3rd Launching Gantry Commissioned for Bangalore Metro’s Reach 4B
On this past Friday night, workers from NCC commissioned their 3rd launching gantry in front of the Nandi Toyota dealership at Thalaghattapura for building the viaduct of Bangalore Metro’s Green Line’s 6.29 km southern extension to Anjanapura Township. This development on Reach 4B of the project comes about 3 months after the 2nd launching gantry was commissioned at Yelachenahalli.
NCC was awarded this section of the 72 km Phase 2 project in January 2016 and as per BMRCL’s May 2017 newsletter:
• LG-1 has completed building 9 spans between Yelachenahalli and Anjanapura Cross
• LG-2 has completed building 13 spans between Krishna Leela Park and Vajarahalli
Reach 4B includes 5 new stations at Anjanapura Cross Road, Krishna Leela Park, Vajrahalli, Thalaghattapura & Anjanapura Township on Kanakapura Road, and is expected to become operational in late 2019. Here’s a map displaying the direction of all 3 launching gantry cranes in orange:
Map of Yelachenahalli – Anjanapura Township extension – view Bangalore Metro’s Phase 2 map & info
LG-1 is travelling south from the Krishna Leela Park Station, LG-2 is travelling south from the existing Reach-4A’s viaduct in Yelachenahalli, and LG-3 has now started erecting segments & will shortly start making its way north from Thalaghattapura Station.
Images shot on May 1 while LG-3 was being set up:
Photo Copyright: Pavan
Photo Copyright: Pavan
Segments being launched on this Saturday morning:
Photo Copyright: Pavan
Each segment weighs 40 tons and usually 10-12 segments are required to build one span between two adjacent piers. For this section, BMRCL’s May 2017 newsletter mentions that NCC had completed casting 621 out of 1916 segments at their yard in Thataguni Village by the end of April.
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:
For more updates, check out the Bangalore section of The Metro Rail Guy!
– TMRG
Is the Anjanapura Township station going to be on the ground? Why would they put the LG starting from Thalaghattapura and go northwards and not southwards towards Anjanapura township? The gantry has to be decommissioned and set again right for this section? Why would they not use LG-2 to go directly towards Thalaghattapura? Or it really doesn’t matter because they will have to decommission LG-2 at the Vajrahalli station anyway?
Hi, Anjanapura Township Station will be elevated like all other stations.
NCC started building the line by casting piers north to south, and can only launch segments where multiple piers are ready. The newsletter indicates only 65/222 piers were ready by April-end, so it’s quite possible that the piers south of Thalagattapura haven’t yet been built.
The LG will indeed be decommissioned after each section, transported and re-setup elsewhere, so its direction doesn’t really matter.
which one is the fastest way to build elevated line , this launch gantry or using that u shape pre molded ducts.?
Depends on city to city and line to line, but I’ve found using U-girders to be faster & ‘cleaner’. Only hitch is that they require a lot of site space to launch, so they’re often not preferred by line designers. The box segments used above require minimal space and can be launched at any time of the day – see this video of a segment being delivered during the day. This ain’t possible with U-girders as currently being witnessed by people in Mumbai.
Thanks for the updates. One thing I observed in the images are that the traffic on the roads arent totally isolated from the construction sites. Shouldn’t the companies barricade the sites of construction in a better manner?
Mostly they would have removed the barricades to allow for easy access for cranes to launch the LG and also for the trailer trucks to bring in the segments for the span.
Poorly managed sites throughout India have always been a major pet peeve of mine. How I wish things were better.
Late 2019 to start Reach 4B Services ? Going by the pace of work in this segment I was hoping for a late 2018 launch on this stretch.
Hi, constructing the viaduct is relatively easier (and more visible) than stations which require a stronger foundation.
Work seem to have slowed down on 4B, Not sure if it’s Rain effect or election getting nearer
Hi, I heard the same thing from another follower via email. Not sure what’s the cause.
Thanks for the updates. Hope for more posts!
@TMGG, Is Gantry used at the stations as well or is it only for segments between stations? I have not seen any further updates from BMRCL for 4B
Only for the viaduct between stations. Different portions of the stations are cast or constructed on-site (“in-situ”).