Originally, Union Railway Minister Ashwini Vaishnaw was scheduled to inaugurate the event officially, but the ceremony was cancelled due to a red alert and heavy rainfall in Mumbai.
The Mixshield TBM, with a diameter of 13.6 metres, will construct a 6-kilometre single-tube tunnel that will carry both up and down tracks for the Bullet Train. This tunnel is part of the 21-kilometre underground section of the Mumbai-Ahmedabad High Speed Rail corridor.
Of the total underground length, 16 kilometres between Sawli in Ghansoli and BKC will be excavated using TBMs, while 5 kilometres have already been completed employing the New Austrian Tunnelling Method (NATM). The TBM has started its tunnelling process from 56 metres below ground level at Vikhroli towards BKC.
The TBM weighs approximately 3,100 tonnes and stretches 96 metres in length, making it one of the largest machines ever used for railway tunnelling in India. It will tunnel beneath densely populated zones, including roads, multi-storey buildings, the Mithi river, and critical infrastructure.
The Mixshield TBM technology is designed for mixed soil conditions and high groundwater pressure areas. It minimizes ground settlement and surface disruption by simultaneously excavating and installing precast concrete lining segments, ensuring faster and safer construction.
The National High Speed Rail Corporation Ltd (NHSRCL) has set up a deep launch shaft at Vikhroli (56 metres below ground), alongside slurry and water treatment plants, a dedicated power substation, backup generators, a concrete grouting plant, and related support infrastructure. Safety monitoring instruments such as settlement markers, tilt meters, seismographs, and 3D monitoring targets have been installed to protect nearby buildings and utilities during excavation.
Meanwhile, an 11.17-hectare casting yard at Mahape is producing approximately 77,000 precast concrete segments needed for the tunnel lining. Officials expect to complete tunnelling from Vikhroli to BKC by early 2027, with the Vikhroli to Ghansoli section scheduled for completion by March 2028.
Separately, suburban train services on Central Railway’s Harbour line experienced a disruption on Sunday morning when a tree branch fell on the overhead equipment (OHE) wire near Sewri at approximately 10:25 AM. A power block was imposed on both up and down lines from 10:45 AM to 11:20 AM for clearing the obstruction and inspecting overhead infrastructure.
Mumbai recorded heavy rainfall of 250-300 mm in various areas over the previous 24 hours, including nearly 200 mm within eight to ten hours. Despite the intense showers stressing drainage and railway infrastructure, suburban train services operated largely without major waterlogging disruptions. Special monitoring was conducted at vulnerable stations including Kurla, Sion, Matunga-Dadar, and Vasai Road to ensure service continuity.
