PUNE: The first segment of tunnel rings to be used in underground metro project was fabricated on Monday morning at Metro casting yard in Deccan College, Yerawda. MahaMetro has appointed the joint venture of Tata and Turkish company Gulermak to build the underground metro from Shivajnagar to Swargate. MahaMetro officials said that Gulermak has prior experience in such work at Lucknow, Istanbul and Warsaw. They informed that six such segments join together to make a tunnel ring, which is 1.4 m in length. Gulermak said that they are targeting to cast 250 tunnel rings on a monthly basis.

“The tunnel boring machines are expected to arrive in October and the tunnelling work is expected to start in November. The work of tunnelling and fixing the tunnel rings will simultaneously take place,” stated an official from Gulermak.

Speaking about the development, Atul Gadgil, Executive Director of Pune Metro project said that the segments are casted in moulds. 

“RO water is used to make these segments. Similarly, steam is used to strengthen the segments. This helps to accelerate the process of segment casting. Similarly, we have labs for quality check of segments,” said Gadgil.

The Executive Director  further said that following space constraints issue at Budhwar Peth metro station and Mandai stations, MahaMetro will have to adopt New Austrian Tunneling Method (NATM) for the tunneling work. Gadgil said that under NATM, they will enter the ground through a narrow shaft and then will dig horizontally for the concourse, platform and base level. 

“Following the resistance from locals in Budhwar Peth, we have moved the location of underground station by 100 metres and now the new location is at Dadoji Konddeo school. As the area is a bit small, we have to use the NATM technique. Currently, we have completed the designing and land acquiring process for the underground metro stations,” added Gadgil.