The Sela tunnel project in China-bordering Arunachal Pradesh, which will allow faster deployment of weapons and soldiers to forward areas in the Tawang sector, has entered a decisive phase, with the defence ministry announcing that the final blast for one of the tunnels being constructed was conducted on Saturday, and all excavation work related to the project was complete.

The final blast for the 980-metre Sela tunnel (Tunnel 1) was conducted through a virtual ceremony by Border Roads Organisation director general Lieutenant General Rajeev Chaudhry, the ministry said in a statement.

“This feat has been achieved by the Border Roads Organisation amidst inclement weather and heavy snowfall. Once completed, it will be a lifeline as it will provide all weather connectivity to Tawang,” the statement said.

The project consists of Tunnel 1 and Tunnel 2, a 1,555-metre twin tube tunnel. The tunnels are coming up through two ridges west of the Sela pass. The project also includes the construction of two roads, measuring 7kmand 1.3km.

Tunnel 2 has one bi-lane tube for traffic and one escape tube for emergencies. Only tunnels longer than 1,500 metres have to have an escape passage alongside.

Prime Minister Narendra Modi laid the foundation of the project in 2019. It is expected to be completed by June 2022, officials familiar with the matter said.

The Sela tunnel, a ₹700-crore project announced by the government in 2018, will be the longest twin-lane tunnel above 13,000 feet in the world, and will cut down travel time to Tawang by at least one hour as well as provide all-weather connectivity.

Winter connectivity to Tawang over the 14,000-foot Sela pass posed a logistics challenge for the army for decades, with the movement of forces, weapons and stores severely affected for at least three months.

The Sela tunnel is a part of the Balipara-Charduar-Tawang road, one of the key strategic projects near the Chinese border.

As many as 50 engineers and 500 workers are directly involved in the construction of the Sela tunnel using latest Austrian tunnelling techniques. The Austrian method involves observing and studying the rock, and designing tunnel support according to rock behaviour.

Around 4,000 army and civilian vehicles are expected to use the tunnel daily. Its dimensions will support the movement of all types of army vehicles and military hardware including the Bofors guns that have to be towed to forward areas by Scania trucks. The Sela tunnel project will result in speedy mobilisation of troops and equipment as also enhance the army’s logistics support capability, experts have said.