ROV Inspection of Hydroelectric Dam in South America
Glenn Underwater Services, Inc. recently completed a detailed ROV inspection of an intake structure at a hydroelectric facility in South America. The work involved the detailed inspection and mapping of defects on the concrete surfaces of the dam’s intake structure and trash racks. In addition to the digital video data collected by the ROV a data management system was incorporated to determine exact positioning of the ROV and mapping of defects during the inspection. The information gathered was converted into CAD drawings during post processing for review by the site engineers.
Installation of Surface Mounted Plates and Caisson
Glenn Underwater Services, Inc. completed extensive upgrading to the sealing surfaces of six draft tube openings at a hydroelectric facility in Tennessee. The project was in support of scheduled upgrades to the plants three units, which have been in operation since 1926. The work included assistance with design parameters, installation of stainless steel surface mounted seal plates, underwater welding, concrete repair, leak sealing, grouting, and test operation of the caisson.
Inspection of Hydroelectric Facility - South America
Glenn Underwater Services, Inc. performed a detailed underwater inspection of a hydroelectric facility in South America. The inspection included, the downstream bridge, spillway toe, training wall, intake gates, and spillway gates in depths of up to 140-feet. This project is situated in a remote location at the inflow to the Amazon basin. GUS divers were also entertained at times by the local piranha, which infest these waters.
Inspection and Repair of Surge Shaft and 6 Mile Tunnel
Glenn Underwater Services, Inc. performed an ROV inspection of a 850-foot surge shaft at a hydroelectric facility located in North Carolina. Entry into the shaft was gained through the opening of a riser pipe in the center of the tank. This point of entry provided unique logistical obstacles and safety factors not typically encountered by a diving company. The ROV was lifted 200-feet and then positioned and lowered into the riser at the center of the surge tank. Glenn Underwater Services, Inc. also performed additional services for this extensive project such as, concrete liner repairs, leak sealing of the Surge Shaft, Tunnel, and Intake Structure.
GUS Repairs Intake Structure in Turkey
Glenn Underwater Services designed and assist with installation of a grouting system capable of resealing joints in an intake and discharge tunnel in Marmara, Turkey. The parameters required that the material achieve cure time of less than 4 hours and be pumpable to a distance of 500-feet. To complicate matters the material selected had to be provided in-country due to the compressed time frame of only three weeks before the scheduled outage was to begin. GUS personnel incorporated a polymer modified, silica fume enhanced product manufactured in Istanbul by Sika®. The grout was specially formulated to increase both mechanical and adhesive bond. Anti washout agents and superplastizers were utilized to prevent segregation during placement underwater. This created an additional benefit for the diver in improved visibility in the confined space of the tunnel. Initial tests showed a 12-hour break of 6,400 psi with a 3-day break of 8,250. The product's low viscosity and density provided the necessary bond and migration that was required. To contain the grout, FRP forms with prefabricated grout ports were installed over the joint openings.