It was an unprecedented assignment. To sink a shaft hundreds of feet deep with no experience and no equipment was a huge challenge – more so as none of the officers had ever visited a mine or seen a shaft; nor had anyone studied mining engineering which is a specialised course. Although site preparations for Pokhran-I were also carried out by the army engineers, the task was of entirely different genre and did not entail sinking of subterranean shafts ab initio. Pokhran-I was conducted at a much shallower depth, using an abandoned dry well.

Site Selection

It was the month of January 1981. After an exercise in the desert, Col Dhingra asked me to accompany him for an operational reconnaissance. While driving to the Pokhran ranges he told me that the regiment had been tasked to sink a deep shaft of more than 500 feet. Repeatedly stressing the need for secrecy of the mission, he gave out other broad parameters. With maps in our hands, we traversed the ranges a number of times over the next two days to get a feel of its extent and zeroed on to a 9 sq km area that satisfied our security and secrecy concerns. It was well away from the highways and the villages. The aim was to identify a location where the water would pose minimal impediment to the shaft sinking operations. Hence, site selection was a highly critical step. But, how to go about it? We had no knowledge.

Within a week, I was back in the Pokhran area with a team of officers and men for detailed ground reconnaissance. After much scouting and ground survey, we selected four tentative sites that lay in the inter-dunal low-lying areas with least sand overburden. We also approached the nearby villagers to draw benefit from their local knowledge. We told them that the army wanted to establish a permanent camp and was looking for reliable water sources. We showed them the four sites and asked them to advise as to where the water could be found. We, of course, intended to eliminate those sites.

One evening, without informing us, the local headman brought a water diviner from Pokhran town and started appraising the sites. It was a full moon night. Water divining is an esoteric ancient method in which the locals have immense faith. It is believed that the flow of underground water induces some vital currents above the surface and a person with induction attributes can sense them through the movement of a freshly plucked twig. We watched in disbelief while the water diviner announced that none of the sites held abundant water. For us, it was just a gratuitous input of little consequence as the technique lacked scientific authentication.

We approached Central Arid Zone Research Institute (CAZRI) at Jodhpur for help in identifying water sources. They explained to us that the availability of perched aquifers (an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials) and underground streams depended on the geology and geomorphology of the area. CAZRI readily gave us geologic and topographic maps of the area. We studied them in detail, trying to relate them to the four sites selected by us. However, we were still not confident and sought application of a more exact and scientific method.

After much persuasion, Col Dhingra agreed to seek help of a local hydrogeology agency that specialised in water prospecting for wells. The agency was told the same story i.e. the army was looking for a camp site with a water source. The agency could carry out core drilling for geologic sampling up to 150 feet only. Once again, the core logging declared all the sites ‘unfit for sinking well’, meaning thereby that water was not available in exploitable quantity. Even the seismic survey gave the same report. Though encouraging, the reports were not a clincher as we had to go down to more than 500 feet.

After studying all the inputs (whatever be their worth), we selected two sites. In consultation with the higher authorities, it was decided to attempt digging at more than one site to cater for unforeseen hold-ups. However, as the work progressed, the authorities decided to go ahead with both the shafts.

Sinking of the Shafts

We sank shafts that were over 600 feet deep. The height of Qutub Minar is 240 feet. In other words, the depth of the shafts was two and a half times the height of the Qutub Minar; or, the shafts could have swallowed two and a half Qutub Minars.

The shafts were absolutely vertical in alignment. Looking up from such depths, against the darkness of the shaft walls, one saw a bright disc of sky of dazzling brilliance. It used to be an awe-inspiring spectacle. The night sky presented a sight of celestial blues. Memories of those experiences are still fresh.

Working at such depths is highly challenging. With water flowing along the walls, it is humid and hot. Normally, after 100 feet depth, temperature rises by one degree in every 30 feet. In the absence of fresh air, ventilation ducts are installed for pumping air from top. Simultaneous operation of multiple rock drills produced unbearable din and clouds of dust hanging in the air. Every soldier had to have ear plugs and wear protective eye goggles.

As water was being pumped out in stages, failure of any pump in the chain used to result in tonnes of water falling down on the working party. In case it happened while the drilled-holes were being loaded with explosive, the problems used to get compounded, causing considerable anxiety and delay. Due to a complete lack of any other source of light, everyone had to wear miners lamps on the helmet. One had to master the art of working with these lamps for long hours, having to turn head frequently to focus the beam.

All soldiers had to be repeatedly cautioned about the lethality of the falling objects. To drive home the point, they were shown that even a bolt falling from a height of 600 feet could split open a protective helmet due to its potential energy. Every single implement and tool had to be stringed and tied to prevent accidental fall from hand.

Two task forces were constituted and the work started at both the sites in Feb 1981 end without much fanfare. A small ceremony was held to invoke blessings of Ramdevra, the ruling deity of the desert whom the locals consider to be an incarnation of Lord Krishna. Thereafter, the diameter of the shaft was marked on the ground with pegs, and the digging commenced with picks and shovels. For a few days, hauling of the dug earth was done manually with mortar pans. Thereafter, the unit crane was deployed with a modified coal-tar drum. Soon the crane rope reached its limit. To prevent caving in, revetment of the walls was done with flattened CGI sheets and iron pickets.

operation-shakti

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