CM, Irrigation Minister to launch aerial electro-magnetic survey for SLBC tunnel

HYDERABAD

Chief Minister A. Revanth Reddy and Irrigation Minister N. Uttam Kumar Reddy will launch a helicopter-borne ‘VTEM Plus Magnetic Geophysical Survey’ on November 3 (Monday) to aid in the assessment of any shear zones or water bodies in the balance alignment of the Alimineti Madhava Reddy Project (AMRP).

The Telangana government has decided to employ this advanced technical methodology to expedite the tunnel works, following the collapse of Tunnel 1, part of the Srisailam Left Bank Canal (SLBC) under the AMRP, on February 22, which resulted in the deaths of eight people and flooding of 2.5 km of the tunnel, burying the 130-meter-long Tunnel Bore Machine (TBM) under muck and water.

Several tunnel experts also recommended conducting a helicopter-borne survey, which will be carried out by the National Geophysical Research Institute (NGRI).

According to irrigation officials, the survey involves flying a helicopter with a specialist underslung transmitter (24-meter diameter loop) over the tunnel alignment, sending electromagnetic signals into the earth to create eddies, which are then reflected and registered on a smaller receiver loop, covering over 200 km. This survey will enable suitable adaptation of excavation methodology to ensure safe and sustainable progress.