Last week, the Afcons-Transtonnelstroy JV team in Kolkata commissioned their 2nd Tunnel Boring Machine at the Howrah Maidan station for building Kolkata Metro’s 16.34 km East-West line! The S639 TBM referred to as Rachna will build the down-line tunnel to the Howrah Junction railway station, and is trailing behind its sister machine, TBM Prerna, which has completed tunneling 147 meters out of the 550 meters for the parallel up-line tunnel on the same route.
At the time of writing this piece, Rachna has completed building 6 temporary rings and 4 permanent rings. Each ring is 1.4 meters wide.
Satellite view of Howrah Maidan station:
Some images of the TBM shot prior to its commissioning:
Here’s a look at the Howrah Junction railway station site where both TBMs will arrive in the 1st half of 2017:
The 9 km first phase of the line from Salt Lake Sector V to Sealdah is expected to be operational by mid 2018 while the 7 km second phase from Sealdah to Howrah which includes this tunnel section is expected to be operational in 2020.
For more updates, check out the Kolkata section of The Metro Rail Guy!