3 days ago
How it was done: ‘For 12 years, we ate, lived, breathed the Chenab'
'In the beginning, there were no roads. We would go by foot, on mules and ponies, perch ourselves on a ledge and even camp on cliffs at night as we surveyed how we could build roads to move the equipment to the bridge site. I knew the Sahyadris. I was just a boy from Mysore and here I was, high on the Himalayas, so very different, terrifyingly high and so very alien.'
The 'boy from Mysore' is L Prakash who, as Chief Engineer of the Konkan Railways' Udhampur-Srinagar-Baramulla Rail Link (USBRL) project, was responsible for laying the roads.
Now an Executive Director, he recalled the early days when he supervised the 30 km-long road stretch and 350-m long tunnels to reach the bridge site.
'We would break through the rocks and advance by a few metres in a whole day. Finding the light at the other end of the tunnel took months. Frequent landslides meant that we would have to abandon the site and find a new tunnel site. It was a classic case of one step forward and two steps backward.'
But Prakash drew inspiration from local residents who rappelled up and down the steep cliffs, tethered to a simple rope, to help survey teams analyse the rocks.
'I learnt a lot from the locals. They opened their homes to us, cooked food because we would be stranded up there for days. The rain would slap us almost every afternoon. And then we would huddle around the campfire. Without the road, it would take a day to come down to Reasi town. The locals walked, used ponies and crossed rope-bridges. They would carry down the sick on charpoys, strapped to their backs,' he said.
Once the survey was done, he would travel downstream by boat. 'The river currents are strong. But the upstream currents are stronger.'
Prakash was responsible for laying the foundation plinths that would hold up the pylons and girders. 'Each foundation was the size of a football field. And constant rain meant that they would be washed out and seasoned all over again,' he said.
The earth was something that Santosh Kumar Jha, CMD of Konkan Railway, thought he could understand given his background in geology. 'The Himalayas are young fold mountains. You are cutting through strata which are maturing and have not become rock yet. And each stratum is different and shifting all the time. The Chenab Valley is a Grade V seismic zone, so any design had to have the swing feature to move with the rocks. There was no template. Everything was on-site innovation,' he said.
Beating nature was the biggest challenge. The team tested the rocks with pinhole boring and then filled up the loose gaps in the strata with concrete. Then they inserted the rock bolts, each of them about 30-40 m long to reinforce the holding layer. 'We would just finish one rock face over several hours. Then we pumped in water jets at a pressure of 300 bars so that the bolt rods expanded inside and could pack the layers even closer. We used a polyurethane grout which increases the standing time of the water to avoid flooding in the tunnel,' Jha said.
The arch bridge design, he said, was done over one-and-a-half years. 'It is made up of interlocking beams and girders. A suspension bridge would have been lighter but it would not have borne the weight of a 300-tonne railway coach or withstand wind speeds of 266 kmph. So we built hollow girders so that they could be moved up by boats, then filled them up with concrete at the site so that they became weighty and sturdy,' said Jha, who had supervised many such improvisations on the site.
So the day the two ends of the arch were joined in the middle, he was a happy and tense man. Happy that the arch bridge was ready, tense because even a millimetre-long misalignment in the joints could destabilise the bridge. 'We had to make thousands of calculations and recalculations at each stage of launching the bridge to get the nuts, bolts and grooves to fit into each other,' he said.
Prakash recalled how the team used Mi-26 helicopters of the Army to lift the machinery in the initial days. 'But there was a lot of human or superhuman effort. At the tallest piers, workmen soared across on an open platform, tethered to girder rails to dodge the winds and rain. Once on the girder, they would have to stay there for 12 hours before they could be hauled down. They would carry their tiffin in their suits. We even had a disposable, mobile toilet which we sent up and parked on the girder through the shift. There were days when the cranes malfunctioned and we would send up our men in cage lifts to repair them. It took some acrobatics from the crew,' he said.
Prakash rarely left the site. 'All of us were mostly from the southern states, toiling hard to build a megastructure in the Himalayas which we were not familiar with. So there was this pressure of leaving a legacy. Steel expands and contracts easily with temperature and for the most effective interlocking, needs a perfect temperature after sunset. So whenever we would install a portion of the bridge, we did that in the evening. Mornings were about making the girders,' he said.
As a result, most engineers would go back to their quarters only to sleep a few hours. 'We ate, lived and breathed the Chenab. There was such spontaneous camaraderie that we would have meals and a game of basketball or chess together. Most of us stayed away from our families for 12 years. Now when they take the first ride, hopefully my children will understand why I had missed their growing-up years,' Prakash said.
In terms of technology, Jha remembers that the site units were completely automated. 'We had self-climbing cranes, and had to crunch, flip, twist and extend their antlers to do the job. We talk about 3D printing today but a long time ago our CNC machines cut the steel sheets into various shapes, sizes and designs, according to the drawings fed into the computer attached to it,' he said. Each pre-fabricated part, no matter how tiny, was lab-tested for air leaks and lastability, cleared and then moved to make a bit of the giant curve.
Despite difficulties, Jha said, the engineers rarely gave up. 'In fact, over the last few years, many women engineers joined the project too. And we have even increased salaries of staff at the Chenab project,' said Jha, who was taken in by the people who lived along the river banks.
'Just days before the inauguration, some of them came to me saying that they would lose their jobs now that the project was over. They have become family, so we will be redeploying them in other parts of the J&K railways or other Konkan Railway projects. Many of them have acquired skills on the job which have indeed made them valuable manpower for any project,' he said.
