The 400 metric tonne Tunnel Boring Machine (TBM) emerged at Najafgarh retrieval shaft near Tura Mandi site after making a 0.67 KM (555 rings) long tunnel from the site near Sai Baba Mandir of Najafgarh, sources said.
At this point the elevated alignment coming from Dwarka goes underground through a ramp. The tunnelling on this stretch began on November 9 last year. The depth of the tunnel varies from 6.1 metre to 10.5 meter below the ground surface, they said.