Uttarkashi, Nov 22 (IANS): Rescue operations to bring out 41 workers trapped in Uttarakhand's Silkyara collapsed tunnel continued for the 11th day, an official said on Wednesday, adding that drilling up to 39 meters has been completed with an additional 23 meters remaining.

Officials said that six pipes of 800 mm diameter have been inserted into the tunnel through the rubble using the auger machine.

Work is underway on welding the seventh pipe.

A total of 62 meters of pipes need to be inserted, and so far drilling up to 39 meters has been completed, with an additional 23 meters remaining to be drilled before rescuers can reach the trapped labourers.

The welding of pipes that are being pushed into the drilled holes will provide workers' an escape route.

At least 41 ambulances have been parked outside the Silkyara Tunnel.

Nigel, the safety chief of Larsen and Toubro involved in the rescue, said: "The drilling work is progressing very well. There is hope that we will reach our goal soon. We are also assisting in micro-tunnelling, and the entire operation is proceeding smoothly."

National Disaster Response Force officer Ravi S. Badhani said that the rescue operation is progressing well. Vertical drilling is underway, and they are very close to the people trapped inside the tunnel.

On Tuesday, officials successfully established communication with the trapped workers with the help of an endoscopic camera.

The labourers appeared on camera for the first time since being trapped ten days ago.

On November 12, it was reported that a portion of the under-construction tunnel from Silkyara to Barkot collapsed due to debris falling in the 60 metre stretch on the Silkyara side of the tunnel.