Delhi Metro Rail Corporation (DMRC) on 23.04.2013 achieved the third tunnel breakthrough of its Phase - III project. The EPB broke through at the North West Shaft of the Janpath Metro station close to the Tibetan Market after six months driving a 1,516 m-long x 5.8 m internal diameter tunnel from Mandi House on the UP Line. The alignment passes beneath central Delhi buildings at a maximum depth of 24 m. The TBM, whose cutter head rotated at the rate of 1 to 2.3 rev/min, installed 1,083 rings manufactured at Mundka Casting Yard, each comprising 5 segments which were 275 mm-thick x 1.4 m-long.

M/s Pratibha Industries and China Rail First Group (CRFG) JV is the contractor for the stretch from Central Secretariat to Mandi House metro station, along with the cut/cover stations at Janpath and Mandi House.

Another TBM is working on the1,492 m-long Down Line tunnel and is expected to break through by May, 2013. Click in/11 for tunnelbuilder archive. Visit www.delhimetrorail.com. 19/13.