The Delhi Metro Rail Corporation (DMRC) has reached a significant milestone in its Phase 4 expansion project by completing an underground tunnel on the Golden Line (Line 8) between Chhatarpur Mandir and IGNOU Station, connecting Tughlakabad to the Aerocity corridor.
Breakthrough Achievement of DMRC Golden Line
Delhi Metro Rail successfully completed an underground tunnel between Chhatarpur Mandir and IGNOU Station. This 1,475-meter-long tunnel was constructed using a 97–meter-long Tunnel Boring Machine (TBM), which broke through at IGNOU Station. Built at an average depth of 26 meters, with a minimum depth of 15 meters and a maximum depth of 36 meters, making it one of the deepest tunnels in the Delhi Metro network.
Tunnel consists of 1,048 precast concrete rings, each with an inner diameter of 5.8 meters, with twin parallel circular tunnels have been constructed to facilitate seamless up-and-down train movements, a testament to the project’s scale and complexity.
Engineering Feat of DMRC
The tunneling process was executed by the construction team using the Earth Pressure Balancing Method (EPBM), with precast concrete segments manufactured at a mechanized casting facility in Mundka. The tunnelling drive project faced challenges, which began on December 4, 2023, due to steep gradients and varied geological conditions, including Mica and Hard Rock formations. These conditions damaged the TBM’s screw auger, necessitating its replacement mid-project. Despite these hurdles, the Earth Pressure Balancing Method (EPBM) ensured stability, which was successfully navigated to complete the tunnel.
Future Prospects of DMRC Golden Line
Once completed, the Golden Line will improve connectivity between southern parts of Delhi, linking the existing Violet Line at Tughlakabad to the Airport Express Line at Aerocity. This corridor project operations is scheduled to start by March 2026, greatly enhancing travel options for commuters in the area.
Commitment to Progress of DMRC
All the achievements of DMRC’s are commitment to develop, expanding and update Delhi’s transportation infrastructure, to create efficient ways for city residents to move across the city. Engineering expertise and staff dedication at the DMRC resulted in the successful construction of a tunnel between Chhatarpur Mandir and IGNOU stations.
The breakthrough of the second parallel tunnel is anticipated in March 2025, further advancing the progress of the DMRC Golden Line. As part of the approved Phase 4 expansion, Delhi Metro Rail Corporation is constructing 40.109 kilometers of underground lines, with the Aerocity-Tughlakabad corridor accounting for 19.343 kilometers.