The Sela Tunnel that will enable all-weather access to western Arunachal Pradesh’s Tawang near the Line of Actual Control (LAC) with China will be ready by the end of this year.
Prime Minister Narendra Modi will, in all probability, inaugurate the tunnel — a rare engineering feat — in January next year, a little under four years after he laid the foundation stone of the mega project.
The Border Roads Organisation (BRO), which is constructing the tunnel, said that the project is nearing completion with the ‘finishing touches’ like paving and electrical works being undertaken now.
The completion of the project will be another landmark achievement of the Modi government. Not only is the project an engineering marvel, it will mark many firsts in the world.
Two tunnels have been constructed at a height of a little over 3,000 metres (9,800 feet) so that vehicles travelling between Guwahati and the strategically-located Tawang can bypass the 13,800 feet-high Sela Pass that remains under snow cover for many months every year.
The first tunnel, which is 980 metres long, will cut through a longitudinal ridge. After emerging, it will be connected with a 1,200-metre-long road to the second tunnel which is 1,555 metres long.
The second tunnel which cuts through the Sela-Chabreal ridge below the Sela Pass has two tubes — one two-lane tube for traffic and a parallel escape tube for emergencies.
A seven-kilometre-long approach road from the existing National Highway 13 (the Balipara-Chariduar-Tawang or BCT road) to Tunnel 1 has already been constructed.
Both the tunnels have an overhead clearance of 5.5 metres and that will allow all military equipment, including battle tanks, heavy field guns and armoured vehicles to pass through easily.
The latest New Austrian Tunnelling Method (NATM) has been used to cut through the rocks and soil for the tunnelling.
The total length of the project, including the two tunnels, the link road and the approach road, is about 12 kilometres.
The total cost of the project is Rs 700 crore.
Strategic Significance Of The Project
Army vehicles carrying troops and vital equipment have to cross the Sela Pass which remains at the mercy of the vagaries of weather.
During the winter months — November to February and even mid-March — the Sela Pass remains under thick snow cover. Heavy snow-cutting vehicles and excavators have to be deployed round the clock to keep the road clear of snow.
Even then, only vehicles fitted with chains over their tyres can pass through, and that reduces speed to a maximum of five kilometres per hour.
During the monsoon season — late April to September — heavy rains often accompanied by light snow make the journey through the pass very difficult.
The heavy and incessant rains trigger minor landslides, thus delaying movement till the blockages are cleared.
The extreme and very adverse weather conditions throughout the year make even routine maintenance of the Sela Pass and a nearly 10km stretch of the BCT road very difficult to maintain. The perennially poor condition of the road forces vehicles to travel at a snail’s pace.
The two-tunnel project will reduce journey time between Bomdilla and Tawang by over one hour. More importantly, it will facilitate round-the-year and quick access to Tawang.
Tawang, which houses India’s largest Buddhist monastery and is the land of the Monpa tribe, is also a strategic military base and about 53 km south of the border with China.
Providing easy access for soldiers and military hardware to Tawang and beyond is of crucial importance since the town is about 330 kilometres north of Tezpur which is the headquarters of the Indian Army’s 4 Corps that oversees the western part of the LAC in Arunachal Pradesh.
In 1962, Chinese troops had occupied Tawang and came very close to Tezpur before withdrawing.
The Many ‘Firsts’ Of The Project
The second tunnel, which is two-lane, has acquired the distinction of becoming the longest bi-lane tunnel at an altitude of above 13,000 feet.
This project has already created history for the fast pace of construction. Even the Covid-19 pandemic, which brought all activities to a complete standstill all over the world, caused only a small delay in the project.
Had it not been for the pandemic, the tunnel would have been operational by March this year. The speed at which the project has been completed even outpaces that of similar projects in China, which has earned an enviable reputation for fast-paced construction of mega projects.
The tunnels can withstand high-intensity earthquakes, thus making them unique. That’s because the eastern Himalayas are young mountains comprising loose rocks, boulders and loose uncompacted soil. That renders even overground constructions in the mountains very difficult, and this difficulty increases manifold in the case of subterranean construction like the two tunnels.
Making them earthquake resistant is thus an engineering marvel and a first in the world in such conditions.
Also, Arunachal Pradesh lies on the windward side of the Himalayas that are lashed by incessant rains and fierce winds. That makes any construction activity very difficult.
In contrast, Chinese-occupied Tibet lies on the leeward side which is dry and facilitates easy construction.
The BRO clocked about 100 metres of tunnelling every month even during the pandemic. That is a world record in itself. Nowhere else in the world has tunnelling works at that altitude clocked such a pace.
The project has also earned the unique distinction of beating cost overruns that have dogged almost all infrastructure projects in the country till the Modi government came to power in 2014.
Considering the magnitude of the project and the adverse climatic and geographical conditions, the project stands out in the world for its low cost (Rs 700 crore). Similar projects elsewhere in the world, leave aside India, would have cost much more.
In contrast, the 9.02 km Atal Tunnel — the longest single tube tunnel above 10,000 feet in the world — costs over Rs 3,200 crore. That was because of the time overruns caused by the lethargy of the United Progressive Alliance (UPA) government.
A comparison with the Atal Tunnel that took over 20 years to complete would be in order. Prime minister Atal Bihari Vajpayee announced the project in 2000 and work actually started in mid-2003.
But after the UPA came to power, it got mired in delays that became the hallmark of all work by the Manmohan Singh government. It was only after the National Democratic Alliance (NDA) came to power that the pace of construction increased and the tunnel was ultimately inaugurated by Prime Minister Modi in October 2020.
There is no doubt that the Sela Tunnel, which will be ready by the end of this year, could be completed in under four years due to constant monitoring and strict deadlines set by the Ministry of Defence as well as the Prime Minister’s Office.
Never before in India’s history has such a project been completed in this record time, and that too during a pandemic-induced lockdown and myriad other restrictions and difficulties.
And that is why the BRO is well-justified in claiming that the Sela Tunnel will be a jewel in India’s crown.
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