Overview
- Chief Minister A. Revanth Reddy and Irrigation Minister N. Uttam Kumar Reddy flagged off the heli‑borne operations in Nagarkurnool on November 3.
- Scientists from NGRI are flying straight, parallel lines with a 24‑metre transmitter loop over roughly 200 km to image subsurface conditions to about 800–1,000 metres.
- Collected data will be processed in Hyderabad to build 3D resistivity maps and a geological model guiding alignment, reinforcement, drainage and the excavation method.
- Officials said the new tunnelling will bypass the collapsed stretch where a February failure flooded 2.5 km and buried a 130‑metre TBM, resulting in eight deaths.
- Technical oversight has been bolstered with Lt. Gen. Harpal Singh (Retd.) as adviser and Col. Parikshit Mehra on deputation, with about 9.8 km remaining of the roughly 44‑km tunnel.