Inauguration of India’s First Longest Electrified Tunnel

INTRODUCTION: India’s first electrified rail tunnel built by Indian Railways was inaugurated between Chelopalli and Rapuru railway station and an electrified railway line between Venkatachalam and Obulavaripalli in Andhra Pradesh. The South Central Railway zone of the Railway Ministry had recently successfully completed the construction of the 6.7km tunnel in a record of 43 months.

On June 25th, 2019, two freight trains successfully ran between the Cherlopalli and Rapuru railway station, marking the full-scale operation of the newly built electrified rail line, thereby opening the viable railway connectivity between the Krishnapatnam port and its hinterland areas for seamless movement of freight train services.


The 6.7km long electrified tunnel, which has been built at a cost of Rs 437 crore,  has a total of 44 trolley refuges and 14 cross- passages in a horseshoe design is a game-changer for freight operations on this zone as it made freight services possible in Obulavaripalli – Venkatachalam – Krishnapatnam port line for a distance of almost 113km. 

The tunnel was built in straight alignment and 6,600 meters long and the height of the tunnel is 6.5 meters. The full – length lining of the tunnel is300mm thick. Further two traction power supply substations have been provided near Cherlopalli and near Adurupalli with the necessary switching railway stations in between. Overhead equipment maintenance depot has been setup at Rapuru along with a tower – car shed. Along with these, LED lighting has also been provided inside the tunnel at 10-meter intervals.


The railway line was completed at a cost of Rs 1,993 crore, with nine railway stations along with the routes, 60 road-under-bridges, and 146 bridges and two tunnels. The railway line reduces the distance by 72km for the train coming from Guntakal Division to Krishnapatnam and eases the traffic density in the Obulavaripalli – Renigunta – Gudur section. Facilitating the operation of freight trains on the Obulavaripalli – Venkatachalam – krishnapatnam port  route , the new line would also provide the shortest path for the Chennai – Howrah and Chennai – Mumbai railway routes. The line will also ease the congestion of both passenger trains and freight trains in the Vijaywada – Gudur – Renigunta – Guntakal sections.

This is also in the continuation of another achievement – Pir Panjal Railway Tunnel, which is also one of the most marvelous achievements of engineers as this tunnel is constructed in the middle of the Himalayas range in Jammu and Kashmir and also its distance of 11.215kms that is almost 7 miles. Pir Panjal Tunnel is also known as the T-80 tunnel that will provide the all-weather link to Kashmir Valley.

Another example is the Karbude Tunnel which is 6.5 km long and also one of India’s biggest engineering achievements that is located on the Konkan railway route near Ratnagiri in Maharashtra. This tunnel is the longest rail tunnel on the Konkan Railway line. 

CONCLUSION: The tunnel construction is one of the most difficult engineering works and are generally requiring a lot of expertise and It is a proud factor for India to have its longest electrified rail tunnel in Andhra Pradesh. This makes our country more innovative and unique and something to take inspiration from.

All image credit: Indian Railways