This calls for a celebration!
On Friday afternoon, the CEC-CICI JV for contract CC-04 of Delhi Metro’s Phase 3 project commissioned the 2nd of 2 ‘rescue’ TBMs from the Majlis Park shaft of the 58.596 km Pink line! This TBM is the last of all TBMs to be commissioned on this line and will build the up-line tunnel towards the Rameshwar Nagar mid-shaft. Like the 1st rescue TBM commissioned earlier this month, this TBM was not part of the original tunneling plan, but became necessary to be deployed as the original 2 TBMs commissioned from Azadpur towards Majlis Park, tasked with tunneling 1100m, got stuck mid-way.
Roughly 600m of tunneling on both tunnels is left which the contractor expects to complete in Q3 (July-September) 2016. At the time of writing this, the 2nd TBM has built 7 temporary rings and 5 permanent rings.
To recap from an earlier post, here’s a little history about this section:
The contract for CC-04 (Majlis Park – Azadpur – Shalimar Bagh) was awarded on December 29 2011 with a completion deadline of September 28 2014, but things started going wrong in early 2014 after CEC-CICI launched the initial drives of both TBMs from Azadpur towards Majlis Park. The ‘Tunnels and Tunneling’ magazine recently published an article with a brief history of the difficulties faced and what CEC-CICI tried to do to resolve:
Both TBMs met with a large mass of intact rock which infringed the lower portion of the tunnel face and extended for approximately 30m. The TBMs used were both soft ground machines which have been used on a previous phase of the metro, and experienced high torque and overheating when attempting to cut through the rock zone. An attempt was made to break up the rock ahead of the cutter face by drilling and placing an expanding chemical to burst the rock and allow the cutter head to rotate and advance one ring at a time. The space within the chamber available to manage this exercise was very limited and matters were made worse by the presence of wet running sand above the rock zone which dictated working under compressed air.
Majlis Park Shaft (at the southern end of the ramp):
Fun Fact: Both rescue TBMs for this section have been leased from HCC-Samsung who built the Magenta line’s 4.5 km section between Vikaspuri – Janakpuri West – Dabri Mor – Dashrathpuri – Palam under contract CC-34.
As I’ve mentioned in the past, this section is located right by the Mukundpur depot (see map above) and trial runs on any part of the 58.596 km Pink line in north, west and south Delhi hinges upon the completion of these tunnels. Due to the delay in completing this section, the Pink line will now only be able to open in mid 2017 and not by December 2016 as originally planned. The DMRC’s MD recently admitted about the delay in an interview and the organization published plans to start trials between Majlis Park and Lajpat Nagar in October 2016, but that would not be possible as all 4 TBMs from the mid-shaft will not be out by then and the slum rehabilitation process at Punjabi Bagh and Mayapuri to enable the construction of two two small sections of roughly 100m has STILL not been initiated yet.
For more updates on the Delhi Metro, please visit the Delhi section of The Metro Rail Guy!