The Delhi Metro Rail Corporation (DMRC) on Saturday achieved a milestone in its Phase-IV expansion with the breakthrough of a tunnel boring machine (TBM) at the Tughlakabad Railway Colony station.
The tunnel is part of the underground stretch of the Tughlakabad–Aerocity corridor, also referred to as the Golden Line.
Health and Transport Minister Pankaj Kumar Singh, who was present at the site, said the completion of this section is a sign that delayed infrastructure work in the capital is now gaining momentum.
“This breakthrough is not just a technical achievement but a symbol of renewed pace in metro expansion. What was stalled earlier is now moving forward,” he said.
The TBM, which is 96 metres long, completed a 792-metre stretch of tunnel between Maa Anandmayee Marg and Tughlakabad Railway Colony.
It is one of two parallel tunnels being constructed for this corridor to support up and down movement of trains.
The second tunnel is expected to be completed by July 2025.
The newly built tunnel lies at an average depth of 18 metres and consists of 566 precast concrete rings with an internal diameter of 5.8 metres. The rings were manufactured at a casting yard in Mundka and were cured using steam to ensure structural strength.
DMRC officials said the tunnel was built using Earth Pressure Balancing Method (EPBM), a technique commonly used in urban tunnelling to minimise disturbance to surrounding structures.
To monitor safety during construction, sensitive instruments were placed on nearby buildings to detect ground movement. No settlement was reported during the process.
The Tughlakabad–Aerocity corridor includes 19.3 km of underground tunnelling out of a total of 40.1 km of underground lines approved in Phase-IV of the Delhi Metro expansion. DMRC has relied on TBMs since its early phases and used nearly 30 machines during Phase-III to construct around 50 km of tunnels.
Senior DMRC officials, including Managing Director Dr Vikas Kumar, were present during the event.
