The Delhi Metro Rail Corporation (DMRC) has announced that it has completed a major construction milestone in the ongoing Phase 4 of the Delhi Metro. In a statement released today, the DMRC said that it has completed an underground tunnel between Chhatarpur and Chhatarpur Mandir Station on the Tughlakabad-Aerocity corridor.
At the Chhatarpur Mandir Station, a Tunnel Boring Machine (TBM) broke through this morning after boring an 860-meter-long tunnel. To achieve this breakthrough, a 97-metre-long TBM was used. Two parallel circular tunnels have been constructed for up and down movement along the Aerocity–Tughlakabad corridor. The breakthrough for the second tunnel was achieved on August 21, 2024.
The new tunnel lies at a depth of about 12 metres and has 613 rings installed within it. It has an inner diameter of 5.8 metres. Under the Phase 4 construction, 40.109 kilometres of underground lines are being laid. This particular corridor measures 19.343 kilometres.
The DMRC said that the tunneling work faced several challenges, including shifting a 66 KV electrical HT line. Besides this, the TBM crossed the Yellow Line viaduct from below but did not affect the operations on the existing Line.
TBMs are especially effective for underground tunneling in densely populated urban areas. The DMRC has utilised TBMs for its tunneling operations since Phase 1. During Phase 3, around 50 kilometers of underground sections were constructed, employing approximately 30 TBMs across the national capital.