Rescue drilling resumed at the Silkyara Tunnel Collapse Site after the restoration of damaged drilling equipment, the government of India informed.
The repaired Augur assembly was re-inserted by 2:30 PM in the afternoon.
In addition to this, the government has informed that placing and positioning of the next pipe which is to be in line with the Augur machine is under progress, and pushing will commence after completion of welding joints.
The Auger machine is expected to be very close to completing its mission of creating a rescue tunnel for the workers trapped inside the collapsed tunnel.
The Auger drilling had started at 12:45 AM on Wednesday and was halted due to a metallic object being encountered in front of the pipe and the pipe could not be inserted further.
Cutting of this Metallic object using Gas cutters has been completed, as per the update from the government.
While the pushing of the 9th pipe reached an additional 1.8-meter distance, minor vibration was noted, so Auger was pushed slightly back to re-assess the force to be applied.
A bent part of the forepole (pipe) from the tunnel lining was struck in the auger assembly which led to vibrations.
Strengthening of platform for augur machine using an accelerating agent for rapid hardening of concrete is completed. Further, the auger was required to pull back fully to assess any other damage to pipe. The government has updated that this has been completed. The bent pipe has been cut and a GPR (Ground Penetration Radar) test has been conducted.
Apart from this, the strengthening of the platform for augur machine using an accelerating agent for rapid hardening of concretehas also been done. A platform for Auger Machine has been strengthened by way of anchoring, bolting, concreting foundation etc, said the government.
In addition to the Augur drilling, there are several other parallel rescue efforts in progress.
Agencies including ONGC, SJVNL, RVNL, NHIDCL, and THDCL—are also trying to open the tunnel using various other methods including vertical and perpendicular-horizontal drilling.
On SJVNL’s operations, the government said: “Platform for launching of drilling machine has been completed. Marking of drilling point over the tunnel has been finalized at ch. 300 L/S after discussion with GSI, RVNL & ONGC. Assembly of machine has started.”
On RVNL’s operations it said, “Equipments for micro tunneling required for horizontal drilling to recue labourers has reached site. Platform likely to be completed by 24.11.2023. Equipment to set up by 25.11.2023.”
THDC, informed the government, “has initiated the construction of a rescue tunnel from the Barkot end, with four blasts already completed, resulting in a 9.10 meter drift.”
“Shotcreting and rib erection has been completed and additional rib fabrication work is in progress,” it added.
Regarding the 6-inch vertical drilling by RVNL at the Silkyara end the government said: “Access road of 1150 meter has been completed by BRO and handed over to RVNL. Machine for drilling towed to location by BRO. Electric Connection has been provided to RVNL. Vertical drilling likely to be completed by 26.11.2023.”
Meanwhile, the government also informed that freshly cooked food and fresh fruits are being inserted inside the tunnel at regular intervals using the 2nd life line (150 mm dia) service which has been extended from the initial position to a distance of 12 m to ensure higher stability and safety.
“Consignment consisting of roti, Dal, mixed vegetable and fruits like apples, oranges, bananas etc.. along with medicines and salts has also been supplied. Modified communication system with wire connectivity developed by SDRF is being used for communication regularly. People inside have reported that they are safe,” the government said.