Twin Tunnel Breakthrough At Mumbai Metro 3 Corridor At Dadar Metro Station
Mumbai Metro Rail Corporation (MMRC) witnessed a twin tunnel breakthrough of the third and fourth TBM of Colaba-Bandra-SEEPZ Metro3 corridor at Dadar Metro Station.
Krishna 1, the Tunnel Boring Machine, which was lowered on 21st September 2017 from Nayanagar launching shaft completed its tunnel drive of 2490 metres in package 4 to see the light at its end at Dadar metro station. Krishna 2, the Tunnel Boring Machine which was lowered on 18th October 2017 from Nayanagar launching shaft completed its tunnel drive of 2472 metres in package 4 at Dadar metro station. Once more it marks the achievement of an important milestone towards the steady completion of the 33.5- km long Metro-3 corridor. It is the result of consistent and continuous effort by a team of nearly 15 engineers, 85 technicians and workers, together in each TBM to make this reach of tunnelling successful. The TBM have been manufactured by Herrenknecht from Germany.
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. 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.
MMRC, as of today, has completed about 18 km of tunnelling. For the purpose, 17 Tunnel Boring Machines have been commissioned at ten TBM shafts. Overall 35% work has been completed till now.
On the occasion Ms Ashwini Bhide, Managing Director, MMRC said “This is the third important milestone for tunnelling in Mumbai Metro III. We are delighted with this accomplishment, the credit for which goes to the team of engineers, supervisors, workers and various other stakeholders. We intend to and are steadfastly working towards realizing Mumbaikar’s dream of faster, comfortable and efficient commute at the earliest”