The first visuals of workers trapped inside the collapsed Silkyara tunnel in Uttarakhand’s Uttarkashi surfaced on Tuesday morning. The major development comes a day after rescuers pushed a six-inch-wide pipeline through the rubble of the collapsed Silkyara tunnel, a breakthrough that would help them supply larger quantities of food to the 41 workers trapped inside for nine days.

The visuals were captured using an endoscopic camera sent in through the alternative six-inch food pipeline. In the video, the workers, wearing yellow and white helmets, are seen receiving food items sent to them through the pipeline and talking to each other. This comes as a big relief to the families of these workers.

So far, a four-inch existing tube was being used to supply oxygen and items like dry fruit and medicines into the section of the tunnel beyond the rubble of the collapsed portion of the under-construction tunnel on the Char Dham route in Uttarakhand.

National Highways and Infrastructure Development Corporation Limited (NHIDCL) director Anshu Manish Khalkho called it the “first breakthrough” at the site. “We have sent the pipe 53 metres to the other side of the rubble and the trapped workers can hear and experience us,” he said.

“First achievement, big achievement. The next step is the more vital one and the most important – that’s to get them out intact, happy,” his colleague Col Deepak Patil said.

Drones and robots from the Defence Research and Development Organisation (DRDO) have also been brought to the site to look into the possibility of other escape routes for the trapped men.

Rescue workers were yet to resume the horizontal boring through the debris after a boulder appeared to block the progress of the heavy-duty auger machine earlier this week. But an official statement said this was scheduled to begin in the evening.

The first machine for the construction of a vertical rescue shaft – possibly around 80-metre deep – by drilling from near the hilltop has also reached the tunnel. A road to the hilltop has been laid, and the Oil and Natural Gas Corporation (ONGC) is arranging for more equipment, the statement said.

Also, work has begun on drilling from the other side, the Barkot-end, of the tunnel, it said.

International tunnelling expert Arnold Dix also reached the disaster site to review rescue efforts. He heads the Geneva-based International Tunnelling and Underground Space Association.

The pipeline development comes on the day Prime Minister Narendra Modi called up Uttarakhand chief minister Pushkar Singh Dhami to take stock of the rescue operation. According to a statement, the PM said it was necessary to keep up the morale of the trapped workers.