T’gana rescuers reach site of tunnel boring machine

Rescuers working at the site of the Srisailam Left Bank Canal tunnel project in Telangana on Sunday managed to get close to the boring machine near which eight workers were left trapped on Saturday after the structure collapsed. They were, however, still not able to reach the trapped workers, officials aware of the details of the operation said.

“It appeared like a cloud burst!” was the first reaction of Deepak Jain, additional general manager of Jaiprakash Associates Ltd, overseeing the tunnel boring work at the project near Domalapenta village in the Nallamala forest hill range.

Jain was outside the tunnel when its roof caved in at the 14th km with a loud sound, leading to the trapping of eight workers, including two engineers. But he was the first to come to the rescue of the workers who rushed out soon after the disaster.

“It was not just cement-concrete blocks and mud that fell on the boring machine, but there was a sudden gush of water from the hole that was formed on the roof. It was a deluge,” the AGM said, quoting one of the workers.

All the 57 workers, who managed to escape from the jaws of death, were relocated to a separate camp a few kilometres away. “They are still in a state of shock and not in a position to talk,” a site engineer, who refused to be named, said.

One of the lucky ones who escaped, Shashikumar Reddy, an assistant engineer who joined the job only three months ago, is yet to recover from shock. “Reddy was pushed away by the swirling water for about three kilometres. Such was the force of the water that gushed into the tunnel from the roof that his clothes were completely torn and both his knees were badly injured,” said SLBC project chief engineer Ajay Kumar.

According to deputy executive engineer A Srinivas, it is extremely difficult for the workers to undertake the job in the tunnel while operating the tunnel bore machine (TBM). “There is hardly any space around the machine, except on the top where they have to fix the cement concrete blocks. So, when such a massive accident takes place, there is little scope for escape for those who are working towards the front side,” he said. “The possibility of workers clinging to the walls to survive is also very less,” he said.

He said there has been a steady stream of water, up to 3,200 litres per minute, flowing into the tunnel and the authorities are continuously dewatering the area. “But because of the sludge, the task is becoming difficult,” he said.

Jain said even after the removal of the slush and water around the machine, “we cannot say there will be no gushing of water and mud from the open hole on the roof. If there is a continuous flow of mud and water, from the roof, then, we cannot continue the work till we identify the fault lines,” he added.

The tunnel is part of the Srisailam Left Bank Canal (SLBC) project, which seeks to provide 30 tmc ft (thousand million cubic feet) of water to Nalgonda from the Srisailam reservoir. The project started in 2005 during the tenure of then chief minister YS Rajasekhara Reddy in the undivided Andhra Pradesh. It came to a halt in 2017 during the BRS regime. The construction work restarted four days ago.

“Soon after the roof collapsed, the electric wires snapped, plunging the tunnel into darkness. Searching for the trapped men has become difficult due to darkness. It seems water filled the tunnel after the cave-in and formed a slush,” state minister for irrigation N Uttam Kumar Reddy, who reached the tunnel site, said.

An official of the Robin India Ltd said the ventilation system inside the tunnel remained functional, ensuring oxygen supply to the trapped workers. “We stopped the excavation work immediately and supervisors quickly evacuated as many workers as possible,” the official said, requesting anonymity.

Reddy added that teams of the National Disaster Response Force (NDRF) and State Disaster Response Force (SDRF) were part of the rescue efforts. “We have also called for the army to help rescue the trapped workers,” Reddy said.

On November 12, 2023, a part of the cavernous tunnel between Silkyara and Barkot collapsed when the workers were attempting to complete the final 400m stretch of the 4.5km-long tunnel on the Yamunotri National Highway. They labourers were rescued 17 days later after a daring but painstaking operation.