On September 2, 2019, former vice president M. Venkaiah Naidu officially opened India’s longest electrified rail tunnel. The Obulavaripalli-Venkatachalam railway line includes the 6.6-km-long tunnel, which is located between the Andhra Pradesh stations of Cherlopalli and Rapuru.
The recently built tunnel will offer seamless rail connectivity for freight movement between Krishnapatnam Port and the hinterland areas.
Travel time between Venkatachalam and Obulavaripalli, which is 112 km long, will be slashed by 5 hours. Currently, the journey by goods train from Krishnapatnam Port to Obulavaripali takes ten hours. The tunnel was described by Venkaiah Naidu as a “engineering marvel.”
“I am overwhelmed with emotion as my long-cherished childhood dream has now come true,” the Vice President said about his trip on the newly-commissioned Obulavaripalli-Krishnapatnam line.
Some of the salient features:
— The country’s first electrified tunnel is built in the shape of a ‘horseshoe’ using the New Austrian Tunneling Method (NATM).
— Construction of the tunnel was a major challenge as the tunnel area was full of quartzite and phyllite rocks. The tunnel construction was completed in a record time of 43 months.
— Built at a cost of ₹437 crore, Vice President M. Venkaiah Naidu termed the tunnel “an engineering marvel.”
— The height of the tunnel (rail level to roof) is 6.5 meters and the minimum height of the contact wire is maintained at 5.2 meters.
— The track is constructed without using Ballast by providing Bi-block sleepers and Vaslo fittings.
— Two sub-stations for the supply of electric traction power are provided near Cherlopalli and Adurupalli with necessary switching stations in between.