Underwater Inspection of the Water conductor system of 4X60 MW Chibro Hydroelectric Project by Remote Operated Vehicle ROV

Head Race Tunnel (HRT): The underwater inspection shall cover the entire accessible length of the Head Race Tunnel (HRT), approximately 6.1 km in length with an internal diameter of 7.0 m, including the concrete lining, crown, sidewalls, invert, construction and expansion joints, bends, transitions, Adit junctions, surge shaft interface, any unlined or shotcrete-lined sections, and the transition zones leading to the pressure shafts.

Surge Shaft: The underwater inspection shall cover the Surge Shaft, approximately 21 m in diameter and 92 m in height, including its walls, base slab, gate slots, embedded steel components, anchor bolts, steel liners, construction and expansion joints, penstock interface joint, and any other submerged civil or hydro-mechanical components.

Penstock internal 3D Scanning: The dry/wet inspection shall cover the penstocks from the surge shaft to the Main Inlet Valve (MIV) for all four units, each approximately 140 m in length. In addition, 3D laser scanning under dry conditions shall be carried out from the inside of the penstock inlet-to-spiral casing joint, including the internal scanning of the spiral casing, stay vanes, adapter cone, and draft tube of one generating unit to accurately capture the as-built geometry and identify any deformation, misalignment, erosion, corrosion, cavitation, or other defects.

3D scanning of the exposed external surfaces of the penstock & Main Inlet Valve (MIV) within the powerhouse building for one generating unit to accurately capture the as-built geometry and identify any deformation, misalignment, erosion, corrosion, cavitation, or other defects.

Draft Tube Gate Cavity: The underwater inspection shall cover the Draft Tube Gate Cavity, including the embedded parts and their surrounding civil structures, such as the concrete lining, pier walls, invert, floor slab, and transition to the tailrace. The inspection shall also include all submerged hydro-mechanical components, including guide tracks, bottom sill beam, top and side sealing interfaces, surrounding concrete of embedded structures, steel-to-concrete interfaces, anchoring arrangements, grout condition, and all other associated submerged structural and hydro-mechanical components.

Collection Gallery, Expansion Chamber, and Stoplog Gate Cavities: The underwater inspection shall cover the Collection Gallery, Expansion Chamber, and Stoplog Gate Cavities, including the embedded parts and surrounding civil structures, such as the gate grooves, top and side sealing interfaces, sill beam, pier walls, invert, tunnel lining, transition zones, and all associated submerged civil and hydro-mechanical components.

Siphon Tunnel Gate Cavities: The underwater inspection shall cover the Siphon Tunnel Gate Cavities, including the embedded parts and their surrounding civil structures, comprising but not limited to the gate grooves, top and side sealing interfaces, sill beam, pier walls, invert, tunnel lining, transition zones, and all associated submerged civil and hydro-mechanical components, including the surrounding concrete of embedded structures, steel-to-concrete interfaces, anchoring arrangements, grout condition, and any other associated structural components.

Outlet Stoplog Gate Cavities: The underwater inspection shall cover the Outlet Stoplog Gate Cavities, including the embedded parts and their surrounding civil structures, comprising but not limited to the gate grooves, top and side sealing interfaces, sill beam, pier walls, invert, tunnel lining, transition zones, and all associated submerged civil and hydro-mechanical components, including the surrounding concrete of embedded structures, steel-to-concrete interfaces, anchoring arrangements, grout condition, and any other associated structural components.