By December, Delhi Metro to Feature the World’s Largest Single-City Network: Manohar Lal

New Delhi, March 6 (NationPress) The Minister of Housing and Urban Affairs, Manohar Lal, announced on Thursday that by December 2025, the Delhi Metro network will become the largest for a single city, exceeding the New York Metro's current record of 399 km.

“The upcoming 12-km segment from Aerocity to Tughlakabad, part of the Golden Line, will elevate the Delhi Metro network to the largest single network globally,” stated Manohar Lal during a tunnel breakthrough ceremony for the Golden Line at the Vasant Kunj metro station.

Currently, the operational network of the Delhi Metro spans 394 km, he mentioned.

The Minister highlighted that metro networks are either operational or in development across 29 states in India, totaling around 1,000 km, making it the third-largest in the world.

“We are on track to become the nation with the second-largest metro network, following China,” he added.

On February 25, a significant construction milestone was reached in Phase 4 with the completion of an underground tunnel connecting Chhatarpur Mandir and IGNOU Station on the Tughlakabad-Aerocity corridor.

The breakthrough of the Tunnel Boring Machine (TBM) at the IGNOU Station occurred in the presence of several senior officials, including Anand Mohan Bajaj, Deputy Comptroller & Auditor General.

A TBM successfully completed a 1475.00 meter-long tunnel at the IGNOU station. This was achieved using a massive 97-meter-long TBM.

Two parallel circular tunnels for dual movement are being constructed on this corridor.

This newly created tunnel is around 26 meters deep, positioning it as one of the deepest tunnels in the Delhi Metro system. The tunnel on the Magenta Line at Hauz Khas is approximately 30 meters deep. A total of 1,048 rings have been installed in the tunnel, having an inner diameter of 5.8 meters.

The tunnel was constructed utilizing the EPBM (Earth Pressure Balancing Method) technology, featuring a concrete lining made from precast tunnel rings. These rings were produced at a fully mechanized yard in Mundka, with segments cured using a steam system to ensure early strength.

The tunneling process commenced on December 4, 2023, facing challenges such as steep gradients and diverse geological conditions, including mica and hard rock, which led to damage and replacement of the screw auger during the operation.

All essential safety measures were implemented during the tunnel construction beneath existing structures, with ground movements monitored through sensitive instruments, ensuring no settlement occurred.

As part of the approved Phase 4 work, 40.109 km of underground lines are underway, including 19.343 km of underground sections in the Aerocity-Tughlakabad corridor.

A TBM is a specialized machine designed to excavate tunnels with a circular cross-section through varying soil and rock types. Its versatility allows it to bore through materials ranging from hard rock to sand, revolutionizing tunneling practices globally by enabling construction without disturbing surface structures.

TBMs are especially beneficial for underground construction in densely populated urban settings.

The DMRC has employed TBMs for its tunneling projects since the initiation of Phase 1 in 1998. The first section became operational on December 25, 2002, linking Shahdara to Tis Hazari. The entire Phase 1 was operational by 2006, followed by Phase 2 starting in 2006, Phase 3 in 2011, and Phase 4 in 2019.

During Phase 3, approximately 50 km of underground sections were constructed with around 30 TBMs deployed across the capital.