Mumbai, Jan 5 (IANS): The Heavy Civil Infrastructure business of L&T Construction has emerged as the lowest bidder for a Package 4 of new broad-gauge line between Rishikesh and Karnaprayag, sources privy to the development said.

The scope of this engineering and construction project includes completing tunnel work by Tunnel Boring Method (TBM) and New Austrian Tunnel Method (NATM) with formation, construction shaft and ancillary works from Chainage 47+360 to 63+117 Km in the Himalayan State of Uttarakhand.

This will be the biggest Tunnel Boring Machine to be deployed in the Himalayan geology and the TBM bored tunnel length of 20.807 km is the maximum in any project in the region.

The purpose of providing rail link between Rishikesh and Karanprayag is for facilitating easy access to pilgrimage centres situated in Uttarakhand, connecting new trade centre, development of hinterlands to serve the population there.

The railway line traverses "very rugged Himalayan terrain", with the alignment oriented across and sometimes sub parallel to the major thrust zones of Himalaya with complex geological conditions.

Project involves construction of 14.577 km upline and 13.123 km downline tunnel with embankment of approximately 800 meters at both ends. Out of 14.577 and 13.123 km; 10.49 Km and 10.317 km of tunnel will be excavated using two Brand New Hard Rock Tunnel Boring Machines (TBMs) of diameter 9.1 meters and balance tunnel will be excavated by New Austrian Tunnelling Method (NATM).

The scope also includes construction of an Ellipsoidal construction cum Ventilation shaft of finished cross section of 79 square meters and depth of 32 meters.

The company is already engaged in the construction of Rishikesh - Karanprayag Tunnel 2 package by RVNL comprising tunnels, bridges and formation works. This project, won by the Heavy Civil Infrastructure business of the company in December 2019, consists of the main tunnel with parallel escape tunnel and ballast-less track that runs inside the main tunnel.