World record for tunnel boring set on Mumbai coastal road project
11 Aug 2022
Slurry TBM with 12.19m diameter and weighing 2,500t operated by India’s L&T bores a distance of 456.72m in a month to set new global mark
A tunnel boring machine (TBM) working on the Mumbai Coastal Road Project in India has achieved a world record for monthly length bored by excavating 456.72m on the Package 4 of the project.
This was revealed by Larsen & Toubro (L&T) the major Indian multinational engaged in EPC projects and hi-tech manufacturing and services, which is constructing the massive infrastructure project in India’s financial capital.
The 12.19-metre diameter Slurry TBM, named ‘Mavala’, presently the largest deployed in the country, started boring from the Girgaon Chowpatty area and broke the previous global record of 455.4m for monthly tunnelling done by a 13m single shield EPB (Earth Pressure Balance) TBM.
“This is a huge achievement for the entire construction industry worldwide and truly an engineering feat to be proud of,” said S V Desai, whole time director and senior executive vice president (Civil Infrastructure), L&T, describing the achievement.
“We achieved this speed of tunnelling thanks to our experienced and qualified team. It has given us a huge boost to speed up construction to deliver this iconic and extremely complex project in time and with quality. I take this opportunity to thank our customer, the Municipal Corporation of Greater Mumbai (MCGM), for reposing faith in us and supporting us through this whole process, as well as our employees, without whom this could not have been achieved.” he added.
For the project team, this achievement reflects their success to face and overcome several challenges. To begin with, TBM ‘Mavala’, named after infantry warriors in the army of Shivaji, a historic ruler of the region, was delivered during the height of the pandemic and since external experts could not travel, the team took it upon themselves to assemble the TBM with only some ‘virtual’ help.
Weighing approximately 2,500t, the TBM was then lowered into the launching shaft in a fully assembled form. Another innovative method they adopted was to ‘rotate’ the TBM inside the shaft to start the second tunnel construction which saved them several months to dis-assemble, lift, transport, re-assemble and lower the TBM at a new location.
Phase-1 of the Mumbai Coastal Road Project is a 9.98km section from Princess Street Flyover at Marine Lines to the Worli end of the Bandra-Worli Sea Link, involving seafront development and is a first-of-its-kind in India.
The project is divided into three packages: Package-I from Amarsons Garden t0 Baroda Palace; Package-II from Baroda Palace connecting to Bandra Worli Sea Link; and Package-IV from Princess Street Flyover at Marine Lines to Priyadarshini Park.
L&T is executing Packages I and IV for MCGM involving the construction of a 3.82km long section over reclaimed land from Priyadarshini Park to Baroda Palace and interchanges at Amarson Garden and Haji Ali. Package IV involves the construction of a 2km long twin bored tunnel along with cut and cover, ramp, etc. to form a combined road length of 4.06km. When completed, it would be the largest and deepest bored road tunnel in India.