Hyderabad, Feb 25 (IANS) Rescue teams involved in the intensive operation to pull out eight persons trapped in an under-construction tunnel which collapsed in Telangana's Nagarkurnool district for three days are re-drawing the strategy to move forward in the last stretch of 40-50 metres.

Facing several hurdles, the authorities have roped in experts from the Geological Survey of India (GSI), the National Geographical Research Institute (NGRI), and the National Remote Sensing Agency (NRSA) to assess the situation and suggest the way forward for rescue operations.

Multiple teams of the National Disaster Response Force (NDRF), Army, Larsen and Toubro (L&T) and various agencies are moving cautiously as the stability of the tunnel has to be taken into consideration while undertaking any excavation work.

While continuing dewatering, the rescue teams were waiting for the experts to suggest the next step.

Various agencies including the Army, Navy, SDRF, National Highway Infrastructure Development Corporation, and Singareni Collieries Company Limited have mapped out the tunnel operation. They prepared a detailed diagram to help prepare a rescue strategy to locate and reach eight trapped men.

Officials said the conveyor belt used to bring back debris from the tunnel after excavation was not working.

Minister for Roads and Buildings Komatireddy Venkat Reddy said the efforts were on to repair the belt.

Deployment of advanced equipment like endoscopic and robotic cameras to trace the trapped men has not yielded results. According to officials, the robotic camera is not working.

Tunnel Boring Machine (TBM) broke into two after a portion of the tunnel roof collapsed on the morning of February 22.

The tail unit of TBM was found 50 metres before the end of the 14 km long tunnel. The head portion of the tunnel has a safe container for workers to take shelter in an emergency. It was not known if the trapped men could enter the container when the roof collapsed and water seepage became intensive.

The drone was also not accessible after the TBM tail unit. The 50-metre area is filled with sediments and debris hampering further movement of the rescue teams for the last 24 hours.

The tunnel map prepared by the rescue teams shows that the loco track is accessible up to 12 km though the track is available for a length of 13.5 km.

There is no water stagnation in the tunnel till 10.7 km point. The teams found 1.5 feet water at 10.95 km There is 2 to 2.5 feet water at 11.30 km.

The NDRF team has also deployed a trained sniffer dog for the rescue operation but the same could not be pressed into service due to slush.

A team of expert rat miners, known for a successful rescue operation in the Silkyara Bend-Barkot tunnel in Uttarakhand in 2023, has arrived, but their services have not yet been used. In Uttarakhand, the team rescued 41 workers who were trapped inside the tunnel for 17 days.

The team members, however, said that the situation in Telangana is different. In the Uttarakhand tunnel, it was rock and they used hand tools to reach trapped workers through small pits. However, the SLBC tunnel is filled with water and mud.

Deputy Chief Minister Mallu Bhatti Vikramarka, Irrigation Minister Uttam Kumar Reddy, Roads and Buildings Minister Komatireddy Venkat Reddy and Tourism Minister Jupally visited the tunnel and reviewed the rescue operations with various agencies.

Uttam Kumar Reddy said he invited Harpal Singh, former engineer-in-chief of Border Road Organisation to share his expertise and knowledge for the rescue operation. The minister quoted Harpal Singh as saying he had never seen such a complicated tunnel accident.

Two workers were injured and eight others were trapped when a portion of the tunnel being dug as part of SLBC collapsed near Domalapenta.

A total of 50 persons were working on the left-side tunnel when the roof collapsed for three metres. The accident occurred at the 14th km point.

While 42 workers came out of the tunnel, the remaining eight were trapped. Those trapped include two engineers and two machine operators.

The trapped men are from Jharkhand, Uttar Pradesh, Punjab and Jammu and Kashmir.

Project manager Manoj Kumar (Uttar Pradesh), Machine engineer Srinivas (Uttar Pradesh) and machine operators Sunny Singh (J&K) and Gurpreet Singh (Punjab) are among those trapped.

The four workers from Jharkhand are Sandeep Sahu, Santosh Sahu, Anju Sahu and Jagta Khes.

--IANS

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