Mumbai, Metro Rail News: Mumbai Metro Line 3 (Underground Metro) 18 km of tunnelling complete. Twin tunnel boring machines Krishna 1 &2, lowered in Sept & Oct 2017 respectively from Nayanagar, Dharavi, reached Dadar Metro station on January 31, 2019.
According to source “Krishna1 & 2 made their way through the rocky strata made of Basalt grade 3 & 2, breccia grade 4, 3 & 2 and tuff grade 4 & 3 drilling relentlessly for exactly 506 and 479days respectively. They charted their course from Nayanagar launching shaft.
Speaking on the occasion Ms Ashwini Bhide MD MMRC said Ths is the 3rd important
The 108 meters long Krishna 1 bored, on an average, 10 to 12 meters daily shaping the tunnel with 1779 RCC cement rings, whereas The 108 meter long Krishna 2 bored, on an average, 10 to 12 meters daily, with shaping the tunnel with 1766 RCC cement rings. These TBM’s were equipped with Earth Pressure Balance Technology. Overall 35% work has been completed till now.
A Herrenknecht make TBMs Krishna 1 & 2 equipped with Earth Pressure Balance Tech tunneled their way through the rocky strata made of Basalt, Breccia & tuff for 506 & 479 days resp. Krishna 1&2 used 1779 & 1766 RCC rings while tunneling at 10 to 12