STN: Delhi Metro Phase 4 has marked another major step forward on the Tughlakabad–Aerocity corridor. On July 29, 2025, Tunnel Boring Machine (TBM) Tejas achieved a breakthrough at the Tughlakabad Railway Colony Station.
The machine completed this tunnel drive as part of Package DC-07, awarded to Afcons Infrastructure.
TBM Tejas and Its Role in Delhi Metro Phase 4
It is also known as S-711, is a refurbished Herrenknecht Earth Pressure Balance (EPB) machine. It started this drive from Maa Anandmayee Marg (MAM) Station. After covering 782.6 meters, it reached Tughlakabad Railway Colony Station.
This was not the first task for Tejas. Earlier, in 2023, it completed a 2.674 km tunnel from the Air Force Launch Shaft near Sangam Vihar Station to Maa Anandmayee Marg Station.
Technical Details of the Latest Breakthrough by TBM Tejas
The Delhi Metro Rail Corporation (DMRC) confirmed that the new tunnel has an average depth of about 18 meters. Around 559 rings have been placed inside the tunnel. Each ring provides an inner diameter of 5.8 meters.
This section is part of Package DC-07. The package covers 6.981 km and includes three underground stations:
- Maa Anandmayee Marg
- Tughlakabad Railway Colony
- Tughlakabad (interchange with the Violet Line)
Contractors and Tunnel Breakthroughs on the Golden Line
Delhi Metro divided Phase 4’s Golden Line into multiple packages, and different contractors handle each package.
Package Contractor Tunnel Breakthroughs Alignment Section DC-07 Afcons Infrastructure 5 East DC-09 L&T 6 Central DC-08 J Kumar 2 West Total — 13 —
Delhi Metro Phase 4 Underground Scope
The approved scope of Delhi Metro Phase 4 includes 40.109 km of underground lines. Out of this, 19.343 km fall on the Aerocity–Tughlakabad corridor. Tejas is playing a key role in making this section a reality.
FAQ on TBM Tejas and Delhi Metro Phase 4
A: TBM Tejas is a Herrenknecht Earth Pressure Balance (EPB) tunnel boring machine, refurbished for use in Delhi Metro Phase 4.
A: It is a major milestone in the construction of the Tughlakabad–Aerocity corridor, which will improve connectivity across South Delhi and towards the airport.
A: The new tunnel constructed by TBM Tejas has an average depth of around 18 meters.
A: Its first drive began in 2023, covering over 2.6 km between Sangam Vihar and Maa Anandmayee Marg.
A: Afcons Infrastructure is executing Package DC-07, which includes the tunnel breakthrough achieved by TBM Tejas.
A: The corridor is 23.622 km long and forms a vital part of Delhi Metro Phase 4.
A: A total of 40.109 km of underground lines are under construction, including 19.343 km along this corridor.
