The Political and Structural Significance of the Atal Tunnel

The Rs 4,000-crore Rohtang Tunnel, the world's longest motorable roadway at an altitude of over 3,000 metres, is ready for opening next month following the completion of civil works that began a decade ago.

The tunnel will be opened by Prime Minister Narendra Modi by mid-September, Satish Paretkar, Director of Hydro & Underground business unit at Afcons told PTI.

The 9-km-long tunnel under the Pir Panjal range is named after former Prime Minister Atal Bihari Vajpayee.

Earlier it was scheduled to be completed by May 2020, in a revised estimate, but the Covid-19 pandemic pushed back the completion by a few months due to lockdown conditions.

Salient features of the Rohtang tunnel

The unique features of this tunnel begin a fair distance away from it on the approach roads to the north and south portals.

Bridges in rivers on the approach to the tunnel from both the portals have also been completed.

Snow galleries have also been built at the approach road to the tunnel from Manali side, and this will ensure all-weather connectivity.

The following parameters have been set in design:

(a) Upper tolerance limit for concentration – 150ppm

(b) Visibility factor – 0.009/m

(c) Vehicles

(i) Cars – 3000 Nos.

(ii Trucks – 1500 Nos.

(d) Peak hour traffic – 337.50 PCUs

(e) Design vehicular speed in Tunnel

(i) Maximum Speed – 80 km/h (50 mph)

(ii) Minimum Speed – 30 km/h (19 mph)

Project Cost : Approximately Rs.(INR)40 billion (Euro 250 million)

Safety features:

A 2.25 m high and 3.6 m wide emergency tunnel will be integrated in the tunnel cross-section beneath the main carriageway for evacuation during emergencies.

The latest Austrian tunnelling method and ventilation system- semi transverse type considered as safest will be adopted for this project. Heavy snowfall in the Rohtang Pass area is a major concern, especially on the approach roads to the main tunnel. To prevent any damage to the roads and to ensure the safety of the roads and tunnel users alike, avalanche control structures are being constructed. The design for these structures is being provided by the Snow and Avalanche Study Establishment of DRDO.

As the Rohtang tunnel will witness heavy traffic, vehicular management and checking pollution is a priority. For this, CCTV cameras would be placed at a regular distance and will be further connected to two monitoring rooms on both ends of the tunnel. Sensors to check the pollution level will keep on updating the data and if the record is above the desired level, then quantity of fresh air injected inside the tunnel would be increased. Pollution level will be controlled within 90 seconds adding that two heavy duty fans each on both openings of the tunnel will be installed to inject fresh air inside.

The tunnel will have semi-transverse ventilation system, where large fans would separately circulate air throughout the tunnel length. Another safety feature being added is that fire inside the tunnel will be controlled within an area of 200 metres and fire hydrants will be provided on specific locations.

The tunnel will also have public announcement system to make important announcement in emergency situations for which loudspeakers will be installed at regular distances.

Genesis of the project

First time the Moravian Mission in 1860 has talked about the possibility of a tunnel through Rohtang Pass to reach Lahaul and later prime minister Nehru talked about a rope way to Rohtang Pass which again made a point of discussion among the local tribes. After almost 139 years of the first instance, when Atal Bihari Vajpayee became the prime minister and a resident of Lahaul, Arjun Gopal, was known as childhood friend of Vajpayee, the locals insisted Arjun Gopal to meet the Prime Minister and talk about Rohtang Tunnel. Then he moved with two of his companions Chhering Dorje and Abhay Chand to Delhi and after continuous discussions of about one year, finally Prime Minister Atal Bihari Vajpayee agreed and visited headquarter of Lahaul in June 2000 and declared that the Rohtang Tunnel will be constructed. A feasibility study for the construction of a tunnel across Rohtang Pass was conducted by RITES.

Rohtang tunnel was planned for ensuring an all-weather road route to strategically important areas of Ladakh and providing round-the-year connectivity to the remote Lahaul-Spiti valley. However, the construction of Rohtang tunnel will provide all-weather connectivity only to the Lahaul Valley of Himachal Pradesh up to Kyelang (Keylong). The all-weather road to Ladakh will require more tunnels: either at Shikunla, or at the passes located on the present Leh-Manali road for a year-round road connectivity to Ladakh.

The project was conceived in 1983 and announced by prime minister Atal Bihari Vajpayee on 3 June 2000. However the project did not take off.

The project was estimated to cost ₹5 billion in 2000 to be completed in seven years. On 6 May 2002, the Border Roads Organization was entrusted with the construction of the tunnel.

However, still the work did not progress much and the project did not move beyond the tree-felling stage by May 2003. By December 2004, the project cost estimate had escalated to ₹17 billion. In May 2007, the contract was awarded to SMEC (Snowy Mountains Engineering Corporation) International Private Limited, an Australian company, and the completion date was revised to 2014. Despite multiple announcements that the work on the tunnel would begin in 2008, no progress had been made by November 2009.

The work was awarded to a joint venture of AFCONS Infrastructure Limited, an Indian construction company of Shapoorji Pallonji Group, and STRABAG AG, Austria in September 2009 after the Cabinet Committee on Security cleared the Rohtang Tunnel Project. The drilling of the Rohtang Tunnel through the Himalayan ranges began on 28 June 2010 at South Portal 30 km (19 miles) north of Manali. Some of the anchoring and slope stabilization work was sub contracted to Spar Geo Infra Pvt Ltd.

The Border Roads Organisation (BRO), a tri-service organisation of the Defence Ministry specialising in road and bridge construction in difficult terrains, is overall in-charge of the project. It had initially estimated that the tunnel would be ready for vehicle flow by 2015.

On 25 December 2019, former Prime Minister Atal Bihari Vajpayee's birthday, the tunnel was renamed after him and dedicated to the nation by the Prime Minister Modi.

Challenges in the Rohtang tunnel project

The construction teams faced fast flowing water from Seri Nullah, which flowed on top of the tunnel route and impeded construction efforts. The sheer volume of water prevented construction for several months while project engineers grappled with a way to tackle the problem. The rock structures faced by the engineers too caused impediments.

A BRO official told The Indian Express on a site visit that the south portal of the tunnel had schist, migmatites and phyllite rocks while the north portal had incoherently folded gneiss and biotite schist which were brittle and ductile in nature.

What is the strategic advantage of the Rohtang tunnel?

Cutting through the Pir Panjal range, the tunnel will reduce the distance between Manali and Leh by 46 km. The Rohtang Pass, to which the tunnel provides an alternate, is located at a height of 13,050 feet, and a journey from Manali Valley to Lahaul and Spiti Valley, which normally takes around five hours to negotiate, would now be completed in little over ten minutes.

While the tunnel will be a boon to the residents of the Lahaul and Spiti Valley who remain cut off from the rest of the country in winters for nearly six months due to heavy snowfall, the tunnel will provide almost all-weather connectivity to the troops stationed in Ladakh.

The ‘strategic’ Rohtang tunnel, christened as Atal Tunnel and connecting Manali to Leh will change the fortunes of the region and help promote tourism, Prime Minister Narendra Modi said on Wednesday.

Speaking at an event held to name the underground motor passage after former Prime Minister Atal Bihari Vajpayee, Modi said the project is very important for the country.

"Rohtang Tunnel, connecting Manali in Himachal Pradesh to Leh in Ladakh, will now be known as Atal Tunnel. This strategic tunnel will change the fortunes of this region. It will help in promoting tourism in the region," he said.

Once thrown open, the tunnel will provide all-weather connectivity to remote border areas of Himachal Pradesh and Ladakh which otherwise remain cut off from the rest of the country for about six months during winters.

Director-General of Border Roads Organisation Lt General Harpal Singh visited the Atal tunnel (Rohtang tunnel) near Manali on the Manali-Leh highway to review the progress of work.

Since the India-China face-off in the Galwan valley of Ladakh region, the need is being felt from defence point of view to accomplish this ambitious project as soon as possible. This tunnel, when completed, will cut short distance between Manali and Leh by 46 kms. The Manali-Leh highway is used by Indian army to supply essential material to the soldiers deployed in Ladakh region.

Due to its strategic importance, the progress of tunnel work is being closely monitored by the DG BRO through daily briefings. He himself has been frequently visiting the tunnel site. He was accompanied by Joint Secretary BRO Satish Singh from the Ministry of Defence today.

According to BRO sources, the DG BRO inspected the progress related to civil, electrical and mechanical works. He appreciated the efforts of the BRO workforce, who is working relentlessly to accomplish this project as soon as possible.

The BRO is planning to hand over this project to the nation in September. Prime Minister Narendra Modi is keen to inaugurate this tunnel, which would provide all-weather connectivity to the residents of Lahaul valley in tribal district Lahaul Spiti.

Currently the residents of the Lahaul valley are cut off from the road facility from the rest of state for months every year during winter season, because of the closure of Rohtang pass, which receives heavy snowfall during winter season, which blocks the traffic movement completely between Manali and Keylong.

More than 700 men are working in shifts to complete the work of the tunnel. When the COVID-19 lockdown was imposed, proactive measures were taken and the project was started again with the state government's coordination and soon to be inaugurated!