Mumbai: In a landmark feat, the Larsen & Toubro (L&T), an Indian multinational engaged in engineering procurement and construction (EPC) projects, has announced achieving a world record for monthly lengths by excavating 456.72 metre at the prestigious Mumbai Coastal Road Project (MCRP) package-4.
The excavation was done by a 12.19 metre dia slurry tunnel boring machine (TBM), named ‘Mavala’. Deployed from Girgaon Chowpatty, the TBM, presently the largest deployed in the country, broke the previous global record of 455.4 m for monthly tunnelling done by a 13m single shield earth pressure balance (EPB) 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 & senior executive vice president (civil infrastructure), L&T.
“The record breaking feat was achieved by efforts of our experienced and qualified team. It had 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.
The tunnel, which would be the longest and deepest bored road tunnel in India, is part of the 29.80 km Mumbai Coastal Road Project (MCRP) is an under construction access-controlled expressway with a route connecting Princess Street Flyover in South Bombay with Kandivali in the northern suburbs.
The 1920 metre tunnel is being constructed by the L&T on 3.39km route, from Princess Street Flyover to Priyarshini Park. L&T is also building package 1 of the project from Priyadarshini Park to Baroda Palace near Haji Ali at the cost of ₹7489 crore. Package-2 of the project from Baroda Palace to Bandra Worli Sea-link (2.23km) is being constructed at the cost of ₹2,126 crore by the joint venture company of Hindustan Construction Company.
The total project cost of MCRP is estimated to be around ₹21,700 crore to be executed in two phases (10.58km and 19km). Currently the work is under construction going on on 9,98 km long section of phase 1 between Marine Drive and Bandra Worli Sea-link.
L&T engineers said that the TBM ‘Mavala’, named after infantry warriors in Shivaji’s army, 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 2,500 tonnes, 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 & lower the TBM at a new location,” explained an engineer.