The bodies of 20 of the 25 workers trapped inside the tunnel of NHPC’s hydropower project in Sikkim were recovered late on Tuesday night. Rescue teams were unable to reach the remaining five workers by the end of the night.
The workers are trapped at different points inside the tunnel. Rescue teams have been trying to reach them for more than 24 hours, but high levels of methane gas inside the tunnel have made the operation extremely difficult. Several rescuers reportedly fainted during the mission.
The incident took place in the Adit-3 tunnel of the Teesta Stage-6 hydropower project at Samardung-Jholungy in Namchi district. The tunnel is being built by Patel Engineering Company.
5 pictures related to the accident
Officials said that the accident occurred on Monday afternoon around 3:40 PM.
Debris accumulated at the mouth of the tunnel after the landslide.
There is a possibility of a methane gas leak in the tunnel. Workers who went for rescue became unconscious.
Rescue operations are facing difficulties due to debris filling the tunnel.
One oxygen cylinder lasts only 40 minutes
Two parallel tunnels, each around 5 kilometres long, are being built to carry water for the project.
The accident occurred in the Face-4B section, where debris from the tunnel roof collapsed and methane gas accumulated. The gas reduces oxygen levels, making it difficult to breathe.
The trapped workers are about 1.5 kilometres from the tunnel entrance, while the remaining sections of the tunnel are considered safe.
Rescue teams are entering the tunnel in groups of eight. Each rescuer’s oxygen cylinder lasts for only 40 minutes, so they must return before it runs out, making the operation slow and difficult.
Fresh air is being pumped into the tunnel through blast-proof blowers and ventilation pipes to reduce the impact of the methane gas.
Rescue teams are also using shotcrete and rock bolting to stabilise the tunnel roof and prevent further collapses. Small loaders and robotic equipment are being used to remove debris.
Bhaskar Knowledge
Question: What is the biggest danger from methane gas?
Answer: Methane is not poisonous, but in a closed tunnel it can reduce oxygen levels, increasing the risk of suffocation and unconsciousness. If it comes into contact with a spark, it can also cause a fire or explosion.
Question: Why is tunnel rescue so difficult?
Answer: Rescue operations inside tunnels are far more challenging than normal rescue missions because the space is limited, access is difficult, and the risk to rescuers is much higher.
