The south end of the Rohtang Tunnel at Dhundi, 23 km from Manali. Photo by writer

MC Thakur

MANALI, DECEMBER 2

With winter setting in and anticipated snowfall closing the 13,050- foot Rohtang Pass, gateway to Lahaul- Spiti, every year for almost six months, the Rohtang Tunnel Project work like every year has almost come to a halt at North Portal near Sisu in Lahaul Valley. There will be no work at the North Portal till May 2017 when the Rohtang Pass is likely to open again. However, the work will continue from the South Portal near Dhundi throughout the winter, said Brig DN Bhatt, Chief Engineer Project Rohtang Tunnel, today.As of now the excavation at the North Portal has been completed for 3.7 km, from South Portal 3.8 km while 1.3 km remains to be excavated.The Chief Engineer further said that South Portal has encountered fractured and weak rock. However, the project work is going round the clock overcoming the challenge. The Chief Engineer confirmed that all efforts are being made to ensure that the breakthrough is achieved in July-August 2017 as planned.Brig DN Bhatt also informed that the project has seen unprecedented progress. The excavation in 2016 has reached 2161 m as against the highest progress achieved earlier in 2011 of 2077 m. It is expected that excavation by December 31, 2016 will reach 2,250 m mark. Similarly, other activities like benching, emergency tunnel, etc, have also progressed considerably to achieve the completion target by the second half of 2019.Brig DN Bhatt further said that construction of this tunnel has not been easy. Whatever challenges thrown have been met successfully. Worst was the water and muck ingress in Seri Nullah fault zone, emission of hazardous gases, encountering of high pressure entrapped gases in the rock and frequent encounter with loose and weak rocks needing additional supports to be installed. Ventilation also became a challenge.Brig Bhatt also emphasized that strict quality control for material and workmanship is being maintained at both the portals. Labs with required testing equipments are being maintained at both portals and regular tests on materials are carried out.