McLaren Engineering Group performed underwater inspection services for the New York Power Authority (NYPA) for its hydroelectric, fossil fuel and transmission facilities throughout New York state – including locations at the Hinckley Dam, Vischer Ferry and Crescent Small Hydroelectric Plants, Crescent Dam, Blenheim Gilboa Reservoir, Charles Polletti Generating Station and Barnhart Island Bridge. To ensure safety and efficiency of the facilities, McLaren performed underwater inspections on trash rack guide brackets, installation of new draft tube gates, submerged sections of gate slots and bottom sill, torqueing nuts on the adjustment wedge and guides, dam face, stop logs, cooling water intake valve cleaning, rodney-hunt sluice gate, reservoir spillway and stilling basin, spillway chute and chute blocks, spillway power cutover/commissioning, tainter gates, diesel fire pumps and steel h-piles.
Due to limited topside access to the trash rack at Hinckley Dam and Crescent Dam, the inspection was staged from McLaren’s 21 foot dive boat. For the inspections at Crescent and Vischer Ferry Hydroelectric Plants, the diver also probed along the mudline at the face of each concrete gravity wall to identify possible undermining. These mudline elevations were updated on the report drawings and compared against previous data to assess the shifting of the mudline and determine the susceptibility of the structure to future undermining.