Last week, Soma Enterprise Ltd. commissioned their 1st launching gantry south of RV College of Engineering in Pattanagere for building the viaduct of Bangalore Metro Purple Line’s 8.814 km western extension to Challeghatta on Mysore Road. The 1st segment was launched at Pier-572, and this feat was accomplished by Soma 13 months after they won a Rs 332.93 crore contract to build the 4.869 km Reach 2B package of the Bangalore Metro’s 72 km Phase 2 project between Pattanagere and Challegata.
Overall, this is the 3rd package of the metro’s Phase 2 project, after Reach 4B (Yelachenahalli – Anjanapura Township) and Reach 2A (Mysore Road – Pattanagere), where segment launching work has started. In January 2017, Soma cast their first pier at this very site and also began conducting test segment launches inside their casting yard at Kanminike.
The western extension of the line is being built in 2 parts by IL&FS (Reach 2A) and Soma Enterprise (Reach 2B), and consists of 7 new stations at Nayandahalli, Rajarajeshwari Nagar, Bangalore University, Pattanagere, Mailasandra, Kengeri and Chellagatta (recently added):
With this development, the Purple Line’s western extension now has 3 launching gantries building it with IL&FS’ LG-1 building south from Nayandahalli towards Rajarajeshwari Nagar, LG-2 building north from Pattanagere towards Bangalore University, and Soma’s LG-1 building south from Pattanagere towards Mailasandra.
Some images of Soma’s blue-colored double-girder launching gantry#1 in action:
The under construction Pattanagere Station can be seen in the above image. A nice video showing the Mailasandra Station’s site can be viewed here.
Each segment weighs 40 tons and typically 10-12 segments are required to build one span between two adjacent piers. As per BMRCL’s April newsletter, Soma had completed casting 205 segments at their yard by the end of March 2017.
Here’s my go-to video to demonstrate how a Launching Gantry works its magic with precast segments to build modern segmental viaducts and bridges:
Meanwhile, NCC is in the process of setting up their 3rd launching gantry in front of the Nandi Toyota dealership on Kanakapura Road for building the Green Line’s 6.29 km southern extension (Yelachenahalli to Anjanapura Township) – see some images here. Watch out for a similar post when it starts to launch segments.
For more updates, check out the Bangalore section of The Metro Rail Guy!