Wearing safety helmets, gumboots and bright orange fluorescent jackets, a battery of young men are working round the clock to see the light at the end of the 3-km-long Dharam Khand tunnel 3 and 5.96-km-long horse shoe tunnel 5 in Reasi district of Jammu.
Only one 220-metre patch is left and the breakthrough is expected anytime in August for tunnel 3. Inside T5, excavation work up to 1,179 metres is complete. T5 starts from the proposed Reasi Railway Station, pierces the hilly terrain in the Gran village and is set to emerge in village Bakkal. The tunnel is 700 m below the hilltop.
The workforce - most of whom are in their early twenties - on ground zero is considered the backbone of the rail link connecting Kashmir valley with the rest of India.
Of the 70-km Katra-Dharam segment, a crucial link on the Udhampur-Srinagar-Baramulla rail link, 59.46 km is covered with 18 tunnels. The longest tunnel is likely to be 11.165 km though survey is still underway.
Konkan Railway Corporation director (way & works) Rajesh Tripathi told The Pioneer, "Inside T3, the geology is very difficult. We encountered fragile dolomite rocks intercepted with calcite intrusions. These are classified grade IV in rock formation." He added that it is considered poor quality rock for tunnel construction.
Tripathi said water is still oozing out of the tunnel - some 150 litres per metre - and this dripping causes a hindrance. However, he said, "We are taking all precautions to ensure the safety of our workforce. We carried out controlled blasting inside the tunnels to minimise damage. In T5, heavy seepage and potential for formation of cavities at crossings of shear zones poses a huge challenge."
Hem Raj, resident of Chamba in Himachal Pradesh, working on the project site for the last eight months, told The Pioneer, "It is not easy to work for long hours. We have to brave adverse conditions wearing a smile. We need lot of motivation and team spirit to survive."
"Once we come inside the tunnel, we say our prayers as we do not know what lies in store for us. It is only when we step out of the tunnel and breathe fresh air do we feel connected with the outside world," he added.
The workers stay near base camp and are provided with food and other basic items of use by the contractor. Hem Raj said, "Whatever savings I manage, I send back home to my family in Chamba."
A large number of workers - some 25 - from Nepal are also here. One of them, Sagar, is working on the drilling machine inside the tunnel. He too struggles in pitch dark conditions, with gaseous emissions takes a heavy toll on the human anatomy. "Our site engineers show us the way and lead us," he said.
Site engineer Virendra Rao told The Pioneer, "Around 250 workers, skilled labourers and technicians manning the drilling and other machines are working in different shifts to meet the deadline. We concentrate on completing 2 metres of tunnelling daily. Sometimes, we overshoot the target and sometimes we fell short."
GB Nagendra, Konkan Railways chief engineer in-charge, said that it is difficult to assess complete geology in advance. As work progresses, adjustments in design have to be made.
Executive director (projects) Rajesh Aggarwal explained, "Initially, we adopted the drill and blast method for the tunnelling. Now, the technique of New Austrian Tunnelling Method (NATM) has been adopted. This is based on 'design as you proceed'. After each blast, the geology is studied and requisite support in the form of shotcrete, rock bolts and lattice girders is provided."
Aggarwal also said longer tunnels will be provided with a forced ventilation system. Tunnels more than 3 km in length will be given a service road of 3 m width or a separate access and rescue tunnel.