Telangana tunnel collapse: Lack of oxygen, extreme humidity and broken conveyor belt hinder final stages of rescue operation

After days of physical and technical exploration, rescuers began cutting away the tunnel-boring machine (TBM) that lies between the end rock where the men are stuck and the rest of the passage on February 27. Another important breakthrough came when the ground-penetrating radar survey by the National Geophysical Research Institute located at least four anomalies in the area where workers were assumed to be trapped. This was believed to indicate the presence of human bodies. “Those anomalies turned out to be mere metal parts,” an official said.

On Monday, a handful of rat-hole mining experts and specialised workers from the Singareni Collieries started exploring the last 40 m of the tunnel, where the eight individuals were believed to be stuck, up to the end rock. The ventilation tube in this area had broken. “Lack of oxygen and sufficient access is hampering progress,” an official said, adding that the TBM blocking the tunnel path to the end rock has been cut away, but its parts are yet to be removed due to a non-operational conveyor belt extending to the mouth of the tunnel.

“The ventilation tube will be fixed, the conveyor belt will also be operational, and once parts of the TBM are removed, access will be clear. We are manually exploring the last 40 m for now. There is very little space, extreme humidity and little oxygen there. Maybe we can take bobcat equipment. We are in the last stages of this operation,” a senior official told indianexpress.com

From the start, there was a huge amount of slush and muck along with a heavy inflow of water that delayed the rescue operation. “Water keeps coming, but there is no water accumulation as such now, and silt removal has been ongoing manually for the last two days. The conveyor belt will be operational from Tuesday morning. The ventilation tube will also be installed by then. The TBM is cut completely, and because they are heavy materials, its manual removal is taking time. From Tuesday, once the TBM parts are removed, our teams will have full and proper access to the last 40 m. Then bobcat equipment can also go,” the senior official added.