The Pakal Dul Hydroelectric Project (HEP) is a 1,000 MW hydroelectric power station under construction on the Marusudar River, a tributary of the Chenab River, in the Kishtwar district of Jammu and Kashmir Union Territory, India. This project falls under the parliamentary constituency of Hon’ble Minister of S&T, Dr Jitendra Singh, and represents a flagship initiative to harness renewable energy in Jammu & Kashmir. The project is being developed by Chenab Valley Power Projects Limited (CVPPL), a joint venture of NHPC Ltd and J&K State Power Development Corporation Limited (JKSPDC). The cost of this Project is ?8,112.00 crore. Out of ?8,112.00 crores, the HRT-TBM package (two HRTs of 7.34 km out of 9.6 km each having 8.34 m circular diameter) was awarded to M/s L&T Limited amounting INR 2575.64 crores with a strict timeline to complete the project in 2026. A Tunnel Boring Machine (TBM) with an 8.34 m diameter, valued at ?180 crore, and having been named Marsu was stuck at HRT-1 since 26 October 2024 while mining.

The location of the stuck TBM was 1,218 m vertically below the surface and 3,496 m horizontally inside the hill. The TBM shield having a 12 m length was immobilised due to squeezing ground conditions in medium-strong quartzite and phyllite rock formations. Mr Vishal Anand, Head of Project, Pakal Dul HEP (1000 MW) of M/s CVPPL, along with M/s L&T management namely Mr Ashwini K Tripathi, played a pivotal role in initiating efforts to restart TBM excavation. On their instruction, M/s L&T Ltd collaborated with CSIR-CIMFR, Dhanbad, to leverage scientific expertise for the recovery operation.

To safely recover the stuck TBM without causing damage, an unprecedented excavation strategy was employed under the direction of Prof. Arvind K Mishra, Director, CSIR-CIMFR and under the complete supervision of his team namely Dr Narayan K Bhagat as Team Leader, Dr C Sawmliana Head of Section, Rock Excavation Engineering, and Dr AK Raina from CIMFR, Nagpur unit.

The parallel cut blasting pattern involved precise drilling and controlled blasting to create a central gullet, ensuring minimal vibrations and protecting the TBM shield from further damage. The CIMFR team started work at the site on 13 January 2025 and the retrieval and complete restoration of TBM mining was restarted on 12 February 2025. This demonstrated a highly cost-effective and efficient operation in the history of TBM recovery worldwide. This achievement highlights India’s growing expertise in tunnelling operations under extreme geological conditions, setting a benchmark for similar projects worldwide.