The TBM completed the tunnelling of a 1,247m long tunnel from Netaji Subhash Place to Shalimar Bagh consisting of 1,037 rings with a diameter of 5.7m. The TBM was lowered in October 2013. The tunnel also crossed the elevated viaduct of the currently operational Dilshad Garden – Rithala Metro corridor near Netaji Subhash Place, which was a major engineering challenge.
This section of the alignment had passed below a drain near Netaji Subhash Place, where tunnelling had to be done 19m below the surface. While carrying out the tunnelling work, the engineers had to be careful about the piling work of a flyover, which is in progress currently above the tunnel on the Ring Road at Shalimar Bagh.
The tunnel also passed below the Kasturba Polytechnic, which is another major landmark in the area. While this tunnelling drive was for the up line, the drive for the down line (parallel tunnel) is expected to start in April.
The 59km long Majlis Park – Shiv Vihar corridor of Phase 3 consists of some 14km of underground lines. Presently, five other TBMs are working in different parts of the corridor across the city. In total, 19 TBMs are operational for the tunnelling works of Phase III at present.