On Thursday, 6 March, two cadaver dogs from the Kerala Police, along with their handlers, were deployed to assist in the ongoing rescue.
Published Mar 06, 2025 | 2:05 PM ⚊ Updated Mar 06, 2025 | 2:05 PM
SLBC tunnel collapse. (Supplied)
Synopsis: The collapse of a section of the Srisailam Left Bank Canal Tunnel in Telangana on February 22 trapped eight workers. Despite a 2020 seismic survey warning of geological risks, construction continued. Political outrage followed, with demands for an investigation. Rescue efforts continue, involving over 300 personnel, while legal action seeks expedited measures.
The collapse of a section of the Srisailam Left Bank Canal (SLBC) Tunnel in Telangana on 22 February, trapping eight workers, has ignited a storm of controversy over ignored safety warnings.
A seismic survey conducted in January 2020 by Amberg Tech AG—a firm specializing in tunnel surveying, had already flagged a “fault zone” at the exact location where the collapse occurred, raising critical concerns about negligence.
The report, commissioned by Jaiprakash Associates Ltd—the company awarded the tunnelling contract in 2005—identified weak rock formations and a water-bearing zone, yet construction continued despite these red flags, reports The Indian Express.
“The report, Tunnel Seismic Prediction (TSP) – 303 Plus, was prepared in January 2020 by Amberg Tech AG, a company that surveys tunnelling. According to the report, the fault zone existed between 13.88 km (13,882 m) and 13.91 km (13,914 m) from the mouth of the tunnel. The report also found a decrease in rock strength in this stretch and highlighted that the stretch was a water-bearing zone,” said the Indian Express report.
Despite these warnings, the tunnel excavation continued, raising concerns about negligence in ensuring worker safety.
Reacting to the revelations, BRS leader KT Rama Rao in a statement strongly criticized the government, and stated: “Shocking will be an understatement! The blatant disregard for the safety of workers and public money in the SLBC project is exposed with this report. Not one, but two reports highlighted the safety issue and even marked the exact accident site as the ‘Red Zone’!”
He further demanded, “One of the reports stated the same just days before the accident, yet the government decided to go ahead with tunnelling work. Eight families are devastated. Thousands of crores in public money wasted. For what? Just for Congress party’s commissions? We demand an investigation led by a High Court sitting judge. The demand is on behalf of those eight families and others seeking justice.”
Tunnel Seismic Prediction. (Supplied)
Tunnel Seismic Prediction (TSP) is a non-destructive method used to assess geological risks in tunnel construction. It helps detect irregularities, faults, fracture zones, and water inrush hazards that could lead to collapses. Despite being a well-established precautionary measure, the warnings in the SLBC tunnel project were apparently not heeded.
A rescue team officer involved in the SLBC operation told South First, “When we arrived for the rescue, we were informed that the site was a ‘Fault Zone’. These are regions where rock formations are fractured and unstable. Any movement in these zones can trigger collapses.”
A project engineer familiar with tunnel construction added, “Fault zones are common in long tunnel projects worldwide. For instance, the Silkyara tunnel in Uttarakhand, which collapsed last year, is located near a major geological fault line in the Himalayas. Similarly, the Atal Tunnel faced cave-ins and water seepage but had multiple exit options. However, in SLBC, there are no alternative entry points, making rescue efforts even harder.”
Rescue operations have entered their 13th day as teams continue their efforts to locate the trapped workers. On Thursday, 6 March, two cadaver dogs from the Kerala Police, along with their handlers, were deployed to assist in the ongoing rescue.
The deployment came following a request from the National Disaster Management Authority (NDMA) to the State Disaster Management Authority.
Cadaver dogs are trained to detect human remains, even in challenging environments, making them invaluable assets in disaster response situations. Their involvement in the rescue operations is expected to enhance the chances of locating those trapped.
NDRF Commandant VVN Prasanna Kumar provided updates on the rescue, stating: “Approximately twelve agencies are working around the clock. Unfortunately, we have not been able to locate the victims so far. Both the Telangana and Union governments have deployed top experts, but due to the complexity of the tunnel operation, success has been elusive. However, maximum manpower is engaged in a planned manner, and we remain hopeful.”
More than 300 personnel, including 100 NDRF members, SDRF, the Indian Army, and Singareni rescue teams, are involved in the mission.
One of the biggest hurdles is the damaged Tunnel Boring Machine (TBM), a 1,500-ton piece of machinery obstructing excavation efforts.
After nearly two weeks of slow progress, the restoration of the conveyor belt system was completed on Tuesday, 4 March, providing a much-needed boost to the debris removal process. The belt will significantly speed up the clearing of slush and metal debris, which had previously been manually loaded onto locomotives.
A review meeting was held on 5 March, led by disaster management special chief secretary Arvind Kumar and Nagarkurnool district collector B Santosh. Officials provided updates on the rescue, using a tunnel boring machine model to demonstrate debris removal techniques.
Colonel Pareekshith from the Border Roads Organisation explained how debris from the rear of the boring machine had been cleared using water jets.
Additionally, the National Institute of Seismology and a robotics team have entered the tunnel to assist in rescue efforts.
Amid public outcry, a Public Interest Litigation (PIL) was filed in the Telangana High Court, demanding expedited rescue operations. The National Union for Migrant Workers, which filed the petition, urged authorities to ensure all possible rescue measures are taken. However, the high court disposed of the PIL after accepting the state government’s explanation of ongoing efforts.
Meanwhile, Telangana Chief Minister Revanth Reddy visited the site to assess the situation firsthand. He assured the public that the government is taking all necessary steps to expedite rescue efforts and explore alternative methods to reach the trapped workers, including the potential use of robotics.
“We are determined to resolve this crisis and provide support to the affected families. The rescue work is our top priority,” said CM Reddy.
The SLBC tunnel collapse occurred just months after the Congress-led Telangana government resumed work on the long-delayed project.
Originally conceived in 1983 as part of the Alimineti Madhava Reddy Project (AMRP), the SLBC tunnel was designed to transport 30 thousand million cubic feet of Krishna River water from the Srisailam dam to drought-prone Nalgonda and Nagarkurnool districts. However, geological challenges, financial constraints, and bureaucratic delays plagued the project for decades.
The 44-km-long tunnel, which relies on gravity to carry water, was particularly challenging to construct due to its location in a fractured rock zone and groundwater aquifer.
Unlike many long tunnels, SLBC lacks intermediate access points, further complicating rescue efforts. The excavation was being carried out by the US-based Robbins Inc., in collaboration with contractor Jaiprakash Associates.
The eight trapped workers include two engineers, two machine operators, and four labourers, identified as Sunny Singh, Gurpreet Singh, Manoj Kumar, Srinivas, Sandeep Sahu, Santosh Sahu, Anuj Sahu, and Jagath Khes.
(edited by Sumavarsha)
