Delhi Metro Rail Corporation completes longest twin tunnel in phase-IV

New Delhi: The Delhi Metro Rail Corporation (DMRC) has completed the first twin tunnel breakthrough as part of its Phase-IV construction works, an official statement said.

With the twin tunnels stretching approximately 3 kilometres, it is the longest built under this phase of the project, the statement read.

According to the official statement, the two tunnel boring machines (TBMs), named Bhoomi and Srishti, emerged simultaneously at Pulbangash Metro Station on Wednesday, marking the completion of the twin tunnels connecting Derawal Nagar to Pulbangash on the Janakpuri West-R K Ashram corridor, an extension of the Magenta line.

"Both TBMs were successfully retrieved at Pulbangash Metro Station on Wednesday, in just over 14 months, covering a length of approximately 2,997 metres, at an average rate of 8.2 metres per tunnel per day. This is also the longest tunnelling drive (almost 3 km) in DMRC’s Phase IV works," the statement said.

The event was attended by Dharmendra, Chief Secretary of Delhi, and Dr. Vikas Kumar, Managing Director of DMRC.

Anuj Dayal, Principal Executive Director of Corporate Communications at DMRC, expressed pride in the accomplishment and reiterated the organization’s commitment to delivering safe and efficient transport infrastructure for the residents of Delhi.

"Afcons is executing the DC-05 package that includes six underground stations, tunnelling of 14.4km including crossover, 10 cross passages, and 170m open and underground ramp. Today 3 km of twin tunnelling has been completed from Derawal Nagar to Pulbangash," the company said in a statement.

The twin tunnels were excavated at a depth of 14-15 meters, passing through densely populated areas such as Rana Pratap Bagh and Punjabi Basti Colony, and crossing beneath the Najafgarh drain, a structurally sensitive zone.

Despite the challenges of tunnelling through submerged water conditions and navigating the under-construction Ghanta Ghar station, no damage was caused to any structures, it said in the statement.

The tunnels, with an internal diameter of 5.8 metres, feature six cross passages which will connect the two for passenger safety. The civil work for this section was carried out by the contractor, M/s Afcons.

The deployment of TBM Bhoomi began on June 18, 2023, and TBM Srishti followed on August 19, 2023.