The Delhi Metro Rail Corporation (DMRC) on Friday marked a major tunnelling milestone on its Aerocity–Tughlakabad corridor—popularly known as the Golden Line—when a Tunnel Boring Machine (TBM) broke through at Tughlakabad Railway Colony station. This breakthrough signifies the completion of a 792 metre underground stretch excavated from Maa Anandmayee Marg.

Built at an average depth of 18 metres, this tunnel forms part of the corridor’s 19.3 kilometre underground alignment within a total route length of 23.6 kilometres. Once fully operational, the Golden Line will enhance east–west connectivity in South Delhi and provide a seamless interchange with the Violet Line at Tughlakabad.

The event was attended by Delhi’s Health and Transport Minister Dr Pankaj Kumar Singh, DMRC Managing Director Dr Vikas Kumar, and other senior officials. A parallel tunnel for the up and down tracks is slated for completion by July 2026.

“This breakthrough is not just a technical achievement but a symbol of renewed momentum,” Dr Singh said. “What was once stalled is now moving at full speed. Today’s event serves both as an inspection and a celebration. Going forward, we will further accelerate metro expansion and ensure Delhi’s citizens receive the quality infrastructure and services they truly deserve.”

The Aerocity–Tughlakabad stretch is one of three corridors under construction in DMRC’s Phase 4 expansion. The other two are the Janakpuri West–RK Ashram extension of the Magenta Line and the Majlis Park–Maujpur extension of the Pink Line. While the Pink Line extension is expected to open by the end of 2025, the Golden Line and Magenta Line corridors are scheduled for mid-2026 completion.

Anuj Dayal, Principal Executive Director of Corporate Communications at DMRC, noted that ground movement during excavation was monitored with precision instruments attached to adjacent buildings to prevent structural disturbances or surface settlement.