The National High Speed Rail Corporation (NHSRCL) has reportedly issued tender for India’s first undersea tunnel as part of the Mumbai-Ahmedabad bullet train project.
The floated tender is for the development of tunneling works of the bullet train project and includes work such as testing as well as commissioning for double-line high speed railway for the project using tunnel boring machine (TBM) and a new Austrian tunnelling method (NATM). The tunnel is expected to be the part of the bullet train corridor, connecting the two cities of Mumbai and Ahmedabad.
Reports suggest that the floated tender demands the work to be completed in the time frame of 3.5 years. Last year, a team of engineers from NHSRCL, RITES and Japan’s Kawasaki Geological Engineering firm had carried out a geo-technical investigation of the undersea tunnel area. Also, a static refraction technique (SRT) survey was carried out by the team in order to study the seabed structure. The study involved firing a high energy sound wave towards the seabed from below the water surface as well as mapping the refracted sound wave in order to determine the density of the rock under the sea bed. Thereafter, a final report had been submitted by the team last year.
The Mumbai-Ahmedabad bullet train project is expected to have a 21-km-long underground corridor from BKC to Kalyan Shilphata in Maharashtra. Nearly 7 km of this underground corridor is under the Thane creek. Of this, 1.8 km-long section will be reportedly developed under the sea bed, while the remaining part of the stretch is to be built under the mangroves marshland on either side of the creek.
For the implementation of this project, as per the NHSRCL, all environmental clearances from the concerned authorities have either been received or authorities have primarily agreed for the approval.
The corridor for of the bullet train is expected to be 508 km-long and cut down the travel time from seven hours to two hours. The bullet train will cover a total of 12 stations, namely, Bandra Kurla Complex, Thane, Boisar, Virar, Vapi, Surat, Bilimora, Bharuch, Sabarmati, Baroda, Anand and Ahmedabad railway stations. The development work of this project is likely to get over by 2022-2023.