Delhi Metro starts lowering work with its first-ever Tunnel Boring Machine for Phase 4

New delhi: The Delhi Metro Rail Corporation (DMRC) on Thursday said that the lowering work of the first-ever Tunnel Boring Machine (TBM) of Delhi Metro's Phase 4 work has been started at Vikaspuri on the Janakpuri West-RK Ashram Marg corridor, adding that as part of the tunneling drive, two tunnels — for up and down movement — of a length of 1.4 kms will be bored between Vikaspuri and Krishna Park Extension.

During the tunneling work with the TBM, which is expected to start next month after the lowering and assembling of the giant 73-metre-long machine is completed, these tunnels will be located between the Janakpuri West and Krishna Park Extension stations of the corridor.

"The tunneling will start from the Vikaspuri area in continuation of the Magenta line tunnel that has been already constructed for the presently operational Botanical Garden-Janakpuri West corridor," Anuj Dayal, Executive Director (Corporate Communications), DMRC, said in a press note.

The tunnel will be constructed approximately at a depth of 14 to 16 metres. About 2,040 concrete rings will be installed in these tunnels. Each tunnel will have an inner diameter of 5.8 metres. The entire tunneling work on this stretch is expected to be completed in about 15 months' time. The alignment of the tunnel will be along the Outer Ring Road.

A TBM is a machine used to excavate tunnels with a circular cross-section through a variety of soil and rock strata. They can be designed to bore through anything from hard rock to sand. TBMs have revolutionised the way tunneling work is done all over the world as now tunnels can be bored without disturbing the buildings and other structures on the surface.

As part of the Phase-4 work approved so far, about 27 kilometres of underground lines will be constructed. The Janakpuri West – RK Ashram Marg corridor will have underground sections of 7.74 kilometres in total.