Rescue Operations Intensify at Silkyara Tunnel Collapse Site

Uttarkashi, 23 November: Continuing their unwavering commitment to saving lives, the government is actively engaged in ongoing rescue operations at the Silkyara Tunnel in Uttarkashi, where 41 workers remain trapped. The 2 km section of the tunnel, with completed concrete work ensuring the safety of the workers, is the focus of the rescue efforts.

According to a press communique issued by Ministry of Road Transport & Highways on 23 November evening in this secured portion of the tunnel, electricity and water supply are operational, and provisions, including food and medicines, are being delivered through a dedicated 4-inch compressor pipeline.

Various government agencies have been mobilized, each assigned specific tasks to ensure the safe evacuation of the workers. The government maintains constant communication to boost the morale of those trapped.

Key Updates on Rescue Operations:

1.         NHIDCL Lifeline Efforts:

• A significant breakthrough was achieved on 20.11.2023 as NHIDCL completed the   drilling of an additional lifeline—a 6-inch diameter pipeline—for the supply of essential items.
• Freshly cooked food and fresh fruits are being inserted inside the tunnel at regular intervals using 2nd life line service (150 mm dia pipe). 2nd service lifeline (food pipe, 150 mm) has been extended from the initial position to a distance of 12 m to ensure higher stability and safety.
• Video communication has been established by SDRF with the stranded workforce.
• A direct communication line connection has been established by NDRF.

2.   Horizontal Boring by NHIDCL

• NHIDCL has resumed horizontal boring from the Silkyara end to rescue workers using an Augur boring machine. Auger drilling started at 0045 Hrs on 22.11.2023. A metallic object (Lattice girder rib) was encountered in the front of the pipe and the pipe could not be inserted further. Cutting of Metallic object (Lattice Girder rib) using Gas cutters has been completed at 0230 hrs. Trenchless team entered in to pipe manually twice to confirm the clearance of the rescue pipe. Pushing of the 9th pipe started at 1310 hrs and the pipe reached to additional 1.8 meters. Minor vibration was noted, so Auger is being pushed slightly back to re-assess the force to be applied. Augering will start shortly thereafter.
• Fabrication of a protective canopy for the drilling machine is underway

3.   Vertical Drilling for Rescue by SJVNL:

• SJVNL’s machine for the vertical rescue tunnel construction has arrived at the site, and has been installed and drilling started on 23.11.2023.

4.   Horizontal Drilling from Barkot Side by THDCL:

• THDC has initiated the construction of a rescue tunnel from the Barkot end, with four blasts already completed, resulting in a 9.10 meter drift. Efforts are being made to carry out three blasts per day.
• Shotcreting completed. Drilling for rock bolts and rib erection work in the portal area is in progress.

5.   Perpendicular-Horizontal Drilling by RVNL:

• Equipment for micro tunneling required for horizontal drilling to rescue laborers has reached the site. Platform likely to be completed by 24.11.2023. Equipment is to be set up by 25.11.2023.

6.   Vertical Drilling Toward Barkot End by ONGC

• Air drilling Rig machine from Indore has reached site. Submission of report by ONGC to be made after completion of field survey.

7.   Drift      Tunnel         by      Manual-Semi Mechanized  Method        by      Joint  Team of  THDCL/Army/Coal India and NHIDCL:

• Work is underway to create a drift inside the tunnel. The Army is mobilizing box culverts for this purpose. Fabrication of frames has started.

8.   Road Cutting and Supportive Work by BRO:

• BRO has completed construction of approach road for vertical drilling by SJVNL and RVNL. BRO is also building approach road for ONGC with geological surveys conducted by ONGC. BRO has made access road of 300 meter.

Background:

On 12th November 2023, a collapse occurred in the under-construction tunnel from Silkyara to Barkot due to debris falling in a 60-meter stretch on the Silkyara side. Immediate mobilization of resources by the State and Central Governments ensued to rescue the 41 trapped labours.

Initially opting for a 900 mm pipe through the debris, safety concerns led to the exploration of multiple rescue options simultaneously. The area of entrapment, measuring 8.5 meters in height and 2 kilometres in length, is the built-up portion of the tunnel, offering safety to the labours with available electricity and water supply.

Five agencies—ONGC, SJVNL, RVNL, NHIDCL, and THDCL—have been assigned specific responsibilities, working collaboratively with occasional task adjustments for operational efficiency.