Prime Minister Narendra Modi on Saturday inaugurated strategically important 9.02-km-long all-weather Atal Tunnel, which the government said, is the longest highway tunnel at an altitude of 3,000 metres.

The tunnel is equipped with "ultra-modern" facilities and connects Manali to Lahaul-Spiti valley, providing greater access to Leh, the capital of Ladakh where Indian Army troops are engaged in a prolonged stand-off with Chinese forces along Line of Actual Control.

In absence of the tunnel, the Lahaul-Spiti valley was cut off for about 6 months each year owing to heavy snowfall. It reduces the road distance by 46 kms between Manali and Leh and saves about 4 to 5 hours.

"It has state of the art electromechanical systems including semi transverse ventilation, SCADA controlled fire-fighting, illumination and monitoring systems. The tunnel has ample safety features built into it," according to the Prime Minister's Office.

9.02 km long Atal Tunnel that connects Manali to Lahaul-Spiti valley inaugurated by Prime Minister Narendra Modi

The Border Road Organisation (BRO) has built an escape tunnel below the main tunnel for cases of any eventuality. The horseshoe-shaped, single tube tunnel has two lanes with a roadway of 8 metres and an overhead clearance of 5.52 metres.

Atal Tunnel, which was announced by former PM Atal Bihari Vajpayee in 2000, has been designed for traffic density of 3,000 cars per day and 1500 trucks per day with maximum speed of 80 km/hour.

Strategic importance of Atal Tunnel

Highlighting the strategic importance of the tunnel, Prime Minister Modi, in his address post inauguration, said that "such border connectivity projects will aid the security forces in ensuring regular supplies to them and also in their patrolling."

In addition, Modi said that the tunnel will aid speedier economic progress in the region.

PM Modi inaugurated the strategic 9.02-km-long Atal tunnel.ANI

"Atal Tunnel is also going to give new strength to India's border infrastructure and would be a living proof of world-class border connectivity. He said despite the longstanding demand to improve the infrastructure and overall development of the border areas, plans were made only to languish for decades without any progress," the Prime Minister told a gathering of Defence Minister Rajnath Singh, Himachal Pradesh CM Jai Ram Thakur and BRO officers.

Accusing the previous governments for "neglecting the project", Modi said, "Atal ji laid the foundation of the approach road for this tunnel in 2002. After Atal ji's government, the work was so neglected that only 1,300 metres of tunnel could be built till 2013-14 -- only about 300 metres each year."

Quoting "experts", PM Modi claimed that the project would have completed in 2014 had the progress continued with that pace. "After 2014, my government fast-tracked the project and completed the work which would have been done in 26 years," he added.

Notably, the tunnel has been inaugurated at a time when the Indian Army is stocking up the supplies in Leh, in anticipation of a longer than expected face-off with China. Defence experts say the Army is expected to remain positioned in highly-rough terrain throughout the winters when weather becomes very harsh and connectivity is cut due to heavy snowfall.