120 hours and counting: Uttarkashi tunnel rescue likely to start only Friday midnight

Union minister of state V.K. Singh, who visited the accident site in Uttarkashi on Thursday in the company of Uttarakhand chief minister Pushkar Dhami, assured people that the 40 workers trapped since the morning of 12 November, when a part of the under-construction tunnel collapsed, have access to food, water and light. They are trapped in an area where the tunnel has already been constructed, he said, and hence they also have sufficient space to stretch their limbs and walk around.

While the information is immensely reassuring, the suspense continues as the temporary tunnel is readied by joining pipes of 3-feet diameter. Once the pipe is put in position, hopefully by Friday midnight, the workers will be hauled out one by one as they crawl through the pipe.

The 4.5-kilometre-long tunnel, under construction for the last six years, is complete barring a 500-metre stretch. The minister, however, brushed aside questions about design flaws, deviations from the Detailed Project Report and previous warnings of the under-construction tunnel having collapsed earlier as well. "This stretch of the mountain and the tunnel has been stable and held up for the last four years and more," the minister reminded the media, and said these obstacles were routine in the Himalayas.

The tunnel was to be completed two years ago. While the minister placated apprehension about the well-being of the trapped workers, the nation and especially the relatives of the workers are waiting with bated breath for them to come out safely.

This is what is known about the project so far:

• The tunnel is part of the project to reduce by 26 kilometres the road length between Uttarkashi and Yamunotri

• A part of the tunnel collapsed early on Sunday morning, trapping 40 workers and junior engineers approximately 245 metres from the mouth

• Experts say that tunnels either use the ‘drill and blast’ method or tunnel boring machines (TBM) which cost a whopping Rs 200 crore and are imported but are safer (the shallow tunnels for the Delhi Metro were drilled by TBMs, for instance). TBMs, however, cannot be used for tunnelling through shorter mountains, say, less than 500 metres in height. As such, blasting the rocks apart after drilling a hole to set explosives is the commonly used method in the Himalayan foothills

• The accident, experts say, could have occurred either because a patch of loose rocks went unnoticed while drilling the tunnel or because seepage of water weakened the rocks after the initial portion of the tunnel was completed

• There are machines like ‘Stress Meters’ and ‘Deformations Meters’ that geologists use to test the strength of the rocks. Samples are also sent for examination before the start of a project

• The ‘Char Dhaam’ project aggressively promoted by the government, which involved widening of roads, tunnelling and use of massive and heavy machinery, experts had warned, required more careful planning and execution to avoid disasters.

• Geologically, Himalaya is a young mountain range and still undergoing changes. Former chief minister of the state, Trivendra Singh Rawat, had also warned officials against construction of tunnels

• The worst apprehension of experts seem to be coming true as not enough time and research are going before commencement of construction. Experts also believe that it is important to ensure that ‘independent’ experts are brought in to examine project and design reports. India, however, does not allow international experts and geologists to examine projects in the Himalayas on grounds of national security. It is a paradox that the same experts’ help are however sought after accidents