Delhi Metro starts lowering of first TBM for Phase-4 project

October 22, 2020 Rail News

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. As part of this tunnelling drive, two tunnels (for up and down movement) of a length of 1.4 kilometres will be bored between Vikaspuri and Krishna Park Extension.  

  • The tunnelling work with the TBM 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 tunnelling will start from Vikaspuri area in continuation of the Magenta line tunnel that has been already constructed for the presently operational Botanical Garden – Janakpuri West corridor.
  • 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 tunnelling work on this stretch is expected to be completed in about 15 month’s time. 
  • The alignment of the tunnel will be along the Outer Ring Road.
  • 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. 

About TBM:

  • 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 tunnelling work is done all over the world as now tunnels can be bored without disturbing the buildings and other structures on the surface. 
  • TBMs are especially useful for underground tunnelling work in congested urban areas. 
  • DMRC has been using TBMs for its tunnelling work since Phase 1.
  • In Phase 3, when about 50 kilometres of underground sections were built, about 30 TBMs were pressed into service in the national capital.

Source: DMRC-Press Release