Communication challenges in SLBC: Access to less than 10 meters in last stretch of tunnel remained unobtainable

Communication challenges are crippling the rescue efforts at the SLBC tunnel collapse site. Rescue teams are unable to communicate with each other deep inside the tunnel as cell phone signals are not present.

Hyderabad: The rescue operations at the Srisailam Left Bank Canal (SLBC) tunnel collapse have encountered critical communication challenges deep inside the tunnels. Despite the urgency of the situation, these challenges have become insurmountable impediments to the rescue efforts.

The rescue mission including the troops that are spearheading the operations could gain access up to 13.790 kms of the 13.85 km tunnel on Tuesday. Their target of reaching the missing workers and engineers trapped in the last six to seven metre towards the extreme end of the tunnel remained unfulfilled.

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Information about the ground situation in the stretch remained unobtainable because of the odds thy faced in the precarious journey Following a long hiatus, work was resumed inside the tunnel, but without addressing the communication gaps.

This oversight has turned into a serious obstacle, complicating the coordination and execution of the rescue mission. Communication limitations were being viewed as the major handicap by almost half a dozen agencies involved in the mission.

Limited range of communication had scuttled all the efforts. Communication is possible only within a 3 km range using BSNL cellphone and landline services. Beyond this range, there is no effective means of communication which poses a major challenge for coordinating the rescue operations effectively. This has led to delays and gaps in full-fledged handling of the task on hand in the rescue mission.

Compounding the communication challenges are the accessibility issues even with the use of the locomotive track within the tunnel. The tunnel has a diameter of 9.2 meters, with an accessible track extending up to 12 km. However, beyond 12 km, the track is not accessible after the Tunnel Boring Machine (TBM) tail unit.

This restricted accessibility complicates efforts to reach the trapped workers and engineers, who are located just a few meters close to the tunnel end. The tunnel is heavily affected by water logging, with water levels ranging from 1.5 feet at 10.95 km to 2.5 feet between 11.3 km and 13.5 km. Additionally, there is a heavy accumulation of sediments and debris, which has spread over a half-kilometer distance. These obstacles further hinder the progress of the rescue teams.