe BMC has set February 2029 as the target for completing the entire GMLR project612 structures demolished in MulundThe project also involves rehabilitation and demolition work at the Mulund end where a retrieval shaft and ramps are being constructedAccording to the BMC a total of 743 structures were affected by the proposed work Of these 612 structures have been demolished so farThe remaining 131 structures are expected to be demolished by the end of December 2026 or early January 2027Families affected by the project will be rehabilitated in buildings at Kanjurmarg where construction of the rehabilitation structures is in its final stagesBMC pushes for faster work and safety measuresAdditional Municipal Commissioner Projects Abhijit Bangar said the commencement of excavation by Vihar alongside the ongoing work by Tulshi would help accelerate construction by allowing both tunnels to progress simultaneouslyHe has directed the concerned agencies to take necessary measures to prevent delays and regularly review construction progress machinery availability technical requirements and manpower needs Additional manpower and technical personnel are to be deployed wherever necessaryBangar also stressed that worker and engineer safety must remain a priority during the technically challenging excavation process Contractors have been instructed to strictly follow safety standards provide the necessary protective equipment and implement preventive measures against potential hazardsProper transportation and disposal of excavated material commonly known as muck and maintaining cleanliness at and around the construction site have also been emphasised