The South Central Zone of Indian Railways has commissioned the longest electrified railway tunnel in the country.

According to local media reports, the construction of the 6.6km-long tunnel took 43 months to complete at a cost of Rs4.6bn ($67.11m).

The electrified railway tunnel is situated between Cherlopalli and Rapuru stations as part of the Obulavaripalli-Venkatachalam railway line.

The tunnel is expected to facilitate freight movement in the region, reducing the distance between Krishnapatnam Port and hinterland areas by nearly 60km.

Currently, the average time taken by a freight train to travel from Krishnapatnam Port to Obulavaripali is ten hours. The new tunnel will reduce the time to nearly five hours.

South Central Railway general manager Gajanan Mallya said: “The tunnel, an engineering marvel, is a pride for SCR zone. The new railway line is helpful for decongesting traffic on the Vijayawada-Gudur main line.”

Authorities developed the tunnel in the shape of ‘Horse Shoe’ employing the New Australian Tunneling Method (NATM).

It has an overall height of 6.5m, with minimum height of the contact wire maintained at 5.2m. Additionally, it features ballastless track with bi-block sleepers and Vaslo fittings.

LED lighting is provided every 10m in the tunnel and two traction power supply substations are located near Cherlopalli and Adurupalli.

Last month, Indian Railways signed a memorandum of understanding (MoU) with RailTel Enterprises (REL) to upgrade signalling systems in four different sections.

The project costs around Rs16.09bn ($230.5m) and will take two years.