A robot was sent along with rescue teams into the Srisailam Left Bank Canal (SLBC) tunnel in Telangana
| Photo Credit: By Arrangement

Efforts to trace the remaining seven persons trapped under the debris in the Srisailam Left Bank Canal (SLBC) tunnel in Nagarkurnool continued on Tuesday (March 11, 2025) – which is the 18th day since a portion of the tunnel collapsed. Rescue teams deployed a robot to help in the digging at one of the two spots indicated by sniffer dogs and Ground Probing Radar (GPR) scanning.

According to officials heading the rescue operation, about 110 rescue personnel from National Disaster Response Force (NDRF), State Disaster Response Force (SDRF), Singareni, SCR, Rat Miners and a few other agencies went inside the tunnel in the morning along with a robot from the ANVI Robotics and the two human remains detection dogs (HRDDs) to intensify the efforts to trace those still trapped under the debris. The rescue teams have also intensified de-silting, dewatering and digging work based on the most probable points identified by HRDDs.

Sources in the Irrigation Department stated that the digging operation at D3 point to trace those trapped was intensified as it is close to the D2 point where the body of Gurpreet Singh, operator of the tunnel boring machine (TBM), was extricated on Sunday. The rescue teams have taken up digging 12 feet deep till afternoon in two locations in the area nearby D2 point but nothing was found. They continued the digging work.

Though Gurpreet Singh was stationed in the first 15 meters (15 meters from the end rock) of the TBM when a portion of the roof collapsed, he was pushed back through mud for about 150 meters or after the tail-end of the TBM that runs for about 132.5 meters along with its support machinery system. The agencies are hopeful that more persons could be found in that area and the D3 point identified by sniffer dogs and GPR scanning falls in that area.

The D1 point, which was also identified by the sniffer dogs and GPR scanning by the National Geophysical Research Institute (NGRI), however, falls in the last 50 meters of the tunnel or 50 meters from the end rock which is in shear zone where the risk factor is very high to take up manual digging. The rescue agencies are strengthening the tunnel roof to prevent it from collapsing before moving forward for search operation as well as digging work, the sources explained.

The material cut from the damaged TBM parts was brought out of the tunnel with the help of locomotive trolleys and the silt was shifted out through the conveyor belt as well as locomotive trolleys. The officials said that the robot unit would become fully functional by Wednesday.